Predicting seizure outcomes and functional outcomes after hemispherotomy: are we any better?

INTRODUCTION: Present study attempted to analyze seizure freedom and detailed functional outcomes after functional hemispherotomy and utility of hemispherotomy outcome prediction scale (HOPS) scores in predicting outcomes. METHODS: Patients who underwent functional hemispherotomy were analyzed for clinical presentation, neuroimaging, seizure outcomes, and functional outcomes. RESULTS: A total of 76 procedures were performed on 69 patients. Mean age at the surgery was 8 ± 6.1 years. Fourteen patients were < 2 years. Age of onset epilepsy of the cohort was 2.0 ± 3.3 years. All had severe catastrophic epilepsy with multiple daily seizures. All patients had motor deficits with 36 (52%) patients had contralateral dysfunctional hand. Perinatal stroke (49%) was most common substrate followed by cortical malformations (21.7%). Eight patients had contralateral imaging abnormalities. Fifty-nine (86.76%) patients remained seizure free (Engle 1a) at 41 + -20.9 months. HOPS scores were available for 53 patients and lowest seizure outcome was 71% for HOPS score of 4. Lower HOPS scores predicted better seizure outcomes. Cortical malformations operated earlier than 2 years predicted poor seizure outcomes (66.6%). Positive functional outcomes are recorded in 80% of patients with 78% reporting improvement from the pre-surgical level. Five (7.2%) patients underwent shunt surgery. One mortality recorded. CONCLUSIONS: Hemispherotomy has excellent seizure outcomes. Early surgery in cortical malformations appears to be predictor of poorer seizure outcomes. HOPS score is a good tool to predict the seizure outcomes. Hemispherotomy is perceived to improve the Cognitive and functional performance.

Temporal encephalocele: a rare but treatable cause of temporal lobe epilepsy

Objective: Although rare, temporal encephalocele is an important causative agent in surgically remediable drug-refractory epilepsy. The ideal treatment for temporal encephalocele remains unclear with a variety of resective surgeries recommended. Here, we analyse patient data on temporal encephalocele with a view to highlighting diagnostic clues and management strategies. Methods: Comprehensive databases at Deenanath Mangeshkar Hospital, Pune from January 2015 to June 2019 were reviewed for this observational study. Of 107 temporal lobe epilepsy surgery patients, nine individuals with temporal encephalocele were identified, who formed the study cohort. Their clinical, neuropsychological, EEG, imaging and long-term outcome data were analysed. Results: The study cohort consisted of seven males and two females with a mean age of 22 years. Epilepsy onset age varied from 4.5 to 19 years. Seven patients had focal non-motor seizures with impaired awareness, while two patients had focal motor seizures. Temporal encephalocele detection by MRI was reported in only two patients, and was missed in seven individuals. Three patients underwent standard anterior temporal lobectomy while the remaining six underwent resection of the temporal encephalocele with surrounding temporal pole. Eight patients showed Engel Class I outcome and one showed Class IIa outcome after a mean follow-up duration of 27 months (17-44 months). Histopathology confirmed gliosis in seven, hippocampal sclerosis type I in one and suspicious dyslamination with prominent gliosis in one patient. Six of eight patients reported an improvement in their psychological state (mood, anxiety and motivation) over time. Significance: A careful review of MRI in patients with temporal lobe epilepsy is necessary, followed by investigations for the presence of an encephalocele. When temporal lobe epilepsy is associated with encephalocele, tailored resection of the encephalocele and the surrounding temporal pole, sparing mesial temporal structures, demonstrates excellent long-term clinical and neuropsychological outcome.

Rituximab in Rasmussen's encephalitis: A single center experience and review of the literature.

