Genome-Wide DNA Methylation Profiling as a Prognostic Marker in Pituitary Adenomas-A Pilot Study.

BACKGROUND: The prediction of the regrowth potential of pituitary adenomas after surgery is challenging. The genome-wide DNA methylation profiling of pituitary adenomas may separate adenomas into distinct methylation classes corresponding to histology-based subtypes. Specific genes and differentially methylated probes involving regrowth have been proposed, but no study has linked this epigenetic variance with regrowth potential and the clinical heterogeneity of nonfunctioning pituitary adenomas. This study aimed to investigate whether DNA methylation profiling can be useful as a clinical prognostic marker. METHODS: A DNA methylation analysis by Illumina's MethylationEPIC array was performed on 54 pituitary macroadenomas from patients who underwent transsphenoidal surgery during 2007-2017. Twelve patients were excluded due to an incomplete postoperative follow-up, degenerated biobank-stored tissue, or low DNA methylation quality. For the quantitative measurement of the tumor regrowth rate, we conducted a 3D volumetric analysis of tumor remnant volume via annual magnetic resonance imaging. A linear mixed effects model was used to examine whether different DNA methylation clusters had different regrowth patterns. RESULTS: The DNA methylation profiling of 42 tissue samples showed robust DNA methylation clusters, comparable with previous findings. The subgroup of 33 nonfunctioning pituitary adenomas of an SF1-lineage showed five subclusters with an approximately unbiased score of 86%. There were no overall statistically significant differences when comparing hazard ratios for regrowth of 100%, 50%, or 0%. Despite this, plots of correlated survival estimates suggested higher regrowth rates for some clusters. The mixed effects model of accumulated regrowth similarly showed tendencies toward an association between specific DNA methylation clusters and regrowth potential. CONCLUSION: The DNA methylation profiling of nonfunctioning pituitary adenomas may potentially identify adenomas with increased growth and recurrence potential. Larger validation studies are needed to confirm the findings from this explorative pilot study.

Idiopathic normal pressure hydrocephalus: Validation of the DESH score as a prognostic tool for shunt surgery response.

OBJECTIVE: Several radiological markers have been linked to clinical improvement after shunt surgery for idiopathic normal pressure hydrocephalus (iNPH). However, iNPH has no pathognomonic feature, and patients are still diagnosed as probable, possible, or unlikely cases based on clinical symptoms, imaging findings, and invasive supplementary tests. The predictive value of the disproportionately enlarged subarachnoid space hydrocephalus (DESH) score is not yet conclusively determined, but it might offer a more accurate diagnostic method. The aim of the present retrospective cohort study was to validate the predictive power of the DESH score for clinical improvement after shunt surgery in iNPH patients. METHODS: We retrospectively obtained presurgical MRI and/or CT scans from 71 patients with iNPH who underwent ventriculoperitoneal shunt surgery. Radiological images were evaluated for Evans index (EI), corpus callosal angle (CA), tight high convexity (THC), Sylvian fissure dilation, and focal sulci dilation. These markers were aggregated to determine the DESH score. Patient journal entries were used to subjectively determine the extent of improvement in gait function, urinary incontinence, and/or cognition as a measure of shunt surgery response. RESULTS: Multiple logistic regression analysis, controlling for age and sex (α = 0.05), showed that DESH score was significantly correlated (OR 1.77) with subjective shunt-surgery response at a minimum of 1-month follow-up. Patients with higher DESH scores were more likely to have a favorable response to shunt surgery. CONCLUSION: Aggregating radiological markers into the DESH score is useful for predicting shunt responders among iNPH patients and can aid the selection of patients for surgery. These findings provide further support for the DESH score as a diagnostic tool for iNPH.

Evaluating the Efficacy of Perfusion MRI and Conventional MRI in Distinguishing Recurrent Cerebral Metastasis from Brain Radiation Necrosis.

