Factors Influencing Long-Term Outcomes of Single-Session Gamma Knife Radiosurgery in Large-Volume Meningiomas >10 cc.

INTRODUCTION: Meningiomas are the most common primary intracranial tumour. Gamma knife radiosurgery (GKRS) is a frequently employed non-invasive method of treatment, with good remission rates and low morbidity in literature. However, the role of GKRS in the management of "large" meningiomas is unclear, with reported outcomes that vary by centre. We aimed to assess the factors that influence long-term outcomes following GKRS in meningiomas >10 cc in volume. METHODS: A retrospectively analysed all patients with meningiomas exceeding 10 cc in volume who underwent GKRS between January 2006 and December 2021 at the National Institute of Mental Health and Neurosciences (NIMHANS), Bengaluru. Demographic, clinical, radiological, and follow-up data were acquired, and factors associated with progression following GKRS were assessed. RESULTS: The cohort comprised 76 patients 29 males (38.2%) and 47 females (61.8%) with a mean age of 46.3 ± 11.02 years. Thirty-nine patients had been previously operated (51.3%). Meningiomas were most frequently located in the parasagittal region (26 tumours, 34.2%) and sphenopetroclival region (23 tumours, 30.3%), with mean lesion volume of 12.55 ± 5.22 cc, ranging 10.3 cc-25 cc. The mean dose administered to the tumour margin was 12.5 Gy ± 1.2 Gy (range 6-15 Gy). The median duration of clinical follow-up was 48 months, over which period radiological progression occurred in 14 cases (20%), with unchanged tumour volume in 20 cases (28.6%) and reduction in size of the tumour in 36 cases (51.4%). Progression-free survival after GKRS was 72% at 5 years, was significantly poorer among meningiomas with tumour volume >14 cc (log-rank test p = 0.045), tumours presenting with limb motor deficits (log-rank test p = 0.012), and tumours that underwent prior Simpson grade 3 or 4 excision (log-rank test p = 0.032). CONCLUSIONS: Meningiomas >10 cc in volume appear to display a high rate of progression and subsequent need for surgery following GKRS. Primary surgical resection, when not contraindicated, may be considered with GKRS serving an adjuvant role, especially in tumours exceeding 14 cc in volume, and presenting with limb motor deficits. Long-term clinical and radiological follow-up is essential following GKRS as the response of large meningiomas may be unpredictable.

Surgical outcomes of trigonal intraventricular meningiomas: a single-centre study.

Trigonal meningiomas are rare intraventricular tumours that present a surgical challenge. There is no consensus on the optimal surgical approach to these lesions, though the transtemporal and transparietal approaches are most frequently employed. We aimed to examine the approach-related morbidity and surgical nuances in treating trigonal meningiomas. This retrospective review assimilated data from 64 trigonal meningiomas operated over 15 years. Details of clinicoradiological presentation, surgical approach and intraoperative impression, pathology and incidence of various postoperative deficits were recorded. In our study, Trigonal meningiomas most frequently presented with headache and visual deterioration. The median volume of tumours was 63.6cc. Thirty-one meningiomas each (48.4%) were WHO Grade 1 and WHO Grade 2, while 2 were WHO Grade 3. The most frequent approach employed was transtemporal (38 patients, 59.4%), followed by transparietal (22 patients, 34.4%). After surgery features of raised ICP and altered mental status resolved in all patients, while contralateral limb weakness resolved in 80%, aphasia in 60%, seizures in 70%, and vision loss in 46.2%. Eighteen patients (28.13%) developed transient postoperative neurological deficits, with one patient (1.5%) developing permanent morbidity. Surgery for IVMs results in rapid improvement of neurological status, though visual outcomes are poorer in patients with low vision prior to surgery, longer duration of complaints and optic atrophy. The new postoperative deficits in some patients tend to improve on follow up. Transtemporal and transparietal approaches may be employed, based on multiple factors like tumour extension, loculation of temporal horn, size of lesion with no significant difference in their safety profile.

Posterior Quadrant Disconnection for Childhood Onset Sub-Hemispheric Posterior Head Region Epilepsy: Indications in an Indian Cohort and Outcome.