Rasmussen's encephalitis (RE) is a rare chronic inflammatory disease of the brain resulting in unilateral hemispheric atrophy with drug-resistant focal epilepsy associated with a variable degree of progressive hemiparesis and cognitive decline. The precise etiology of RE is unknown but presumed to have a neuroinflammatory pathobiological basis. Only surgery halts progression of the disease, but may occur at the expense of a fixed but otherwise inevitable neurological deficit. Therefore, the question of medical management is an important consideration. Reports of rituximab use in patients with RE were presented at the American Epilepsy Society annual meeting in 2008. Good published evidence for its usage has been very slow to emerge since then. However, rituximab continues to be listed in discussions of treatment options for patients with RE, though other monoclonal antibodies have since been used with comparable outcomes. We describe a series of nine patients including two with adult-onset RE. Rituximab was used early in the disease course (range 1-108 months; mean 32 months). Of nine patients with RE, there was significant benefit in their seizure burden with rituxamab. Seizure freedom occurred in 3 patients. Epilepsia partialis continua (EPC) was present in 4/9 and no focal motor deficit noted in 4/9. No progression of a neurological deficit was present in 2/9 and evidence of progression with neuroimaging was terminated with rituxamab in 5/9 supporting early use of rituxamab in patients with RE.

Evaluation of periprocedural anxiety during Gamma Knife radiosurgery (GKRS) frame fixation for brain lesions.

INTRODUCTION: Application of stereotaxy frame for gamma knife under local anesthesia creates anxiety and phobia in many patients. Vasovagal syncopal attacks and events of bradycardia are not infrequently seen. We tried to analyse the various factors affecting these events and set standards and safety recommendations for the procedure. MATERIALS AND METHODS: This prospective study was carried out in Gamma Knife Centre, AIIMS, New Delhi over a 6 month period between June, 2021- November, 2021. All patients coming to Gamma knife for various etiologies were asked to fill Hamilton Anxiety Rating Scale (HAM-A) before frame application. Baseline pulse rate was evaluated and with every pin application pulse rate was recorded. A VAS (visual analogue scale) for pain was also administered after the procedure. Twenty percent fall in pulse rate were considered as significant bradycardia. Intraprocedural syncopal events were also recorded. RESULTS: A total of 141 patients were studied of which 6% patients had intraprocedural syncopal attacks requiring medical treatment while 32% patients had bradycardia. Having previous surgery, having breakfast before the procedure, duration of pin application, quantity of local anaesthetia, primary diagnosis, sex of patients were not found to alter the syncope or bradycardia events. Patients who were found anxious (score > 18 on HAM-A) had a significantly higher risk of having a procedural event. Previous history of syncope was also associated with 1.7 times more chances of developing Intraprocedural bradycardia. CONCLUSIONS: Frame application for gamma-knife is a relatively safe procedure however procedure rooms should be equipped with emergency drugs and fluids for management of syncope. A Simple anxiety questionnaire can predict 'at risk' patients' for procedural events.

Clinical profile and outcomes of epilepsy surgery in children from a tertiary epilepsy care center in India.

INTRODUCTION: The present study aims to describe epilepsy surgery outcomes in the pediatric population from a tertiary center in India. METHODOLOGY: Children less than 18 years who underwent epilepsy surgery between June 2015 and December 2019 for whom at least a 1-year follow-up was available, were retrospectively evaluated for clinical presentation, radiology, surgical intervention, and seizure outcomes. OBSERVATIONS: Out of a total of 355 epilepsy surgeries performed, 242 were in the pediatric group (140 males, 80 females). The mean age at surgery was 9.4 years ±4.8 years (range 4 months-18 years). The mean duration of epilepsy was 5.64 years ±3.91 (range 2 months-17 years). 126 patients experienced daily seizures, 45 weekly and 39 reported monthly seizures. Six had refractory status epilepticus. All the patients were on multiple anti-epileptic drugs (AEDs): the mean number of AEDs was 3.27 ± 0.98 (range 2-7 AEDs). Focal seizure was the most common seizure type seen in 72.27% of children (159/220). The most frequent etiology was focal cortical dysplasia (70), followed by bilateral parieto-temporo-occipital gliosis (48). All the patients underwent standard pre-surgical evaluation. Eleven patients needed stage 2 evaluation (intracranial EEG). The different surgeries performed were electrocorticography (ECOG) and navigation-guided resection (65), anterior temporal lobectomy and hippocampectomy (ATLAH) (48), functional hemispherotomy (39), callosotomy (28), disconnection surgeries (16), and multilobar resection (12). Twelve patients underwent more than one surgery. The patients were followed up between a minimum of 12 months and a maximum of 66 months (median 32 months; IQR 20 months). Engel class 1 outcome was observed in 81.38% in definitive surgeries. Outcomes of temporal lobe (TL) surgeries (92.3%) were better compared to hemispheric (87.17%) and extratemporal lobe (ETL) surgeries (75.32%). We encountered unexpected transient motor deficits in 2 patients and culture-proven meningitis in 8 patients. Post-surgery drug freedom (P-value 0.003) was the most important factor for better developmental, cognitive and behavioral outcomes. CONCLUSION: Epilepsy surgeries are safe and seizure outcomes are excellent in properly selected cases with thorough presurgical evaluation. Early referral to a tertiary epilepsy center is needed for timely intervention.

