332 results on '"David D. Limbrick"'
Search Results
2. Cognition and Brain System Segregation in Pediatric Brain Tumor Patients Treated with Proton Therapy
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Anna V. Dowling, BS, Benjamin A. Seitzman, PhD, Timothy J. Mitchell, PhD, Michael Olufawo, BS, Donna L. Dierker, BS, Hari Anandarajah, BS, Ally Dworetsky, BS, Alana McMichael, MA, Catherine Jiang, BS, Dennis L. Barbour, MD, PhD, Bradley L. Schlaggar, MD, PhD, David D. Limbrick, MD, PhD, Jennifer M. Strahle, MD, Joshua B. Rubin, MD, PhD, Joshua S. Shimony, MD, PhD, and Stephanie M. Perkins, MD
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proton therapy ,neurocognitive ,resting state ,brain tumor ,late effects ,Medical physics. Medical radiology. Nuclear medicine ,R895-920 ,Nuclear and particle physics. Atomic energy. Radioactivity ,QC770-798 - Abstract
Purpose: Pediatric brain tumor patients often experience significant cognitive sequelae. Resting-state functional MRI (rsfMRI) provides a measure of brain network organization, and we hypothesize that pediatric brain tumor patients treated with proton therapy will demonstrate abnormal brain network architecture related to cognitive outcome and radiation dosimetry. Participants and Methods: Pediatric brain tumor patients treated with proton therapy were enrolled on a prospective study of cognitive assessment using the NIH Toolbox Cognitive Domain. rsfMRI was obtained in participants able to complete unsedated MRI. Brain system segregation (BSS), a measure of brain network architecture, was calculated for the whole brain, the high-level cognition association systems, and the sensory-motor systems. Results: Twenty-six participants were enrolled in the study for cognitive assessment, and 18 completed rsfMRI. There were baseline cognitive deficits in attention and inhibition and processing speed prior to radiation with worsening performance over time in multiple domains. Average BSS across the whole brain was significantly decreased in participants compared with healthy controls (1.089 and 1.101, respectively; P = 0.001). Average segregation of association systems was significantly lower in participants than in controls (P
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- 2023
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3. Outcomes of the 2019 hydrocephalus association workshop, 'Driving common pathways: extending insights from posthemorrhagic hydrocephalus'
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Jason K. Karimy, Jessie C. Newville, Cameron Sadegh, Jill A. Morris, Edwin S. Monuki, David D. Limbrick, James P. McAllister II, Jenna E. Koschnitzky, Maria K. Lehtinen, and Lauren L. Jantzie
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Hydrocephalus ,Posthemorrhagic ,Post-infectious ,Intraventricular hemorrhage ,Germinal matrix hemorrhage ,Cilia ,Neurology. Diseases of the nervous system ,RC346-429 - Abstract
Abstract The Hydrocephalus Association (HA) workshop, Driving Common Pathways: Extending Insights from Posthemorrhagic Hydrocephalus, was held on November 4 and 5, 2019 at Washington University in St. Louis. The workshop brought together a diverse group of basic, translational, and clinical scientists conducting research on multiple hydrocephalus etiologies with select outside researchers. The main goals of the workshop were to explore areas of potential overlap between hydrocephalus etiologies and identify drug targets that could positively impact various forms of hydrocephalus. This report details the major themes of the workshop and the research presented on three cell types that are targets for new hydrocephalus interventions: choroid plexus epithelial cells, ventricular ependymal cells, and immune cells (macrophages and microglia).
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- 2023
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4. The effect of A1 and A2 reactive astrocyte expression on hydrocephalus shunt failure
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Fatemeh Khodadadei, Rooshan Arshad, Diego M. Morales, Jacob Gluski, Neena I. Marupudi, James P. McAllister, David D. Limbrick, and Carolyn A. Harris
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Neuroprosthetic device failure ,Hydrocephalus ,Glial Scar ,A1 and A2 reactive astrocyte phenotype ,Targeted drug delivery ,Neurology. Diseases of the nervous system ,RC346-429 - Abstract
Abstract Background The composition of tissue obstructing neuroprosthetic devices is largely composed of inflammatory cells with a significant astrocyte component. In a first-of-its-kind study, we profile the astrocyte phenotypes present on hydrocephalus shunts. Methods qPCR and RNA in-situ hybridization were used to quantify pro-inflammatory (A1) and anti-inflammatory (A2) reactive astrocyte phenotypes by analyzing C3 and EMP1 genes, respectively. Additionally, CSF cytokine levels were quantified using ELISA. In an in vitro model of astrocyte growth on shunts, different cytokines were used to prevent the activation of resting astrocytes into the A1 and A2 phenotypes. Obstructed and non-obstructed shunts were characterized based on the degree of actual tissue blockage on the shunt surface instead of clinical diagnosis. Results The results showed a heterogeneous population of A1 and A2 reactive astrocytes on the shunts with obstructed shunts having a significantly higher proportion of A2 astrocytes compared to non-obstructed shunts. In addition, the pro-A2 cytokine IL-6 inducing proliferation of astrocytes was found at higher concentrations among CSF from obstructed samples. Consequently, in the in vitro model of astrocyte growth on shunts, cytokine neutralizing antibodies were used to prevent activation of resting astrocytes into the A1 and A2 phenotypes which resulted in a significant reduction in both A1 and A2 growth. Conclusions Therefore, targeting cytokines involved with astrocyte A1 and A2 activation is a promising intervention aimed to prevent shunt obstruction.
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- 2022
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5. A Refined, Controlled 16S rRNA Gene Sequencing Approach Reveals Limited Detection of Cerebrospinal Fluid Microbiota in Children with Bacterial Meningitis
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Christopher E. Pope, Kathryn B. Whitlock, Paul Hodor, David D. Limbrick, Patrick J. McDonald, Jason Hauptman, Lucas R. Hoffman, and Tamara D. Simon
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bacterial meningitis ,cerebrospinal fluid ,high-throughput sequencing ,Microbiology ,QR1-502 - Abstract
ABSTRACT Advances in both laboratory and computational components of high-throughput 16S amplicon sequencing (16S HTS) have markedly increased its sensitivity and specificity. Additionally, these refinements have better delineated the limits of sensitivity, and contributions of contamination to these limits, for 16S HTS that are particularly relevant for samples with low bacterial loads, such as human cerebrospinal fluid (CSF). The objectives of this work were to (i) optimize the performance of 16S HTS in CSF samples with low bacterial loads by defining and addressing potential sources of error, and (ii) perform refined 16S HTS on CSF samples from children diagnosed with bacterial meningitis and compare results with those from microbiological cultures. Several bench and computational approaches were taken to address potential sources of error for low bacterial load samples. We compared DNA yields and sequencing results after applying three different DNA extraction approaches to an artificially constructed mock-bacterial community. We also compared two postsequencing computational contaminant removal strategies, decontam R and full contaminant sequence removal. All three extraction techniques followed by decontam R yielded similar results for the mock community. We then applied these methods to 22 CSF samples from children diagnosed with meningitis, which has low bacterial loads relative to other clinical infection samples. The refined 16S HTS pipelines identified the cultured bacterial genus as the dominant organism for only 3 of these samples. We found that all three DNA extraction techniques followed by decontam R generated similar DNA yields for mock communities at the low bacterial loads representative of CSF samples. However, the limits of detection imposed by reagent contaminants and methodologic bias precluded the accurate detection of bacteria in CSF from children with culture-confirmed meningitis using these approaches, despite rigorous controls and sophisticated computational approaches. Although we did not find current DNA-based diagnostics to be useful for pediatric meningitis samples, the utility of these methods for CSF shunt infection remains undefined. Future advances in sample processing methods to minimize or eliminate contamination will be required to improve the sensitivity and specificity of these methods for pediatric meningitis. IMPORTANCE Advances in both laboratory and computational components of high-throughput 16S amplicon sequencing (16S HTS) have markedly increased its sensitivity and specificity. These refinements have better delineated the limits of sensitivity, and contributions of contamination to these limits, for 16S HTS that are particularly relevant for samples with low bacterial loads such as human cerebrospinal fluid (CSF). The objectives of this work were to (i) optimize the performance of 16S HTS in CSF samples by defining and addressing potential sources of error, and (ii) perform refined 16S HTS on CSF samples from children diagnosed with bacterial meningitis and compare results with those from microbiological cultures. We found that the limits of detection imposed by reagent contaminants and methodologic bias precluded the accurate detection of bacteria in CSF from children with culture-confirmed meningitis using these approaches, despite rigorous controls and sophisticated computational approaches.
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- 2023
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6. Acquired hydrocephalus is associated with neuroinflammation, progenitor loss, and cellular changes in the subventricular zone and periventricular white matter
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Maria Garcia-Bonilla, Leandro Castaneyra-Ruiz, Sarah Zwick, Michael Talcott, Ayodamola Otun, Albert M. Isaacs, Diego M. Morales, David D. Limbrick, and James P. McAllister
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Kaolin-induced hydrocephalus ,Pig model ,Ventriculomegaly ,Subventricular zone reduction ,White matter alteration ,Neuroinflammation ,Neurology. Diseases of the nervous system ,RC346-429 - Abstract
Abstract Background Hydrocephalus is a neurological disease with an incidence of 80–125 per 100,000 births in the United States. Neuropathology comprises ventriculomegaly, periventricular white matter (PVWM) alterations, inflammation, and gliosis. We hypothesized that hydrocephalus in a pig model is associated with subventricular and PVWM cellular alterations and neuroinflammation that could mimic the neuropathology described in hydrocephalic infants. Methods Hydrocephalus was induced by intracisternal kaolin injections in 35-day old female pigs (n = 7 for tissue analysis, n = 10 for CSF analysis). Age-matched sham controls received saline injections (n = 6). After 19–40 days, MRI scanning was performed to measure the ventricular volume. Stem cell proliferation was studied in the Subventricular Zone (SVZ), and cell death and oligodendrocytes were examined in the PVWM. The neuroinflammatory reaction was studied by quantifying astrocytes and microglial cells in the PVWM, and inflammatory cytokines in the CSF. Results The expansion of the ventricles was especially pronounced in the body of the lateral ventricle, where ependymal disruption occurred. PVWM showed a 44% increase in cell death and a 67% reduction of oligodendrocytes. In the SVZ, the number of proliferative cells and oligodendrocyte decreased by 75% and 57% respectively. The decrease of the SVZ area correlated significantly with ventricular volume increase. Neuroinflammation occurred in the hydrocephalic pigs with a significant increase of astrocytes and microglia in the PVWM, and high levels of inflammatory interleukins IL-6 and IL-8 in the CSF. Conclusion The induction of acquired hydrocephalus produced alterations in the PVWM, reduced cell proliferation in the SVZ, and neuroinflammation.
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- 2022
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7. Characterization of cerebrospinal fluid (CSF) microbiota at the time of initial surgical intervention for children with hydrocephalus
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Shailly Pandey, Kathryn B. Whitlock, Matthew R. Test, Paul Hodor, Christopher E. Pope, David D. Limbrick, Patrick J. McDonald, Jason S. Hauptman, Lucas R. Hoffman, and Tamara D. Simon
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Medicine ,Science - Abstract
Objective To characterize the microbiota of the cerebrospinal fluid (CSF) from children with hydrocephalus at the time of initial surgical intervention. Study design CSF was obtained at initial surgical intervention. One aliquot was stored in skim milk-tryptone-glucose-glycerol (STGG) medium and the second was unprocessed; both were then stored at –70°C. Bacterial growth for CSF samples stored in STGG were subsequently characterized using aerobic and anaerobic culture on blood agar and MALDI-TOF sequencing. All unprocessed CSF samples underwent 16S quantitative polymerase chain reaction (qPCR) sequencing, and a subset underwent standard clinical microbiological culture. CSF with culture growth (either after storage in STGG or standard clinical) were further analyzed using whole-genome amplification sequencing (WGAS). Results 11/66 (17%) samples stored in STGG and 1/36 (3%) that underwent standard clinical microbiological culture demonstrated bacterial growth. Of the organisms present, 8 were common skin flora and 4 were potential pathogens; only 1 was also qPCR positive. WGAS findings and STGG culture findings were concordant for only 1 sample, identifying Staphylococcus epidermidis. No significant difference in time to second surgical intervention was observed between the STGG culture-positive and negative groups. Conclusion(s) Using high sensitivity methods, we detected the presence of bacteria in a subset of CSF samples at the time of first surgery. Therefore, the true presence of bacteria in CSF of children with hydrocephalus cannot be ruled out, though our findings may suggest these bacteria are contaminants or false positives of the detection methods. Regardless of origin, the detection of microbiota in the CSF of these children may not have any clinical significance.