BACKGROUND: Posterior quadrant disconnection (PQD) is an under-utilized surgical technique in the management of refractory epilepsy. There is a dearth of data pertinent to post-PQD seizure outcomes. METHODS: This retrospective study analyzed patients with drug-resistant childhood-onset epilepsy who underwent PQD at our center from 2009 to 2018. The clinical, imaging, and electrophysiological data were reviewed. The seizure outcome was noted from the latest follow-up in all patients. RESULTS: Fifteen patients underwent PQD, with a mean age at onset of epilepsy of 3.3 ± 4.6 years. All patients had seizure onset in childhood with focal onset of seizures, and in addition, 5 had multiple seizure types. All cases underwent presurgical workup with MRI, video-EEG, psychometry, while PET/MEG was done if required. Engel Ia and ILAE I outcomes were considered to be favorable. The histology of the specimen showed 9 patients (60%) had gliosis, 4 (26.7%) had focal cortical dysplasia (FCD), while 1 patient had nodular heterotopia and another had polymicrogyria-pachygyria complex. Postoperative follow-up was available in 14 cases. One patient was lost to follow-up. Mean follow-up duration for the cohort was 45 + 24 months. At last, follow-up (n = 14), 66.7% (10 cases) had favorable outcome (Engel Ia). At the end of 1-year follow-up, up to 73% (n = 11) of the patients were seizure-free. Four patients developed transient hemiparesis after surgery which improved completely by 3-6 months. CONCLUSIONS: Gliosis was more common etiology requiring PQD in our series than Western series, where FCD was more common. PQD is a safe and effective surgical modality in childhood-onset epilepsy with posterior head region epileptogenic focus.

Machine learning identifies "rsfMRI epilepsy networks" in temporal lobe epilepsy.

OBJECTIVES: Experimental models have provided compelling evidence for the existence of neural networks in temporal lobe epilepsy (TLE). To identify and validate the possible existence of resting-state "epilepsy networks," we used machine learning methods on resting-state functional magnetic resonance imaging (rsfMRI) data from 42 individuals with TLE. METHODS: Probabilistic independent component analysis (PICA) was applied to rsfMRI data from 132 subjects (42 TLE patients + 90 healthy controls) and 88 independent components (ICs) were obtained following standard procedures. Elastic net-selected features were used as inputs to support vector machine (SVM). The strengths of the top 10 networks were correlated with clinical features to obtain "rsfMRI epilepsy networks." RESULTS: SVM could classify individuals with epilepsy with 97.5% accuracy (sensitivity = 100%, specificity = 94.4%). Ten networks with the highest ranking were found in the frontal, perisylvian, cingulo-insular, posterior-quadrant, thalamic, cerebello-thalamic, and temporo-thalamic regions. The posterior-quadrant, cerebello-thalamic, thalamic, medial-visual, and perisylvian networks revealed significant correlation (r > 0.40) with age at onset of seizures, the frequency of seizures, duration of illness, and a number of anti-epileptic drugs. CONCLUSIONS: IC-derived rsfMRI networks contain epilepsy-related networks and machine learning methods are useful in identifying these networks in vivo. Increased network strength with disease progression in these "rsfMRI epilepsy networks" could reflect epileptogenesis in TLE. KEY POINTS: • ICA of resting-state fMRI carries disease-specific information about epilepsy. • Machine learning can classify these components with 97.5% accuracy. • "Subject-specific epilepsy networks" could quantify "epileptogenesis" in vivo.

Predictors of outcome of subdural empyema in children.

