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Primary spinal cord astrocytomas are rare, fatal, and poorly studied.This study included a 2-center, retrospective analysis of primary spinal cord astrocytoma patients from 1997 to 2020. Patients with drop metastases or without at least one follow-up were excluded.Seven World Health Organization grade I, 6 grade II, 7 grade III, and 4 grade IV astrocytoma patients were included. Older patients had higher grades (median 20 years in grade I vs. 36.5 in grade IV). The median follow-up was 15 months. Thirteen patients were discharged to rehabilitation. Eight patients demonstrated radiographic progression. Adjuvant therapy was utilized more in higher grades (5 of 13 grades III vs. all 11 grades IIIIV). Six patients died (1 death in grades III vs. 5 in grades IIIIV). Ten patients had worsened symptoms at the last follow-up. The median progression-free survival in grade I, II, III, and IV tumors was 116, 36, 8, and 8.5 months, respectively. The median overall survival in grade I, II, III, and IV tumors was 142, 69, 19, and 12 months, respectively. Thrombotic complications occurred in 2 patients, one with isocitrate dehydrogenasewild type glioblastoma.Outcomes worsen with higher grades and lead to difficult postoperative periods. Clinicians should be vigilant for thromboembolic complications. Further research is needed to understand these rare tumors.

Introduction There are many reported modifications to the retrosigmoid approach including variations in skin incisions, soft tissue dissection, bone removal/replacement, and closure. Objective The aim of this study was to report the technical nuances developed by two senior skull base surgeons for retrosigmoid craniectomy with reconstruction and provide anatomic dissections, surgical video, and outcomes. Methods The regional soft tissue and bony anatomy as well as the steps for our retrosigmoid craniectomy were recorded with photographs, anatomic dissections, and video. Records from 2017 to 2019 were reviewed to determine the incidence of complications after the authors began using the described approach. Results Dissections of the relevant soft tissue, vascular, and bony structures were performed. Key surgical steps are (1) a retroauricular C-shaped skin incision, (2) developing a skin and subgaleal tissue flap of equal thickness above the fascia over the temporalis and sub-occipital muscles, (3) creation of subperiosteal soft tissue planes over the top of the mastoid and along the superior nuchal line to expose the suboccipital region, (4) closure of the craniectomy defect with in-lay titanium mesh and overlay hydroxyapatite cranioplasty, and (5) reapproximation of the soft tissue edges during closure. Complications in 40 cases were pseudomeningocele requiring shunt (n = 3, 7.5%), wound infection (n = 1, 2.5%), and aseptic meningitis (n = 1, 2.5%). There were no incisional cerebrospinal fluid leaks. Conclusion The relevant regional anatomy and a revised technique for retrosigmoid craniectomy with reconstruction have been presented with acceptable results. Readers can consider this technique when using the retrosigmoid approach for pathology in the cerebellopontine angle.

The New England Neurosurgical Society (NENS) was founded in 1951 under the leadership of its first President (Dr. William Beecher Scoville) and Secretary-Treasurer (Dr. Henry Thomas Ballantine). The purpose of creating the NENS was to unite local neurosurgeons in the New England area; it was one of the first regional neurosurgical societies in America. Although regional neurosurgical societies are important supplements to national organizations, they have often been overshadowed in the available literature. Now in its 70th year, the NENS continues to serve as a platform to represent the needs of New England neurosurgeons, foster connections and networks with colleagues, and provide research and educational opportunities for trainees. Additionally, regional societies enable discussion of issues uniquely relevant to the region, improve referral patterns, and allow for easier attendance with geographic proximity. In this paper, the authors describe the history of the NENS and provide a roadmap for its future. The first section portrays the founders who led the first meetings and establishment of the NENS. The second section describes the early years of the NENS and profiles key leaders. The third section discusses subsequent neurosurgeons who steered the NENS and partnerships with other societies. In the fourth section, the modern era of the NENS and its current activities are highlighted.

BACKGROUND Primary meningeal melanocytic neoplasms are exceedingly rare tumors, representing only 0.06% to 0.1% of all primary brain tumors and ranging in spectrum from benign localized tumors to highly aggressive malignant lesions. The diagnosis of these tumors is often challenging from clinical, radiological, and pathologic standpoints. Equally challenging is the distinction between primary meningeal melanocytic neoplasm and metastatic melanoma. OBSERVATIONS The authors reported the case of a 41-year-old man with imaging findings diagnostic of neurofibromatosis type 2: bilateral internal auditory canal lesions (most consistent with bilateral vestibular schwannomas), two dura-based lesions presumed to be meningiomas, multiple spinal lesions consistent with peripheral nerve sheath tumors, and one intramedullary spinal lesion consistent with an ependymoma. Biopsy of these lesions revealed melanocytic neoplasms with mild to moderate atypia and a mildly elevated proliferation index, which made the distinction between benign and malignant challenging. In addition, the disseminated nature of these tumors made it difficult to determinate whether they arose from the meninges or represented metastases from an occult primary melanoma. LESSONS This case illustrated the challenges presented by the diagnosis of meningeal melanocytic neoplasms and highlighted the importance of integrating the clinical and radiographic findings with histologic appearance and molecular studies.