Role of epilepsy surgery in refractory status epilepticus in children.

INTRODUCTION: Status epilepticus (SE) is one of the most common medical emergencies, requiring urgent treatment; nearly 30 % patients develop refractory SE. The role of epilepsy surgery (ES) for refractory SE however remains unclear with empirical evidence limited to single case reports and small case series. The aim of the present study was to determine the clinical presentation, imaging characteristics and outcome of children with refractory SE who underwent emergency ES for refractory SE. MATERIAL AND METHOD: Patients who had SE, failed to respond to escalating medical treatment of SE with/ without pharmacological suppression therapy, and eventually underwent ES were included. RESULTS: There were ten children, 7 boys and 3 girls (range 6 months to 14 years). The age of onset of epilepsy varied from day 2 of life to 12.8 years. The duration of SE prior to surgery was 2-6 days (mean 3.7 days). Four patients had hemimegalencephaly, 3 had focal cortical dysplasia, 2 had Rasmussen's encephalitis, and one had hemispheric porencephalic cyst. The time interval between onset of seizures and ES ranged from 2 months to 8 years (mean 3.1 year). Seven patients underwent hemispherotomy, resection of dysplasia in two and temporo-parieto-occipital disconnection in one. Nine had Engel I outcome and Engel IIIa in one, at follow up of 12-44 months (mean 31 months). CONCLUSION: Emergency ES is an effective treatment option for termination of refractory SE in children with structural pathology, after failure of medical treatment. Patients with refractory SE with focal or hemispheric structural abnormality on MRI, and concordant semiology with/without concordant EEG can be surgical candidates with or without invasive monitoring.

Surgical outcomes for medically refractory epilepsy secondary to posterior cortex ulegyria as sequelae of perinatal insults.

BACKGROUND: To study surgical outcomes in pharmaco-resistant epilepsy associated with posterior cortex ulegyria secondary to perinatal insults. METHODS: A cohort was analysed for clinico-radiological charectaristics, surgical interventions and seizure outcomes. OBSERVATIONS: A total of 38 patients underwent surgery, divided as group A - curative surgeries (n = 20) and group B - palliative surgeries (n = 18). Mean age of onset of epilepsy in group A was 5.2 ± 3.4 years against 2.7 ± 2.4 years in group B (p < 0.01). Electroclinical Lennox Gastaut Syndrome was encountered in 9/20 patients in group A, against all 18 patients in group B. Disabling reflex epilepsy was seen in 10 (26 %) patients. Interictal electrophysiology localized in the posterior cortex in all patients in group A, but ictal onsets contributed in only 7/20 patients. Nine patients from group A had unilateral parieto-occipital ulegyria while bilateral in 11/20 patients, and 16/18 from group B. Group A patients underwent parieto-occipital resection (n = 10) and temporo-parieto-occipital disconnection (n = 10) while group B underwent complete corpus callosotomy (n = 18). In group A, Engel Ia outcome was achieved in 15/20 patients (75 %) at mean follow up of 23.5 ± 7.9 months. Group B patients experienced cessation of head drops in all 18 patients, with two-third reduction in seizure frequency at 29.2± 12.4 months of mean follow up. Reflex seizures responded completely in both groups. CONCLUSIONS: Epilepsy surgeries for posterior cortex ulegyria results in excellent seizure outcomes. Corpus callosotomy appears highly effective as a palliation for head drop as well as disabling reflex seizures in a well selected cohort.