OBJECTIVE: The aim of this study was to report the etiology, clinical features, microbiology, surgical outcome, and predictors of outcome of spontaneous subdural empyema (SDE). METHODS: The authors conducted a retrospective study in a tertiary hospital. Children up to 18 years of age, with a diagnosis of SDE with infective etiology, were included in the present cohort. Patients with posttraumatic, postsurgery, and tubercular origin of SDE were excluded from the study. The Glasgow Outcome Scale was used for outcome assessment at the end of 3 months. For analysis purposes, the demographic data, clinical features, radiological data, microbiology, type of surgery, and complication data were categorized, and univariate and multivariable logistic regression analyses were performed to identify the factors associated with outcome. RESULTS: Ninety-eight children were included in the study and the mean age was 10.9 years. Otogenic origin (34.7%) was the most common source of infection, followed by meningitis (14.3%). The mean duration of symptoms was 12 days. Seventy-six children presented with Glasgow Coma Scale (GCS) score > 8 and the supratentorial location was the most common location. Almost 75% of the children underwent craniotomy or craniectomy and the rest had burr-hole evacuation. Beta-hemolytic Streptococcus (10%) was the most common organism isolated. Cerebral venous thrombosis (CVT; 10.2%) was the most frequent complication in this cohort. The other complications were infarction (6.1%), new-onset seizure (4.1%), and bone flap osteomyelitis (4.1%). Thirteen cases had a recurrence of pus collection, which was more common in the craniotomy group than in the burr-hole group. Age (p = 0.02), GCS score ≤ 8 (OR 8.15, p = 0.001), CVT (OR 15.17, p = 0.001), and presence of infarction (OR 7, p = 0.05) were strongly associated with unfavorable outcome. In multivariable logistic regression analysis, only GCS score ≤ 8 (p = 0.01), CVT (p = 0.02), and presence of infarction (p = 0.04) had a significant impact on unfavorable outcome. CONCLUSIONS: Prompt diagnosis and immediate intervention is the goal of management of SDE, especially in children as a delay in diagnosis can result in unconsciousness and secondary complications such as CVT and infarction, which adversely affect outcome.

Incidence of deep venous thrombosis in patients undergoing elective neurosurgery - A prospective cohort based study.

INTRODUCTION: The exact incidence of deep vein thrombosis (DVT) in the Indian neurosurgical patient population is uncertain. This situation is quite different from its well-documented incidence in the Caucasian population.This study aims to analyze the incidence, etiopathogenesis, and risk factors in the development of DVT in Indians. This will enable us to formulate country-specific guidelines for its appropriate and timely prophylaxis. AIMS AND OBJECTIVES: To study the incidence of deep venous thrombosis in patients undergoing elective neurosurgery. MATERIALS AND METHODS: This was a prospective cohort based study analyzing a total of 273 adult (>18 years) patients who underwent elective neurosurgery during a period of 1 year from November 2013 to December 2014.A preoperative baseline Doppler ultrasonography and coagulation profile was performed, followed by postoperative surveillance Doppler ultrasonography biweekly until discharge. Statistical analysis was performed using chi-square test and Pearson's correlation analysis. RESULTS: A total of 33 patients (12.08%) developed DVT in the postoperative period. Hypertension, frequent alcohol intake, smoking, and obesity were found to be the risk factors (P = 0.001). Significant association was observed between malignant tumors, meningiomas, and DVT (P = 0.001). Intraoperative supine and lateral position for more than 5 h, the severity of postoperative motor deficit, and ambulation delay of more than 2 days were significant risk factors (P = 0.001). CONCLUSION: Our study, one of the first of its kind, details the incidence and etiopathogenesis of DVT in the Indian neurosurgical population. We recommend an early usage of prophylaxis (mechanical and/or pharmacological) in the perioperative period for the high risk category of patients. We hope that this data can be used for preparing country-specific guidelines for DVT prophylaxis.

Pediatric thoracolumbar spinal injuries: The etiology and clinical spectrum of an uncommon entity in childhood.

BACKGROUND: Pediatric thoracolumbar (TL) spinal injuries are uncommon entities with an incidence of 5-34% of all pediatric spinal injuries. There is a scarcity of studies done on the pediatric population in the developing countries like India. This study aims to review our experience with TL spine injuries in children over a 12-year period. MATERIALS AND METHODS: We retrospectively reviewed the epidemiology, risk factors, mechanisms, patterns of injury and management of pediatric TL injuries in our population. RESULTS: There were 90 children with TL spine injuries comprising 2% of all the spine injuries treated in our institute. The mean age was 15.9 ± 3.2 years (range: 2-18 years) with a male predominance (3:1). The most common mode of injury was fall from height. 64/90 (71.1%) children sustained injury due to fall from height, 18/90 (20%) children sustained injury following motor vehicle accident and rest of the children sustained injury due to the fall of a heavy object over the neck. Most of the patients (27.8%) sustained Grade A injury. Lumbar spine was the most common spinal level injured (53.3%), and fractures were the most common type of injury (93.3%). Surgical fixation was performed in 18/90 (20%) children. Follow-up was available for 21 children of which 13 (62%) were ambulant at follow-up. CONCLUSION: TL injuries are rare and are most common in children older than 10 years and mainly involve the lumbar region. When indicated, surgical fusion of the involved vertebrae is safe and effective.