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- 2023
8. Biochemical profile of human infant cerebrospinal fluid in intraventricular hemorrhage and post-hemorrhagic hydrocephalus of prematurity
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Ayodamola Otun, Diego M. Morales, Maria Garcia-Bonilla, Seth Goldberg, Leandro Castaneyra-Ruiz, Yan Yan, Albert M. Isaacs, Jennifer M. Strahle, James P. McAllister, and David D. Limbrick
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Post-hemorrhagic hydrocephalus (PHH) ,Intraventricular hemorrhage (IVH) ,CSF osmolality ,CSF electrolytes ,Cerebrospinal fluid (CSF) ,Neurology. Diseases of the nervous system ,RC346-429 - Abstract
Abstract Background Intraventricular hemorrhage (IVH) and post-hemorrhagic hydrocephalus (PHH) have a complex pathophysiology involving inflammatory response, ventricular zone and cell–cell junction disruption, and choroid-plexus (ChP) hypersecretion. Increased cerebrospinal fluid (CSF) cytokines, extracellular matrix proteins, and blood metabolites have been noted in IVH/PHH, but osmolality and electrolyte disturbances have not been evaluated in human infants with these conditions. We hypothesized that CSF total protein, osmolality, electrolytes, and immune cells increase in PHH. Methods CSF samples were obtained from lumbar punctures of control infants and infants with IVH prior to the development of PHH and any neurosurgical intervention. Osmolality, total protein, and electrolytes were measured in 52 infants (18 controls, 10 low grade (LG) IVH, 13 high grade (HG) IVH, and 11 PHH). Serum electrolyte concentrations, and CSF and serum cell counts within 1-day of clinical sampling were obtained from clinical charts. Frontal occipital horn ratio (FOR) was measured for estimating the degree of ventriculomegaly. Dunn or Tukey’s post-test ANOVA analysis were used for pair-wise comparisons. Results CSF osmolality, sodium, potassium, and chloride were elevated in PHH compared to control (p = 0.012 −
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- 2021
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9. Type IV Pili Are a Critical Virulence Factor in Clinical Isolates of Paenibacillus thiaminolyticus
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Christine Hehnly, Aiqin Shi, Paddy Ssentongo, Lijun Zhang, Albert Isaacs, Sarah U. Morton, Nicholas Streck, Petra Erdmann-Gilmore, Igor Tolstoy, R. Reid Townsend, David D. Limbrick, Joseph N. Paulson, Jessica E. Ericson, Michael Y. Galperin, Steven J. Schiff, and James R. Broach
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Paenibacillus thiaminolyticus ,postinfectious hydrocephalus ,type IV pilus ,virulence factors ,Microbiology ,QR1-502 - Abstract
ABSTRACT Hydrocephalus, the leading indication for childhood neurosurgery worldwide, is particularly prevalent in low- and middle-income countries. Hydrocephalus preceded by an infection, or postinfectious hydrocephalus, accounts for up to 60% of hydrocephalus in these areas. Since many children with hydrocephalus suffer poor long-term outcomes despite surgical intervention, prevention of hydrocephalus remains paramount. Our previous studies implicated a novel bacterial pathogen, Paenibacillus thiaminolyticus, as a causal agent of neonatal sepsis and postinfectious hydrocephalus in Uganda. Here, we report the isolation of three P. thiaminolyticus strains, Mbale, Mbale2, and Mbale3, from patients with postinfectious hydrocephalus. We constructed complete genome assemblies of the clinical isolates as well as the nonpathogenic P. thiaminolyticus reference strain and performed comparative genomic and proteomic analyses to identify potential virulence factors. All three isolates carry a unique beta-lactamase gene, and two of the three isolates exhibit resistance in culture to the beta-lactam antibiotics penicillin and ampicillin. In addition, a cluster of genes carried on a mobile genetic element that encodes a putative type IV pilus operon is present in all three clinical isolates but absent in the reference strain. CRISPR-mediated deletion of the gene cluster substantially reduced the virulence of the Mbale strain in mice. Comparative proteogenomic analysis identified various additional potential virulence factors likely acquired on mobile genetic elements in the virulent strains. These results provide insight into the emergence of virulence in P. thiaminolyticus and suggest avenues for the diagnosis and treatment of this novel bacterial pathogen. IMPORTANCE Postinfectious hydrocephalus, a devastating sequela of neonatal infection, is associated with increased childhood mortality and morbidity. A novel bacterial pathogen, Paenibacillus thiaminolyticus, is highly associated with postinfectious hydrocephalus in an African cohort. Whole-genome sequencing, RNA sequencing, and proteomics of clinical isolates and a reference strain in combination with CRISPR editing identified type IV pili as a critical virulence factor for P. thiaminolyticus infection. Acquisition of a type IV pilus-encoding mobile genetic element critically contributed to converting a nonpathogenic strain of P. thiaminolyticus into a pathogen capable of causing devastating diseases. Given the widespread presence of type IV pilus in pathogens, the presence of the type IV pilus operon could serve as a diagnostic and therapeutic target in P. thiaminolyticus and related bacteria.
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- 2022
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10. A novel model of acquired hydrocephalus for evaluation of neurosurgical treatments
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James P. McAllister, Michael R. Talcott, Albert M. Isaacs, Sarah H. Zwick, Maria Garcia-Bonilla, Leandro Castaneyra-Ruiz, Alexis L. Hartman, Ryan N. Dilger, Stephen A. Fleming, Rebecca K. Golden, Diego M. Morales, Carolyn A. Harris, and David D. Limbrick
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Hydrocephalus ,Animal models ,Kaolin ,Acquired hydrocephalus ,Shunt ,Ventriculomegaly ,Neurology. Diseases of the nervous system ,RC346-429 - Abstract
Abstract Background Many animal models have been used to study the pathophysiology of hydrocephalus; most of these have been rodent models whose lissencephalic cerebral cortex may not respond to ventriculomegaly in the same way as gyrencephalic species and whose size is not amenable to evaluation of clinically relevant neurosurgical treatments. Fewer models of hydrocephalus in gyrencephalic species have been used; thus, we have expanded upon a porcine model of hydrocephalus in juvenile pigs and used it to explore surgical treatment methods. Methods Acquired hydrocephalus was induced in 33–41-day old pigs by percutaneous intracisternal injections of kaolin (n = 17). Controls consisted of sham saline-injected (n = 6) and intact (n = 4) animals. Magnetic resonance imaging (MRI) was employed to evaluate ventriculomegaly at 11–42 days post-kaolin and to plan the surgical implantation of ventriculoperitoneal shunts at 14–38-days post-kaolin. Behavioral and neurological status were assessed. Results Bilateral ventriculomegaly occurred post-induction in all regions of the cerebral ventricles, with prominent CSF flow voids in the third ventricle, foramina of Monro, and cerebral aqueduct. Kaolin deposits formed a solid cast in the basal cisterns but the cisterna magna was patent. In 17 untreated hydrocephalic animals. Mean total ventricular volume was 8898 ± 5917 SD mm3 at 11–43 days of age, which was significantly larger than the baseline values of 2251 ± 194 SD mm3 for 6 sham controls aged 45–55 days, (p
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- 2021
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11. Electronic clinical decision support for children with minor head trauma and intracranial injuries: a sociotechnical analysis
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Jacob K. Greenberg, Ayodamola Otun, Azzah Nasraddin, Ross C. Brownson, Nathan Kuppermann, David D. Limbrick, Po-Yin Yen, and Randi E. Foraker
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Sociotechnical analysis ,Traumatic brain injury ,Head trauma ,Electronic clinical decision support ,Implementation science ,Health information technology ,Computer applications to medicine. Medical informatics ,R858-859.7 - Abstract
Abstract Background Current management of children with minor head trauma (MHT) and intracranial injuries is not evidence-based and may place some children at risk of harm. Evidence-based electronic clinical decision support (CDS) for management of these children may improve patient safety and decrease resource use. To guide these efforts, we evaluated the sociotechnical environment impacting the implementation of electronic CDS, including workflow and communication, institutional culture, and hardware and software infrastructure, among other factors. Methods Between March and May, 2020 semi-structured qualitative focus group interviews were conducted to identify sociotechnical influences on CDS implementation. Physicians from neurosurgery, emergency medicine, critical care, and pediatric general surgery were included, along with information technology specialists. Participants were recruited from nine health centers in the United States. Focus group transcripts were coded and analyzed using thematic analysis. The final themes were then cross-referenced with previously defined sociotechnical dimensions. Results We included 28 physicians and four information technology specialists in seven focus groups (median five participants per group). Five physicians were trainees and 10 had administrative leadership positions. Through inductive thematic analysis, we identified five primary themes: (1) clinical impact; (2) stakeholders and users; (3) tool content; (4) clinical practice integration; and (5) post-implementation evaluation measures. Participants generally supported using CDS to determine an appropriate level-of-care for these children. However, some had mixed feelings regarding how the tool could best be used by different specialties (e.g. use by neurosurgeons versus non-neurosurgeons). Feedback from the interviews helped refine the tool content and also highlighted potential technical and workflow barriers to address prior to implementation. Conclusions We identified key factors impacting the implementation of electronic CDS for children with MHT and intracranial injuries. These results have informed our implementation strategy and may also serve as a template for future efforts to implement health information technology in a multidisciplinary, emergency setting.
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- 2021
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12. Generation of Periventricular Reactive Astrocytes Overexpressing Aquaporin 4 Is Stimulated by Mesenchymal Stem Cell Therapy
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María García-Bonilla, Betsaida Ojeda-Pérez, Kirill Shumilov, Luis-Manuel Rodríguez-Pérez, Dolores Domínguez-Pinos, Javier Vitorica, Sebastián Jiménez, Reposo Ramírez-Lorca, Miriam Echevarría, Casimiro Cárdenas-García, Teresa Iglesias, Antonia Gutiérrez, James P. McAllister, David D. Limbrick, Patricia Páez-González, and Antonio J. Jiménez
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hydrocephalus ,aquaporin 4 ,astrocyte reaction ,mesenchymal stem cell ,stem cell therapy ,proteomic ,Biology (General) ,QH301-705.5 ,Chemistry ,QD1-999 - Abstract
Aquaporin-4 (AQP4) plays a crucial role in brain water circulation and is considered a therapeutic target in hydrocephalus. Congenital hydrocephalus is associated with a reaction of astrocytes in the periventricular white matter both in experimental models and human cases. A previous report showed that bone marrow-derived mesenchymal stem cells (BM-MSCs) transplanted into the lateral ventricles of hyh mice exhibiting severe congenital hydrocephalus are attracted by the periventricular astrocyte reaction, and the cerebral tissue displays recovery. The present investigation aimed to test the effect of BM-MSC treatment on astrocyte reaction formation. BM-MSCs were injected into the lateral ventricles of four-day-old hyh mice, and the periventricular reaction was detected two weeks later. A protein expression analysis of the cerebral tissue differentiated the BM-MSC-treated mice from the controls and revealed effects on neural development. In in vivo and in vitro experiments, BM-MSCs stimulated the generation of periventricular reactive astrocytes overexpressing AQP4 and its regulatory protein kinase D-interacting substrate of 220 kDa (Kidins220). In the cerebral tissue, mRNA overexpression of nerve growth factor (NGF), vascular endothelial growth factor (VEGF), hypoxia-inducible factor-1 (HIF1α), and transforming growth factor beta 1 (TGFβ1) could be related to the regulation of the astrocyte reaction and AQP4 expression. In conclusion, BM-MSC treatment in hydrocephalus can stimulate a key developmental process such as the periventricular astrocyte reaction, where AQP4 overexpression could be implicated in tissue recovery.