Failed Hemispherotomy: Insights from Our Early Experience in 40 Patients.

OBJECTIVE: To study the factors responsible for failure of hemispherotomy and outcomes of revision surgery. The effect of the surgeon's learning curve on failures was also analyzed. METHODS: Forty consecutive patients, who underwent functional hemispherotomy through a 4-year period, from the inception of the single-surgeon epilepsy surgery program, were analyzed. RESULTS: A total of 47 functional hemispherotomies were performed in the study period in 40 patients (7 revision surgeries on 6 patients). Mean age of the cohort was 9.45 ± 14.84 years and it included 7 infants (<2 years). Of the 9 patients (23.5%) who failed the first procedure, 6 qualified for revision surgery, all of whom belonged to the cohort of the first 15 patients treated during the first 2 years of the program. Hemimegalencephaly was the most common disease (n = 4). Ipsilateral temporal stem (n = 3), frontobasal connections (n = 2), splenium of corpus callosum (n = 2), and posterior insula (n = 2) were residual undisconnected substrates identified for revision on imaging. The substrates for failure were obvious in 5/6 patients and resulted from incomplete disconnection, implying surgical inadequacy. At the mean follow-up of 30 ± 13.17 months (range, 13-55 months), 35 of 40 patients (87.5%) remained seizure free (Engel class Ia), including 4/6 patients who underwent redo surgery. Revision did not benefit the remaining 2 patients (Engel class III). There was no mortality. CONCLUSIONS: Surgical revision is more common in hemimegalencephaly and in the early days of a surgical program. Affirmative neuroimaging improves the outcomes of subsequent revision surgery.

Frontal lobe epilepsy with focal neuronal lipofuscinosis - Case report of a rare entity.

Focal neuronal lipofuscinosis is a unique neuronal pathology, characterised by accumulation of lipofuscin within dysmorphic neurons. We report a case of 12-year-old female with drug resistant epilepsy since one and a half years of age. MRI brain showed right frontal dysplasia, and PET showed right frontal hypometabolism. She underwent electrocorticography-guided resection of the lesion. Histopathology revealed cortical dyslamination with several hypertrophic dysmorphic neurons showing intracytoplasmic granular accumulation of lipofuscin which was positive for Periodic acid-Schiff, Luxol fast blue, and autofluorescent. Ultrastructural examination revealed intracytoplasmic, non-membrane bound, electron dense material with characteristics of lipofuscin filling the neuronal soma. On immunohistochemistry, the neurons showed ring-like non-phosphorylated and phosphorylated neurofilaments enveloping the lipofuscin material, few being positive for ubiquitin. It is important to be aware of this rare entity as it can be associated with family history of seizures and has a distinct pathobiology.

Valproic acid as an antiepileptic drug: Is there a clinical relevance for the epilepsy surgeon?

Valproic acid (VPA) has been associated with coagulation factors deficiency, platelet dysfunction and hemorrhagic complications. We investigated 169 patients with drug resistant epilepsy (DRE), who underwent surgery, to look for clinical implications of VPA associated bleeding problems. All patients had normal preoperative coagulation profile. VPA was a part of polytherapy in 54% of patients (Group A), however 46% patients were not on VPA (Group B). The groups were comparable with mean age of 17.3±10.3years. Mean duration of surgery in group A and B were 255±70 and 250±60min respectively (p=0.26). Average blood loss in group A was 399±254 and 389±228ml in group B. (p=0.62). The percentage of total blood volume lost was 12.7% (Group A) and 17.7% (Group B) respectively (p=0.7). There were no bleeding complications in either group. Hyperammonemic encephalopathy occurred in 4 patients postoperateively requiring withdrawal or dose reduction of VPA. No mortality was recorded. We conclude that VPA does not increase clinically relevant perioperative haemorrhagic complications in patients having normal coagulation screen and platelet counts. However, hyperammonemic encephalopathy is observed in 4% of patients in perioperative period, favorably responding to discontinuation of VPA.