Preservation of cognitive and musical abilities of a musician following surgery for chronic drug-resistant temporal lobe epilepsy: a case report.

Mesial temporal lobe epilepsy (TLE) affects a range of cognitive functions and musical abilities. We report a 16-year-old boy diagnosed with drug-resistant right-medial TLE. He is a professional musician, trained in Carnatic classical music. Clinical, electrophysiological, magnetic resonance imaging (MRI) and positron emission tomography evaluation localized the seizure focus to the right medial temporal lobe. Patient underwent detailed neuropsychological evaluation and functional MRI (fMRI) for musical abilities prior to surgery. He underwent an awake craniotomy and tailored resection of lateral neocortex as well as amygdalohippocampectomy under guidance of cortical stimulation and clinical monitoring. The superior temporal gyrus where activation was revealed on task-based fMRI was preserved. At 16-month follow-up, there was no seizure recurrence and his cognitive functions including musical abilities did not deteriorate with surgery. The task-based fMRI while listening to music revealed bilateral frontotemporal activation. There was evidence of increased left frontotemporal connectivity during the postsurgical period in the resting state fMRI. It is hypothesized that the intact neuropsychological and musical abilities might be as a result of intense musical training from an early age despite the illness leading to functional and neural adaptation of the brain might have contributed to his preserved cognitive functions and musical skills. Intense musical training at a young age perhaps not only honed a range of cognitive functions but also resulted in functionally more efficient cognitive networks despite the surgical resection.

Spectrum of primary intracranial tumors at a tertiary care neurological institute: A hospital-based brain tumor registry.

BACKGROUND: Hospital-based cancer registries (HBCRs) provide information on the magnitude and distribution of cancers in a given hospital. Hospital-based brain tumor registry (HBBTR) data on primary intracranial tumors from a tertiary care neurological center is presented. This is compared with related national and international data. MATERIALS AND METHODS: Data of patients operated for brain tumors at the National Institute of Mental Health and Neurosciences, Bangalore, India, between January 2010 and December 2014 was collected. Patients' clinical details and histopathological diagnosis were recorded. Data was analyzed and compared with that of Tata Memorial Hospital (TMH), Mumbai, and the Central Brain Tumor Registry of the United States (CBTRUS). RESULTS: A total of 4295 primary intracranial tumors in 1847 (43%) females and 2448 (57%) male patients were recorded. Pediatric and adult patients accounted for 16.2% and 83.8% of the cases, respectively. The maximum proportion of tumors was noted in the fourth decade. Among children, astrocytomas (25.1%), embryonal (20.6%), and ependymal tumors (14.8%) were the most frequently reported histology. In adults, meningiomas (23.2%), glioblastomas (15.5%), and nerve sheath tumors (12.7%) were common. Glioblastomas and all other tumors showed a male predilection whereas meningiomas presented more commonly in females. While our HBBTR followed similar trends as TMH data, marked difference was seen in the median age of some tumor subtypes when compared to CBTRUS. CONCLUSION: This HBBTR data gives a glimpse of the prevalence of varied primary intracranial tumors. Such data can be linked to other HBCRs and population-based cancer registries in India for improved research and policy-making decisions.

Rare pathologies in the posterior third ventricular region in children: case series and review.

Tumors of the pineal region in children often belong to 2 categories, namely germ cell tumors and pineal parenchymal tumors. Very rare pathologies have previously been reported in this region. Most of these tumors may be similar radiologically, while their management differs. The present series reports 2 children with pineal region tumors, each one being a rare pathological entity by itself, namely an embryonal tumor with abundant neuropil and true rosettes (ETANTR) and a rosette-forming glioneuronal tumor (RGNT). Very few such cases in each pathology have been reported in the literature for the pediatric age group up to now. Our series consists of 2 children, both presenting with a raised intracranial pressure of short duration. Imaging revealed lesions in the pineal region with similar radiological features. Both ETANTR and RGNT demonstrated mild enhancement. The 2 patients underwent surgical decompression either by Poppen's approach (n = 1) or a supracerebellar infratentorial approach (n = 1). The patient with ETANTR was advised radiotherapy, while the child with RGNT was advised a regular follow-up. This series presents some rare pathologies which can occur in the posterior third ventricular region with similar radiological features. Management differs based on the histology of the case.