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- 2023
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13. Cerebrospinal fluid biomarkers of neuroinflammation in children with hydrocephalus and shunt malfunction
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Carolyn A. Harris, Diego M. Morales, Rooshan Arshad, James P. McAllister, and David D. Limbrick
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Neuroinflammation ,Cytokines ,Mmps ,Hydrocephalus ,Revisions ,Multiplex ELISA ,Neurology. Diseases of the nervous system ,RC346-429 - Abstract
Abstract Background Approximately 30% of cerebrospinal fluid (CSF) shunt systems for hydrocephalus fail within the first year and 98% of all patients will have shunt failure in their lifetime. Obstruction remains the most common reason for shunt failure. Previous evidence suggests elevated pro-inflammatory cytokines in CSF are associated with worsening clinical outcomes in neuroinflammatory diseases. The aim of this study was to determine whether cytokines and matrix metalloproteinases (MMPs) contribute towards shunt failure in hydrocephalus. Methods Using multiplex ELISA, this study examined shunt failure through the CSF protein concentration profiles of select pro-inflammatory and anti-inflammatory cytokines, as well as select MMPs. Interdependencies such as the past number of previous revisions, length of time implanted, patient age, and obstruction or non-obstruction revision were examined. The pro-inflammatory cytokines were IL-1β, IL-2, IL-5, IL-6, IL-8, IL-12, IL-17, TNF-α, GM-CSF, IFN-γ. The anti-inflammatory cytokines were IL-4 and IL-10, and the MMPs were MMP-2, MMP-3, MMP-7, MMP-9. Protein concentration is reported as pg/mL for each analyte. Results Patient CSF was obtained at the time of shunt revision operation; all pediatric (
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- 2021
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14. Robust deep learning classification of adamantinomatous craniopharyngioma from limited preoperative radiographic images
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Eric W. Prince, Ros Whelan, David M. Mirsky, Nicholas Stence, Susan Staulcup, Paul Klimo, Richard C. E. Anderson, Toba N. Niazi, Gerald Grant, Mark Souweidane, James M. Johnston, Eric M. Jackson, David D. Limbrick, Amy Smith, Annie Drapeau, Joshua J. Chern, Lindsay Kilburn, Kevin Ginn, Robert Naftel, Roy Dudley, Elizabeth Tyler-Kabara, George Jallo, Michael H. Handler, Kenneth Jones, Andrew M. Donson, Nicholas K. Foreman, and Todd C. Hankinson
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Medicine ,Science - Abstract
Abstract Deep learning (DL) is a widely applied mathematical modeling technique. Classically, DL models utilize large volumes of training data, which are not available in many healthcare contexts. For patients with brain tumors, non-invasive diagnosis would represent a substantial clinical advance, potentially sparing patients from the risks associated with surgical intervention on the brain. Such an approach will depend upon highly accurate models built using the limited datasets that are available. Herein, we present a novel genetic algorithm (GA) that identifies optimal architecture parameters using feature embeddings from state-of-the-art image classification networks to identify the pediatric brain tumor, adamantinomatous craniopharyngioma (ACP). We optimized classification models for preoperative Computed Tomography (CT), Magnetic Resonance Imaging (MRI), and combined CT and MRI datasets with demonstrated test accuracies of 85.3%, 83.3%, and 87.8%, respectively. Notably, our GA improved baseline model performance by up to 38%. This work advances DL and its applications within healthcare by identifying optimized networks in small-scale data contexts. The proposed system is easily implementable and scalable for non-invasive computer-aided diagnosis, even for uncommon diseases.
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- 2020
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15. Preterm intraventricular hemorrhage in vitro: modeling the cytopathology of the ventricular zone
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Leandro Castaneyra-Ruiz, James P. McAllister, Diego M. Morales, Steven L. Brody, Albert M. Isaacs, and David D. Limbrick
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Cell culture ,Neural stem cells ,Ependyma ,Ventricular zone ,Intraventricular hemorrhage ,Post- hemorrhagic hydrocephalus ,Neurology. Diseases of the nervous system ,RC346-429 - Abstract
Abstract Background Severe intraventricular hemorrhage (IVH) is one of the most devastating neurological complications in preterm infants, with the majority suffering long-term neurological morbidity and up to 50% developing post-hemorrhagic hydrocephalus (PHH). Despite the importance of this disease, its cytopathological mechanisms are not well known. An in vitro model of IVH is required to investigate the effects of blood and its components on the developing ventricular zone (VZ) and its stem cell niche. To address this need, we developed a protocol from our accepted in vitro model to mimic the cytopathological conditions of IVH in the preterm infant. Methods Maturing neuroepithelial cells from the VZ were harvested from the entire lateral ventricles of wild type C57BL/6 mice at 1–4 days of age and expanded in proliferation media for 3–5 days. At confluence, cells were re-plated onto 24-well plates in differentiation media to generate ependymal cells (EC). At approximately 3–5 days, which corresponded to the onset of EC differentiation based on the appearance of multiciliated cells, phosphate-buffered saline for controls or syngeneic whole blood for IVH was added to the EC surface. The cells were examined for the expression of EC markers of differentiation and maturation to qualitatively and quantitatively assess the effect of blood exposure on VZ transition from neuroepithelial cells to EC. Discussion This protocol will allow investigators to test cytopathological mechanisms contributing to the pathology of IVH with high temporal resolution and query the impact of injury to the maturation of the VZ. This technique recapitulates features of normal maturation of the VZ in vitro, offering the capacity to investigate the developmental features of VZ biogenesis.
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- 2020
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16. Characterization of a multicenter pediatric-hydrocephalus shunt biobank
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Jacob Gluski, Paul Zajciw, Prashant Hariharan, Amanda Morgan, Diego M. Morales, Andrew Jea, William Whitehead, Neena Marupudi, Steven Ham, Sandeep Sood, James P. McAllister, David D. Limbrick, and Carolyn A. Harris
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Hydrocephalus ,Biobank ,Shunt failure ,Shunt obstruction ,CSF = cerebrospinal fluid ,Ventriculoperitoneal shunt ,Neurology. Diseases of the nervous system ,RC346-429 - Abstract
Abstract Background Pediatric hydrocephalus is a devastating and costly disease. The mainstay of treatment is still surgical shunting of cerebrospinal fluid (CSF). These shunts fail at a high rate and impose a significant burden on patients, their families and society. The relationship between clinical decision making and shunt failure is poorly understood and multifaceted, but catheter occlusion remains the most frequent cause of shunt complications. In order to investigate factors that affect shunt failure, we have established the Wayne State University (WSU) shunt biobank. Methods To date, four hospital centers have contributed various components of failed shunts and CSF from patients diagnosed with hydrocephalus before adulthood. The hardware samples are transported in paraformaldehyde and transferred to phosphate-buffered saline with sodium azide upon deposit into the biobank. Once in the bank, they are then available for study. Informed consent is obtained by the local center before corresponding clinical data are entered into a REDCap database. Data such as hydrocephalus etiology and details of shunt revision history. All data are entered under a coded identifier. Results 293 shunt samples were collected from 228 pediatric patients starting from May 2015 to September 2019. We saw a significant difference in the number of revisions per patient between centers (Kruskal–Wallis H test, p value
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- 2020
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17. Transcriptional analyses of adult and pediatric adamantinomatous craniopharyngioma reveals similar expression signatures regarding potential therapeutic targets
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Eric Prince, Ros Whelan, Andrew Donson, Susan Staulcup, Astrid Hengartner, Trinka Vijmasi, Chibueze Agwu, Kevin O. Lillehei, Nicholas K. Foreman, James M. Johnston, Luca Massimi, Richard C. E. Anderson, Mark M. Souweidane, Robert P. Naftel, David D. Limbrick, Gerald Grant, Toba N. Niazi, Roy Dudley, Lindsay Kilburn, Eric M. Jackson, George I. Jallo, Kevin Ginn, Amy Smith, Joshua J. Chern, Amy Lee, Annie Drapeau, Mark D. Krieger, Michael H. Handler, Todd C. Hankinson, and on behalf of the Advancing Treatment for Pediatric Craniopharyngioma Consortium
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Adamantinomatous Craniopharyngioma ,Transcriptional analysis ,Age-related therapy ,Pediatric Craniopharyngioma ,Suprasellar tumor ,Neurology. Diseases of the nervous system ,RC346-429 - Abstract
Abstract Adamantinomatous craniopharyngioma (ACP) is a biologically benign but clinically aggressive lesion that has a significant impact on quality of life. The incidence of the disease has a bimodal distribution, with peaks occurring in children and older adults. Our group previously published the results of a transcriptome analysis of pediatric ACPs that identified several genes that were consistently overexpressed relative to other pediatric brain tumors and normal tissue. We now present the results of a transcriptome analysis comparing pediatric to adult ACP to identify biological differences between these groups that may provide novel therapeutic insights or support the assertion that potential therapies identified through the study of pediatric ACP may also have a role in adult ACP. Using our compiled transcriptome dataset of 27 pediatric and 9 adult ACPs, obtained through the Advancing Treatment for Pediatric Craniopharyngioma Consortium, we interrogated potential age-related transcriptional differences using several rigorous mathematical analyses. These included: canonical differential expression analysis; divisive, agglomerative, and probabilistic based hierarchical clustering; information theory based characterizations; and the deep learning approach, HD Spot. Our work indicates that there is no therapeutically relevant difference in ACP gene expression based on age. As such, potential therapeutic targets identified in pediatric ACP are also likely to have relvance for adult patients.
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- 2020
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18. Multi-omic analysis elucidates the genetic basis of hydrocephalus
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Andrew T. Hale, Lisa Bastarache, Diego M. Morales, John C. Wellons, III, David D. Limbrick, Jr., and Eric R. Gamazon
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PrediXcan ,human genetics ,transcriptomics ,hydrocephalus ,TWAS ,GWAS ,Biology (General) ,QH301-705.5 - Abstract
Summary: We conducted PrediXcan analysis of hydrocephalus risk in ten neurological tissues and whole blood. Decreased expression of MAEL in the brain was significantly associated (Bonferroni-adjusted p < 0.05) with hydrocephalus. PrediXcan analysis of brain imaging and genomics data in the independent UK Biobank (N = 8,428) revealed that MAEL expression in the frontal cortex is associated with white matter and total brain volumes. Among the top differentially expressed genes in brain, we observed a significant enrichment for gene-level associations with these structural phenotypes, suggesting an effect on disease risk through regulation of brain structure and integrity. We found additional support for these genes through analysis of the choroid plexus transcriptome of a murine model of hydrocephalus. Finally, differential protein expression analysis in patient cerebrospinal fluid recapitulated disease-associated expression changes in neurological tissues, but not in whole blood. Our findings provide convergent evidence highlighting the importance of tissue-specific pathways and mechanisms in the pathophysiology of hydrocephalus.
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- 2021
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19. Immune activation during Paenibacillus brain infection in African infants with frequent cytomegalovirus co-infection
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Albert M. Isaacs, Sarah U. Morton, Mercedeh Movassagh, Qiang Zhang, Christine Hehnly, Lijun Zhang, Diego M. Morales, Shamim A. Sinnar, Jessica E. Ericson, Edith Mbabazi-Kabachelor, Peter Ssenyonga, Justin Onen, Ronnie Mulondo, Mady Hornig, Benjamin C. Warf, James R. Broach, R. Reid Townsend, David D. Limbrick, Jr., Joseph N. Paulson, and Steven J. Schiff
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Immunology ,Proteomics ,Transcriptomics ,Science - Abstract
Summary: Inflammation during neonatal brain infections leads to significant secondary sequelae such as hydrocephalus, which often follows neonatal sepsis in the developing world. In 100 African hydrocephalic infants we identified the biological pathways that account for this response. The dominant bacterial pathogen was a Paenibacillus species, with frequent cytomegalovirus co-infection. A proteogenomic strategy was employed to confirm host immune response to Paenibacillus and to define the interplay within the host immune response network. Immune activation emphasized neuroinflammation, oxidative stress reaction, and extracellular matrix organization. The innate immune system response included neutrophil activity, signaling via IL-4, IL-12, IL-13, interferon, and Jak/STAT pathways. Platelet-activating factors and factors involved with microbe recognition such as Class I MHC antigen-presenting complex were also increased. Evidence suggests that dysregulated neuroinflammation propagates inflammatory hydrocephalus, and these pathways are potential targets for adjunctive treatments to reduce the hazards of neuroinflammation and risk of hydrocephalus following neonatal sepsis.
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- 2021
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20. Semi-automated segmentation of the lateral periventricular regions using diffusion magnetic resonance imaging
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Albert M. Isaacs, Rowland H. Han, Christopher D. Smyser, David D. Limbrick, Jr., and Joshua S. Shimony
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Segmentation of lateral ventricular perimeter regions of interest ,Science - Abstract
The lateral ventricular perimeter (LVP) of the brain is a critical region because in addition to housing neural stem cells required for brain development, it facilitates cerebrospinal fluid (CSF) bulk flow and functions as a blood-CSF barrier to protect periventricular white matter (PVWM) and other adjacent regions from injurious toxins. LVP injury is common, particularly among preterm infants who sustain intraventricular hemorrhage or post hemorrhagic hydrocephalus and has been associated with poor neurological outcomes. Assessment of the LVP with diffusion MRI has been challenging, primarily due to issues with partial volume artifacts since the LVP region is in close proximity to CSF and other structures of varying signal intensities that may be inadvertently included in LVP segmentation.This research method presents: • A novel MATLAB-based method to segment a homogenous LVP layer using high spatial resolution parameters (voxel size 1.2 × 1.2 × 1.2 mm3) to only capture the innermost layer of the LVP. • The segmented LVP is averaged from three contiguous axial slices to increase signal to noise ratio and reduce the effect of any residual volume averaging effect and eliminates manual and inter/intrarater-related errors.
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- 2020
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21. Opportunities in posthemorrhagic hydrocephalus research: outcomes of the Hydrocephalus Association Posthemorrhagic Hydrocephalus Workshop
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Jenna E. Koschnitzky, Richard F. Keep, David D. Limbrick, James P. McAllister, Jill A. Morris, Jennifer Strahle, and Yun C. Yung
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Hydrocephalus ,Posthemorrhagic ,Intraventricular hemorrhage ,Germinal matrix hemorrhage ,Blood brain barrier ,Premature ,Neurology. Diseases of the nervous system ,RC346-429 - Abstract
Abstract The Hydrocephalus Association Posthemorrhagic Hydrocephalus Workshop was held on July 25 and 26, 2016 at the National Institutes of Health. The workshop brought together a diverse group of researchers including pediatric neurosurgeons, neurologists, and neuropsychologists with scientists in the fields of brain injury and development, cerebrospinal and interstitial fluid dynamics, and the blood–brain and blood–CSF barriers. The goals of the workshop were to identify areas of opportunity in posthemorrhagic hydrocephalus research and encourage scientific collaboration across a diverse set of fields. This report details the major themes discussed during the workshop and research opportunities identified for posthemorrhagic hydrocephalus. The primary areas include (1) preventing intraventricular hemorrhage, (2) stopping primary and secondary brain damage, (3) preventing hydrocephalus, (4) repairing brain damage, and (5) improving neurodevelopment outcomes in posthemorrhagic hydrocephalus.
