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Background Hemispherectomy has an established role as a treatment of last resort in patients with unilateral hemispheric lesions suffering from refractory epilepsy. Methods Seven patients were evaluated at our Epilepsy Unit. We compared the seizure outcome at 6 months, 1, 2, 5 years post-surgery, as well as at end follow-up (mean 7.1 years) using Engel classification. Reduction of antiepileptic drugs (AEDs) was also assessed utilizing equal time frames. Results The mean age of seizure onset was 5.4 years. Engel I was achieved in 5 patients at 6 months (71.4%). Engel at 1 year was predicted by the Engel at 6 months (p = 0.013) with a similar number of patients being classified as Engel I outcome. Engel at 2 years was also predicted by Engel at 6 months and at 1 year (p = 0.030). At end follow-up only 3 patients (42.9%) remained categorized as Engel I outcome. There was a trend toward a stability in Engel classification. All patients with developmental causes for their epilepsy experienced some deterioration of the surgical outcomes. Conversely, all patients with acquired causes were stable throughout follow-up. Seizure outcome at 6 months was worse in the patients who had post-op complications (p = 0.044). Adult and pediatric populations did not differ significantly in any tested variable. Conclusions Hemispherectomy is a valuable resource for seizure control in properly selected patients. Engel patient's evolution could be predicted at 6 months interval. Hemispherectomy could be considered a useful attitude in difficult cases.

Neuronal remodeling after brain injury is essential for functional recovery. After unilateral cortical lesion, axons from the intact cortex ectopically project to the denervated midbrain, but the molecular mechanisms remain largely unknown. To address this issue, we examined gene expression profiles in denervated and intact mouse midbrains after hemispherectomy at early developmental stages using mice of either sex, when ectopic contralateral projection occurs robustly. The analysis showed that various axon growth-related genes were upregulated in the denervated midbrain, and most of these genes are reportedly expressed by glial cells. To identify the underlying molecules, the receptors for candidate upregulated molecules were knocked out in layer 5 projection neurons in the intact cortex, using the CRISPR/Cas9-mediated method, and axonal projection from the knocked-out cortical neurons was examined after hemispherectomy. We found that the ectopic projection was significantly reduced when integrin subunit β three or neurotrophic receptor tyrosine kinase 2 (also known as TrkB) was knocked out. Overall, the present study suggests that denervated midbrain-derived glial factors contribute to lesion-induced remodeling of the cortico-mesencephalic projection via these receptors.SIGNIFICANCE STATEMENTAfter brain injury, compensatory neural circuits are established that contribute to functional recovery. However, little is known about the intrinsic mechanism that underlies the injury-induced remodeling. We found that after unilateral cortical ablation expression of axon-growth promoting factors is elevated in the denervated midbrain and is involved in the formation of ectopic axonal projection from the intact cortex. Evidence further demonstrated that these factors are expressed by astrocytes and microglia, which are activated in the denervated midbrain. Thus, our present study provides a new insight into the mechanism of lesion-induced axonal remodeling and further therapeutic strategies after brain injury.

Background: Paediatric epilepsy surgery reduces seizure burden in drug-refractory epilepsy reducing long-term neurocognitive damage. Methods: Single-centre retrospective audit of pre-surgical evaluations and outcomes of the paediatric epilepsy and epilepsy surgery programme over eleven years at KK Women’s and Children’s Hospital, Singapore. Data were collected based on National Institute of Neurological Disorders and Stroke Common Data Elements guidelines. Outcome was categorized using Engel classification scale, and favourable outcome defined as greater than 50% decrease in seizure frequency or drop attacks. Results: Thirty-three children underwent epilepsy surgery, with mean follow-up 3.8±3.1 years. Median age at surgery was 10.9 years. Twenty-four children with focal epilepsy underwent resection of the epileptogenic focus, including lesionectomy (n=8), anterior temporal lobectomy (n=7), extratemporal lobectomy (n=7) and hemispherectomy (n=2). Nine children underwent corpus callosotomy for Lennox Gastaut Syndrome (n=8) and West Syndrome (n=1). Median hospital stay duration was ten days. All twenty-three focal epilepsy patients with minimum three-month follow-up achieved greater than 50% seizure reduction. Fifteen (65%) focal epilepsy patients achieved seizure-freedom (Engel Class IA) after first surgeries. Four patients required second surgeries, with two achieving seizure-freedom. Intraoperative MRI (iMRI) is beneficial. All nine corpus callosotomy patients (100%) achieved greater than 50% decrease in drop attacks. Number of antiepileptic drugs was weaned for 21/32 (66%) patients. Post-operative complications were low and some patients had anticipated neurological deficits. Outcomes were comparable to current literature. Conclusions: In well-selected candidates with tailored evaluation, paediatric epilepsy surgery is a safe therapeutic option with favourable outcomes and can be performed across the entire paediatric age range.