Background The tegmen tympani and mastoideum are insidious locations of bony dehiscence. Large defects may result in encephalocele, cerebrospinal fluid leak, recurrent meningitis, and intracranial abscess. A rare complication is spontaneous otogenic pneumocephalus (SOP). Herein, we describe the clinical course and operative repair strategy of a case of SOP presenting uniquely with anomic aphasia managed by middle cranial fossa (MCF) approach with inlay AlloDerm. The proposed mechanisms behind the SOP development and rationale for the selected operative approach is subsequently discussed. Case description A 68-year-old woman presented with a two-week history of intermittent headaches and word-finding difficulty after attempting to auto-equalize her middle ear pressure by Valsalva maneuver during an airplane flight. CT and MRI demonstrated a left temporal intraparenchymal pneumatocele with dehiscence in the tegmen tympani and mastoideum. A multi-layered MCF approach craniotomy using inlay AlloDerm was performed to repair the defect. Conclusions Although rare, SOP is a diagnosis to consider in patients that develop otologic symptoms with focal neurological deficits in the context of ambient air pressure changes or a history of Valsalva maneuver. The patient developed this pathology likely due to congenitally thin bone, ectopic arachnoid granulations, obesity-related elevated intracranial pressure, and an underlying encephalocele that established a one-way valve during Valsalva maneuver. The MCF approach with inlay AlloDerm is an effective strategy for large and multiple defect repair.

Surgical ventriculoperitoneal shunting remains standard treatment for communicating hydrocephalus, despite persistently elevated infection and revision rates. A novel minimally invasive endovascular cerebrospinal fluid (CSF) shunt was developed to mimic the function of the arachnoid granulation which passively filters CSF from the central nervous system back into the intracranial venous sinus network. The endovascular shunt is deployed via a femoral transvenous approach across the dura mater into the cerebellopontine angle cistern. An octogenarian with intractable hydrocephalus following subarachnoid hemorrhage underwent successful endovascular shunting, resulting in swift intracranial pressure reduction from 38 to 2O (

BACKGROUND Paragangliomas (PGLs) are rare neoplasms that may be associated with hereditary PGL syndromes and variable risk of metastasis. Middle ear adenomas are extremely rare tumors with no known hereditary predisposition and extremely low risk of metastasis. Although often easily differentiated, they may share clinical and pathological features that misdirect and confuse the diagnosis. OBSERVATIONS The authors discussed a 35-year-old woman with left-sided hearing loss and bleeding from the external ear canal who presented to an outside hospital. She underwent resection of a middle ear and mastoid mass, initially diagnosed as a middle ear adenoma with neuroendocrine features, with later mastoidectomy and ligation of the sigmoid sinus with microsurgical excision of persistent tumor in the jugular foramen and temporal bone. Histopathologically, her tumor was vascular, composed of benign-appearing epithelioid cells with “salt and pepper” neuroendocrine chromatin arranged in vague nests. Lesional cells were GATA3-immunopositive, glucagon-negative, and succinate dehydrogenase-immunonegative, consistent with PGL rather than middle ear adenoma, and required further workup for hereditary PGL syndromes. LESSONS This case demonstrates potential challenges in differentiating a PGL from a middle ear adenoma. The authors offer clinical, histopathological, and imaging principles to aid in diagnosis and workup.

Childhood cancer survivors are at risk for ongoing health risks related to their initial treatment. One potential long-term complication following radiation is the development of secondary tumors, including peripheral nerve tumors, such as schwannomas. We present three adolescent and young adult (AYA)-aged survivors of pediatric cancer (22-40 years), followed in our AYA survivorship clinic. Each was found to have a schwannoma many years following total body irradiation for a childhood primary malignancy. We highlight a late effect of low-dose total body irradiation as well as the importance of long-term monitoring in this population.

Background Optimal management of third ventricular colloid cysts remains debated. While microsurgery offers greater resection rates and lower recurrences, endoscopy offers a perceived less invasive option. Objective To describe the evolution of our practice to favor microsurgery and determine the optimal management of recurrent colloid cysts. Methods Any patient having undergone surgery for a colloid cyst by the senior author was identified and included in the study cohort. Clinical, radiographic, and operative records were reviewed, with attention paid to those patients requiring recurrent surgery. Results Thirty-three patients were treated for intracranial colloid cysts between 1995 and 2017. Two patients had initial surgical treatment at an outside institution prior to presentation at our institution. Microsurgery was used in 15/31 initial cases, endoscopy in 13 cases, and ventriculoperitoneal shunting in 3 cases. Between 1995 and 2005, 89% of colloid cysts (8/9 cases) were resected endoscopically, whereas 74% of colloid cysts (14/19 cases) were resected by microsurgery after 2005. Of the 13 patients treated endoscopically, 6 (46%) required surgery for recurrent cysts. Incomplete cyst wall resection at the initial operation increased the recurrence rate to 55%. There were no recurrences in the microsurgery cohort. Conclusion Surgical resection of recurrent colloid cysts should focus on complete removal of the cyst wall to minimize the chance of recurrence. Microsurgery has been shown to provide the highest success rates for cyst wall resection and lowest rates of recurrence and is therefore recommended for patients undergoing surgery for primary and recurrent colloid cysts.