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- 2018
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22. Chemokine and cytokine levels in the lumbar cerebrospinal fluid of preterm infants with post-hemorrhagic hydrocephalus
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Gakwaya Habiyaremye, Diego M. Morales, Clinton D. Morgan, James P. McAllister, Travis S. CreveCoeur, Rowland H. Han, Mohamed Gabir, Brandon Baksh, Deanna Mercer, and David D. Limbrick
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Cytokines ,Chemokines ,Post-hemorrhagic ,Hydrocephalus ,CSF ,Cerebrospinal fluid ,Neurology. Diseases of the nervous system ,RC346-429 - Abstract
Abstract Background Neuroinflammation has been implicated in the pathophysiology of post-hemorrhagic hydrocephalus (PHH) of prematurity, but no comprehensive analysis of signaling molecules has been performed using human cerebrospinal fluid (CSF). Methods Lumbar CSF levels of key cytokines (IL-1α, IL-1β, IL-4, IL-6, IL-8, IL-10, IL-12, TNF-α, TGF-β1, IFN-γ) and chemokines (XCL-1, CCL-2, CCL-3, CCL-19, CXCL-10, CXCL-11, CXCL-12) were measured using conventional and multiplexed Enzyme-linked Immunosorbent Assays and compared between preterm infants with PHH and those with no known neurological injury. The relationships between individual biomarker levels and specific CSF cell counts were examined. Results Total protein (TP) CSF levels were elevated in the PHH subjects compared to controls. CSF levels of IL-1α, IL-4, IL-6, IL-12, TNF-α, CCL-3, CCL-19, and CXCL-10 were significantly increased in PHH whereas XCL-1 was significantly decreased in PHH. When normalizing by TP, IL-1α, IL-1β, IL-10, IL-12, CCL-3, and CCL-19 levels were significantly elevated compared to controls, while XCL-1 levels remained significantly decreased. Among those with significantly different levels in both absolute and normalized levels, only absolute CCL-19 levels showed a significant correlation with CSF nucleated cells, neutrophils, and lymphocytes. IL-1β and CXCL-10 also were correlated with total cell count, nucleated cells, red blood cells, and neutrophils. Conclusions Neuroinflammation is likely to be an important process in the pathophysiology of PHH. To our knowledge, this is the first study to investigate CSF levels of chemokines in PHH as well as the only one to show XCL-1 selectively decreased in a diseased state. Additionally, CCL-19 was the only analyte studied that showed significant differences between groups and had significant correlation with cell count analysis. The selectivity of CCL-19 and XCL-1 should be further investigated. Future studies will further delineate the role of these cytokines and chemokines in PHH.
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- 2017
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23. Impaired hippocampal development and outcomes in very preterm infants with perinatal brain injury
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Jennifer M. Strahle, Regina L. Triplett, Dimitrios Alexopoulos, Tara A. Smyser, Cynthia E. Rogers, David D. Limbrick, Jr, and Christopher D. Smyser
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Computer applications to medicine. Medical informatics ,R858-859.7 ,Neurology. Diseases of the nervous system ,RC346-429 - Abstract
Preterm infants are at high risk for brain injury during the perinatal period. Intraventricular hemorrhage and periventricular leukomalacia, the two most common patterns of brain injury in prematurely-born children, are associated with poor neurodevelopmental outcomes. The hippocampus is known to be critical for learning and memory; however, it remains unknown how these forms of brain injury affect hippocampal growth and how the resulting alterations in hippocampal development relate to childhood outcomes. To investigate these relationships, hippocampal segmentations were performed on term equivalent MRI scans from 55 full-term infants, 85 very preterm infants (born ≤32 weeks gestation) with no to mild brain injury and 73 very preterm infants with brain injury (e.g., grade III/IV intraventricular hemorrhage, post-hemorrhagic hydrocephalus, cystic periventricular leukomalacia). Infants then underwent standardized neurodevelopmental testing using the Bayley Scales of Infant and Toddler Development, 3rd edition at age 2 years, corrected for prematurity. To delineate the effects of brain injury on early hippocampal development, hippocampal volumes were compared across groups and associations between neonatal volumes and neurodevelopmental outcomes at age 2 years were explored. Very preterm infants with brain injury had smaller hippocampal volumes at term equivalent age compared to term and very preterm infants with no to mild injury, with the smallest hippocampi among those with grade III/IV intraventricular hemorrhage and post-hemorrhagic hydrocephalus. Further, larger ventricle size was associated with smaller hippocampal size. Smaller hippocampal volumes were related to worse motor performance at age 2 years across all groups. In addition, smaller hippocampal volumes in infants with brain injury were correlated with impaired cognitive scores at age 2 years, a relationship specific to this group. Consistent with our preclinical findings, these findings demonstrate that perinatal brain injury is associated with hippocampal size in preterm infants, with smaller volumes related to domain-specific neurodevelopmental impairments in this high-risk clinical population. Keywords: Hippocampus, Very preterm infant, White matter injury, Neurodevelopment, Magnetic resonance imaging
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- 2019
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24. A comparison of resting state functional magnetic resonance imaging to invasive electrocortical stimulation for sensorimotor mapping in pediatric patients
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Jarod L. Roland, Carl D. Hacker, Abraham Z. Snyder, Joshua S. Shimony, John M. Zempel, David D. Limbrick, Matthew D. Smyth, and Eric C. Leuthardt
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Computer applications to medicine. Medical informatics ,R858-859.7 ,Neurology. Diseases of the nervous system ,RC346-429 - Abstract
Localizing neurologic function within the brain remains a significant challenge in clinical neurosurgery. Invasive mapping with direct electrocortical stimulation currently is the clinical gold standard but is impractical in young or cognitively delayed patients who are unable to reliably perform tasks. Resting state functional magnetic resonance imaging non-invasively identifies resting state networks without the need for task performance, hence, is well suited to pediatric patients. We compared sensorimotor network localization by resting state fMRI to cortical stimulation sensory and motor mapping in 16 pediatric patients aged 3.1 to 18.6 years. All had medically refractory epilepsy that required invasive electrographic monitoring and stimulation mapping. The resting state fMRI data were analyzed using a previously trained machine learning classifier that has previously been evaluated in adults. We report comparable functional localization by resting state fMRI compared to stimulation mapping. These results provide strong evidence for the utility of resting state functional imaging in the localization of sensorimotor cortex across a wide range of pediatric patients. Keywords: Resting state, Functional MRI, Mapping, Pediatric, Neurosurgery
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- 2019
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25. MR diffusion changes in the perimeter of the lateral ventricles demonstrate periventricular injury in post-hemorrhagic hydrocephalus of prematurity
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Albert M. Isaacs, Christopher D. Smyser, Rachel E. Lean, Dimitrios Alexopoulos, Rowland H. Han, Jeffrey J. Neil, Sophia A. Zimbalist, Cynthia E. Rogers, Yan Yan, Joshua S. Shimony, and David D. Limbrick, Jr.
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Computer applications to medicine. Medical informatics ,R858-859.7 ,Neurology. Diseases of the nervous system ,RC346-429 - Abstract
Objectives: Injury to the preterm lateral ventricular perimeter (LVP), which contains the neural stem cells responsible for brain development, may contribute to the neurological sequelae of intraventricular hemorrhage (IVH) and post-hemorrhagic hydrocephalus of prematurity (PHH). This study utilizes diffusion MRI (dMRI) to characterize the microstructural effects of IVH/PHH on the LVP and segmented frontal-occipital horn perimeters (FOHP). Study design: Prospective study of 56 full-term infants, 72 very preterm infants without brain injury (VPT), 17 VPT infants with high-grade IVH without hydrocephalus (HG-IVH), and 13 VPT infants with PHH who underwent dMRI at term equivalent. LVP and FOHP dMRI measures and ventricular size-dMRI correlations were assessed. Results: In the LVP, PHH had consistently lower FA and higher MD and RD than FT and VPT (p.050). Ventricular size correlated negatively with FA, and positively with MD and RD (p
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- 2019
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26. Left hemisphere structural connectivity abnormality in pediatric hydrocephalus patients following surgery
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Weihong Yuan, Artur Meller, Joshua S. Shimony, Tiffany Nash, Blaise V. Jones, Scott K. Holland, Mekibib Altaye, Holly Barnard, Jannel Phillips, Stephanie Powell, Robert C. McKinstry, David D. Limbrick, Akila Rajagopal, and Francesco T. Mangano
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Diffusion tensor imaging ,Graph theoretical analysis ,Left hemisphere ,Pediatric hydrocephalus ,Small-worldness ,Computer applications to medicine. Medical informatics ,R858-859.7 ,Neurology. Diseases of the nervous system ,RC346-429 - Abstract
Neuroimaging research in surgically treated pediatric hydrocephalus patients remains challenging due to the artifact caused by programmable shunt. Our previous study has demonstrated significant alterations in the whole brain white matter structural connectivity based on diffusion tensor imaging (DTI) and graph theoretical analysis in children with hydrocephalus prior to surgery or in surgically treated children without programmable shunts. This study seeks to investigate the impact of brain injury on the topological features in the left hemisphere, contratelateral to the shunt placement, which will avoid the influence of shunt artifacts and makes further group comparisons feasible for children with programmable shunt valves. Three groups of children (34 in the control group, 12 in the 3-month post-surgery group, and 24 in the 12-month post-surgery group, age between 1 and 18 years) were included in the study. The structural connectivity data processing and analysis were performed based on DTI and graph theoretical analysis. Specific procedures were revised to include only left brain imaging data in normalization, parcellation, and fiber counting from DTI tractography. Our results showed that, when compared to controls, children with hydrocephalus in both the 3-month and 12-month post-surgery groups had significantly lower normalized clustering coefficient, lower small-worldness, and higher global efficiency (all p
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- 2016
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27. Abnormal structural connectivity in the brain networks of children with hydrocephalus
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Weihong Yuan, Scott K. Holland, Joshua S. Shimony, Mekibib Altaye, Francesco T. Mangano, David D. Limbrick, Blaise V. Jones, Tiffany Nash, Akila Rajagopal, Sarah Simpson, Dustin Ragan, and Robert C. McKinstry
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Graph theoretical analysis ,Network ,Pediatric hydrocephalus ,Small-worldness ,Computer applications to medicine. Medical informatics ,R858-859.7 ,Neurology. Diseases of the nervous system ,RC346-429 - Abstract
Increased intracranial pressure and ventriculomegaly in children with hydrocephalus are known to have adverse effects on white matter structure. This study seeks to investigate the impact of hydrocephalus on topological features of brain networks in children. The goal was to investigate structural network connectivity, at both global and regional levels, in the brains in children with hydrocephalus using graph theory analysis and diffusion tensor tractography. Three groups of children were included in the study (29 normally developing controls, 9 preoperative hydrocephalus patients, and 17 postoperative hydrocephalus patients). Graph theory analysis was applied to calculate the global network measures including small-worldness, normalized clustering coefficients, normalized characteristic path length, global efficiency, and modularity. Abnormalities in regional network parameters, including nodal degree, local efficiency, clustering coefficient, and betweenness centrality, were also compared between the two patients groups (separately) and the controls using two tailed t-test at significance level of p
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- 2015
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28. Toward rational use of repeat imaging in children with mild traumatic brain injuries and intracranial injuries
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Gabrielle W. Johnson, Jacob K. Greenberg, Andrew T. Hale, Ranbir Ahluwalia, Madelyn Hill, Ahmed Belal, Shawyon Baygani, Randi E. Foraker, Christopher R. Carpenter, Yan Yan, Laurie L. Ackerman, Corina Noje, Eric Jackson, Erin C. Burns, Christina M. Sayama, Nathan R. Selden, Shobhan Vachhrajani, Chevis N. Shannon, Nathan Kuppermann, and David D. Limbrick
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General Medicine - Abstract
OBJECTIVE Limited evidence exists on the utility of repeat neuroimaging in children with mild traumatic brain injuries (mTBIs) and intracranial injuries (ICIs). Here, the authors identified factors associated with repeat neuroimaging and predictors of hemorrhage progression and/or neurosurgical intervention. METHODS The authors performed a multicenter, retrospective cohort study of children at four centers of the Pediatric TBI Research Consortium. All patients were ≤ 18 years and presented within 24 hours of injury with a Glasgow Coma Scale score of 13–15 and evidence of ICI on neuroimaging. The outcomes of interest were 1) whether patients underwent repeat neuroimaging during index admission, and 2) a composite outcome of progression of previously identified hemorrhage ≥ 25% and/or repeat imaging as an indication for subsequent neurosurgical intervention. The authors performed multivariable logistic regression and report odds ratios and 95% confidence intervals. RESULTS A total of 1324 patients met inclusion criteria; 41.3% of patients underwent repeat imaging. Repeat imaging was associated with clinical change in 4.8% of patients; the remainder of the imaging tests were for routine surveillance (90.9%) or of unclear prompting (4.4%). In 2.6% of patients, repeat imaging findings were reported as an indication for neurosurgical intervention. While many factors were associated with repeat neuroimaging, only epidural hematoma (OR 3.99, 95% CI 2.22–7.15), posttraumatic seizures (OR 2.95, 95% CI 1.22–7.41), and age ≥ 2 years (OR 2.25, 95% CI 1.16–4.36) were significant predictors of hemorrhage progression and/or neurosurgery. Of patients without any of these risk factors, none underwent neurosurgical intervention. CONCLUSIONS Repeat neuroimaging was commonly used but uncommonly associated with clinical deterioration. Although several factors were associated with repeat neuroimaging, only posttraumatic seizures, age ≥ 2 years, and epidural hematoma were significant predictors of hemorrhage progression and/or neurosurgery. These results provide the foundation for evidence-based repeat neuroimaging practices in children with mTBI and ICI.