Objectives:This research aimed to study the short-term seizure outcomes following treatment with 8 mg/kg/day prednisolone in children with infantile spasms (IS) refractory to vigabatrin. We hypothesized that high-dose prednisolone may result in similar rates of electroclinical remission when compared to published ACTH rates.Methods:All consecutive children with hypsarrhythmia or hypsarrhythmia variant on EEG with/without IS, who had been treated with vigabatrin as first-line anti-seizure medication (ASM) followed by high-dose oral prednisolone (8 mg/kg/day; maximum 60 mg/day) in cases who did not respond to vigabatrin, were included. Clinical and electroclinical response (ECR) at 2 weeks following initiation of treatment and adverse effects were assessed.Results:Sixty-five children were included. A genetic etiology was seen in 38.5% cases. Complete ECR was seen in 30.8% (20/65) of the patients 2 weeks after vigabatrin. Complete ECR was noted in 77.8% (35/45) of the patients, 2 weeks after prednisolone initiation in children who failed vigabatrin, and this was sustained at 6 weeks in 66.7% (30/45) patients. Prednisolone was generally well tolerated.Conclusions:High-dose (8 mg/kg/day) oral prednisolone resulted in sustained complete ECR (at 6 weeks) in two-thirds of the children with hypsarrhythmia or hypsarrhythmia variant on EEG with/without parentally reported IS. It was generally well tolerated and found to be safe.

Purpose To conduct a pilot study to assess the feasibility and effectiveness of an intensive bimanual intervention on upper limb function in children who have undergone hemispherectomy. Methods Thirteen children received 90 hours of intensive bimanual training (Hand-Arm Bimanual Intensive Therapy, HABIT). The Jebsen-Taylor Test of Hand Function (JTTHF), Box and Block Test (BBT), Assisting Hand Assessment (AHA), ABILHAND-Kids, and Canadian Occupational Performance Measure (COPM) were assessed by a masked clinician twice before, immediately, and 6 months after treatment. Results Significant improvements over time were found in the JTTHF, AHA, ABILHAND-Kids, and COPM. Conclusion Completion of HABIT was feasible for children with hemispherectomy. Improvement of bimanual function and functional goals can be related to the nature of the activities prioritized in HABIT training.

Background and Purpose: Refractory epilepsy is when seizures are unresponsive to two or more medications. Hemispherectomy, one of the treatment options, is the complete removal or functional disconnection of a cerebral hemisphere. Hemiparesis, a symptom of epilepsy, is defined as weakness of one side of the body. Patients with refractory epilepsy, who experience extreme seizure frequency, are subjected to hemispherectomy. This study focuses on finding the correlation between hemispherectomy and hemiparesis, discovering a pattern in its severity levels before and after surgery.Methods: Data was collected from 59 epileptic patients suffering from refractory epilepsy, who underwent hemispherectomy, at the King Faisal Specialist Hospital and Research Centre, from 1998 to 2014. Each patient was monitored over a period of 1-year post-surgery. In this study, we wanted to further explore the correlation between hemispherectomy and hemiparesis.Results: Upon analyzing the sample size, the level of hemiparesis pre and post hemispherectomy remained the same for 32 patients, of which 13 patients had mild levels pre-surgery and 19 patients had moderate to severe levels pre-surgery. However, 20 of the patients who had moderate to severe levels of hemiparesis before the surgery had either no hemiparesis or a mild level after surgery, which signified an improvement in their severity level. On the other hand, seven of the patients went from having no hemiparesis before the surgery to having moderate or severe levels of hemiparesis post-surgery. Although the results were clinically significant, they were not statistically significant as the p-value obtained was 0.31.Conclusions: After analyzing the results, it can be concluded that hemispherectomy does decrease the severity of hemiparesis in an epileptic patient, thereby improving his/her quality of life drastically.

