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.

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.

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.

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.

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.

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.

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.

What Happens after Therapy? Quality of Life and Neurocognitive Functions of Children with Malignant Posterior Fossa Tumors after Adjuvant Therapy.

PURPOSE: The health-related quality of life (HRQoL) is an important endpoint in modern clinical practice with improved survival of pediatric posterior fossa malignant brain tumors (PFMBTs). We evaluated the effect of environmental and psychosocial milieu on QoL and cognitive functioning (CF) of Indian children with PFMBT. METHODS: In a cross-sectional study, 47 children <18 years of age with medulloblastoma or anaplastic ependymoma were evaluated ≥6 months after completion of adjuvant therapy. All clinical and socioeconomic details, educational status of child and family members, socioeconomic status, environmental factors affecting QoL were documented. Children underwent HRQoL evaluation using Pediatric quality of life Inventory (PedsQL) questionnaire and neuropsychological evaluation. RESULTS: The median age of the cohort at presentation was 7 years (1-18) and median duration of evaluation after adjuvant therapy was 16 months. In 47 families, 72.34% had low monthly income and 76.6% of mothers took formal education. QoL scores were above median values. Parents reported scores highlighted that Lansky performance score (P = 0.001) and maternal education (P = 0.043) significantly influenced the cognitive component of QoL. Twenty-seven children had below-average IQ. Young age at presentation (P = 0.020), maternal education (P = 0.032), high socioeconomic status (P = 0.001) influenced the IQ score. Even though the majority of children (57.44%) had below-average IQ, they had a score of more than 50 on the cognitive functioning scale. A total of 72.5% of the eligible children in our cohort went back to school following therapy, though often with a delay of one academic year. CONCLUSIONS: Overall cognitive functioning scores of these children are good, but they are not representative of actual neurocognitive tasks based performance or IQ scores. Children should remain under regular follow-up with a neurocognitive assessment and psychological counseling at regular intervals.

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.

Combined amino acid PET-MRI for identifying recurrence in post-treatment gliomas: together we grow.

PURPOSE: The aim of this study is to compare the diagnostic accuracy of amino acid PET, MR perfusion and diffusion as stand-alone modalities and in combination in identifying recurrence in post-treatment gliomas and to qualitatively assess spatial concordance between the three modalities using simultaneous PET-MR acquisition. METHODS: A retrospective review of 48 cases of post-treatment gliomas who underwent simultaneous PET-MRI using C11 methionine as radiotracer was performed. MR perfusion and diffusion sequences were acquired during the PET study. The following parameters were obtained: TBRmax, TBRmean, SUVmax, and SUVmean from the PET images; rCBV from perfusion; and ADCmean and ADCratio from the diffusion images. The final diagnosis was based on clinical/imaging follow-up and histopathology when available. ROC curve analysis in combination with logistic regression analysis was used to compare the diagnostic performance. Spatial concordance between modalities was graded as 0, 1, and 2 representing discordance, < 50% and > 50% concordance respectively. RESULTS: There were 35 cases of recurrence and 13 cases of post-treatment changes without recurrence. The highest area under curve (AUC) was obtained for TBRmax followed by rCBV and ADCratio. The AUC increased significantly with a combination of rCBV and TBRmax. Amino acid PET showed the highest diagnostic accuracy and maximum agreement with the final diagnosis. There was discordance between ADC and PET in 22.9%, between rCBV and PET in 16.7% and between PET and contrast enhancement in 14.6% cases. CONCLUSION: Amino acid PET had the highest diagnostic accuracy in identifying recurrence in post-treatment gliomas. Combination of PET with MRI further increased the AUC thus improving the diagnostic performance.

Neuropathological spectrum of drug resistant epilepsy: 15-years-experience from a tertiary care centre.