BACKGROUND Odontoidectomy is a challenging yet effective operation for decompression of non-neoplastic craniovertebral junction disease. Though both the endoscopic endonasal approach (EEA) and the transoral approach (TOA) have been discussed in the literature, there remain few direct comparisons between the techniques. OBJECTIVE To evaluate the perioperative outcomes of EEA vs TOA odontoidectomy. METHODS A retrospective review of all cases undergoing odontoidectomy by either the EEA or TOA was performed. Attention was paid to the need for prolonged nutritional support, prolonged respiratory support, and hospitalization times. RESULTS During the study period between 2000 and 2018, 25 patients underwent odontoid process resection (18 TOA and 7 EEA). The most common indication for surgery was basilar invagination. Hospital length of stay, intensive care unit length of stay, and intubation days were all significantly shorter in the EEA group compared to the TOA group (P < .01, P = .01, P < .01, respectively). Prolonged nutritional support in the form of a gastrostomy tube was required in 5 patients and tracheostomy was required in 4 patients; all of these underwent odontoidectomy by the TOA. There was no statistical difference in neurological outcomes between the EEA and TOA groups (P = .17). CONCLUSION Odontoidectomy can be performed safely through both the EEA and TOA. The results of this study suggest the EEA has shorter hospitalizations and a lower probability of requiring prolonged nutritional support. These advantages are likely the results of decreased oropharyngeal mucosa disruption as compared to the TOA.

The American Board of Neurological Surgery (ABNS) was incorporated in 1940 in recognition of the need for detailed training in and special qualifications for the practice of neurological surgery and for self-regulation of quality and safety in the field. The ABNS believes it is the duty of neurosurgeons to place a patient’s welfare and rights above all other considerations and to provide care with compassion, respect for human dignity, honesty, and integrity. At its inception, the ABNS was the 13th member board of the American Board of Medical Specialties (ABMS), which itself was founded in 1933. Today, the ABNS is one of the 24 member boards of the ABMS.To better serve public health and safety in a rapidly changing healthcare environment, the ABNS continues to evolve in order to elevate standards for the practice of neurological surgery. In connection with its activities, including initial certification, recognition of focused practice, and continuous certification, the ABNS actively seeks and incorporates input from the public and the physicians it serves. The ABNS board certification processes are designed to evaluate both real-life subspecialty neurosurgical practice and overall neurosurgical knowledge, since most neurosurgeons provide call coverage for hospitals and thus must be competent to care for the full spectrum of neurosurgery.The purpose of this report is to describe the history, current state, and anticipated future direction of ABNS certification in the US.

Background and purposeWe evaluated the inferior petrosal sinus (IPS) and adjacent cerebellopontine angle (CPA) cistern as a potential implantation site for a novel venous endovascular transdural CSF shunt concept to treat communicating hydrocephalus. We analyzed the dimensions of the IPS, CPA cistern, and distances to adjacent neurovascular structures.Materials and methodsGadolinium enhanced T1 weighted brain MRI datasets of 36 randomly selected patients, aged 20–80 years, were analyzed with three-dimensional multiplanar reconstruction to measure IPS diameter and length, CPA cistern depth, and IPS proximity to the vertebrobasilar arteries and brainstem. Statistical analysis was used to assess gender, sidedness, and age dependence.ResultsMean IPS diameter ranged from 2.27 mm to 3.31 mm at three axial levels, with >90% larger than 1.46 mm. CPA cistern adjacent to the IPS exhibited a mean depth of 3.86 mm to 7.39 mm between the dura and brainstem at corresponding axial levels. There was no side dependence except for a longer distance from the IPS to the basilar artery on the left compared with the right (9.72 vs 7.28, PConclusionOur results demonstrate sufficient CSF CPA cisternal space adjacent to the IPS and support the feasibility of an endovascular catheter delivered transdural implantable shunt. Such a device could serve to mimic the function of the arachnoid granulation by establishing a regulated path for CSF flow from the intracranial subarachnoid space to the venous system and provide a treatment for communicating hydrocephalus.

BACKGROUND AND PURPOSE: Currently no quantitative objective test exists to determine disease severity in a patient with Chiari I malformation. Our aim was to correlate disease severity in symptomatic patients with Chiari I malformation with cough-associated changes in CSF flow as measured with real-time MR imaging. MATERIALS AND METHODS: Thirteen symptomatic patients with Chiari I malformation (tonsillar herniation of ≥5 mm) were prospectively studied. A real-time, flow-sensitized pencil-beam MR imaging scan was used to measure CSF stroke volume during rest and immediately following coughing and relaxation periods (total scan time, 90 seconds). Multiple posterior fossa and craniocervical anatomic measurements were also obtained. Patients were classified into 2 groups by neurosurgeons blinded to MR imaging measurements: 1) nonspecific Chiari I malformation (5/13)—Chiari I malformation with nonspecific symptoms like non-cough-related or mild occasional cough-related headache, neck pain, dizziness, paresthesias, and/or trouble swallowing; 2) specific Chiari I malformation (8/13)—patients with Chiari I malformation with specific symptoms and/or objective findings like severe cough-related headache, myelopathy, syringomyelia, and muscle atrophy. The Spearman correlation was used to determine correlations between MR imaging measurements and disease severity, and both groups were also compared using a Mann-Whitney U test. RESULTS: There was a significant negative correlation between the percentage change in CSF stroke volume (resting to postcoughing) and Chiari I malformation disease severity ( R = 0.59; P = .03). Mann-Whitney comparisons showed the percentage change in CSF stroke volume (resting to postcoughing) to be significantly different between patient groups ( P = .04). No other CSF flow measurement or anatomic measure was significantly different between the groups. CONCLUSIONS: Our exploratory study suggests that assessment of CSF flow response to a coughing challenge has the potential to become a valuable objective noninvasive test for clinical assessment of disease severity in patients with Chiari I malformation.

