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Simple Summary: This paper discusses the challenges in treating high-grade gliomas, particularly glioblastomas, which are aggressive brain tumors with high recurrence rates. It highlights the limitations of current diagnostic imaging modalities, such as gadolinium-based MRI, in accurately detecting tumor recurrence versus treatment-related changes. The paper explores the emerging role of positron emission tomography (PET) in glioma imaging, especially with the use of radiotracers like PSMA, which can help differentiate between tumor recurrence and treatment effects. Furthermore, the paper reviews the concept of theranostics, which integrates diagnostics and therapy, offering a targeted approach to glioma treatment. It discusses various radioligands, including PSMA, 213Bi-DOTA-substance P, 90Y-DOTATOC, 18F-FDOPA, p-[131I]-iodo-L-phenylalanine, and 18F-GE-180, which have shown promise in diagnosing and treating recurrent gliomas. The potential of theranostics to minimize systemic toxicity and improve treatment outcomes is emphasized. Moreover, the paper highlights the importance of considering quality-of-life (QOL) outcomes in glioma patients, as conventional treatments often have significant impacts on patients' well-being. While theranostics offers a personalized approach to treatment, its potential promise for functional outcomes and QOL needs further investigation. The paper suggests that future research should focus on understanding the broader implications of theranostics on patient well-being, incorporating factors such as demographics, tumor characteristics, and treatment-related effects into QOL assessments. Overall, the paper underscores the potential of theranostics to revolutionize glioma management and improve patient outcomes in the future. Gliomas represent the most commonly occurring tumors in the central nervous system and account for approximately 80% of all malignant primary brain tumors. With a high malignancy and recurrence risk, the prognosis of high-grade gliomas is poor, with a mean survival time of 12–18 months. While contrast-enhanced MRI serves as the standard diagnostic imaging modality for gliomas, it faces limitations in the evaluation of recurrent gliomas, failing to distinguish between treatment-related changes and tumor progression, and offers no direct therapeutic options. Recent advances in imaging modalities have attempted to address some of these limitations, including positron emission tomography (PET), which has demonstrated success in delineating tumor margins and guiding the treatment of recurrent gliomas. Additionally, with the advent of theranostics in nuclear medicine, PET tracers, when combined with therapeutic agents, have also evolved beyond a purely diagnostic modality, serving both diagnostic and therapeutic roles. This review will discuss the growing involvement of theranostics in diagnosing and treating recurrent gliomas and address the associated impact on quality of life and functional recovery. [ABSTRACT FROM AUTHOR]

Introduction. Positron emission tomography (PET) imaging with prostate-specific membrane antigen- (PSMA-) binding tracers has been found incidentally to demonstrate uptake in CNS tumors. Following the encouraging findings of several such case reports, there is a growing interest in the potential application of PSMA-targeted PET imaging for diagnostics, theranostics, and monitoring of CNS tumors. This is a systematic literature review on PSMA-binding tracers in CNS tumors. Methods. A PubMed search was conducted, including preclinical and clinical reports. One hundred and twelve records were identified, and after screening, 56 were included in the final report. Results. Tissue studies demonstrated PSMA expression in tumor vascular endothelial cells, without expression in normal brain tissue, though the extent and intensity of staining varied by anti-PSMA antibody and methodology. Most included studies reported on gliomas, which showed strong PSMA ligand uptake and more favorable tumor to background ratios than other PET tracers. There are also case reports demonstrating PSMA ligand uptake in prostate cancer brain metastases, nonprostate cancer brain metastases, and meningiomas. We also review the properties of the various PSMA-binding radiotracers available. Therapeutic and theranostic applications of PSMA-binding tracers have been studied, including labeled alpha- and beta-ray emitting isotopes, as well as PSMA targeting in directing MRI-guided focused ultrasound. Conclusions. There is a potential application for PSMA-targeted PET in neuro-oncology as a combination of diagnostic and therapeutic use, as a theranostic modality for managing CNS tumors. Further research is needed regarding the mechanism(s) of PSMA expression in CNS tumors and its differential performance by tumor type. [ABSTRACT FROM AUTHOR]