Neuropathology of drug resistant epilepsy (DRE) has direct bearing on the clinical outcome. Classification of the most common pathologies, hippocampal sclerosis (HS) and focal cortical dysplasia (FCD) have undergone several revisions and studies on the surgical pathology of DRE employing the updated ILAE classification are scarce. Here, we report the neuropathological spectrum of 482 surgically treated cases of DRE from a single institute using the latest ILAE classifications along with clinicoradiologic correlation. Majority of the cases (324, 67.2%) had temporal lobe epilepsy (TLE), with 158 (32.8%) having extratemporal seizure focus. Among TLE, HS was most common (n = 208, 64.2%), followed by neoplasms (42, 13%), FCD (26, 8%) and dual pathology (23, 7%). Less frequent were vascular malformations (cavernoma-3, arteriovenous malformation-1), mild malformation of cortical development (mMCD, 3), gliotic lesions (5), cysticercosis (2), double pathology (2) and polymicrogyria (1). Among extratemporal epilepsies, FCD was most common (46, 29.1%), followed by neoplasms (29, 18.3%), gliotic lesions (27, 17.1%), Rasmussen encephalitis (18, 11.4%), hypothalamic hamartoma (12, 7.6%), malformations of cortical development (10, 6.3%) and vascular malformations (6, 3.8%). Less frequent were double pathology (2, cysticercosis + FCD type IIb, DNET + FCD type IIb), mMCD (2), cysticercosis (1) and dual pathology (1). No underlying pathology was detected in 12 cases (2.5%). Radiopathological concordance was noted in 83%. In 36 cases (7.5%), histopathology detected an unsuspected second pathology that included FCD type III (n = 16) dual pathology (n = 18) and double pathology (n = 2). Further, in four MRI negative cases, histopathology was required for a conclusive diagnosis.

Altered vascular permeability but not angiogenesis may play a role in the epileptogenesis of human hippocampal sclerosis.

OBJECTIVE: We investigated the role of angiogenesis and vascular permeability in the pathogenesis of human drug-resistant epilepsy due to hippocampal sclerosis. METHODS: Resected hippocampi from 30 histologically confirmed cases of hippocampal sclerosis and 30 age-matched post-mortem controls were examined by immunohistochemical quantitation of vascular endothelial markers, CD31 and CD105 (markers of newly formed vessels), and data were analysed relative to MR volumetry. The blood-brain barrier was evaluated based on immunohistochemistry for IgG, albumin, VEGF and AQP4. RESULTS: Mean vascular density in the hippocampus was 8.71/mm2 in hippocampal sclerosis samples compared to 7.94/mm2 in age-matched controls. No statistically significant increase in vascular density was found in hippocampal sclerosis samples. Although no neoangiogenesis was found in hippocampal sclerosis samples based on CD105, breakdown of the blood-brain barrier, enhanced neuronal expression of VEGF, and perivascular seepage of IgG and albumin with uptake within neurons and astrocytes were found. Redistribution of the water channel protein, AQP4, reflected by change from normal punctate labelling to intense diffuse staining in hippocampal sclerosis samples, indicated an altered glia-vascular interface, disrupting blood-brain barrier permeability. SIGNIFICANCE: Our data show no objective histological evidence of angiogenesis in hippocampal sclerosis samples. When controlled for the confounding variable of hippocampal area, there was no difference in vascular density between cases and controls. A leaky blood-brain barrier and redistribution of AQP4 were identified which may contribute to epileptogenesis. This constitutes the largest study in the published literature evaluating a role of vascular permeability and angiogenesis in human hippocampal sclerosis.

Role of Clinical Neuropsychologists in Awake-Craniotomy.