Differentiating recurrent cerebral metastasis (CM) from brain radiation necrosis (BRN) is pivotal for guiding appropriate treatment and prognostication. Despite advances in imaging techniques, however, accurately distinguishing these conditions non-invasively is still challenging. This single-center retrospective study reviewed 32 cases (28 patients) with confirmed cerebral metastases who underwent surgical excision of lesions initially diagnosed by MRI and/or MR perfusion scans from 1 January 2015 to 30 September 2020. Diagnostic accuracy was assessed by comparing imaging findings with postoperative histopathology. Conventional MRI accurately identified recurrent CM in 75% of cases. MR perfusion scans showed significantly higher mean maximum relative cerebral blood volume (max. rCBV) in metastasis cases, indicating its potential as a discriminative biomarker. No single imaging modality could definitively distinguish CM from BRN. Survival analysis revealed gender as the only significant factor affecting overall survival, with no significant survival difference observed between patients with CM and BRN after controlling for confounding factors. This study underscores the limitations of both conventional MRI and MR perfusion scans in differentiating recurrent CM from BRN. Histopathological examination remains essential for accurate diagnosis. Further research is needed to improve the reliability of non-invasive imaging and to guide the management of patients with these post-radiation events.

Meningioma animal models: a systematic review and meta-analysis.

BACKGROUND: Animal models are widely used to study pathological processes and drug (side) effects in a controlled environment. There is a wide variety of methods available for establishing animal models depending on the research question. Commonly used methods in tumor research include xenografting cells (established/commercially available or primary patient-derived) or whole tumor pieces either orthotopically or heterotopically and the more recent genetically engineered models-each type with their own advantages and disadvantages. The current systematic review aimed to investigate the meningioma model types used, perform a meta-analysis on tumor take rate (TTR), and perform critical appraisal of the included studies. The study also aimed to assess reproducibility, reliability, means of validation and verification of models, alongside pros and cons and uses of the model types. METHODS: We searched Medline, Embase, and Web of Science for all in vivo meningioma models. The primary outcome was tumor take rate. Meta-analysis was performed on tumor take rate followed by subgroup analyses on the number of cells and duration of incubation. The validity of the tumor models was assessed qualitatively. We performed critical appraisal of the methodological quality and quality of reporting for all included studies. RESULTS: We included 114 unique records (78 using established cell line models (ECLM), 21 using primary patient-derived tumor models (PTM), 10 using genetically engineered models (GEM), and 11 using uncategorized models). TTRs for ECLM were 94% (95% CI 92-96) for orthotopic and 95% (93-96) for heterotopic. PTM showed lower TTRs [orthotopic 53% (33-72) and heterotopic 82% (73-89)] and finally GEM revealed a TTR of 34% (26-43). CONCLUSION: This systematic review shows high consistent TTRs in established cell line models and varying TTRs in primary patient-derived models and genetically engineered models. However, we identified several issues regarding the quality of reporting and the methodological approach that reduce the validity, transparency, and reproducibility of studies and suggest a high risk of publication bias. Finally, each tumor model type has specific roles in research based on their advantages (and disadvantages). SYSTEMATIC REVIEW REGISTRATION: PROSPERO-ID CRD42022308833.

Focused ultrasound for the treatment of brain tumors.

This review investigates focused ultrasound for treating neuro-oncological diseases as an emerging treatment modality. The technique is based on focused ultrasound waves guided by MRI. By using high or low-frequency waves, thermoablation of smaller tissue volumes centrally in the brain or a safe, temporary opening of the blood-brain barrier can be carried out for better penetration of chemotherapy. Numerous studies on neuro-oncological treatments are ongoing, signaling increasing popularity for the technique in the near future.

Ventriculosinus shunt: a pilot study to investigate new technology to treat hydrocephalus and mimic physiological principles of cerebrospinal fluid drainage.

OBJECTIVE: Devices draining CSF to the intracranial venous sinus for the treatment of hydrocephalus have been tested in the past, and while clinically effective, have not shown efficacy in the long term. The majority of these devices become obstructed within 3 months due to endothelial overgrowth. In this study, the authors investigated a newly developed ventriculosinus (VS) shunt outlet device with the objective of showing it would remain patent for at least 6 months. METHODS: Twelve patients in need of shunting for hydrocephalus underwent an operation using the investigational device and were followed for 6 months to record patency of the shunt. RESULTS: In 10 patients, the shunt was patent at 6 months, with the outlet device remaining unobstructed. In the remaining 2 patients, one died just before reaching the 6-month endpoint, and in the other the outlet was misplaced during surgery and therefore ceased to function after 3 months. No occlusion of the internal jugular vein or thrombus formation was noted in any of the 12 cases. CONCLUSIONS: These findings indicate that the outlet device can remain patent and has the capability to mimic physiological drainage by diverting CSF to the intracranial sinus. Additional confirmation of its potential as part of a new VS shunt system and ultimately as a viable alternative for ventriculoperitoneal and ventriculoatrial shunting to reduce complication rates requires further clinical trials.