Cortical ependymomas are currently not considered a subgroup of supratentorial ependymomas; however, there is a growing body of literature investigating the natural history of these lesions compared to supratentorial ependymomas. We performed a systematic literature review of cortical ependymomas with a focus on the natural history, clinical characteristics, and clinical outcomes of these lesions as compared to supratentorial ependymomas. Our search revealed 153 unique cases of cortical ependymomas. The mean age on presentation was 21.2 years. Males and females comprised 58.8% (90/153) and 41.2% (63/153) of cases, respectively. The most common presenting symptom was seizure activity occurring in 44.4% of the cohort (68/153). The recently recognized C11orf95-RELA fusion was identified in 13.7% of the cohort (21/153) and 95.5% of cases (21/22) reporting molecular characterization. World Health Organization grades 2 and 3 were reported in 52.3% (79/151) and 47.7% (72/151) of cases, respectively. The frontal lobe was involved in the majority of cases (54.9%, 84/153). Gross total resection was achieved in 80.4% of cases (123/153). Tumor recurrence was identified in 27.7% of cases (39/141). Mean clinical follow-up was 41.3 months. Mean overall survival of patients who expired was 27.4 months whereas mean progression-free survival was 15.0 months. Comparatively, cortical ependymomas with C11orf95 - RELA fusions and supratentorial ependymomas with C11orf95 RELA fusions exhibited differing clinical outcomes. Further studies with larger sample sizes are necessary to investigate the significance of RELA fusions on survival in cortical ependymomas and to determine whether cortical ependymomas with C11orf95 - RELA fusions should be classified as a distinct entity. [ABSTRACT FROM AUTHOR]

Introduction. Positron emission tomography (PET) imaging with prostate-specific membrane antigen- (PSMA-) binding tracers has been found incidentally to demonstrate uptake in CNS tumors. Following the encouraging findings of several such case reports, there is a growing interest in the potential application of PSMA-targeted PET imaging for diagnostics, theranostics, and monitoring of CNS tumors. This is a systematic literature review on PSMA-binding tracers in CNS tumors. Methods. A PubMed search was conducted, including preclinical and clinical reports. One hundred and twelve records were identified, and after screening, 56 were included in the final report. Results. Tissue studies demonstrated PSMA expression in tumor vascular endothelial cells, without expression in normal brain tissue, though the extent and intensity of staining varied by anti-PSMA antibody and methodology. Most included studies reported on gliomas, which showed strong PSMA ligand uptake and more favorable tumor to background ratios than other PET tracers. There are also case reports demonstrating PSMA ligand uptake in prostate cancer brain metastases, nonprostate cancer brain metastases, and meningiomas. We also review the properties of the various PSMA-binding radiotracers available. Therapeutic and theranostic applications of PSMA-binding tracers have been studied, including labeled alpha- and beta-ray emitting isotopes, as well as PSMA targeting in directing MRI-guided focused ultrasound. Conclusions. There is a potential application for PSMA-targeted PET in neuro-oncology as a combination of diagnostic and therapeutic use, as a theranostic modality for managing CNS tumors. Further research is needed regarding the mechanism(s) of PSMA expression in CNS tumors and its differential performance by tumor type. [ABSTRACT FROM AUTHOR]

Cortical ependymomas are currently not considered a subgroup of supratentorial ependymomas; however, there is a growing body of literature investigating the natural history of these lesions compared to supratentorial ependymomas. We performed a systematic literature review of cortical ependymomas with a focus on the natural history, clinical characteristics, and clinical outcomes of these lesions as compared to supratentorial ependymomas. Our search revealed 153 unique cases of cortical ependymomas. The mean age on presentation was 21.2 years. Males and females comprised 58.8% (90/153) and 41.2% (63/153) of cases, respectively. The most common presenting symptom was seizure activity occurring in 44.4% of the cohort (68/153). The recently recognized C11orf95-RELA fusion was identified in 13.7% of the cohort (21/ 153) and 95.5% of cases (21/22) reporting molecular characterization. World Health Organization grades 2 and 3 were reported in 52.3% (79/151) and 47.7% (72/151) of cases, respectively. The frontal lobe was involved in the majority of cases (54.9%, 84/153). Gross total resection was achieved in 80.4% of cases (123/153). Tumor recurrence was identified in 27.7% of cases (39/141). Mean clinical follow-up was 41.3 months. Mean overall survival of patients who expired was 27.4 months whereas mean progression-free survival was 15.0 months. Comparatively, cortical ependymomas with C11orf95-RELA fusions and supratentorial ependymomas with C11orf95 RELA fusions exhibited differing clinical outcomes. Further studies with larger sample sizes are necessary to investigate the significance of RELA fusions on survival in cortical ependymomas and to determine whether cortical ependymomas with C11orf95-RELA fusions should be classified as a distinct entity. [ABSTRACT FROM AUTHOR]