P53 stratification reveals the prognostic utility of matrix metalloproteinase-9 protein expression in glioblastoma.

BACKGROUND: Despite the conventional acceptance of the matrix metalloproteinases (MMP)-2 and MMP-9, as markers of invasion in glioblastoma (GBM), there is no large body of evidence supporting their role as prognostic markers. Since the co-expression of MMPs with p53 was noted to be prognostic in other cancers, we evaluated the protein expression of MMP-2 and MMP-9 in GBM and explored their prognostic relevance with respect to p53 expression. MATERIALS AND METHODS: Tumor tissues from a uniformly treated cohort of 132 GBM patients were examined for MMP-2, MMP-9, and p53 protein expression by immunohistochemistry (IHC). Survival analyses were performed by Cox-regression and Kaplan-Meier (KM) survival analysis. P53 IHC-based stratification of all GBM cases was performed, and subgroup-specific expression of MMP-2 and MMP-9 was correlated with survival. RESULTS: MMP-2 and MMP-9 were expressed in p53 positive as well as p53 negative GBM tumors. MMP-2 and MMP-9 protein expressions had no correlation with prognosis. MMP-9 expression, however, emerged as a strong independent predictor of poor survival in p53 positive GBMs on both Cox-regression analysis (P = 0.036) and KM survival analysis (P = 0.008). Further, even on multivariate analysis, MMP-9 remained strongly associated with poor prognosis (P = 0.010). CONCLUSIONS: MMP-9 expression strongly associates with poor prognosis in p53 positive GBMs, but the absence of such correlation in p53 negative GBMs, skews the overall relation of this molecule with prognosis. The study highlights that the dual positivity of MMP-9 and p53 is of prognostic relevance in GBM.

Factors That Predict Recurrence Following Endoscopic Repair of Cerebrospinal Fluid Rhinorrhea.

BACKGROUND: The endoscopic approach has gained popularity in cerebrospinal fluid (CSF) rhinorrhea repair with high success rates, yet recurrence is frequent. We analyzed our cases to determine the outcomes of endoscopic repair of CSF rhinorrhea and the effect of several perioperative factors on the success of repair. METHODS: A retrospective review of 50 patients who underwent endoscopic repair of CSF rhinorrhea between January 2013 and July 2023 was performed, collecting details of presentation, surgery, and postoperative period. RESULTS: The most frequent etiology was nontraumatic CSF rhinorrhea (76%), in which the defect was most commonly located at the left cribriform plate, followed by traumatic CSF rhinorrhea (24%), in which sphenoid defects were most frequent. Traumatic CSF rhinorrhea was more common among male patients and was significantly associated with anosmia. Success rate at first repair attempt was 84%. Persistent CSF rhinorrhea was present in 3 patients (6%), and 5 patients (10%) developed recurrence of CSF rhinorrhea. Overall, 7 patients required reoperation, with 100% success rate after the second surgery. The use of 3-layered repair with fat, fascia lata, and mucosal flap was protective against repair failure, whereas bilateral defects and duration of symptoms >1 year were significantly associated with repair failure. The use of lumbar drain did not demonstrate a difference in repair success rate. CONCLUSIONS: Endoscopic repair of CSF rhinorrhea appears to be safe and effective when performed with accurate localization of the site of the lesion and multilayered repair. Potential predictors of recurrence include bilateral and long-standing defects.

Thalamic H3K27M altered diffuse midline gliomas: Clinicopathological and outcome analysis.