Virtual magnetic resonance elastography predicts the intraoperative consistency of meningiomas.

BACKGROUND AND PURPOSE: Virtual magnetic resonance elastography (vMRE) is an experimental imaging modality designed to non-invasively predict the haptic properties of tissues. The modality is sensitive to tissue stiffness and fibrosis. Information about meningioma consistency prior to resection is of great interest in neurological surgery as the surgical plan and outcome may be affected by the tumor's stiffness. In this study, we assessed the ability of vMRE to predict the intraoperative consistency and mechanical heterogeneity of intracranial meningiomas. MATERIALS AND METHODS: We included 12 patients scheduled for meningioma resection, of which one patient was found to have a solitary fibrous tumor on histological examination. All participants underwent preoperative vMRE and intraoperative consistency grading. RESULTS AND CONCLUSIONS: Intraoperative qualitative consistency correlated positively with vMRE-based consistency assessment (odds ratio 5.63, 95% CI 1.12-28.30, p = 0.04) at b1000. Mechanically homogenous tumors had significantly lower ∆ mean stiffness than heterogeneous tumors (8.13 vs 18.07 kPa, p = 0.01). This study thus demonstrates a possible clinical application of vMRE in predicting the intraoperative consistency and mechanical heterogeneity of meningiomas.

Diagnosis, treatment, and outcome of primary CNS lymphoma-a single-center experience.

BACKGROUND: Primary CNS lymphoma (PCNSL) is a highly aggressive non-Hodgkin lymphoma (NHL) that occurs in the CNS (e.g. brain, meninges, spinal cord, cerebrospinal fluid, or intraocular involvement) in the absence of systemic NHL. Tumor resection does not improve survival, and neurosurgical intervention is generally limited to stereotactic biopsy to provide a histopathological diagnosis. OBJECTIVE: The objective of this single-center study was to evaluate the management and outcome of PCNSL patients diagnosed by biopsy, using overall survival and progression-free survival as endpoints. METHODS: At our department of neurosurgery, 140 patients were diagnosed with PCNSL by biopsy between January 1, 2009, and December 31, 2018. Of these, 37 patients were included in the study and were divided into three groups according to their postoperative therapy. RESULTS: Median OS was 35.7 months for the intensive treatment group, 29.5 months for the moderate treatment group, and 8.6 months for the palliative treatment group. The intensive and moderate treatment groups had similar progression-free survival, while the palliative treatment group had poor overall and progression-free survival. Six patients were long-term survivors (> 80 months). Age under 65 years was the main significant parameter affecting overall survival. CONCLUSION: In this cohort, patients with PCNSL had an overall fair prognosis if they (1) were under 65 years old, (2) had a performance score < 2 at the time of diagnosis, and (3) received either intensive or moderate chemotherapeutic treatment. Biopsy is still the primary diagnostic tool; other methods have been investigated but are not yet recommended.

Effect of 5-Aminolevulinic Acid and Sodium Fluorescein on the Extent of Resection in High-Grade Gliomas and Brain Metastasis.

Surgery is essential in the treatment of high-grade gliomas (HGG) and gross total resection (GTR) is known to increase the overall survival and progression-free survival. Several studies have shown that fluorescence-guided surgery with 5-aminolevulinic acid (5-ALA) increases GTR considerably compared to white light surgery (65% vs. 36%). In recent years, sodium fluorescein (SF) has become an increasingly popular agent for fluorescence-guided surgery due to numerous utility benefits compared to 5-ALA, including lower cost, non-toxicity, easy administration during surgery and a wide indication range covering all contrast-enhancing lesions with disruption of the blood-brain barrier in the CNS. However, currently, SF is an off-label agent and the level of evidence for use in HGG surgery is inferior compared to 5-ALA. Here, we give an update and review the latest literature on fluorescence-guided surgery with 5-ALA and SF for brain tumors with emphasis on fluorescence-guided surgery in HGG and brain metastases. Further, we assess the advantages and disadvantages of both fluorophores and discuss their future perspectives.

Magnetic Resonance Elastography in Intracranial Neoplasms: A Scoping Review.