Headache is a common symptom in patients with Chiari I malformation (CMI), characterized by 5 mm or greater cerebellar tonsillar herniation below foramen magnum. Radiologists should be aware of the different types of headaches reported by CMI patients and which headache patterns are distinctive features of the diagnosis. A methodical imaging strategy is required to fully assess a CMI patient to exclude secondary causes of tonsillar herniation such as intracranial hypotension or associated conditions such as syrinx. Both anatomic and physiologic imaging can help determine if headaches are CMI associated, and assist clinicians in therapeutic decision making.

Background Intracranial metastasis is a common complication of systemic malignancy. A rare subset of intracranial masses constitutes tumor-to-tumor metastasis, in which an extracranial neoplasm hematogenously spreads to an existing intracranial lesion. Case Description Here we present the unique case of a 59-year-old man with known hepatocellular carcinoma who presented with acute headaches, double vision, vertigo, and gait instability in the context of 2 years of right-sided hearing loss. Head imaging showed a heterogeneous right cerebellopontine angle mass extending into the porus acousticus with adjacent cerebellar edema. Histopathologic analysis after resection found coexisting hepatocellular carcinoma within a vestibular schwannoma. Conclusions Tumor-to-tumor metastasis is an important consideration in the diagnostic work-up and treatment of patients with known systemic malignancy who present with a new intracranial lesion. This pathologic entity could be missed if this patient were treated with single-fraction radiosurgery such as Gamma Knife.

We thank the authors for their interest in our study1 and would like to address the points that they raise in their letter to the editor.2 Based on preclinical and clinical testing of the endovascular shunt implant, we have determined that antiplatelet drugs are not required before the deployment of the device in the inferior petrosal sinus (IPS). As in other neurointerventional procedures, navigation of a modern low-profile catheter can be readily performed while on intravenous anticoagulation with reversal at the time of dural puncture. The described endovascular shunting device bears a proprietary heparin-based coating and is not intended to occlude or thrombose the IPS itself. Rather, the IPS is utilized as the path towards the cistern. Once connection between the IPS and the cerebellopontine angle (CPA) cistern is established, the device allows flow of cerebrospinal fluid (CSF) via a low-profile tubular valved shunt directly to the internal jugular vein, without needing to rely on IPS patency. Piercing of the dura overlying the IPS is …

Recent trends in graduate medical education have emphasized the mastery of nontechnical skills, especially leadership, for neurosurgical trainees. Accordingly, we introduced leadership development and self-awareness training to interns attending the Society of Neurological Surgeons Post-Graduate Year 1 Boot Camp in the Northeast (New England/New York/New Jersey) region in 2015. Feedback about the session was collected from interns. While neurosurgical interns conveyed a desire to receive more information on improving their leadership skills, most indicated that guidance seemed to be lacking in this critical area. We discuss some of the professional development needs uncovered during this process.

Objectives Initially treating vestibular schwannomas (VSs) with subtotal resection (STR) followed by Gamma Knife radiosurgery (GKRS) for progression of tumor residual is a strategy that balances maximal tumor resection with preservation of neurological function. The effect of timing of GKRS for residual and recurrent VSs remains poorly defined. We developed a simple and practical treatment algorithm for the timing of GKRS after STR of VSs and reviewed our follow-up results to determine outcomes between patients treated with early vs. late GKRS. Patients and methods Patients that underwent STR between 1999 and 2017 for a VS at Tufts Medical Center were identified and included in the study cohort. Patients who received GKRS ≤ 12 months after STR were included in the early intervention group. Patients who received GKRS > 12 months after STR or did not have tumor progression on follow-up thus not requiring GKRS were included in the observation/delayed intervention group. Results STR of VSs was performed on 23 patients. Mean patient age at the time of STR was 53.0 years (range: 20–86.2). The mean follow-up was 4.2 years (range: 1 month-15.5 years). Patients most frequently presented with hearing loss. There were 5 patients (21.7 %) in the early intervention group and 18 (78.3 %) patients in the observation/delayed intervention group. Ten of 23 patients (43.5 %) required GKRS. Thirteen (56.5 %) did not receive GKRS. None of the patients in the early intervention group or the observation/delayed intervention group had changes in House-Brackmann (HB) Grade either after GKRS or at the end of the study period. Conclusions GKRS of residual or recurrent tumor is safe following STR of VS and appears to carry a low risk of worsening facial nerve function when performed for progressive tumor growth.