To investigate the association between immunologic counts on admission and acute symptomatic hydrocephalus after aneurysmal subarachnoid hemorrhage (aSAH). We conducted a retrospective analysis of 143 consecutive patients with aSAH. Patient demographics, clinical parameters, laboratory values, and radiographic imaging were obtained. Univariate and multivariate logistic regression analyses were performed to investigate parameters independently associated with acute symptomatic hydrocephalus. Receiver operating characteristic (ROC) curve analysis determined the best threshold value of neutrophil count to differentiate patients with and without hydrocephalus. Overall, acute symptomatic hydrocephalus developed in 39.16% of patients. In an adjusted multivariate logistic regression model, Hunt and Hess grade 4–5 (odds ratio [OR]: 16.052, 95% confidence interval [CI]: 1.188–216.983; P = 0.037), modified Fisher score 3–4 (OR: 10.107, 95% CI: 1.715–59.572; P = 0.011), intraventricular hemorrhage (OR: 4.578, 95% CI: 1.417–14.788; P = 0.011), neutrophil count (OR: 1.183, 95% CI: 1.033–1.354; P = 0.015), and prior ischemic stroke (OR: 7.003, 95% CI: 1.293–37.929; P = 0.024) were significantly associated with hydrocephalus. ROC analysis for neutrophil count confirmed an acceptable area under the curve (AUC 0.780, 95% CI: 0.701–0.859; P < 0.001). The best threshold value of neutrophil count to predict hydrocephalus was ≥9.80 × 103/mL. Overall, 81.25% of patients who developed shunt dependence had a neutrophil count ≥9.80 × 103/mL on admission (P = 0.003). Neutrophil count ≥9.80 × 103/mL on admission predicts acute symptomatic hydrocephalus after aSAH in an adjusted multivariate logistic regression model. Moreover, shunt dependence was associated with higher neutrophil counts. [ABSTRACT FROM AUTHOR]

Objective: The purpose of this study was to evaluate seizure outcome in children with intractable secondary generalized epilepsy without a resectable focus who underwent complete corpus callosotomy and compare these results to those of anterior two-third callosotomy. Method: Data were obtained for all patients who underwent a corpus callosotomy from 2000 to 2005. The study involved 37 patients. Eleven patients had anterior two-third corpus callosotomy compared with 28patients who underwent complete corpus callosotomy. Two of these patients had completion of their callosotomy following initial partial callosotomy. Seizure type, seizure frequency, and family satisfaction were evaluated for all patients pre- and postoperatively. Results: A reduction of ≥75% in seizures occurred in 75% of the total-callosotomy patients compared to 55% of the partial-callosotomy patients. Family satisfaction for complete and partial callosotomy was 89 and 73%, respectively. No prolonged neurologic deficits were observed in either group. Conclusion: Complete corpus callosotomy is the most effective treatment for secondary generalized intractable seizures not amenable to focal resection in children. Copyright © 2007 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

The noradrenaline (NA) system is one of the brain's major neuromodulatory systems; it originates in a small midbrain nucleus, the locus coeruleus (LC), and projects widely throughout the brain. 1,2 The LC-NA system is believed to regulate arousal and attention 3,4 and is a pharmacological target in multiple clinical conditions. 5,6,7 Yet our understanding of its role in health and disease has been impeded by a lack of direct recordings in humans. Here, we address this problem by showing that electrochemical estimates of sub-second NA dynamics can be obtained using clinical depth electrodes implanted for epilepsy monitoring. We made these recordings in the amygdala, an evolutionarily ancient structure that supports emotional processing 8,9 and receives dense LC-NA projections, 10 while patients (n = 3) performed a visual affective oddball task. The task was designed to induce different cognitive states, with the oddball stimuli involving emotionally evocative images, 11 which varied in terms of arousal (low versus high) and valence (negative versus positive). Consistent with theory, the NA estimates tracked the emotional modulation of attention, with a stronger oddball response in a high-arousal state. Parallel estimates of pupil dilation, a common behavioral proxy for LC-NA activity, 12 supported a hypothesis that pupil-NA coupling changes with cognitive state, 13,14 with the pupil and NA estimates being positively correlated for oddball stimuli in a high-arousal but not a low-arousal state. Our study provides proof of concept that neuromodulator monitoring is now possible using depth electrodes in standard clinical use. • Sub-second neuromodulator dynamics can be measured using clinical depth electrodes • Noradrenaline dynamics in human amygdala reflect attention and arousal • Coupling between noradrenaline and pupil dilation depends on cognitive state Bang et al. demonstrate that electrochemical estimates of sub-second neuromodulator dynamics can be obtained in humans using clinical depth electrodes. They show that noradrenaline tracks the emotional modulation of attention and that the coupling between noradrenaline and pupil dilation—a common behavioral proxy for noradrenaline—depends on cognitive state. [ABSTRACT FROM AUTHOR]