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- 2023
29. Endoscopic third ventriculostomy in previously shunt-treated patients
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Brandon G. Rocque, Hailey Jensen, Ron W. Reeder, Abhaya V. Kulkarni, Ian F. Pollack, John C. Wellons, Robert P. Naftel, Eric M. Jackson, William E. Whitehead, Jonathan A. Pindrik, David D. Limbrick, Patrick J. McDonald, Mandeep S. Tamber, Todd C. Hankinson, Jason S. Hauptman, Mark D. Krieger, Jason Chu, Tamara D. Simon, Jay Riva-Cambrin, John R. W. Kestle, and Curtis J. Rozzelle
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General Medicine - Abstract
OBJECTIVE Endoscopic third ventriculostomy (ETV) is an option for treatment of hydrocephalus, including for patients who have a history of previous treatment with CSF shunt insertion. The purpose of this study was to report the success of postshunt ETV by using data from a multicenter prospective registry. METHODS Prospectively collected data in the Hydrocephalus Clinical Research Network (HCRN) Core Data Project (i.e., HCRN Registry) were reviewed. Children who underwent ETV between 2008 and 2019 and had a history of previous treatment with a CSF shunt were included. A Kaplan-Meier survival curve was created for the primary outcome: time from postshunt ETV to subsequent CSF shunt placement or revision. Univariable Cox proportional hazards models were created to evaluate for an association between clinical and demographic variables and subsequent shunt surgery. Postshunt ETV complications were also identified and categorized. RESULTS A total of 203 children were included: 57% male and 43% female; 74% White, 23% Black, and 4% other race. The most common hydrocephalus etiologies were postintraventricular hemorrhage secondary to prematurity (56, 28%) and aqueductal stenosis (42, 21%). The ETV Success Score ranged from 10 to 80. The median patient age was 4.1 years. The overall success of postshunt ETV at 6 months was 41%. Only the surgeon’s report of a clear view of the basilar artery was associated with a lower likelihood of postshunt ETV failure (HR 0.43, 95% CI 0.23–0.82, p = 0.009). None of the following variables were associated with postshunt ETV success: age at the time of postshunt ETV, etiology of hydrocephalus, sex, race, ventricle size, number of previous shunt operations, ETV performed at time of shunt infection, and use of external ventricular drainage. Overall, complications were reported in 22% of patients, with CSF leak (8.6%) being the most common complication. CONCLUSIONS Postshunt ETV was successful in treating hydrocephalus, without subsequent need for a CSF shunt, in 41% of patients, with a clear view of the basilar artery being the only variable significantly associated with success. Complications occurred in 22% of patients. ETV is an option for treatment of hydrocephalus in children who have previously undergone shunt placement, but with a lower than expected likelihood of success.
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- 2022
30. Surgical management of colloid cysts of the third ventricle: a single-institution comparison of endoscopic and microsurgical resection
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Thomas L, Beaumont, David D, Limbrick, Bhuvic, Patel, Michael R, Chicoine, Keith M, Rich, and Ralph G, Dacey
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General Medicine - Abstract
OBJECTIVE Colloid cysts of the third ventricle are histologically benign lesions that can cause obstructive hydrocephalus and death. Historically, colloid cysts have been removed by open microsurgical approaches. More recently, minimally invasive endoscopic and port-based techniques have offered decreased complications and length of stay, with improved patient satisfaction. METHODS A single-center retrospective analysis of patients with colloid cysts who underwent surgery at a large tertiary care hospital was performed. The cohort was assessed based on the surgical approach, comparing endoscopic resection to open microsurgical resection. The primary endpoint was rate of perioperative complications. Univariate analysis was used to assess several procedure-related variables and the cost of treatment. Multivariate analysis was used to assess predictors of perioperative complications. Total inpatient cost for each case was extracted from the health system financial database. RESULTS The study included 78 patients with colloid cysts who underwent resection either via an endoscopic approach (n = 33) or through a craniotomy (n = 45) with an interhemispheric-transcallosal or transcortical-transventricular approach. Nearly all patients were symptomatic, and half had obstructive hydrocephalus. Endoscopic resection was associated with reduced operative time (3.2 vs 4.9 hours, p < 0.001); lower complication rate (6.1% vs 33.1%, p = 0.009); reduced length of stay (4.1 vs 8.9 days, p < 0.001); and improved discharge to home (100% vs 75.6%, p = 0.008) compared to microsurgical resection. Coagulated residual cyst wall remnants were more common after endoscopic resection (63.6% vs 19.0%, p < 0.001) although this was not associated with a significantly increased rate of reoperation for recurrence. The mean follow-up was longer in the microsurgical resection group (3.1 vs 4.9 years, p = 0.016). The total inpatient cost of endoscopic resection was, on average, one-half (47%) that of microsurgical resection. When complications were encountered, the total inpatient cost of microsurgical resection was 4 times greater than that of endoscopic resection where no major complications were observed. The increased cost-effectiveness of endoscopic resection remained during reoperation. CONCLUSIONS Endoscopic resection of colloid cysts of the third ventricle offers a significant reduction in perioperative complications when compared to microsurgical resection. Endoscopic resection optimizes nearly all procedure-related variables compared to microsurgical resection, and reduces total inpatient cost by > 50%. However, endoscopic resection is associated with a significantly increased likelihood of residual coagulated cyst wall remnants that could increase the rate of reoperation for recurrence. Taken together, endoscopic resection represents a safe and effective minimally invasive approach for removal of colloid cysts.
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- 2022
31. MRI-guided laser interstitial thermal therapy for deep-seated gliomas in children with neurofibromatosis type 1: report of two cases
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Kevin A. Cross, Afshin Salehi, Mohamed S. Abdelbaki, David H. Gutmann, and David D. Limbrick
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Pediatrics, Perinatology and Child Health ,Neurology (clinical) ,General Medicine - Published
- 2022
32. Complications and outcomes of posterior fossa decompression with duraplasty versus without duraplasty for pediatric patients with Chiari malformation type I and syringomyelia: a study from the Park-Reeves Syringomyelia Research Consortium
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S. Hassan A. Akbari, Alexander T. Yahanda, Laurie L. Ackerman, P. David Adelson, Raheel Ahmed, Gregory W. Albert, Philipp R. Aldana, Tord D. Alden, Richard C. E. Anderson, David F. Bauer, Tammy Bethel-Anderson, Karin Bierbrauer, Douglas L. Brockmeyer, Joshua J. Chern, Daniel E. Couture, David J. Daniels, Brian J. Dlouhy, Susan R. Durham, Richard G. Ellenbogen, Ramin Eskandari, Herbert E. Fuchs, Gerald A. Grant, Patrick C. Graupman, Stephanie Greene, Jeffrey P. Greenfield, Naina L. Gross, Daniel J. Guillaume, Todd C. Hankinson, Gregory G. Heuer, Mark Iantosca, Bermans J. Iskandar, Eric M. Jackson, George I. Jallo, James M. Johnston, Bruce A. Kaufman, Robert F. Keating, Nicklaus R. Khan, Mark D. Krieger, Jeffrey R. Leonard, Cormac O. Maher, Francesco T. Mangano, J. Gordon McComb, Sean D. McEvoy, Thanda Meehan, Arnold H. Menezes, Michael S. Muhlbauer, Brent R. O’Neill, Greg Olavarria, John Ragheb, Nathan R. Selden, Manish N. Shah, Chevis N. Shannon, Joshua S. Shimony, Matthew D. Smyth, Scellig S. D. Stone, Jennifer M. Strahle, Mandeep S. Tamber, James C. Torner, Gerald F. Tuite, Elizabeth C. Tyler-Kabara, Scott D. Wait, John C. Wellons, William E. Whitehead, Tae Sung Park, and David D. Limbrick
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General Medicine - Abstract
OBJECTIVE The aim of this study was to determine differences in complications and outcomes between posterior fossa decompression with duraplasty (PFDD) and without duraplasty (PFD) for the treatment of pediatric Chiari malformation type I (CM1) and syringomyelia (SM). METHODS The authors used retrospective and prospective components of the Park-Reeves Syringomyelia Research Consortium database to identify pediatric patients with CM1-SM who received PFD or PFDD and had at least 1 year of follow-up data. Preoperative, treatment, and postoperative characteristics were recorded and compared between groups. RESULTS A total of 692 patients met the inclusion criteria for this database study. PFD was performed in 117 (16.9%) and PFDD in 575 (83.1%) patients. The mean age at surgery was 9.86 years, and the mean follow-up time was 2.73 years. There were no significant differences in presenting signs or symptoms between groups, although the preoperative syrinx size was smaller in the PFD group. The PFD group had a shorter mean operating room time (p < 0.0001), fewer patients with > 50 mL of blood loss (p = 0.04), and shorter hospital stays (p = 0.0001). There were 4 intraoperative complications, all within the PFDD group (0.7%, p > 0.99). Patients undergoing PFDD had a 6-month complication rate of 24.3%, compared with 13.7% in the PFD group (p = 0.01). There were no differences between groups for postoperative complications beyond 6 months (p = 0.33). PFD patients were more likely to require revision surgery (17.9% vs 8.3%, p = 0.002). PFDD was associated with greater improvements in headaches (89.6% vs 80.8%, p = 0.04) and back pain (86.5% vs 59.1%, p = 0.01). There were no differences between groups for improvement in neurological examination findings. PFDD was associated with greater reduction in anteroposterior syrinx size (43.7% vs 26.9%, p = 0.0001) and syrinx length (18.9% vs 5.6%, p = 0.04) compared with PFD. CONCLUSIONS PFD was associated with reduced operative time and blood loss, shorter hospital stays, and fewer postoperative complications within 6 months. However, PFDD was associated with better symptom improvement and reduction in syrinx size and lower rates of revision decompression. The two surgeries have low intraoperative complication rates and comparable complication rates beyond 6 months.
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- 2022
33. Usability and Acceptability of Clinical Decision Support Based on the KIIDS-TBI Tool for Children with Mild Traumatic Brain Injuries and Intracranial Injuries
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Jacob K. Greenberg, Ayodamola Otun, Pyi Theim Kyaw, Christopher R. Carpenter, Ross C. Brownson, Nathan Kuppermann, David D Limbrick, Randi E. Foraker, and Po-Yin Yen
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Traumatic ,clinical decision support ,Physical Injury - Accidents and Adverse Effects ,mixed methods ,Clinical Sciences ,Decision Support Systems ,clinical information ,Health Informatics ,Bioengineering ,Traumatic Brain Injury (TBI) ,Clinical ,Health Information Management ,children ,Clinical Research ,Brain Injuries, Traumatic ,Craniocerebral Trauma ,Electronic Health Records ,Humans ,Child ,Traumatic Head and Spine Injury ,Pediatric ,traumatic brain injury ,Injuries and accidents ,Decision Support Systems, Clinical ,Hospitals, Pediatric ,Childhood Injury ,Hospitals ,Computer Science Applications ,Brain Disorders ,Good Health and Well Being ,Networking and Information Technology R&D (NITRD) ,Brain Injuries ,Information Systems - Abstract
Background The Kids Intracranial Injury Decision Support tool for Traumatic Brain Injury (KIIDS-TBI) tool is a validated risk prediction model for managing children with mild traumatic brain injuries (mTBI) and intracranial injuries. Electronic clinical decision support (CDS) may facilitate the clinical implementation of this evidence-based guidance. Objective Our objective was to evaluate the acceptability and usability of an electronic CDS tool for managing children with mTBI and intracranial injuries. Methods Emergency medicine and neurosurgery physicians (10 each) from 10 hospitals in the United States were recruited to participate in usability testing of a novel CDS prototype in a simulated electronic health record environment. Testing included a think-aloud protocol, an acceptability and usability survey, and a semi-structured interview. The prototype was updated twice during testing to reflect user feedback. Usability problems recorded in the videos were categorized using content analysis. Interview transcripts were analyzed using thematic analysis. Results Among the 20 participants, most worked at teaching hospitals (80%), freestanding children's hospitals (95%), and level-1 trauma centers (75%). During the two prototype updates, problems with clarity of terminology and navigating through the CDS interface were identified and corrected. Corresponding to these changes, the number of usability problems decreased from 35 in phase 1 to 8 in phase 3 and the number of mistakes made decreased from 18 (phase 1) to 2 (phase 3). Through the survey, participants found the tool easy to use (90%), useful for determining a patient's level of care (95%), and likely to improve resource use (90%) and patient safety (79%). Interview themes related to the CDS's ability to support evidence-based decision-making and improve clinical workflow proposed implementation strategies and potential pitfalls. Conclusion After iterative evaluation and refinement, the KIIDS-TBI CDS tool was found to be highly usable and useful for aiding the management of children with mTBI and intracranial injuries.