Surgery within the posterior cranial fossa requires a detailed anatomic understanding of the relevant vascular and neural structures to minimize the risk of inadvertent injury. Dissection near or on vital neural structures must be performed delicately because undue tension can lead to traction injury on the brainstem. Inadvertent loss of a single perforating artery from the vertebrobasilar vasculature can lead to a brainstem infarct. Several studies have identified a low but consistent rate of postoperative brainstem infarction from 0.5% to 0.75% of cases. Vascular complications remain the greatest source of permanent postoperative morbidity after surgery in the posterior fossa. Though these are rare complications, the neurologic deficits they produce can be devastating.

Background and purpose We describe the development of a novel endovascular cerebrospinal fluid (CSF) shunt device, intended for transdural deployment through a transvenous transfemoral approach into the cerebellopontine angle cistern, for the treatment of communicating hydrocephalus. The implant mimics the function of the arachnoid granulations by diverting excess cerebrospinal fluid from the subarachnoid space into a dural venous sinuses. Materials and methods Review of published literature points to an intracranial to dural venous sinus estimated time-averaged pressure gradient of 3–5 mmHg, with transient venous pressure increases of 40 mmHg occurring during coughing, sneezing, or straining events. The design must include a valve capable of resisting venous blood reflux into the subarachnoid space during these spikes, while permitting a target antegrade CSF flow rate of 10 mL/hr at the normal physiologic pressure gradient. An in vitro intracranial and venous pressure circuit, capable of acquiring instantaneous pressure and flow data at the location of the valve, was developed to evaluate valve dynamic characteristics. Implant size was selected based on anatomical boundaries for transdural deployment at the inferior petrosal sinus, hemodynamic resistance of CSF flow, and the associated postural hydrostatic pressure column effect. Results The resulting endovascular shunt prototype is comprised of a polyurethane shunt body that resides within venous blood flow and possesses a full-length 0.016’ diameter inner lumen to enable CSF flow. The shunt length of 35 mm creates a hydrostatic pressure gradient of Conclusion A novel tubular low-profile endovascular valved CSF shunt that mimics the function of the arachnoid granulations has been successfully developed and built for transdural deployment via the transvenous route. CSF Outflow into the venous sinuses may simplify valve requirements by re-establishing the physiologic venous pressure regulation in patients with communicating hydrocephalus and avoiding the postural siphon effect via a low-profile implant. Disclosures A. Malek: 2; C; CereVasc LLC. 3; C; Stryker Neurovascular, Microvention-Terumo. 4; C; CereVasc LLC. C. Heilman: 2; C; CereVasc LLC. 4; C; CereVasc LLC.

OBJECTIVESurgical resection of sphenoid wing tumors and intraorbital pathology carries the dual goal of appropriately treating the target pathology as well as correcting proptosis. Residual proptosis following surgery can lead to cosmetic and functional disability. The authors sought to quantitatively assess the effect of orbital volume before and after reconstruction to determine the optimal strategy to achieve proptosis correction.METHODSAll surgeries involving orbital wall reconstruction for orbital or intracranial pathology that preoperatively resulted in proptosis between 2007 and 2017 were reviewed. Proptosis was measured by the exophthalmos index (EI): the ratio of the distance of the anterior limit of each globe to a line drawn between the anterior limit of the frontal processes of the zygomas, comparing the pathological eye to the normal eye. Postoperative radiographic measurements were taken at least 60 days after surgery to allow surgical swelling to abate. The orbit contralateral to the pathology was used as an internal control for normal anatomical orbital volume. Cases with preoperative EI < 1.10, orbital exenteration, or enucleation were excluded.RESULTSTwenty-three patients (16 females and 7 males, with a mean age of 43.6 ± 22.8 years) were treated surgically for tumor-associated proptosis. Nineteen patients harbored meningiomas (11 en-plaque; 8 sphenoid wing), and one patient each harbored an orbital schwannoma, glomangioma, arteriovenous malformation, or cavernous hemangioma. Preoperative EI averaged 1.28 ± 0.10 (range 1.12–1.53). Median time to postoperative imaging was 19 months. Postoperatively, the EI decreased to a mean of 1.07 ± 0.09. Greater increases in size of the reconstructed orbit were positively correlated with greater quantitative reductions in proptosis (p < 0.01). Larger volume of soft tissue pathology was also associated with achieving greater proptosis correction (p < 0.01). Residual exophthalmos (defined as EI > 1.10) was present in 8 patients, while reconstruction in 2 patients resulted in clinically asymptomatic enophthalmos (defined as EI < 0.95). Tumor invasion into the superior orbital fissure sinus was associated with residual proptosis (p = 0.04).CONCLUSIONSProptosis associated with intracranial and orbital pathology represents a surgical challenge. The EI is a reliable and quantitative assessment of proptosis. For orbital reconstruction in cases of superior orbital fissure involvement, surgeons should consider rebuilding the orbit at slightly larger than anatomical volume.