BACKGROUND: Magnetic resonance elastography (MRE) allows noninvasive assessment of intracranial tumor mechanics and may thus be predictive of intraoperative conditions. Variations in the use of technical terms complicate reading of current literature, and there is need of a review using consolidated nomenclature. OBJECTIVES: We present an overview of current literature on MRE relating to human intracranial neoplasms using standardized nomenclature suggested by the MRE guidelines committee. We then discuss the implications of the findings, and suggest approaches for future research. METHOD: We performed a systematic literature search in PubMed, Embase, and Web of Science; the articles were screened for relevance and then subjected to full text review. Technical terms were consolidated. RESULTS: We identified 12 studies on MRE in patients with intracranial tumors, including meningiomas, glial tumors including glioblastomas, vestibular schwannomas, hemangiopericytoma, central nervous system lymphoma, pituitary macroadenomas, and brain metastases. The studies had varying objectives that included prediction of intraoperative consistency, histological separation, prediction of adhesiveness, and exploration of the mechanobiology of tumor invasiveness and malignancy. The technical terms were translated using standardized nomenclature. The literature was highly heterogeneous in terms of image acquisition techniques, post-processing, and study design and was generally limited by small and variable cohorts. CONCLUSIONS: MRE shows potential in predicting tumor consistency, adhesion, and mechanical homogeneity. Furthermore, MRE provides insight into malignant tumor behavior and its relation to tissue mechanics. MRE is still at a preclinical stage, but technical advances, improved understanding of soft tissue rheological impact, and larger samples are likely to enable future clinical introduction.

Preclinical cerebral cryoablation in non-tumor bearing pigs.

Patients with brain metastases, the most common intracranial tumor, have an average survival ranging from a few months to 40 months, and new treatment initiatives are needed. Cryoablation is a minimally invasive, well-tolerated, and effective procedure commonly applied for treatment of renal tumors and certain other malignancies. We aimed to examine the clinical usefulness of this procedure in a step-by-step program starting with cerebral cryoablation in healthy pigs. In four terminal and four non-terminal non-tumor bearing pigs, we studied immediate and delayed effects of cerebral cryoablation. Safety was assessed by computed tomography (CT), and clinical observation of behavior, neurological deficits, and wellbeing. Effects were assessed by histological and immuno-histochemical analyses addressing structural and metabolic changes supported by additional magnetic resonance imaging (MRI) and positron emission tomography (PET) in the non-terminal animals. Using CT-guidance, cryoablation probes were successfully inserted without complications, and ice formation could be monitored real-time with CT. No animal developed neurological deficits or signs of discomfort. Histological and immunohistochemical analyses, MRI, and PET revealed profound structural and biological damage within the lesion. MRI and PET revealed no long-term damage to healthy tissue outside the cryoablation zone. Cerebral cryoablation appears to be a feasible, safe, and controllable procedure that can be monitored successfully with CT. The net effect is a dead brain lesion without damage of either nearby or remote healthy structures. Immediate changes are local hemorrhage and edema; delayed effects are perfusion defects, immune system activation, and astrogliosis.

Idiopathic normal pressure hydrocephalus; treatment and outcome in the Region of Southern Denmark.

OBJECTIVE: Idiopathic normal pressure hydrocephalus (iNPH) is a prevalent and cost-effective disease to treat. However, no gold standard exists to confidently select patients for shunt surgery. The aim of this study was to investigate how patients with suspected iNPH at our center responded to shunt surgery and to compare pre-surgical variables between shunt responders and non-responders. METHODS: Preoperative baseline characteristics, MRI and/or CT scans were retrospectively obtained in 55 shunt-operated iNPH patients. Evan's index, third ventricle diameter, dilation of Sylvian fissures, tight high convexity, focal sulci, callosal angle, Rout value, MMSE score, CSF phosphorylated tau, CSF tau, and a combination of radiologic findings (DESH score) were compared according to whether or not patients expressed satisfactory response to shunt treatment at 1-month follow-up. RESULTS: Multiple logistic regression controlling for age and gender (α = 0.05) showed that tight high convexity, dilated Sylvian fissures, focal sulci, CSF tau, CSF phosphorylated tau, and DESH score correlated significantly with subjective shunt response at 1-month follow-up. CONCLUSION: In line with current literature, Shunt responders had lower levels of CSF tau and CSF phosphorylated tau compared to non-responders. While commonly used radiologic markers are of value, they can be aggregated into a score for better selection of shunt candidates.