Several variations of functional disconnection surgery have been described for the treatment of lateralized, hemispheric, drug-resistant epilepsy in children. The purpose of this study is to investigate the existing literature regarding patient selection, approach, and outcomes after hemispherotomy. A systematic review of the English literature through February 2019 was performed in accordance with the PRISMA statement. The articles were classified by level of evidence and summarized in an evidentiary table. Seizure outcomes, functional outcomes, surgical techniques, complications, and patient selection were critically analyzed. A total of 173 papers were reviewed, of which 37 met criteria of inclusion and exclusion. Thirteen studies were classified as level III evidence, the remaining reached level IV. Vertical and lateral hemispherotomy achieve similar rates of seizure freedom and functional outcomes, though parasagittal and interhemispheric approaches may have shorter operative times and less blood loss. Etiology, bilateral MRI abnormalities, and nonlateralizing EEG did not predict worse seizure or functional outcomes. Both vertical and lateral hemispherotomy approaches result in durable, reproducible benefits to epilepsy severity and functional status in appropriately selected pediatric patients.

Objective To develop and validate a model to predict seizure freedom in children undergoing cerebral hemispheric surgery for the treatment of drug-resistant epilepsy. Methods We analyzed 1267 hemispheric surgeries performed in pediatric participants across 32 centers and 12 countries to identify predictors of seizure freedom at 3 months after surgery. A multivariate logistic regression model was developed based on 70% of the dataset (training set) and validated on 30% of the dataset (validation set). Missing data were handled using multiple imputation techniques. Results Overall, 817 of 1237 (66%) hemispheric surgeries led to seizure freedom (median follow-up = 24 months), and 1050 of 1237 (85%) were seizure-free at 12 months after surgery. A simple regression model containing age at seizure onset, presence of generalized seizure semiology, presence of contralateral 18-fluoro-2-deoxyglucose-positron emission tomography hypometabolism, etiologic substrate, and previous nonhemispheric resective surgery is predictive of seizure freedom (area under the curve = .72). A Hemispheric Surgery Outcome Prediction Scale (HOPS) score was devised that can be used to predict seizure freedom. Significance Children most likely to benefit from hemispheric surgery can be selected and counseled through the implementation of a scale derived from a multiple regression model. Importantly, children who are unlikely to experience seizure control can be spared from the complications and deficits associated with this surgery. The HOPS score is likely to help physicians in clinical decision-making.

Magnetic resonance imaging–guided laser-induced thermal therapy (MRgLITT) is a minimally invasive surgical approach increasingly employed for precise targeted ablation of epileptogenic brain foci. Recent reports have described corpus callosotomy using MRgLITT, though its application in more extensive functional disconnections has not been documented. Here, the authors detail its use in achieving a palliative hemispherotomy in a 5-year-old with medically refractory hemiclonic seizures following a hemispheric infarction, highlighting a novel use of this surgical technique. In this particular case, open craniotomy was deemed high risk given the multiple medical comorbidities including congenital cardiac disease and end-stage renal failure. MRgLITT was considered an alternative approach with a lower risk for periprocedural hemodynamic perturbations. The patient tolerated the procedure well, attaining an Engel class IB outcome at 16 months’ follow-up. This suggests that MRgLITT may be an alternative approach to an open hemispherectomy, particularly in cases in which multiple comorbidities pose significant risks and preclude an open procedure.

ObjectiveTo conduct a systematic review on language outcomes after left and right hemispherectomy in childhood, a surgical procedure that involves removing or disconnecting a cerebral hemisphere.MethodsWe searched MEDLINE, Embase, and PsycInfo for articles published between January 1, 1988, and May 16, 2019. We included (1) all types of observational studies; (2) studies in which hemispherectomy was performed before age 18 years; and (3) studies with standardized scores measuring receptive vocabulary, expressive vocabulary, sentence comprehension, and/or sentence production. We calculated mean z scores after left and right hemispherectomy in the whole group and within etiology-specific subgroups.ResultsOur search identified 1,096 studies, of which 17 were eligible. The cohort added up to 205 individuals (62% left hemispherectomy) assessed 1 to 15 years after surgery. In the left surgery group, all language skills were impaired (z scores z scores ∼ −1.5). Children with cortical dysplasia showed the worst outcomes irrespective of surgery side (z scores ConclusionEvidence based on the largest patient cohort to date (205 participants) suggests that the risk of language impairment after hemispherectomy is high, with few exceptions. Etiology plays a major role in postsurgical plasticity. We recommend specialist evaluation of language skills soon after surgery to identify intervention targets. Large-scale studies examining outcomes in consecutive cases are still needed.