INTRODUCTION: Diffuse midline glioma (DMG) is a relatively new entity which was introduced in the fourth edition of the WHO classification of CNS tumours in 2016 and later underwent revision in 2021. It is an infiltrative glioma arising from midline structures, viz., thalamus, spine, and brainstem. Current literature on DMG is based majorly on brainstem lesions, and DMGs arising elsewhere remain unexplored. In our study, we have discussed our experience with thalamic DMGs. METHODOLOGY: This is a retrospective observational study of all patients with histopathologically proven DMG H3K27M altered, arising in the thalamus from 2018 to 2022. Clinical, neuroimaging, and pathology were re-reviewed, and prognostic factors for 3 months, 6 months, and overall survival (OS) were analyzed for all patients. RESULTS: There were 89 patients- 64 adults and 25 pediatric patients with thalamic DMG. The median age at presentation was 24 years. Raised ICP followed by limb weakness were the most common presenting complaints. Stereotactic biopsy was performed in 64 (71.9 %) patients and surgical decompression in 25 (28.1 %) patients. CSF diversion was required in 53 (59.6 %) patients. Median survival was 8 months in adults and 7 months in pediatric (p-value: 0.51). Raised ICP and TP53 mutation were prognostic factors in pediatric population. Radiotherapy with or without chemotherapy improved survival (p-value- <0.01). CONCLUSION: Thalamic DMGs have a poor prognosis which is comparable to brainstem DMGs. Radiotherapy improves survival in these patients. However, the disease remains an enigma and further work delving into its molecular characterization should be encouraged.

Yield of video electro encephalography for phase 1 pre-surgical evaluation of drug resistant epilepsy in 1200 adults: retrospective study from a tertiary center situated in a lower-middle-income country.

INTRODUCTION: Video Electroencephalography (VEEG) is crucial for presurgical evaluation of Drug Refractory Epilepsy (DRE). The yield of VEEG in large volume centers, particularly those situated in Low-and Middle-Income countries (LMIC) is not well studied. METHODOLOGY: We studied 1200 adults with drug resistant focal epilepsy whose seizures were recorded during VEEG in the epilepsy monitoring unit. VEEG review and analysis was done independently by trained epileptologists. Video EEG and MRI data were examined for concordance in order to generate a hypothesis for the presumed epileptogenic zone. RESULTS: Analysis of seizure semiology provided information on the symptomatogenic zone in most cases except for 33 (2.75%) patients. A total of 1050 (87.5%) patients showed interictal epileptiform discharges (IEDs) with most (58.3%) showing unilateral IEDs. Most patients (n = 1162, 96.83%) showed ictal EEG discharges of which 951(81.8%) had unilateral ictal onset. Abnormal MRI was seen in 978 (81.5%) patients. Concordance of electroclinical data obtained by analysis of VEEG with MRI abnormality could be established in most patients (63%). Concordance was higher for patients with ictal onset from temporal regions (83.71%) as compared to posterior cortex (55.4%) and frontal regions (43.5%.) CONCLUSION: This study highlights the high yield of VEEG in phase 1 presurgical evaluation in DRE. Systematic evaluation of data from VEEG provided lateralizing and localizing information in most cases. Concordance between VEEG and MRI findings was noted in most patients. These findings support steps to increase referral for pre-surgical evaluation in DRE.

Gamma Knife Radiosurgery in Partially Embolised Arteriovenous Malformations: Management Dilemmas and Outcomes.