Magnetic resonance elastography in normal pressure hydrocephalus-a scoping review.

BACKGROUND: Magnetic resonance elastography (MRE) of the brain allows quantitative measurement of tissue mechanics. Multiple studies are exploring possible applications in normal pressure hydrocephalus (NPH) in clinical and paraclinical contexts. This is of great interest in neurological surgery due to challenges related to diagnosis and prediction of treatment effects. In this scoping review, we present a topical overview and discuss the current literature, with particular attention to clinical implications and current challenges. METHODS: The protocol was based on the PRISMA extension for scoping reviews. After a systematic database search (PubMed, Embase, and Web of Science), the articles were screened for relevance. Thirty articles were subject to detailed screening, and key technical and clinical data items were extracted. The inclusion criteria included the use of MRE on human subjects with NPH. RESULTS: Seven articles were included in the final study. These studies had various objectives including the role of MRE in the assessment of regional elastic changes in NPH, shunt effect, and evaluation of NPH symptoms. MRE revealed patterns of mechanical changes in NPH that differed from other dementias. Regional MRE changes were associated with specific NPH signs and symptoms. Neurosurgical shunting caused partial normalization in tissue scaffold parameters. The studies were highly heterogeneous in technical aspects and design. CONCLUSION: MRE studies in NPH are still limited by few participants, variable cohorts, inconsistent methodologies, and technical challenges, but the approach shows great potential for future clinical application.

[Magnetic resonance elastography of the brain].

Magnetic resonance elastography (MRE) is a novel imaging modality allowing quantification of tissue consistency. Multiple trials have focused on the use of MRE to describe meningioma consistency prior to surgery and on improving diagnostic accuracy of normal pressure hydrocephalus and other dementias. MRE shows promising results, but still lacks direct clinical translational value. Within neurosurgery and neurosciences MRE could contribute and improve decision-making, diagnosis and treatment. Furthermore, the use of MRE will improve the basic understanding of neuroanatomy, physiology and pathology.

[Intraoperative neuromonitoring during brain surgery].

Intraoperative neuromonitoring is a perioperative method, supplementary to stealth navigation and fluorescence microscopic imaging in brain surgery. It allows cortical and subcortical mapping, hence real time identification of eloquent brain areas through electrical stimulation of the cerebral cortex and subcortical areas. The method allows for functional guidance during both awake and asleep neurosurgery and aids in optimizing the extent of resection of the relevant pathology while preserving neurological function as summarised in this review.

Hemispheric tumor location and the impact on health-related quality of life, symptomatology, and functional performance outcomes in patients with glioma: an exploratory cross-sectional study.

PURPOSE: To inform high-quality rehabilitation services, this study investigates if patients with glioma located in the right- or left-hemisphere present with different health-related quality of life, symptomatology, and functional performance in the early disease state. MATERIAL AND METHODS: Between 2013 and 2017, 81 adult patients were assessed during the first week of chemo-radiation, following resection. Patients were stratified into two groups depending on a right- or left-hemispheric lesion. Independent t-tests analyzed potential differences regarding health-related quality of life, symptomatology, and functional performance. RESULTS: Forty-five patients (56%) had a tumor located in the right hemisphere, whereas 36 patients (44%) had a tumor in the left hemisphere. Except for more patients with tumors in the left hemisphere having their tumor located in eloquent brain areas, the groups were well matched. No group differences were found in health-related quality of life. Group differences were found in communication deficits (Δ-10.9, 95%CI -19.1; -2.3, p = 0.01), which were more frequent in patients with left-sided lesions, and of headaches (Δ13.9, 95%CI 1.8; 25.9, p = 0.02), which were more frequent in patients with right-hemispheric lesions, who also had significantly greater difficulties with process-skills when performing everyday life tasks (Δ-0.3, 95%CI -0.5; -0.1, p < 0.01). Also, weak evidence suggests that patients with Glioblastoma Multiforme located in the right hemisphere are more affected by fatigue compared to their left-hemispheric comparisons (Δ14.6, 95%CI 0.19; 29.0, p < 0.05). CONCLUSIONS: The hemispheric location of a glial-cell brain tumor has no consequence for health-related quality of life at the beginning of chemo-radiation treatments. However, findings of tumor-location dependent conditions of communication, headache, patients' ability to perform executive functions, and fatigue should be considered in rehabilitation situations when designing an intervention to potentially improve executive functions and relieve the symptoms.Implications for rehabilitationIt is unclear if laterality impact glioma patients health-related quality of life and functional performance, which might implicate differentiated rehabilitation interventions.The hemispheric location of a glial-cell brain tumor has no consequence for the health-related quality of life at the beginning of chemo-radiation, following surgery.Tumor-location dependent conditions of communication, headache, fatigue, and patients' ability to perform executive functions should be considered when designing an intervention to improve executive functions and symptom-relieve.In rehabilitation interventions, tumor laterality is not a factor that needs to be considered before recommending aerobic training to improve the functional capacity of patients with glioma.