Objective Solitary fibrous tumors (SFT) and hemangiopericytomas (HPC) are now classified along a single spectrum of fibroblastic mesenchymal tumors with NAB2–STAT6 fusion. This fusion acts as a driver mutation that constitutively activates EGR1, which is known to be involved in the p16 pathway. Overexpression of p16 is associated with malignancy and worse prognosis in multiple mesenchymal tumors. The authors sought to investigate p16 immunoexpression in association with malignancy and prognosis of SFT/HPC tumors. Design Twenty-three SFT/HPC tumors (central nervous system [CNS]: 12, non CNS: 11) diagnosed at our institution from 2002 to 2016 were assigned into 3 grades. Data from microarray immunohistochemistry for STAT6, synaptophysin, CD56, chromogranin, SST2A, EGR1, Ki67, and p16, grade and survival were analyzed. Results CNS SFT/HPCs tend to be malignant (grade 3; 67 vs. 18%, p = 0.036) and more likely to express synaptophysin (33 vs. 0%, p = 0.035) than non CNS tumors. Overexpression of p16 (immunopositivity ≥ 50% tumor cells) was associated with malignant (grade 3) tumors, and has a sensitivity of 70% (7/10), and a specificity of 77% (10/13), as a predictive marker for malignancy. SFT/HPC patients with low p16 expression demonstrated significantly longer disease-free survival time (median survival > 113 months) than those with high p16 expression (median survival = 30 months, p = 0.045). Conclusions SFT/HPCs in the CNS are more likely to be malignant than the tumors in other sites. High p16 expression is also associated with malignancy and shorter disease-free survival time in SFT/HPC tumors in our study cohort. Clinically, p16 overexpression can be used as predictive marker for malignancy and prognosis and a possible therapeutic target.

BACKGROUND AND PURPOSE: Invasive pressure studies have suggested that CSF flow across the foramen magnum may transiently decrease after coughing in patients with symptomatic Chiari I malformation. The purpose of this exploratory study was to demonstrate this phenomenon noninvasively by assessing CSF flow response to coughing in symptomatic patients with Chiari I malformation by using MR pencil beam imaging and to compare the response with that in healthy participants. MATERIALS AND METHODS: Eight symptomatic patients with Chiari I malformation and 6 healthy participants were studied by using MR pencil beam imaging with a temporal resolution of ∼50 ms. Patients and healthy participants were scanned for 90 seconds (without cardiac gating) to continuously record cardiac cycle–related CSF flow waveforms in real-time during resting, coughing, and postcoughing periods. CSF flow waveform amplitude, CSF stroke volume, and CSF flow rate (CSF Flow Rate = CSF Stroke Volume × Heart Rate) in the resting and immediate postcoughing periods were determined and compared between patients and healthy participants. RESULTS: There was no significant difference in CSF flow waveform amplitude, CSF stroke volume, and the CSF flow rate between patients with Chiari I malformation and healthy participants during rest. However, immediately after coughing, a significant decrease in CSF flow waveform amplitude ( P < .001), CSF stroke volume ( P = .001), and CSF flow rate ( P = .001) was observed in patients with Chiari I malformation but not in the healthy participants. CONCLUSIONS: Real-time MR imaging noninvasively showed a transient decrease in CSF flow across the foramen magnum after coughing in symptomatic patients with Chiari I malformation, a phenomenon not seen in healthy participants. Our results provide preliminary evidence that the physiology-based imaging method used here has the potential to be an objective clinical test to differentiate symptomatic from asymptomatic patients with Chiari I malformation. ACSF : CSF flow waveform amplitude CMI : Chiari I malformation FRCSF : CSF flow rate PBI : pencil beam imaging SVCSF : CSF stroke volume

Background The differential diagnosis of skull base masses is diverse and includes benign and malignant neoplasms, vascular anomalies, congenital lesions, as well as infectious and inflammatory processes. Metastatic masses of the skull base are a rare manifestation of systemic malignancies. Breast cancer is the most common cause of skull base metastases.[1] Villaret syndrome refers to cranial nerves IX, X, XI, and XII and sympathetic chain neuropathies. It is a clinical subtype of jugular foramen syndromes. Methods and Results A 62-year-old woman with a history of breast carcinoma presented with hoarseness dating to shortly after her mastectomy years earlier. CT angiography showed enhancing tissue just outside the right jugular foramen, and biopsy confirmed metastatic adenocarcinoma consistent with breast cancer. Conclusion Villaret syndrome caused by breast cancer metastases has not been previously described. We present a case of Villaret syndrome caused by metastasis of invasive breast adenocarcinoma and a review of the literature of metastases of breast cancer to the skull base. © 2015 Wiley Periodicals, Inc. Head Neck 37: E146–E149, 2015

The cerebellopontine angle (CPA) is the most common location of posterior fossa tumors. Common pathologic entities in the CPA include vestibular schwannomas, which account for 10% of all primary brain neoplasms, meningiomas, and arachnoid cysts. Surgical approaches to the CPA vary depending on the tumor size, location, and preoperative neurologic function of the patient. The retrosigmoid approach is perhaps the most versatile approach, affording excellent visualization for large tumors and allowing for hearing preservation. Radiosurgery plays an increasing role in the treatment of CPA pathology due to high rates of facial nerve function preservation and tumor growth arrest.