- Published
- 2023
34. Data from Targeted Inhibition of Cyclic AMP Phosphodiesterase-4 Promotes Brain Tumor Regression
- Author
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Joshua B. Rubin, David Piwnica-Worms, Arie Perry, Erin Jackson, B. Mark Woerner, Andrew Hope, David D. Limbrick, Nicole M. Warrington, and Patricia Goldhoff
- Abstract
Purpose: As favorable outcomes from malignant brain tumors remain limited by poor survival and treatment-related toxicity, novel approaches to cure are essential. Previously, we identified the cyclic AMP phosphodiesterase-4 (PDE4) inhibitor Rolipram as a potent antitumor agent. Here, we investigate the role of PDE4 in brain tumors and examine the utility of PDE4 as a therapeutic target.Experimental Design: Immunohistochemistry was used to evaluate the expression pattern of a subfamily of PDE4, PDE4A, in multiple brain tumor types. To evaluate the effect of PDE4A on growth, a brain-specific isoform, PDE4A1 was overexpressed in xenografts of Daoy medulloblastoma and U87 glioblastoma cells. To determine therapeutic potential of PDE4 inhibition, Rolipram, temozolomide, and radiation were tested alone and in combination on mice bearing intracranial U87 xenografts.Results: We found that PDE4A is expressed in medulloblastoma, glioblastoma, oligodendroglioma, ependymoma, and meningioma. Moreover, when PDE4A1 was overexpressed in Daoy medulloblastoma and U87 glioblastoma cells, in vivo doubling times were significantly shorter for PDE4A1-overexpressing xenografts compared with controls. In long-term survival and bioluminescence studies, Rolipram in combination with first-line therapy for malignant gliomas (temozolomide and conformal radiation therapy) enhanced the survival of mice bearing intracranial xenografts of U87 glioblastoma cells. Bioluminescence imaging indicated that whereas temozolomide and radiation therapy arrested intracranial tumor growth, the addition of Rolipram to this regimen resulted in tumor regression.Conclusions: This study shows that PDE4 is widely expressed in brain tumors and promotes their growth and that inhibition with Rolipram overcomes tumor resistance and mediates tumor regression.
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- 2023
35. Supplementary Figures S1-S3 from Targeted Inhibition of Cyclic AMP Phosphodiesterase-4 Promotes Brain Tumor Regression
- Author
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Joshua B. Rubin, David Piwnica-Worms, Arie Perry, Erin Jackson, B. Mark Woerner, Andrew Hope, David D. Limbrick, Nicole M. Warrington, and Patricia Goldhoff
- Abstract
Supplementary Figures S1-S3 from Targeted Inhibition of Cyclic AMP Phosphodiesterase-4 Promotes Brain Tumor Regression
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- 2023
36. Genetic and histopathological associations with outcome in pediatric pilocytic astrocytoma
- Author
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Samuel J. Cler, Alexander Skidmore, Alexander T. Yahanda, Kimberly Mackey, Joshua B. Rubin, Andrew Cluster, Stephanie Perkins, Karen Gauvain, Allison A. King, David D. Limbrick, Sean McEvoy, Tae Sung Park, Matthew D. Smyth, Ali Y. Mian, Michael R. Chicoine, Sonika Dahiya, and Jennifer M. Strahle
- Subjects
General Medicine - Abstract
OBJECTIVE Pilocytic astrocytomas (PAs) have a generally favorable prognosis; however, progression or recurrence after resection is possible. The prognostic value of histopathological qualifiers (defined below) or BRAF alterations is not well understood. The aim of this study was to identify the prognostic value of genetic and histopathological features of pediatric PAs. METHODS Patients treated for a WHO grade I PA at a single institution were analyzed for histopathological and genetic features and outcomes. “Histopathological qualifier” refers to designations such as "WHO grade I PA with increased proliferative index." BRAF alterations include gene fusions and point mutations. Patients with neurofibromatosis type 1 were excluded. RESULTS A total of 222 patients were analyzed (51% female, mean age 9.6 years). Tumors were located in the cerebellum/fourth ventricle (51%), optic pathway/hypothalamus (15%), brainstem (12%), and cerebral cortex (11%). BRAF alterations were screened for in 77 patients and identified in 56 (73%). Histopathological qualifiers were present in 27 patients (14%). Resection was performed in 197 patients (89%), 41 (21%) of whom displayed tumor progression or recurrence after resection. Tumor progression or recurrence was not associated with histopathologic qualifiers (p = 0.36) or BRAF alterations (p = 0.77). Ki-67 proliferative indices were not predictive of progression or recurrence (p = 0.94). BRAF alterations, specifically KIAA1549 fusions, were associated with cerebellar/fourth ventricular tumor location (p < 0.0001) and younger patient age (p = 0.03). Patients in whom gross-total resection was achieved had lower rates of progression and recurrence (p < 0.0001). CONCLUSIONS Histopathological features/qualifiers and BRAF alterations were not associated with tumor recurrence/progression in pediatric PAs. The extent of resection was the only factor analyzed that predicted outcome.
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- 2022
37. Socioeconomic and demographic factors in the diagnosis and treatment of Chiari malformation type I and syringomyelia
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Robert F. Keating, Gerald F. Tuite, Alexander K. Powers, James M. Johnston, W. Jerry Oakes, Daniel E. Couture, Stephanie Greene, Jacob K. Greenberg, Michael S. Muhlbauer, Nickalus R. Khan, Robert C. Dauser, Jeffrey R. Leonard, Asad A Rizvi, Gerald A. Grant, Robert C. McKinstry, David J. Daniels, Toba N. Niazi, Arnold H. Menezes, Bruce A. Kaufman, Travis S. CreveCoeur, Rowland H. Han, Scellig S D Stone, Prithvi Narayan, John C. Wellons, Richard G. Ellenbogen, Karin S. Bierbrauer, Francesco T. Mangano, Bermans J. Iskandar, Philipp R. Aldana, J. Gordon McComb, Daniel J. Guillaume, Brent R. O'Neill, Douglas L. Brockmeyer, Jeffrey G. Ojemann, Laurie L. Ackerman, Mark Iantosca, Andrew Jea, David D. Limbrick, William R. Boydston, Joshua S. Shimony, Tae Sung Park, Richard C. E. Anderson, Raheel Ahmed, Lissa C Baird, Nathan R. Selden, Matthew D. Smyth, Eric M. Jackson, Jennifer Strahle, P. David Adelson, Joshua J. Chern, Chevis N. Shannon, Naina L. Gross, Ralph G. Dacey, Todd C. Hankinson, Manish N. Shah, Syed Hassan A Akbari, Herbert E. Fuchs, James C. Torner, William E. Whitehead, Tord D. Alden, Cormac O. Maher, Susan R Durham, Paul Klimo, John Ragheb, Jodi L. Smith, and Gregory W. Albert
- Subjects
Platybasia ,Pediatrics ,medicine.medical_specialty ,business.industry ,Hearing loss ,Basilar invagination ,General Medicine ,medicine.disease ,medicine ,Gait Ataxia ,medicine.symptom ,business ,Socioeconomic status ,Medicaid ,Syringomyelia ,Chiari malformation - Abstract
OBJECTIVE The goal of this study was to assess the social determinants that influence access and outcomes for pediatric neurosurgical care for patients with Chiari malformation type I (CM-I) and syringomyelia (SM). METHODS The authors used retro- and prospective components of the Park-Reeves Syringomyelia Research Consortium database to identify pediatric patients with CM-I and SM who received surgical treatment and had at least 1 year of follow-up data. Race, ethnicity, and insurance status were used as comparators for preoperative, treatment, and postoperative characteristics and outcomes. RESULTS A total of 637 patients met inclusion criteria, and race or ethnicity data were available for 603 (94.7%) patients. A total of 463 (76.8%) were non-Hispanic White (NHW) and 140 (23.2%) were non-White. The non-White patients were older at diagnosis (p = 0.002) and were more likely to have an individualized education plan (p < 0.01). More non-White than NHW patients presented with cerebellar and cranial nerve deficits (i.e., gait ataxia [p = 0.028], nystagmus [p = 0.002], dysconjugate gaze [p = 0.03], hearing loss [p = 0.003], gait instability [p = 0.003], tremor [p = 0.021], or dysmetria [p < 0.001]). Non-White patients had higher rates of skull malformation (p = 0.004), platybasia (p = 0.002), and basilar invagination (p = 0.036). Non-White patients were more likely to be treated at low-volume centers than at high-volume centers (38.7% vs 15.2%; p < 0.01). Non-White patients were older at the time of surgery (p = 0.001) and had longer operative times (p < 0.001), higher estimated blood loss (p < 0.001), and a longer hospital stay (p = 0.04). There were no major group differences in terms of treatments performed or complications. The majority of subjects used private insurance (440, 71.5%), whereas 175 (28.5%) were using Medicaid or self-pay. Private insurance was used in 42.2% of non-White patients compared to 79.8% of NHW patients (p < 0.01). There were no major differences in presentation, treatment, or outcome between insurance groups. In multivariate modeling, non-White patients were more likely to present at an older age after controlling for sex and insurance status (p < 0.01). Non-White and male patients had a longer duration of symptoms before reaching diagnosis (p = 0.033 and 0.004, respectively). CONCLUSIONS Socioeconomic and demographic factors appear to influence the presentation and management of patients with CM-I and SM. Race is associated with age and timing of diagnosis as well as operating room time, estimated blood loss, and length of hospital stay. This exploration of socioeconomic and demographic barriers to care will be useful in understanding how to improve access to pediatric neurosurgical care for patients with CM-I and SM.
- Published
- 2022
38. Anterior versus posterior entry site for ventriculoperitoneal shunt insertion: a randomized controlled trial by the Hydrocephalus Clinical Research Network
- Author
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William E. Whitehead, Eric M. Jackson, Samuel R. Browd, Vanessa L Wall, Patrick J. McDonald, James M. Drake, Mark D. Krieger, Jenna E. Koschnitzky, Abhaya V. Kulkarni, Jason Chu, Richard Holubkov, Chevis N. Shannon, Paul Gross, Curtis J. Rozzelle, Ron W Reeder, David D. Limbrick, Hailey Jensen, Todd C. Hankinson, Mandeep S. Tamber, Tamara D. Simon, Ian F. Pollack, Jason S. Hauptman, Jay Riva-Cambrin, Robert P. Naftel, Jonathan Pindrik, John R. W. Kestle, and John C. Wellons
- Subjects
medicine.medical_specialty ,Randomization ,business.industry ,Hazard ratio ,General Medicine ,medicine.disease ,Hydrocephalus ,Surgery ,Shunt (medical) ,law.invention ,Randomized controlled trial ,Aqueductal stenosis ,law ,Medicine ,business ,Complication ,Ventriculomegaly - Abstract
OBJECTIVE The primary objective of this trial was to determine if shunt entry site affects the risk of shunt failure. METHODS The authors performed a parallel-design randomized controlled trial with an equal allocation of patients who received shunt placement via the anterior entry site and patients who received shunt placement via the posterior entry site. All patients were children with symptoms or signs of hydrocephalus and ventriculomegaly. Patients were ineligible if they had a prior history of shunt insertion. Patients received a ventriculoperitoneal shunt after randomization; randomization was stratified by surgeon. The primary outcome was shunt failure. The planned minimum follow-up was 18 months. The trial was designed to achieve high power to detect a 10% or greater absolute difference in the shunt failure rate at 1 year. An independent, blinded adjudication committee determined eligibility and the primary outcome. The study was conducted by the Hydrocephalus Clinical Research Network. RESULTS The study randomized 467 pediatric patients at 14 tertiary care pediatric hospitals in North America from April 2015 to January 2019. The adjudication committee, blinded to intervention, excluded 7 patients in each group for not meeting the study inclusion criteria. For the primary analysis, there were 229 patients in the posterior group and 224 patients in the anterior group. The median patient age was 1.3 months, and the most common etiologies of hydrocephalus were postintraventricular hemorrhage secondary to prematurity (32.7%), myelomeningocele (16.8%), and aqueductal stenosis (10.8%). There was no significant difference in the time to shunt failure between the entry sites (log-rank test, stratified by age < 6 months and ≥ 6 months; p = 0.061). The hazard ratio (HR) of a posterior shunt relative to an anterior shunt was calculated using a univariable Cox regression model and was nonsignificant (HR 1.35, 95% CI, 0.98–1.85; p = 0.062). No significant difference was found between entry sites for the surgery duration, number of ventricular catheter passes, ventricular catheter location, and hospital length of stay. There were no significant differences between entry sites for intraoperative complications, postoperative CSF leaks, pseudomeningoceles, shunt infections, skull fractures, postoperative seizures, new-onset epilepsy, or intracranial hemorrhages. CONCLUSIONS This randomized controlled trial comparing the anterior and posterior shunt entry sites has demonstrated no significant difference in the time to shunt failure. Anterior and posterior entry site surgeries were found to have similar outcomes and similar complication rates.