Introduction: The role of Gamma Knife radiosurgery (GKRS) in partially embolized arteriovenous malformations (AVMs) has always remained a subject of debate. The aim of this study was to evaluate the efficacy of GKRS in partially embolized AVMs and to analyze factor that influence its obliteration. Methods: This was a retrospective study from a single institute performed over a period of 12 years (2005-2017). It included all patients who underwent GKRS for partially embolized AVMs. Demographic characteristics, treatment profiles, and clinical and radiological data were obtained during treatment and follow-up. Obliteration rates and factors affecting the same were sought and analyzed. Results: A total of 46 patients with a mean age of 30 years (range: 9-60 years) were included in the study. Follow-up imaging was available for 35 patients either by digital subtraction angiography (DSA) or magnetic resonance imaging (MRI). We found complete AVM obliteration in 21 patients (60%): one had near total obliteration (>90% obliteration), 12 had subtotal obliteration (<90%), and one had no change in the volume following GKRS. Following embolization alone, an average of 67% of the AVM volume was obliterated which resulted in an average 79% final obliteration rate after Gamma Knife radiosurgery. Mean duration to complete obliteration was found to be 3.45 years (range: 1-10 years). There was a significant difference (P = 0.04) in the mean interval between embolization and GKRS among cases with complete obliteration (12 months) and those with incomplete obliteration (36 months). There was no significant difference (P = 0.49) in the average obliteration rate between the ARUBA-eligible unruptured AVMs (79.22%) and ruptured AVMs (79.04%). Bleeding after GKRS during the latency period had a negative impact on obliteration (P = 0.05). Other factors like age, sex, Spetzler-Martin (SM)-grade, Pollock Flickinger score (PF-score), nidus volume, radiation dose, or presentation before embolization had no significant influence on obliteration. Three patients had permanent neurological deficits after embolization and none after radiosurgery. Six out of nine patients (66%) presenting with seizures were seizure-free after the treatment. Hemorrhage was noted in three patients following combined treatment and were managed non-surgically. Conclusion: Obliteration rates in partially embolized AVM after Gamma Knife are inferior when compared to Gamma Knife alone; moreover with volume staging and/or dose staging being increasingly plausible due to the new ICON machine, embolization may be completely replaced. However we have shown that in complicated and carefully chosen AVMs, embolization followed by GKRS is a valid modality of management. This study represents a real-world picture of individualized AVM treatment depending on patient choices and resources available.

Corpus Callosotomy for Non-Localizing Drug Resistant Epilepsy with Drop Attacks.

BACKGROUND: Corpus callosotomy (CC) is a surgical palliative procedure done for a selected group of patients with drug resistant epilepsy (DRE) to stop drop attacks and prevent falls. METHODS: We performed a retrospective chart review of consecutive patients who underwent CC for DRE with drop attacks at our center between 2015 and 2019. Clinical, imaging details and surgical findings were noted. Clinical outcomes and functional status were evaluated. RESULTS: During the study period, 17 patients underwent corpus callosotomy (Male: Female 14:3). The mean age at surgery was 10.3 years (standard deviation - 5.85, interquartile range [IQR] = 6.5). The mean age at onset of seizure was 2.23 years (standard deviation - 3.42, IQR = 1.5). Preoperative seizure frequency ranged from 2 to 60 attacks per day (median: 20, IQR= 36). All patients had atonic seizures/drop attacks. One patient underwent anterior CC and 16 underwent complete CC. Three patients had complications in the postoperative period. The median follow-up was 26 months. All patients had cessation of drop attacks immediately following surgery. One patient with anterior CC had a recurrence of drop attacks for which she underwent completion CC. Another patient had recurrent drop attacks 3 years later and was found to have a residual callosal connection. Three patients had complete seizure freedom and 4 patients had a <50% reduction in seizure frequency. CONCLUSIONS: Our study lends additional support to the efficacy of CC in patients with DRE, with the cessation of drop attacks. It also provided a reasonable reduction in seizure frequency. Complete CC led to better control of drop attacks.

Resting-State Functional MRI/PET Profile as a Potential Alternative to Tri-Modality EEG-MR/PET Imaging: An Exploratory Study in Drug-Refractory Epilepsy.

Objective The study explores whether the epileptic networks associate with predetermined seizure onset zone (SOZ) identified from other modalities such as electroencephalogram/video electroencephalogram/structural MRI (EEG/VEEG/sMRI) and with the degree of resting-state functional MRI/positron emission tomography (RS-fMRI/PET) coupling. Here, we have analyzed the subgroup of patients who reported having a seizure on the day of scan as postictal cases and compared the findings with interictal cases (seizure-free interval). Methods We performed independent component analysis (ICA) on RS-fMRI and 20 ICA were hand-labeled as large scale, noise, downstream, and epilepsy networks (Epinets) based on their profile in spatial, time series, and power spectrum domains. We had a total of 43 cases, with 4 cases in the postictal group (100%). Of 39 cases, 14 cases did not yield any Epinet and 25 cases (61%) were analyzed for the final study. The analysis was done patient-wise and correlated with predetermined SOZ. Results The yield of finding Epinets on RS-fMRI is more during the postictal period than in the interictal period, although PET and RS-fMRI spatial, time series, and power spectral patterns were similar in both these subgroups. Overlaps between large-scale and downstream networks were noted, indicating that epilepsy propagation can involve large-scale cognition networks. Lateralization to SOZ was noted as blood oxygen level-dependent activation and correlated with sMRI/PET findings. Postoperative surgical failure cases showed residual Epinet profile. Conclusion RS-fMRI may be a viable option for trimodality imaging to obtain simultaneous physiological information at the functional network and metabolic level.