Few studies have directly compared operative and non-operative outcomes in Chiari I patients. We evaluated risk factors for clinical improvement in 177 patients in order to help determine the optimal treatment of these often difficult to treat patients. The mean age at surgery for the operative treatment group was 29.9 years. The most common presenting signs and symptoms included cough headache (63.0%), migraine and non-cough type headaches (23.9%), paresthesias (32.1%), and abnormal reflexes or clonus (27.5%). The mean age of diagnosis for the non-operative treatment group was 30.2 years. The most common presenting signs or symptoms included migraine and other types of non-cough-associated headache (57.4%), paresthesias (45.6%), cough headache (44.1%), cerebellar signs or symptoms (41.2%), and dysphagia or apnea (15.7%). A propensity score was generated using cough headache, any headache, other headache, syrinx, abnormal reflexes or clonus, cerebellar symptoms, and miscellaneous symptoms as independent predictors of selection for surgery. The propensity score-adjusted odds of overall improvement for patients treated with surgery were 16.5 times the odds of overall improvement for patients treated conservatively (95% confidence interval 5.5–57.1, p < 0.0001). Overall 94.5% and 47.1% of operative and conservatively treated patients reported improvement, respectively. Only 26.5% of conservatively treated patients reported worsening of any of their symptoms. In conclusion, we provided further evidence for the use of cough headache as surgical indication for suboccipital decompression in patients with Chiari I malformation.

Arachnoid cysts are common, accounting for approximately 1% of intracranial mass lesions. Most are congenital, clinically silent, and remain static in size. Occasionally, they increase in size and produce symptoms due to mass effect or obstruction. The mechanism of enlargement of arachnoid cysts is controversial. One-way slit valves are often hypothesized as the mechanism for enlargement. The authors present 4 cases of suprasellar prepontine arachnoid cysts in which a slit valve was identified. The patients presented with hydrocephalus due to enlargement of the cyst. The valve was located in the arachnoid wall of the cyst directly over the basilar artery. The authors believe this slit valve was responsible for the net influx of CSF into the cyst and for its enlargement. They also present 1 case of an arachnoid cyst in the middle cranial fossa that had a small circular opening but lacked a slit valve. This cyst did not enlarge but surgery was required because of rupture and the development of a subdural hygroma. One-way slit valves exist and are a possible mechanism of enlargement of suprasellar prepontine arachnoid cysts. The valve was located directly over the basilar artery in each of these cases. Caudad-to-cephalad CSF flow during the cardiac cycle increased the opening of the valve, whereas cephalad-to-caudad CSF flow during the remainder of the cardiac cycle pushed the slit opening against the basilar artery and decreased the size of the opening. Arachnoid cysts that communicate CSF via circular, nonslit valves are probably more likely to remain stable.

The aim of this study is to review and summarize the relevant literature regarding pharmacologic and non-pharmacologic methods of prophylaxis against gastrointestinal (GI) stress ulceration, and upper gastrointestinal bleeding in critically ill patients. Stress ulcers are a known complication of a variety of critical illnesses. The literature regarding epidemiology and management of stress ulcers and complications thereof, is vast and mostly encompasses patients in medical and surgical intensive care units. This article aims to extrapolate meaningful data for use with a population of critically ill neurologic and neurosurgical patients in the neurological intensive care unit setting. Studies were identified from the Cochrane Central Register of controlled trials and NLM PubMed for English articles dealing with an adult population. We also scanned bibliographies of relevant studies. The results show that H(2)A, sucralfate, and PPI all reduce the incidence of UGIB in neurocritically ill patients, but H(2)A blockers may cause encephalopathy and interact with anticonvulsant drugs, and have been associated with higher rates of nosocomial pneumonias, but causation remains unproven and controversial. For these reasons, we advocate against routine use of H(2)A for GI prophylaxis in neurocritical patients. There is a paucity of high-level evidence studies that apply to the neurocritical care population. From this study, it is concluded that stress ulcer prophylaxis among critically ill neurologic and neurosurgical patients is important in preventing ulcer-related GI hemorrhage that contributes to both morbidity and mortality. Further, prospective trials are needed to elucidate which methods of prophylaxis are most appropriate and efficacious for specific illnesses in this population.

The purpose of this study was to analyze the CSF flow in patients with Chiari I to determine differences between patients with and without CAH. Thirty patients with Chiari I malformation underwent cine-PC CSF flow imaging in the sagittal plane. CSF flow pulsations were analyzed by placing regions of interest in the anterior cervical subarachnoid space. Maximum CSF systolic (craniocaudal) and diastolic (caudocranial) velocities as well as the durations of CSF systole and diastole (measured in fractions of the cardiac cycle) were determined. In the region of interest just below the foramen magnum, patients with CAH had a significantly shorter CSF systole and longer diastole (P = .02). A CSF diastolic length of ≥0.75 of the cardiac cycle was 67% sensitive and 86% specific for CAH. Our results indicate that Cine-PC imaging can show differences in CSF flow patterns in patients with Chiari I with and without CAH.