BACKGROUND: Awake craniotomy encompasses surgical resection of focal zone of neurological impairment, using intraoperative functional zone mapping. The strength of the procedure is maximum retention of functionally significant zones to ensure better function and quality of life outcomes in patients. A clinical neuropsychologist plays a vital role in profiling the patient's cognitive and psychosocial functioning as well as increasing the efficacy of functional zone mapping procedures. OBJECTIVE: Aim of this article is to summarize the literature on the role of clinical neuropsychologists in awake craniotomy and underscoring the need for establishing standardized operating procedures for neuropsychologists in awake craniotomy highlighting experiential anecdotes from a tertiary care facility. MATERIALS AND METHODS: A review of articles that elucidate the role of clinical neuropsychologists was done and summarized to highlight the role of clinical neuropsychologists. An attempt was made to explain the implementation of this role in regular clinical practice at a tertiary care facility. RESULTS: The role of a clinical neuropsychologist is highly crucial at pre-/during and postawake craniotomy, and has a significant bearing on the overall psychological outcome of the individual. The need for a standardized protocol to unify practice and increase the efficacy of the awake-craniotomy procedure is put forth. Recommendations for future directions in research to increase the scope of neuropsychologists in awake craniotomy have also been made.

Is Elective Neurosurgery Justified During COVID-19 Pandemic?

BACKGROUND: As the world faces a new viral pandemic, which has spread very rapidly, initial response from most countries was to suspend nonemergent health services so that available resources can be diverted to handle the large numbers of patients with COVID-19 infection. Many societies issued guidelines to suspend or postpone nonemergent surgeries. METHODS: We reviewed the emerging evidence regarding the impact of COVID-19 infection in neurosurgery and the postponement of elective surgeries. RESULTS AND OBSERVATIONS: COVID-19 infection poses serious threat in hospitals in the form of cross-infection, hospital staff falling sick, with potential risk to overwhelm or paralyze the healthcare. In addition, we have come to realize the significant perioperative morbidity and mortality secondary to active COVID-19 infection. All these strongly favor suspension of elective neurosurgical services. However, these have to be weighed against the fallout due to prolonged postponement of neurosurgical treatment for conditions, which can progress and cause neurological deterioration. CONCLUSION: This article discusses the contemporary published literature regarding the perioperative risk of COVID-19 infection, impact of postponed surgeries, challenges, risk assessment and guidelines for elective neurosurgery at this point of time.

Transcranial approach for pituitary adenomas - An evaluation of surgical approaches over two decades and factors influencing peri-operative morbidity.

PURPOSE: Transcranial surgery(TCS) for pituitary adenoma(PA) is mostly reserved for lesions with widespread extensions. We sought to analyse the intraoperative challenges, morbidity and the factors associated with morbidity of transcranial approaches, in a large series from a tertiary neurosurgical institute. METHODS: We retrospectively evaluated 137 patients who underwent TCS for PA in our institute. The details of their clinical features, imaging, operative and peri-operative events and complications were collected and analysed. The factors associated with morbidity were evaluated. RESULTS: The mean age of the cohort was 40.86 ± 13.35 years. 21 (15.3%) patients developed significant post-operative hematoma, out of which 7 patients (5.1%) required re-exploration. Post-operative diabetes insipidus was noted in 45 patients (32.84%), while SIADH was noted in 10 patients (7.35%). Other complications were cranial nerve palsy in 14 patients (10.2%), visual deterioration in 7 patients (5.1%). Neither tumour characteristics nor the choice of approach was associated with occurrence of post op hematoma. SIADH was significantly associated with patients with tumours involving cavernous sinus (p = 0.019) and subfrontal extension (p = 0.031). Patients with post-operative hematoma had significantly higher incidence of post-op DI (57.1% vs 28.7%; p = 0.021), while similar correlation was not noticed with SIADH (4.7 vs 7.8%). CONCLUSION: TCS plays a distinct, albeit a small role in surgical management of pituitary adenoma. Tumour related or approach related factors are not significantly associated with the incidence of hematoma. Post-operative hematoma significantly influences the incidence of DI. A proper and judicious selection of approach and meticulous surgical technique should result in a reduction in associated morbidity and mortality.

Dual/double pathology in neurocysticercosis causing drug resistant epilepsy - Chance association or causal?