Endoscopic vs. microscopic transsphenoidal pituitary surgery: a single centre study.

Endoscopic pituitary surgery has shown promising results. This study reports the experiences of experienced microscopic pituitary surgeons changing to the endoscopic technique, and the beneficial effects on the postoperative outcomes. 45 transsphenoidal endoscopic-assisted surgeries performed in 2016-2017 were compared with 195 microscope-assisted surgeries performed in 2007-2017 for pituitary adenoma. Tumour size, hormonal status and vision were assessed preoperatively and 3-5 months postoperatively. Cases were identified through electronic patient records. GTR was achieved in 39% of the endoscopic operations vs. 22% of microscopic operations, p = 0.018. Mean duration of surgery was 86 min (77-95) with the endoscopic technique vs. 106 min (101-111) with the microscopic technique, p < 0.001. New hypothalamus-pituitary-adrenal axis deficiencies were observed after 3% of endoscopic vs. 34% microscopic operations, p = 0.001, and overall fewer postoperative pituitary deficiencies were observed in the endoscope-assisted group. Complications within 30 days of surgery occurred in 17% of endoscopic operations vs. 27% of microscopic operations (p > 0.05). Normalization of visual impairment occurred in 37% of the cases with preoperative visual impairment in the endoscopic group vs. 35% of those in the microscopic group (p > 0.05). The endoscopic technique performed better as a surgical procedure for pituitary adenomas. We found no statistically significant differences in complication rate or visual improvement between the two techniques.

[Primary central nervous system lymphomas].

In this review, we discuss primary central nervous system lymphomas: a rare type of tumours confined to the central nervous system. The disease is associated with a poor prognosis, which, however, generally has seen steady improvement over the last four decades, particularly in the younger population. Modern surgical techniques are reserved for diagnosis and has no place in the treatment, which mainly relies on high-dose polychemotherapy treatment regimes with methotrexate as the backbone.

[Thermal ablation of brain tumours].

The diagnosis of a malignant brain tumour is often associated with a poor prognosis. Current treatment is surgical resection followed by radio-chemotherapy. Surgical resection is most favourable in relation to survival time. Unfortunately, many patients are not suitable for surgical resection, due to inoperable tumour location or the patients' poor state. Minimally invasive thermal ablation may pose an interesting new treatment alternative. In this review, we describe the evolution, the underlying physiology and the clinical applications of cryo- and laser-induced thermal therapy of primary and secondary brain tumours.

The risk of developing seizures before and after surgery for brain metastases.

OBJECTIVE: Several risk factors have been shown to be associated with pre- and postoperative seizures in patients undergoing neurosurgical intervention for meningiomas and other primary brain tumors. This study aimed to identify risk factors associated with pre- and postoperative seizures in patients undergoing surgery for brain metastases (BM). PATIENTS AND METHODS: 286 patients who had undergone neurosurgical resection for brain metastases between 2007 and 2015 were included in this single-center retrospective cohort. Seizure incidence and patient characteristics were recorded. Univariate and multivariate logistic regression was performed for both pre- and postoperative seizures. RESULTS: 16.8 % of patients presented with seizures before surgical intervention, and a further 7.7 % of patients developed seizures within 3 months of surgical resection of BM. Patient age, cerebellar location, large tumor size, and headache were negatively correlated with pre-operative seizures, whereas parietal location was positively correlated. Surgery for recurrent tumor was positively correlated with newly developed seizures after surgery. CONCLUSION: Age, cerebellar location, large tumor size, and headache were negatively correlated with development of seizures while parietal location was found to be a risk factor. Lower age and resection of recurrent tumors was correlated with an increased risk of developing postoperative seizures. There was no correlation between type of primary tumor and development of seizures.