Leukocytosis after routine cranial surgery: A potential marker for brain damage in intracranial surgery.

AIMS AND OBJECTIVES: Leukocytosis after intracranial surgery may create concern about possible infection, especially when associated with fever. Knowledge of the expected degree of leukocytosis after surgery would assist in the interpretation of leukocytosis. It was hypothesized that the degree of leukocytosis after intracranial surgery correlated with the extent of brain damage inflicted during the surgery. MATERIALS AND METHODS: In this prospective study conducted over 6 months, consecutive patients undergoing either elective resections of brain tumors (having significant collateral brain damage) or aneurysm clipping (with minimal collateral brain damage) were studied. Total blood leukocyte count was checked daily in the morning for the first five postoperative days in both the groups. The mean of the leukocyte count ratio (postoperative leukocyte count/preoperative leukocyte count) on each day was calculated for each group. RESULTS: There were 76 patients, 46 in the test group and 30 controls. Both groups were well matched in age, sex, duration of surgery, and intraoperative fluid balance. The mean leukocyte count ratio on POD1 in the tumor group was significantly higher (1.87) as compared to 1.1 in the aneurysm group (P = 0.001). This difference in the leukocyte count ratio between the groups was maintained on the second and third postoperative days, with decreasing level of significance after the third day. CONCLUSIONS: This study shows that intraoperative brain injury is associated with leukocytosis in the immediate postoperative period. This can assist in the interpretation of leukocytosis after intracranial surgeries and could be a quantitative marker for brain injury in patients undergoing intracranial surgery.

Endoscopic-Assisted (Through a Mini Craniotomy) Corpus Callosotomy Combined With Anterior, Hippocampal, and Posterior Commissurotomy in Lennox-Gastaut Syndrome: A Pilot Study to Establish Its Safety and Efficacy.

BACKGROUND: Corpus callosotomy is a palliative procedure especially for Lennox-Gastaut semiology without localization with drop attacks. OBJECTIVE: To describe endoscopic-assisted complete corpus callosotomy combined with anterior, hippocampal, and posterior commissurotomy. METHODS: Patients with drug refractory epilepsy having drop attacks as the predominant seizure type, bilateral abnormalities on imaging, and moderate to severe mental retardation were included. All underwent a complete workup (including magnetic resonance imaging). RESULTS: Patients (n = 16, mean age 11.4 ± 6.4 years, range 6-19 years) had a mean seizure frequency of 24.5 ± 19.8/days (range 1-60) and a mean intelligence quotient of 25.23 ± 10.71. All had syndromic diagnosis of Lennox-Gastaut syndrome, with the following etiologies: hypoxic insult (10), lissencephaly (2), bilateral band heterotropia (2), and microgyria and pachygyria (2). Surgery included complete callosotomy and the section of anterior and posterior commissure by microscopic approach through a mini craniotomy (11) and endoscopic-assisted approach (5). Complications included meningitis (1), hyperammonemic encephalopathy (2), and acute transient disconnection (5). There was no mortality or long-term morbidity. Mean follow-up was 18 ± 4.7 months (range 16-27 months). Drop attacks stopped in all. Seizure frequency/duration decreased >90% in 10 patients and >50% in 5 patients, and increased in 1 patient. All patients attained presurgical functional levels in 3 to 6 months. Child behavior checklist scores showed no deterioration. Parental questionnaires reported 90% satisfaction attributed to the control of drop attacks. The series was compared retrospectively with an age/sex-matched cohort (where a callosotomy only was performed), and showed better outcome for drop attacks (P < .003). CONCLUSION: This preliminary study demonstrated the efficacy and safety of complete callosotomy with anterior, hippocampal, and posterior commissurotomy in Lennox-Gastaut syndrome (drop attacks) with moderate to severe mental retardation.