INTRODUCTION: Neurocysticercosis (NCC) as cause of drug resistant epilepsy (DRE) is commonly reported from India. We reviewed the neuropathological findings in patients undergoing resective surgery for DRE due to NCC, to determine the pathomechanism of epileptogenesis. METHODS: Clinical, demographic and neuropathological findings of histologically confirmed cases of NCC causing DRE between 2005-2019 were reviewed. NeuN, GFAP, phosphorylated neurofilament, vimentin, CD34 for glial/ neuronal alterations, and Masson trichrome, Luxol Fast blue for evidence of fibrosis/ demyelination was used to determine cause of epileptogenesis. RESULTS: There were 12 cases of NCC associated with dual/ double pathology, which constituted 3.02 % (12/398) of all the operated DRE. [Age range: 17-37y, Male:Female = 1.4:1]. Seizure duration ranged from 3-32y, with seizure onset between 4-27y. On MRI, lesions were of variable signal intensity on T1 and isointense on T2 with blooming on GRE/ SWI, and CT revealed calcification. Majority (11/12) had associated hippocampal sclerosis (HS) type 1 (dual pathology), localised to the same side as cysticercal cyst, suggesting it may be involved in the pathogenesis of HS. Ten had single cysticercal lesion involving ipsilateral hippocampus in 6, parahippocampal gyrus in 2, amygdala and temporal lobe in 1 case each. One had multiple NCC located in bilateral frontal, parietal and ipsilateral hippocampus. Adjacent cortex around the NCC evaluated in 6 cases, revealed inflammation, gliosis, axonal disruption/ beading, and variable synaptic/ neuronal dystrophic changes. There was a single case of NCC with Focal cortical dysplasia (FCD) type IIb (double pathology). In 11/12 cases Engel's post-surgery outcome was available with all having class I outcome. CONCLUSION: HS was most common pathology associated with cysticercosis (Dual pathology), localised ipsilateral to the cysticercal cyst, suggesting that HS is a secondary/ epiphenomenon. Perilesional changes such as inflammation, gliosis, dystrophic synaptic and axonal pathology play a role in inducing or perpetuating the epileptiform activity. The association of FCD IIb with NCC in one case is likely to be a chance occurrence.

Endoscopic intervention for intraventricular neurocysticercal cyst: Challenges and outcome analysis from a single institute experience.

OBJECTIVE: Endoscopic intervention is presently proposed as standard approach for the treatment of Intraventricular neurocysticercal cyst (IVNCC) as it helps to retrieve the cyst as well as CSF diversion. We present our series of 61 patients with IVNCC managed by endoscopic intervention and analyze the outcome. METHOD: A retrospective analysis of 61 patients with IVNCC managed between 1998-2019 at our institute was performed. We reviewed the clinical details of consecutive patients, management, and outcome. RESULTS: There were 61 patients with 34 males and 27 females. The mean age was 25 years. Fourth ventricular location is the most common (n = 34) followed by third ventricle(n = 14) and lateral ventricle (n = 13). Cyst retrieval could be done in 43 cases, while the cyst could not be retrieved in 18 cases due to intraventricular bleed, CSF turbidity, adhesion of cyst wall etc. Along with cyst retrieval, some patients underwent Endoscopic Third ventriculostomy, septostomy, foraminotomy for internal CSF diversion. Seven patients had a preoperative VP shunt surgery. The median follow-up was 12 months. Preoperative shunt (CI:1.33-62, P = 0.02) was associated with failure of cyst retrieval in univariate analysis as well as in multivariate regression analysis (CI: 0.02-0.94, P = 0.04). Two patients underwent shunt surgery at follow-up period due to the failure of endoscopic CSF diversion. CONCLUSION: Endoscopic management of IVNCC is a safe and effective management option, avoiding an indwelling shunt system. Endoscopic third ventriculostomy should be considered for patients with IVNCC and hydrocephalus.

Schwannoma of the Greater Superficial Petrosal Nerve: An Unusual Site for a Common Tumor.

Greater superficial petrosal nerve (GSPN) schwannoma is a rare clinical entity. It forms a small subset of the larger group of facial nerve schwannomas. A thorough literature search yielded only 27 such cases reported to date in the English literature. We present one such rare case of GSPN schwannoma and discuss the clinical spectrum and management along with a review of the literature. We demonstrate the surgical steps in an operative video.