Background Epidermoid cysts in Meckel cave are exceedingly rare. Since 1971, only 17 cases have been reported in the literature, with most patients presenting with trigeminal hypesthesia. However, outgrowth of these lesions from Meckel cave can rarely lead to compression of the proximate cavernous sinus and the neurovascular structures contained within. To date, 2 cases have reported a Meckel cave epidermoid cyst presenting clinically as an intracavernous cranial nerve palsy, presumably a clinical manifestation of cavernous sinus compression from the lesion. Case Description We describe a case involving a 51-year-old woman presenting with unilateral refractory trigeminal neuralgia, facial hypesthesia, abducens palsy, plus new-onset partial ptosis. Magnetic resonance imaging revealed a mass in the left Meckel cave that was T1 hypointense, T2 hyperintense, peripherally enhancing, and restricting diffusion. A stereotactic left subtemporal extradural approach was used to resect the lesion, which alleviated most of the patient's symptomatology except for minimal intermittent left-sided facial hypesthesia that remained at her 1-year postoperative visit. Conclusions This is a unique report depicting an epidermoid cyst in the Meckel cave causing numerous cranial nerve deficits because of indirect tumoral compression of cranial nerves within the cavernous sinus. Highlights • A 51-year-old woman presented with multiple cranial nerve deficits. • Imaging revealed a lesion in the left Meckel cave compressing the cavernous sinus. • We achieved gross total resection and pathology revealed an epidermoid cyst. • Surgical intervention alleviated the patient of nearly all preoperative deficits. • The current literature on epidermoid cysts in Meckel cave is discussed in-depth. [ABSTRACT FROM AUTHOR]

Neurostimulation is a promising therapy for abating epileptic seizures. However, it is extremely difficult to identify optimal stimulation patterns experimentally. In this study, human recordings are used to develop a functional 24 neuron network statistical model of hippocampal connectivity and dynamics. Spontaneous seizure-like activity is induced in silico in this reconstructed neuronal network. The network is then used as a testbed to design and validate a wide range of neurostimulation patterns. Commonly used periodic trains were not able to permanently abate seizures at any frequency. A simulated annealing global optimization algorithm was then used to identify an optimal stimulation pattern, which successfully abated 92% of seizures. Finally, in a fully responsive, or closed-loop, neurostimulation paradigm, the optimal stimulation successfully prevented the network from entering the seizure state. We propose that the framework presented here for algorithmically identifying patient-specific neurostimulation patterns can greatly increase the efficacy of neurostimulation devices for seizures. [ABSTRACT FROM AUTHOR]

In the mammalian brain, dopamine is a critical neuromodulator whose actions underlie learning, decision-making, and behavioral control. Degeneration of dopamine neurons causes Parkinson's disease, whereas dysregulation of dopamine signaling is believed to contribute to psychiatric conditions such as schizophrenia, addiction, and depression. Experiments in animal models suggest the hypothesis that dopamine release in human striatum encodes reward prediction errors (RPEs) (the difference between actual and expected outcomes) during ongoing decision-making. Blood oxygen level-dependent (BOLD) imaging experiments in humans support the idea that RPEs are tracked in the striatum; however, BOLD measurements cannot be used to infer the action of any one specific neurotransmitter. We monitored dopamine levels with subsecond temporal resolution in humans (n = 17) with Parkinson's disease while they executed a sequential decision-making task. Participants placed bets and experienced monetary gains or losses. Dopamine fluctuations in the striatum fail to encode RPEs, as anticipated by a large body of work in model organisms. Instead, subsecond dopamine fluctuations encode an integration of RPEs with counterfactual prediction errors, the latter defined by how much better or worse the experienced outcome could have been. How dopamine fluctuations combine the actual and counterfactual is unknown. One possibility is that this process is the normal behavior of reward processing dopamine neurons, which previously had not been tested by experiments in animal models. Alternatively, this superposition of error terms may result from an additional yet-to-be-identified subclass of dopamine neurons. [ABSTRACT FROM AUTHOR]