Intraventricular Gangliogliomas: A Review.

OBJECTIVE: Gangliogliomas (GG) are benign, primary neoplasms most commonly noted in young adults. Intraventricular location is rare. We report a case of a multicentric intraventricular GG posing diagnostic and therapeutic challenges and in addition provide a detailed literature review of intraventricular GG. METHODS: A 15-year-old girl presented with features of raised intracranial pressure of short duration. Imaging revealed 2 separate lesions situated in the anterior and posterior third ventricle with hydrocephalus. The patient underwent ventriculoperitoneal shunt insertion, followed by excision of lesions in 2 stages. Both specimens revealed features of GG and the patient had an uneventful recovery. For the literature review, only pure intraventricular GG were included and intraventricular extensions of paraventricular/extraventricular GG were not considered. A brief comparison of clinicoradiologic characteristics between intraventricular and parenchymal GG is provided. RESULTS: Including ours, 21 cases were identified. Male/female ratio was 1.3:1. Peak age of occurrence was the third to fourth decade. Features of increased intracranial pressure were the most common presenting features and seizures were noted in one quarter of cases. Gross total resection was achieved in 90% and recurrences and mortality were noted in 10% each. CONCLUSIONS: Intraventricular GG are rare tumors. Complete surgical excision achieves excellent results. The role of adjuvant therapy is controversial.

Role of bone marrow derived pluripotent stem cells in peripheral nerve repair in adult rats: A morphometric evaluation.

OBJECTIVES: Semi-quantitative and quantitative assessment of the effect of bone marrow-derived mononuclear cells (BM-MNC) on early and late phase of nerve regeneration in rat sciatic nerve model. MATERIALS AND METHODS: Sciatic nerve transection and repair was performed in 50 inbred female Wistar albino rats divided equally in two groups. In the test group the gap was filled with BM-MNCs obtained from the two male rats and fibrin sealant, while in the control group only fibrin sealant was used. Sciatic nerve was harvested at 15 days and at 60 days interval. Parameters of regeneration were assessed at anastomosis (G), intermediate distal (C), and distal site (A). Semi-quantitative (histopathological) and quantitative (morphometric) parameters were analyzed. RESULTS: At 15 days there was a statistically significant difference found in mean axon diameter, mean nerve thickness and myelin thickness at the repair site (P < 0.05). However, in the distal areas, the axons were sparse and myelin rings were very thin in both the groups. At 60 days, the difference in above-mentioned parameters was statistically significant at the distal most sites. FISH assay confirmed the presence of Y chromosome, confirming the presence of BM-MNCs from the male rats. CONCLUSIONS: Transplanting BM-MNCS at the site of peripheral nerve injury leads to significantly better recovery. These differences were evident at the repair site and at the intermediate distal site at 15 days and at the distal most sites at 60 days. With practically no ethical issue regarding their isolation and application, they can be easily used for clinical trials.

Impact of intraoperative MRI on outcomes in epilepsy surgery: preliminary experience of two years.

PURPOSE: To determine the impact of intraoperative magnetic resonance imaging (iMRI) in epilepsy surgeries on the extent of surgical resection and seizure outcome along with its feasibility and limitations. METHODS: Patients with pharmacoresistant epilepsy (PRE), who underwent surgeries in operating theater equipped with high-field 1.5-Tesla MRI, were evaluated for extent of resection, operative time, scanning time, pathologies, resultant extra resection, and seizure outcomes. RESULTS: Thirty-nine patients with mean age of 18 (range: 3-65) years with PRE underwent surgical intervention. Mean duration of epilepsy was 10.2 years. Surgical interventions included tumor resection (31%), resection of focal cortical dysplasia (28%), mesial temporal lobe surgeries (18%), and disconnection surgeries (23%). iMRI alone, apart from navigation and electrophysiology, improved resection rates in 13% (5 out of 39) of these patients. In lesional group, iMRI modified operative strategy resulting in increased resections in 21% (5/23) patients. Complete resection was observed in 87% of patients. iMRI scanning time constituted 25% (mean: 72 ± 21 min) of time spent under anesthesia by the patient. Major and minor complications were observed in 2.5% and 7.5% of patients, respectively. The mean follow-up was 14 months. Favorable postoperative seizure control (Engel Classes I and II) was achieved in 85% and complete seizure freedom was achieved in 77% of patients (Engel Class IA) at 1-year follow-up. CONCLUSIONS: iMRI increases the extent of resection mainly in lesional epilepsy surgeries translating into good seizure outcomes but not found to be much beneficial in prototype mesial temporal sclerosis surgeries and disconnection surgeries.