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- 2022
39. Does ventricle size contribute to cognitive outcomes in posthemorrhagic hydrocephalus? Role of early definitive intervention
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Dimitrios Alexopoulos, David D. Limbrick, Mounica Paturu, Jennifer Strahle, Regina L. Triplett, Christopher D. Smyser, and Siddhant Thukral
- Subjects
medicine.medical_specialty ,Infant, Premature, Diseases ,Hippocampus ,Ventriculoperitoneal Shunt ,Bayley Scales of Infant Development ,Article ,Cerebral Ventricles ,Time-to-Treatment ,Ventriculostomy ,Child Development ,Internal medicine ,medicine ,Humans ,Longitudinal Studies ,Toddler ,Cerebral Intraventricular Hemorrhage ,business.industry ,Infant, Newborn ,Endoscopic third ventriculostomy ,Gestational age ,General Medicine ,medicine.disease ,medicine.anatomical_structure ,Intraventricular hemorrhage ,Ventricle ,Neuroendoscopy ,Cardiology ,Gestation ,business ,human activities ,Infant, Premature ,Hydrocephalus ,Ventriculomegaly - Abstract
OBJECTIVE Posthemorrhagic hydrocephalus (PHH) is associated with significant morbidity, smaller hippocampal volumes, and impaired neurodevelopment in preterm infants. The timing of temporary CSF (tCSF) diversion has been studied; however, the optimal time for permanent CSF (pCSF) diversion is unknown. The objective of this study was to determine whether cumulative ventricle size or timing of pCSF diversion is associated with neurodevelopmental outcome and hippocampal size in preterm infants with PHH. METHODS Twenty-five very preterm neonates (born at ≤ 32 weeks’ gestational age) with high-grade intraventricular hemorrhage (IVH), subsequent PHH, and pCSF diversion with a ventriculoperitoneal shunt (n = 20) or endoscopic third ventriculostomy (n = 5) were followed until 2 years of age. Infants underwent serial cranial ultrasounds from birth until 1 year after pCSF diversion, brain MRI at term-equivalent age, and assessment based on the Bayley Scales of Infant and Toddler Development, Third Edition, at 2 years of age. Frontooccipital horn ratio (FOHR) measurements were derived from cranial ultrasounds and term-equivalent brain MRI. Hippocampal volumes were segmented and calculated from term-equivalent brain MRI. Cumulative ventricle size until the time of pCSF diversion was estimated using FOHR measurements from each cranial ultrasound performed prior to permanent intervention. RESULTS The average gestational ages at tCSF and pCSF diversion were 28.9 and 39.0 weeks, respectively. An earlier chronological age at the time of pCSF diversion was associated with larger right hippocampal volumes on term-equivalent MRI (Pearson’s r = −0.403, p = 0.046) and improved cognitive (r = −0.554, p = 0.047), motor (r = −0.487, p = 0.048), and language (r = −0.414, p = 0.021) outcomes at 2 years of age. Additionally, a smaller cumulative ventricle size from birth to pCSF diversion was associated with larger right hippocampal volumes (r = −0.483, p = 0.014) and improved cognitive (r = −0.711, p = 0.001), motor (r = −0.675, p = 0.003), and language (r = −0.618, p = 0.011) outcomes. There was no relationship between time to tCSF diversion or cumulative ventricle size prior to tCSF diversion and neurodevelopmental outcome or hippocampal size. Finally, a smaller cumulative ventricular size prior to either tCSF diversion or pCSF diversion was associated with a smaller ventricular size 1 year after pCSF diversion (r = 0.422, p = 0.040, R2 = 0.178 and r = 0.519, p = 0.009, R2 = 0.269, respectively). CONCLUSIONS In infants with PHH, a smaller cumulative ventricular size and shorter time to pCSF diversion were associated with larger right hippocampal volumes, improved neurocognitive outcomes, and reduced long-term ventriculomegaly. Future prospective randomized studies are needed to confirm these findings.
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- 2022
40. Co-occurrence of subcutaneous myxopapillary ependymoma, dermal sinus tract, and filum terminale lipoma: a review of the pathobiology of caudal spinal cord development and spinal cord tethering. Illustrative case
- Author
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Gabrielle W. Johnson, Yuxiao Xu, Ali Y. Mian, and David D. Limbrick
- Subjects
General Medicine - Abstract
BACKGROUND Myxopapillary ependymoma (MPE) is typically benign and found in the conus medullaris and/or filum terminale, although rare cases of subcutaneous and extra-axial MPE have been reported. The co-occurrence of MPE, tethered cord syndrome (TCS) with lipoma of the filum terminale, and a dermal sinus tract is extremely rare, with only 6 reported cases in the literature. Here, the authors present the first case, to their knowledge, of an extra-axial, subcutaneous MPE co-presenting with TCS, lipoma of the filum terminale, and a dermal sinus tract and discuss the underlying pathobiology. OBSERVATIONS A 14-month-old male who presented for evaluation of a dermal sinus tract underwent magnetic resonance imaging, which revealed a tethered cord with associated lipoma. At 14 months, the patient underwent spinal cord detethering with resection of his sacral dimple and sinus tract. Histopathological evaluation revealed an incidentally found MPE within the dermal sinus tract. LESSONS The authors review the underlying biology of MPEs, tethered cord syndrome, and dermal sinus tracts, and explore possible points of convergence within the developmental pathways that may result in this unique concomitant presentation. Additionally, they suggest that extra-axial MPE may be underappreciated and underdiagnosed; this case suggests that extra-axial MPE may be only effectively diagnosed with histological studies.
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- 2023
41. Nonoperative Management of Childhood Calvarial Langerhans-Cell Histiocytosis
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Paul Steinbok, Alexander Cheong, David B. Dix, Sanjiv Bhatia, Michael H. Handler, David D. Limbrick, Toba Niazi, Angela V. Price, John Ragheb, Mark Souweidane, Mandeep S. Tamber, and David I. Sandberg
- Subjects
Histiocytosis, Langerhans-Cell ,Humans ,General Medicine ,Child ,Conservative Treatment - Published
- 2022
42. An iPad-based intervention to improve visual-motor, visual-attention, and visual-perceptual skills in children with surgically treated hydrocephalus: A pilot study
- Author
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Holly Barnard, Nicole Weckherlin, Mekibib Altaye, Karen Harpster, Stephanie K. Powell, Weihong Yuan, Darren S. Kadis, David D. Limbrick, Francesco T. Mangano, Jack R. Engsberg, Marissa Li Garrett, and Jonathan N. Dodd
- Subjects
Occupational therapy ,medicine.medical_specialty ,Visual perception ,genetic structures ,medicine.diagnostic_test ,business.industry ,Wechsler Adult Intelligence Scale ,General Medicine ,Audiology ,behavioral disciplines and activities ,Test (assessment) ,Intervention (counseling) ,Pediatrics, Perinatology and Child Health ,medicine ,Neurology (clinical) ,Neuropsychological assessment ,business ,Motor skill ,Wechsler Intelligence Scale for Children - Abstract
PURPOSE Develop and pilot an iPad-based intervention for improving visual-motor coordination, visual-spatial processing/reasoning, and visual attention in children with surgically treated hydrocephalus (HCP). METHODS We developed an intervention protocol targeting visual-motor coordination, visual-spatial processing/reasoning, and visual attention. Fourteen participants with HCP completed 30 h of training over 6 weeks. The primary outcome measure was the Perceptual Reasoning Index from the Wechsler Abbreviated Scale of Intelligence, Second Edition. Secondary measures included subtests from the Wechsler Intelligence Scale for Children, Fourth Edition, Developmental NEuroPSYchological Assessment, Second Edition (NEPSY-II), and Purdue Pegboard. RESULTS Children with HCP demonstrated gains with statistical significance on the Perceptual Reasoning Index. We also observed significant improvement on a timed test of visuo-motor coordination (Wechsler Intelligence Scale for Children, Fourth Edition, Coding). CONCLUSION Our iPad-application-based intervention may promote visual-motor coordination, visual-spatial processing/reasoning, and visual attention skills in children with HCP, offering an engaging and economical supplement to more conventional therapies.
- Published
- 2021
43. Advances in the Field of Chiari I Malformation and Integrating Them into Clinical Practice
- Author
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David D. Limbrick and Jeffrey R. Leonard
- Subjects
Surgery ,Neurology (clinical) ,General Medicine - Published
- 2022
44. Posterior Fossa Decompression with or Without Duraplasty for Chiari I Malformation
- Author
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Alexander T. Yahanda and David D. Limbrick
- Subjects
Humans ,Surgery ,Neurology (clinical) ,General Medicine ,Dura Mater ,Decompression, Surgical ,Syringomyelia ,Arnold-Chiari Malformation - Abstract
Posterior fossa decompression (PFD) with/without duraplasty is the standard surgical treatment for symptomatic CM-1. Posterior fossa decompression without duraplasty (PFD) may be associated with shorter operative times and hospital stays, fewer complications, and may yield improvements in symptoms and syrinx sizes. Posterior fossa decompression with duraplasty (PFDD) may be associated with superior long-term symptomatic improvements, larger syrinx reductions, and a lower need for revision decompression. Various dural graft materials may be used for PFDD, though the ideal type of graft has not been definitively established. Other adjunct surgical procedures may be added to PFD/PFDD given certain symptomatic or anatomical considerations.
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- 2022
45. Cystic dissemination of choroid plexus papilloma: illustrative cases
- Author
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Gabrielle W. Johnson, Ali Y. Mian, Sonika Dahiya, Keith M. Rich, Michael R. Chicoine, and David D. Limbrick
- Subjects
General Medicine - Abstract
BACKGROUND Choroid plexus papillomas are benign tumors of the choroid plexus. Although typically focal, they can metastasize. Rarely, patients may present with numerous cystic lesions throughout the craniospinal axis. OBSERVATIONS The authors present three cases of pathologically confirmed fourth ventricular World Health Organization (WHO) grade 1 choroid plexus papillomas presenting with numerous cystic lesions throughout the craniospinal axis. Two cases were treated with only resection of the fourth ventricular mass; one was treated with a partial cyst fenestration. During follow-up, there was only mild interval growth of the cystic lesions over time, and all patients remained asymptomatic from their cystic lesions. The authors summarize five additional cases of cystic dissemination in the published literature and discuss hypotheses for the pathophysiology of this rare presentation. LESSONS Choroid plexus papillomas may present with numerous, widely disseminated cystic lesions within the craniospinal axis. Thus, the authors recommend preoperative and routine imaging of the entire neuroaxis in patients with choroid plexus tumors, regardless of WHO grade. Although the role of adjuvant therapy and cyst fenestration in the treatment of these lesions remains unclear, watchful waiting may be indicated, especially in asymptomatic patients, because the lesions often demonstrate slow, if any, growth over time.