Granular Cell Tumor and Spindle Cell Oncocytoma of the Pituitary Gland: Imaging and Intraoperative Cytology Diagnostic Dilemmas and Management Challenges.

BACKGROUND: Tumors arising from the posterior pituitary gland are rare and closely resemble pituitary adenoma in presentation and imaging. Most of them come as a histopathologic surprise. We have analyzed the posterior pituitary tumors managed in our institute and have discussed the dilemmas in imaging, challenges in intraoperative squash cytology, and surgical management. METHODS: We retrospectively reviewed our operative database of pituitary tumors over the past 10 years, which included five posterior pituitary tumors (three granular cell tumors [GCTs] and two spindle cell oncocytomas [SCOs]). Clinical, imaging, and endocrine characteristics; intraoperative details; histopathologic features; and postoperative outcomes were collected and analyzed. RESULTS: The mean age of the patients was 47 years. All patients presented with varying degrees of vision loss. Radiology revealed a sellar / suprasellar lesion with the pituitary gland seen separately in two of three GCTs, whereas a separate pituitary gland could not be identified in both the SCOs. Pituitary adenoma was a radiologic diagnosis in only two of five cases. Three patients underwent a transsphenoidal surgery, whereas two underwent surgery by the transcranial approach. Intraoperative cytology was challenging, though a possibility of posterior pituitary tumor was considered in three of four cases, whereas one was considered meningioma. All the tumors were very vascular and influenced the extent of resection. CONCLUSIONS: GCTs and SCOs are relatively uncommon tumors that are difficult to diagnose on preoperative imaging. Intraoperative squash cytology too can pose challenges. A preoperative suspicion can prepare the surgeon for surgery of these hypervascular tumors. The transcranial approach may be necessary in cases of uncertainty in imaging.

Spectrum of Surgically Resected Lesions of the Cavernous Sinus: A Neuropathologic Audit.

Background The cavernous sinus is a complex space composed of extradural venous plexus within dural folds. Several important structures like the carotid artery, cranial nerves, and sympathetic nerve fibers traverse through this space. Radiological diagnosis may not be definitive and in the context of discordance between clinical and neuroimaging diagnosis, histopathological evaluation becomes essential for diagnosis and management. Literature on the pathological spectrum of lesions is scarce as, with a shift in the treatment paradigm, most small lesions of cavernous sinus are treated with radiosurgery. However, surgical management still plays a role for larger lesions and in radiologically ambiguous cases for planning the definitive management. Materials and Methods We retrospectively reviewed all surgically resected lesions of the cavernous sinus over the last two decades (1998-2019). The clinical presentation, neuroimaging features, and histopathological findings were reviewed. Lesions extending from sella and other adjacent areas were excluded. Results Thirty-eight cases of isolated cavernous sinus mass lesions were diagnosed over the last two decades (1998-2019). Cavernous hemangiomas (19 cases, 50%) constituted the most frequent pathology, followed by aspergilloma, meningioma, schwannoma, metastatic adenocarcinoma, chondrosarcoma, and chordoma. Overall, 29.4% (10/34) could not be accurately diagnosed on neuroimaging. Of these, four cases of cavernous hemangiomas were mistaken for either meningioma (three cases) or schwannoma (one case). Neither chordoma nor chondrosarcoma was suspected. Conclusion This is the first study in literature, enumerating the pathological and imaging spectrum of surgically resected cavernous sinus lesions. Cavernous hemangiomas, metastases and chordomas, and chondrosarcoma posed the greatest difficulty in diagnosis on neuroimaging and the reasons for the same are analyzed. In the context of clinical and neuroimaging discordance in diagnosis, pathological characterization becomes essential for appropriate and timely management.