Endoscopy-assisted interhemispheric transcallosal hemispherotomy: preliminary description of a novel technique.

BACKGROUND: Various hemispherotomy techniques have been developed to reduce complication rates and achieve the best possible seizure control. OBJECTIVE: To present a novel and minimally invasive endoscopy-assisted approach to perform this procedure. METHODS: Endoscopy-assisted interhemispheric transcallosal hemispherotomy was performed in 5 children (April 2013-June 2014). The procedure consisted of performing a small craniotomy (4 × 3 cm) just lateral to midline using a transverse skin incision. After dural opening, the surgery was performed with the assistance of a rigid high-definition endoscope, and bayoneted self-irrigating bipolar forceps and other standard endoscopic instruments. Steps included a complete corpus callosotomy followed by the disconnection of the hemisphere at the level of the basal nuclei and thalamus. The surgeries were performed in a dedicated operating room with intraoperative magnetic resonance imaging and neuronavigation. Intraoperative magnetic resonance imaging confirmed a total disconnection. RESULTS: The pathologies for which surgeries were performed included sequelae of middle a cerebral artery infarct (n = 2), Rasmussen syndrome (n = 1), and hemimegalencephaly (2). Four patients had an Engel class I and 1 patient had a class II outcome at a mean follow-up of 10.2 months (range, 3-14 months). The mean blood loss was 80 mL, and mean operating time was 220 minutes. There were no complications in this study. CONCLUSION: This study describes a pilot novel technique and the feasibility of performing a minimally invasive, endoscopy-assisted hemispherotomy.

Epileptogenic networks and drug-resistant epilepsy: Present and future perspectives of epilepsy research-Utility for the epileptologist and the epilepsy surgeon.

A multidisciplinary approach is required to understand the complex intricacies of drug-resistant epilepsy (DRE). A challenge that neurosurgeons across the world face is accurate localization of epileptogenic zone. A significant number of patients who have undergone resective brain surgery for epilepsy still continue to have seizures. The reason behind this therapy resistance still eludes us. Thus to develop a cure for the difficult to treat epilepsy, we need to comprehensively study epileptogenesis. Till date, most of the studies on DRE is focused on undermining the abnormal functioning of receptors involved in synaptic transmission and reduced levels of antiepileptic drugs around there targets. But recent advances in imaging and electrophysiological techniques have suggested the role epileptogenic networks in the process of epileptogenesis. According to this hypothesis, the local neurons recruit distant neurons through complex oscillatory circuits, which further recruit more distant neurons, thereby generating a hypersynchronus neuronal activity. The epileptogenic networks may be confined to the lesion or could propagate to distant focus. The success of surgery depends on the precision by which the epileptogenic network is determined while planning a surgical intervention. Here, we summarize various modalities of electrophysiological and imaging techniques to determine the functionally active epileptogenic networks. We also review evidence pertaining to the proposed role of epileptogenic network in abnormal synaptic transmission which is one of the major causes of epileptiform activity. Elucidation of current concepts in regulation of synaptic transmission by networks will help develop therapies for epilepsy cases that cannot be managed pharmacologically.

Extended costotransversectomy to achieve circumferential fusion for pathologies causing thoracic instability.