A 71-year-old female patient was referred in 2013 for evaluation of an asymptomatic nonsecreting pituitary adenoma. The adenoma, measuring 13 mm in height by 10 mm in width, was discovered incidentally on imaging in 2012. Biochemical testing demonstrated a nonfunctioning adenoma. Given the relatively small lesion size and the lack of symptoms, observation was preferred over surgical intervention. The patient was monitored with routine MRI, which until 2016 demonstrated minimal growth. In early 2016, the patient developed recurrence of metastatic breast cancer and was treated with palbociclib, a cyclin-dependent kinase (CDK) 4/6 inhibitor. This inhibitor acts on a pathway believed to be involved in pituitary adenoma tumorigenesis. One year after starting palbociclib, routine imaging demonstrated significant regression of her pituitary adenoma. The authors hypothesize that inhibition of the CDK4/6 pathway by palbociclib contributed to adenoma regression in this patient, and that palbociclib may represent a possible adjuvant therapy for the treatment of nonfunctioning pituitary adenomas.

Background Pneumocephalus is commonly encountered after neurosurgical procedures but can also be caused by craniofacial trauma and tumors of the skull base and rarely, can occur spontaneously. Contributing factors for the development of pneumocephalus include head position, duration of surgery, nitrous oxide (N2O) anesthesia, hydrocephalus, intraoperative osmotherapy, hyperventilation, spinal anesthesia, barotauma, continuous CSF drainage via lumbar drain, epidural anesthesia, infections, and neoplasms. Clinical presentation includes headaches, nausea and vomiting, seizures, dizziness, and depressed neurological status. In this article, we review the incidence, mechanisms, precipitating factors, diagnosis, and management of pneumocephalus. Search of Medline, databases, and manual review of article bibliographies. Considering four case illustrations that typify pneumocephalus in clinical practice, we discuss the common etiologies, and confirm the diagnosis with neuroimaging and management strategies. Avoidance of contributing factors, high index of suspicion, and confirmation with neuroimaging are important in attenuating mortality and morbidity. A significant amount of pneumocephalus can simulate a space-occupying lesion. Supplemental oxygen increases the rate of absorption of pneumocephalus.

Chiari I malformations are often associated with congenital craniocervical anomalies such as platybasia, basilar invagination, and retroflexion of the odontoid process. Management of ventral brain stem compression associated with Chiari I malformations remains controversial, but several authors report a significant rate of failure with suboccipital decompression alone in the presence of pronounced ventral brain stem compression (VBSC). Treatment options described in the literature for these patients involve anterior, posterior, or combined decompressions with or without concurrent arthrodesis. A combined anterior and posterior approach provides a definitive circumferential decompression but also significantly disrupts the stability of the occipitocervical junction usually necessitating occipitocervical fixation. We describe an alternative surgical treatment for Chiari I patients with significant ventral brain stem compression where a combined anterior and posterior decompression was considered necessary. We report two patients who underwent transoral odontoidectomy with preservation of the anterior arch of the atlas and suboccipital craniectomy with C1 laminectomy followed by C1–C2 arthrodesis. Preservation of the anterior arch of the atlas in conjunction with C1–C2 arthrodesis stabilizes the occipito–atlanto-axial segments while conserving more cervical mobility as compared to an occipitocervical fusion.

Background: We evaluated in a canine duraplasty model how specific differences in device physicomechanical properties, porosity, and crosslinking influenced the biological performance of three processed collagen dural substitutes. Methods: Three collagen dural substitutes were studied: Dura-Guard, DuraGen, and Durepair. The initial strength, stiffness, and suture retention force were measured using standard mechanical test methods. The relative pore sizes of each device were assessed with a scanning electron microscope. Differential scanning calorimetry was used to measure their respective collagen denaturation temperatures. The biologic response and performance of the materials were evaluated via an acute (1 month) and long-term (3 and 6 months) canine bilateral duraplasty study. Results: The mechanical properties of Dura-Guard and Durepair were similar to native dura. We could not quantify the mechanical properties of DuraGen because of its fragile nature. The denaturation temperature of DuraGen and Dura-Guard differed significantly from that reported for native collagens. The denaturation temperature of Durepair was comparable with the values reported for native collagens. All three materials were tolerated well by the animals. DuraGen did not maintain its structural integrity beyond 1 month. Dura-Guard and Durepair persisted for 6 months. Durepair was populated by fibroblasts and blood vessels, whereas Dura-Guard was not. Conclusions: The three dural substitutes tested were found to be safe and effective in healing surgically created defects in the dura mater. Although each of these dura substitutes are composed of collagen, differences in the collagen source and processing influenced device physicomechanical properties, porosity, and the nativity of the collagen polymer. These measured differences influenced device intraoperative handling and installation as well as the post-operative biological response, where differences in device resorption, cell penetration, vascularization, and collagen remodeling were observed. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2007

The jugular foramen (JF) is an anatomically complex region where important bony, neural, and vascular structures converge. Tumors are the primary cause of JF pathology and often present therapeutic challenges. In this article we discuss the clinical and pathologic aspects of JF tumors. These aspects include the classic JF clinical syndromes, imaging characteristics of specific JF tumors, and gross pathologic and histopathologic features. The three most common and important JF tumors, glomus jugulare tumors, meningiomas, and schwannomas, are discussed in depth. A wide variety of tumors can occur in the JF. Nonetheless, our current clinical and radiographic knowledge usually allows a clinician to ascertain the pathology of a JF tumor preoperatively with a high degree of certainty. Doing so allows the clinician not only to formulate the most effective treatment plan but also to provide accurate and thorough preoperative counseling to patients harboring these serious lesions.