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- 2022
46. Longitudinal <scp>CSF</scp> Iron Pathway Proteins in <scp>Posthemorrhagic</scp> Hydrocephalus: Associations with Ventricle Size and Neurodevelopmental Outcomes
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William E. Whitehead, Jay Riva-Cambrin, Diego M. Morales, Jennifer Strahle, Chevis N. Shannon, Richard Holubkov, Robert P. Naftel, Kelly B. Mahaney, Curtis J. Rozzelle, David D. Limbrick, Chandana Buddhala, Abhaya V. Kulkarni, Hailey Jensen, Ron W Reeder, Ian F. Pollack, John R. W. Kestle, John C. Wellons, and Mandeep S. Tamber
- Subjects
Male ,0301 basic medicine ,medicine.medical_specialty ,Iron ,Germinal matrix ,Gastroenterology ,Article ,Cerebral Ventricles ,Cohort Studies ,03 medical and health sciences ,Post-Hemorrhagic Hydrocephalus ,Child Development ,0302 clinical medicine ,Cerebrospinal fluid ,Hepcidin ,Internal medicine ,Humans ,Medicine ,Longitudinal Studies ,Prospective Studies ,Cerebral Hemorrhage ,chemistry.chemical_classification ,biology ,business.industry ,Infant, Newborn ,Transferrin ,Infant ,Cerebrospinal Fluid Proteins ,Hemopexin ,Organ Size ,medicine.disease ,Cerebrospinal Fluid Shunts ,Hydrocephalus ,Ferritin ,030104 developmental biology ,Neurology ,chemistry ,Child, Preschool ,Ferritins ,biology.protein ,Premature Birth ,Female ,Neurology (clinical) ,business ,Infant, Premature ,030217 neurology & neurosurgery - Abstract
OBJECTIVE Iron has been implicated in the pathogenesis of brain injury and hydrocephalus after preterm germinal matrix hemorrhage-intraventricular hemorrhage, however, it is unknown how external or endogenous intraventricular clearance of iron pathway proteins affect the outcome in this group. METHODS This prospective multicenter cohort included patients with posthemorrhagic hydrocephalus (PHH) who underwent (1) temporary and permanent cerebrospinal fluid (CSF) diversion and (2) Bayley Scales of Infant Development-III testing around 2 years of age. CSF proteins in the iron handling pathway were analyzed longitudinally and compared to ventricle size and neurodevelopmental outcomes. RESULTS Thirty-seven patients met inclusion criteria with a median estimated gestational age at birth of 25 weeks; 65% were boys. Ventricular CSF levels of hemoglobin, iron, total bilirubin, and ferritin decreased between temporary and permanent CSF diversion with no change in CSF levels of ceruloplasmin, transferrin, haptoglobin, and hepcidin. There was an increase in CSF hemopexin during this interval. Larger ventricle size at permanent CSF diversion was associated with elevated CSF ferritin (p = 0.015) and decreased CSF hemopexin (p = 0.007). CSF levels of proteins at temporary CSF diversion were not associated with outcome, however, higher CSF transferrin at permanent CSF diversion was associated with improved cognitive outcome (p = 0.015). Importantly, longitudinal change in CSF iron pathway proteins, ferritin (decrease), and transferrin (increase) were associated with improved cognitive (p = 0.04) and motor (p = 0.03) scores and improved cognitive (p = 0.04), language (p = 0.035), and motor (p = 0.008) scores, respectively. INTERPRETATION Longitudinal changes in CSF transferrin (increase) and ferritin (decrease) are associated with improved neurodevelopmental outcomes in neonatal PHH, with implications for understanding the pathogenesis of poor outcomes in PHH. ANN NEUROL 2021;90:217-226.
- Published
- 2021
47. A multicenter validation of the condylar–C2 sagittal vertical alignment in Chiari malformation type I: a study using the Park-Reeves Syringomyelia Research Consortium
- Author
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Thanda Meehan, Rajiv R. Iyer, Tae Sung Park, Douglas L. Brockmeyer, Vijay M. Ravindra, Evan Joyce, Tammy Bethel-Anderson, Alexander T. Yahanda, Huirong Zhu, Matthew D. Smyth, David D. Limbrick, Jennifer Strahle, and Robert J. Bollo
- Subjects
Decompression ,Intraclass correlation ,business.industry ,General Medicine ,medicine.disease ,Sagittal plane ,Condyle ,03 medical and health sciences ,0302 clinical medicine ,medicine.anatomical_structure ,CHIARI MALFORMATION TYPE I ,030220 oncology & carcinogenesis ,Cohort ,medicine ,Nuclear medicine ,business ,030217 neurology & neurosurgery ,Syringomyelia ,Chiari malformation - Abstract
OBJECTIVE The condylar–C2 sagittal vertical alignment (C-C2SVA) describes the relationship between the occipitoatlantal joint and C2 in patients with Chiari malformation type I (CM-I). It has been suggested that a C-C2SVA ≥ 5 mm is predictive of the need for occipitocervical fusion (OCF) or ventral brainstem decompression (VBD). The authors’ objective was to validate the predictive utility of the C-C2SVA by using a large, multicenter cohort of patients. METHODS This validation study used a cohort of patients derived from the Park-Reeves Syringomyelia Research Consortium; patients < 21 years old with CM-I and syringomyelia treated from June 2011 to May 2016 were identified. The primary outcome was the need for OCF and/or VBD. After patients who required OCF and/or VBD were identified, 10 age- and sex-matched controls served as comparisons for each OCF/VBD patient. The C-C2SVA (defined as the position of a plumb line from the midpoint of the O–C1 joint relative to the posterior aspect of the C2–3 disc space), pBC2 (a line perpendicular to a line from the basion to the posteroinferior aspect of the C2 body), and clival-axial angle (CXA) were measured on sagittal MRI. The secondary outcome was the need for ≥ 2 CM-related operations. RESULTS Of the 206 patients identified, 20 underwent OCF/VBD and 14 underwent repeat posterior fossa decompression. A C-C2SVA ≥ 5 mm was 100% sensitive and 86% specific for requiring OCF/VBD, with a 12.6% misclassification rate, whereas CXA < 125° was 55% sensitive and 99% specific, and pBC2 ≥ 9 was 20% sensitive and 88% specific. Kaplan-Meier analysis demonstrated that there was a significantly shorter time to second decompression in children with C-C2SVA ≥ 5 mm (p = 0.0039). The mean C-C2SVA was greater (6.13 ± 1.28 vs 3.13 ± 1.95 mm, p < 0.0001), CXA was lower (126° ± 15.4° vs 145° ± 10.7°, p < 0.05), and pBC2 was similar (7.65 ± 1.79 vs 7.02 ± 1.26 mm, p = 0.31) among those who underwent OCF/VBD versus decompression only. The intraclass correlation coefficient for the continuous measurement of C-C2SVA was 0.52; the kappa value was 0.47 for the binary categorization of C-C2SVA ≥ 5 mm. CONCLUSIONS These results validated the C-C2SVA using a large, multicenter, external cohort with 100% sensitivity, 86% specificity, and a 12.6% misclassification rate. A C-C2SVA ≥ 5 mm is highly predictive of the need for OCF/VBD in patients with CM-I. The authors recommend that this measurement be considered among the tools to identify the “high-risk” CM-I phenotype.
- Published
- 2021
48. Survival After Resection of Newly-Diagnosed Intracranial Grade II Ependymomas: An Initial Multicenter Analysis and the Logistics of Intraoperative Magnetic Resonance Imaging
- Author
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Alexander T. Yahanda, Keith M. Rich, Ralph G. Dacey, Gregory J. Zipfel, Gavin P. Dunn, Joshua L. Dowling, Matthew D. Smyth, Eric C. Leuthardt, David D. Limbrick, John Honeycutt, Garnette R. Sutherland, Randy L. Jensen, John Evans, and Michael R. Chicoine
- Subjects
Surgery ,Neurology (clinical) - Abstract
To identify factors, including the use of intraoperative magnetic resonance imaging (iMRI), impacting overall survival (OS) and progression-free survival (PFS) after resections of newly diagnosed intracranial grade II ependymomas performed across 4 different institutions.Analyses of a multicenter mixed retrospective/prospective database assessed the impact of patient, treatment, and tumor characteristics on OS and PFS. iMRI workflow and logistics were also outlined.Forty-three patients were identified (mean age 25.4 years, mean follow-up 52.8 months). The mean OS was 52.8 ± 44.7 months. Univariate analyses failed to identify prognostic factors associated with OS, likely due to relatively shorter follow-up time for this less aggressive glioma subtype. The mean PFS was 43.7 ± 39.8 months. Multivariate analyses demonstrated that gross-total resection was associated with prolonged PFS compared to both subtotal resection (STR) (P = 0.005) and near-total resection (P = 0.01). Infratentorial location was associated with improved PFS compared to supratentorial location (P = 0.04). Log-rank analyses of Kaplan-Meier survival curves showed that increasing extent of resection (EOR) led to improved OS specifically for supratentorial tumors (P = 0.02) and improved PFS for all tumors (P0.001). Thirty cases (69.8%) utilized iMRI, of which 12 (27.9%) involved additional resection after iMRI. Of these, 8/12 (66.7%) resulted in gross-total resection, while 2/12 (16.7%) were near-total resection and 2/12 (16.7%) were subtotal resection. iMRI was not an independent prognosticator of PFS (P = 0.72).Greater EOR and infratentorial location were associated with increased PFS for grade II ependymomas. Greater EOR was associated with longer OS only for supratentorial tumors. A longer follow-up is needed to establish prognostic factors for this cohort, including use of iMRI.
- Published
- 2022
49. Leptomeningeal disease and tumor dissemination in a murine diffuse intrinsic pontine glioma model: implications for the study of the tumor-cerebrospinal fluid-ependymal microenvironment
- Author
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Shelei Pan, Dezhuang Ye, Yimei Yue, Lihua Yang, Christopher P Pacia, Dakota DeFreitas, Prabagaran Esakky, Sonika Dahiya, David D Limbrick, Joshua B Rubin, Hong Chen, and Jennifer M Strahle
- Subjects
General Medicine - Abstract
Background Leptomeningeal disease and hydrocephalus are present in up to 30% of patients with diffuse intrinsic pontine glioma (DIPG), however there are no animal models of cerebrospinal fluid (CSF) dissemination. As the tumor–CSF–ependymal microenvironment may play an important role in tumor pathogenesis, we identified characteristics of the Nestin-tumor virus A (Nestin-Tva) genetically engineered mouse model that make it ideal to study the interaction of tumor cells with the CSF and its associated pathways with implications for the development of treatment approaches to address CSF dissemination in DIPG. Methods A Nestin-Tva model of DIPG utilizing the 3 most common DIPG genetic alterations (H3.3K27M, PDGF-B, and p53) was used for this study. All mice underwent MR imaging and a subset underwent histopathologic analysis with H&E and immunostaining. Results Tumor dissemination within the CSF pathways (ventricles, leptomeninges) from the subependyma was present in 76% (25/33) of mice, with invasion of the choroid plexus, disruption of the ciliated ependyma and regional subependymal fluid accumulation. Ventricular enlargement consistent with hydrocephalus was present in 94% (31/33). Ventricle volume correlated with region-specific transependymal CSF flow (periventricular T2 signal), localized anterior to the lateral ventricles. Conclusions This is the first study to report CSF pathway tumor dissemination associated with subependymal tumor in an animal model of DIPG and is representative of CSF dissemination seen clinically. Understanding the CSF–tumor–ependymal microenvironment has significant implications for treatment of DIPG through targeting mechanisms of tumor spread within the CSF pathways.
- Published
- 2022
50. Impact of Neurosurgery Research and Education Foundation awards on subsequent grant funding and career outcomes of neurosurgeon-scientists
- Author
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Saad Javeed, Sangami Pugazenthi, Anna L. Huguenard, Regis W. Haid, Michael W. Groff, David D. Limbrick, and Gregory J. Zipfel
- Subjects
General Medicine - Abstract
OBJECTIVE The Neurosurgery Research and Education Foundation (NREF) provides diverse funding opportunities for in-training and early-career neurosurgeon-scientists. The authors analyzed the impact of NREF funding on the subsequent career success of neurosurgeons in obtaining research funding and academic achievements. METHODS The NREF database was queried to identify NREF winners from 2000 to 2015. The award recipients were surveyed to obtain information about their demographic characteristics, academic career, and research funding. Only subsequent research support with an annual funding amount of $50,000 or greater was included. The primary outcome was the NREF impact ratio, defined as the ratio between NREF award research dollars and subsequent grant funding dollars. The secondary outcomes were time to subsequent grant funding as principal investigator (PI), clinical practice settings, and final academic position achieved. RESULTS From 2000 to 2015, 158 neurosurgeons received 164 NREF awards totaling $8.3 million (M), with $1.7 M awarded to 46 Young Clinician Investigators (YCIs), $1.5 M to 18 Van Wagenen Fellows (VWFs), and $5.1 M to 100 resident Research Fellowship Grant (RFG) awardees. Of all awardees, 73% have current academic appointments, and the mean ± SD number of publications and H-index were 71 ± 82 and 20 ± 15, respectively. The overall response rate to our survey was 70%, and these respondents became the cohort for our analysis. In total, respondents cumulatively obtained $776 M in post–NREF award grant funding, with the most common sources of funding including the National Institutes of Health ($327 M) and foundational awards ($306 M). The NREF impact ratios for awardees were $1:$381 for YCI, $1:$113 for VWF, and $1:$41 for resident RFG. Awardees with NREF projects in functional neurosurgery, pediatric neurosurgery, and neuro-oncology had the highest NREF impact ratios of $1:$194, $1:$185, and $1:$162, respectively. Of respondents, 9% became department chairs, 26% became full professors, 82% received at least 1 subsequent research grant, and 66% served as PI on a subsequent research grant after receiving their NREF awards. CONCLUSIONS In-training and early-career neurosurgeons who were awarded NREF funding had significant success in acquiring subsequent grant support, research productivity, and achievements of academic rank. NREF grants provide a tremendous return on investment across various career stages and subspecialities. They also appeared to have a broader impact on trajectory of research and innovation within the field of neurosurgery.
- Published
- 2022
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