BACKGROUND CONTEXT: Conventional circumferential stabilization for pathologies causing instability of the thoracic spine requires a two or even a three-staged procedure. The authors present their tertiary care center experience of single-staged procedure to establish a circumferential fusion through an extended costotransversectomy approach. OBJECTIVE: To demonstrate neural canal decompression, removal of the pathology, achieve circumferential fusion, and correcting the deformity through a single procedure. STUDY DESIGN: Prospective and observational. PATIENT SAMPLE: Forty-six patients with pan thoracic column instability due to various pathologies. OUTCOME MEASURES: Neurologic condition was evaluated using American Spinal Injury Association and Eastern Cooperative Oncology Group grading systems. Outcome was evaluated with regard to the decompression of neural canal, correction of deformity, and neurologic improvement. All patients were evaluated for neural canal compromise and degree of kyphosis preoperatively, early, and late postoperatively. METHODS: All patients had severe spinal canal compromise (mean, 59%±9%) and loss of vertebral body height (mean, 55%±10%). A single-stage circumferential fusion was performed (four-level pedicle screw fixation along with a ventral cage fixation after a vertebrectomy or corpectomy) through an extended costotransversectomy approach. RESULTS: The pathologies included trauma (21), tuberculosis (18), hemangioma (2), aneurysmal bone cyst (1), recurrent hemangioendothelioma (1), solitary metastasis (1) and plasmacytoma (1), and neurofibromatosis (1). Thirty-five of 46 patients (76%) demonstrated improvement in the performance status. The major complications included pneumonitis (3), pneumothorax (3) and neurologic deterioration (3; improved in two), deep venous thrombosis (2), and recurrent hemoptysis (1). No implant failures were noted on last radiology follow-up. There were two mortalities; one because of myocardial infarction and another because of respiratory complications. CONCLUSIONS: The following study demonstrated that extended costotrasversectomy approach is a good option for achieving single-staged circumferential fusion for correcting unstable thoracic spine due to both traumatic and nontraumatic pathologies.

Suprasellar dermoid cyst associated with colloid cyst of the third ventricle: Disordered embryogenesis or a mere coincidence?

Intracranial dermoid cyst and colloid cysts of the third ventricle are rare benign congenital lesions of early adulthood. Both lesions are thought to be congenital in origin however association is rare. Only one case of this association has been reported. We report a 22-year-old male with suprasellar dermoid cyst and colloid cyst of the third ventricle presenting simultaneously. Embryogenesis of this association has been discussed.

Post operative pituitary apoplexy: preoperative considerations toward preventing nightmare.

INTRODUCTION: Post operative pituitary apoplexy after partial resection of a giant pituitary adenoma is mostly fatal, despite early and best management. Pathophysiology, clinical presentation and preoperative consideration toward prevention of apoplexy are discussed. MATERIAL AND METHODS: Patients with post operative pituitary apoplexy were critically reviewed for clinical presentation, endocrine status, preoperative imaging and post operative course with outcome. Operative findings and histopathology were correlated. RESULTS: Thirteen patients over 11 years with a mean age of 36 years were reviewed. All patients had giant pituitary adenomas. Four patients had functional adenomas. All patients were optimized for endocrine status before surgery. Twelve patients underwent transsphenoidal excision of the tumor. Only partial excision could be achieved in all cases. Deterioration of consciousness (9), visual deterioration (3), delayed reversal and excessive bleeding (1) were the primary indicators toward apoplexy. Ten patients were reexplored within 24 h of first surgery. All except one were explored transcranially a second time. Twelve patients died with variable post operative course. Hypothalamic dysfunction and dyselectolytemia (9) were leading causes of death, followed by meningitis and raised intracranial pressure. CONCLUSIONS: Post operative pituitary apoplexy is associated with high mortality, despite early and best management. Partial resection of the giant pituitary adenoma is directly responsible for post operative apoplexy. Maximum possible resection of the tumor by suitable exposure should be the optimal goal of surgery. Surgical exposure, either transcranial or transsphenoidal, should be dictated by tumor configuration on preoperative imaging. Endocrine status, histology of the tumor and clinical presentation do not appear to contribute to post operative pituitary apoplexy.