OBJECTIVERasmussen encephalitis (RE) is a rare inflammatory neurological disorder typically involving one hemisphere and resulting in drug-resistant epilepsy and progressive neurological decline. Here, the authors present seizure outcomes in children who underwent epilepsy surgery for RE at a single institution.METHODSThe records of consecutive patients who had undergone epilepsy surgery for RE at the UCLA Mattel Children’s Hospital between 1982 and 2018 were retrospectively reviewed. Basic demographic information, seizure history, procedural notes, and postoperative seizure and functional outcome data were analyzed.RESULTSThe cohort included 44 patients, 41 of whom had sufficient data for analysis. Seizure freedom was achieved in 68%, 48%, and 22% of the patients at 1, 5, and 10 years, respectively. The median time to the first seizure for those who experienced seizure recurrence after surgery was 39 weeks (IQR 11–355 weeks). Anatomical hemispherectomy, as compared to functional hemispherectomy, was independently associated with a longer time to postoperative seizure recurrence (HR 0.078, p = 0.03). There was no statistically significant difference in postoperative seizure recurrence between patients with complete hemispherectomy and those who had less-than-hemispheric surgery. Following surgery, 68% of the patients could ambulate and 84% could speak regardless of operative intervention.CONCLUSIONSA large proportion of RE patients will have seizure relapse after surgery, though patients with anatomical hemispherectomies may have a longer time to postoperative seizure recurrence. Overall, the long-term data in this study suggest that hemispheric surgery can be seen as palliative treatment for seizures rather than a cure for RE.

Objective To investigate the effect and medical imaging of modified hemispherectomy on patients with infantile hemiparesis and medically refractory epilepsy. Patients and methods Forty-three patients with infantile hemiparesis and refractory epilepsy who underwent hemispherectomy were enrolled. The treatment effect and medical imaging were analyzed. Results Anatomical hemispherectomy was successfully performed in all patients (100%). In all patients, the muscular tension decreased and the contracted limbs relaxed. In the pathological examination of the resected brain tissue, secondary cicatricial gyri with concomitant cortical dysplasia was present in 36 cases and polycerebellar gyrus malformation and porencephalia in the other 7 cases. Followed up for 7–15 years (mean 11.3), all patients were alive without a long-term sequela. Epilepsy was satisfactorily controlled, with complete seizure relief in 39 cases (91%) classified as Engel I and basic control in the other 4 (9%) defined as Engel II. The posthemispherectomy medical imaging demonstrated that the intracranial space on the operative side shrank, and the healthy cerebral hemisphere shifted markedly toward the hemispherectomy side, with expanded lateral ventricle on the healthy side and thickened skull and enlarged frontal sinus on the operative side. After 4–5 years, the intracranial space on the operative side disappeared in 75% of the patients, demonstrating enlarged cerebral peduncle on the healthy side. Conclusion Further modified hemispherectomy in patients with infantile hemiparesis and medically refractory epilepsy demonstrated markedly ameliorated effects on epilepsy control and the prevention of superficial cerebral hemosiderosis in the long-term follow-up.

Epilepsy surgery reduces seizure burden and antiepileptic use while improving quality of life. Neuroplasticity and rehabilitation aid in recovery after epilepsy surgery. We aimed to examine the impact and role of inpatient rehabilitation after epilepsy surgery in pediatric patients with refractory epilepsy. A retrospective chart review examined patients aged 0–18 years old undergoing epilepsy surgery for refractory epilepsy at our institution between 2012 and 2018, with subsequent admission to inpatient rehabilitation. Demographic, clinical, neurocognitive, and functional outcomes were measured. Thirty-six patients were included: 17 male (47.2%) and 19 female (52.8%). Mean age was 9.3 years (SD 5.2, range 1.1–18.9). The most common procedures were hemispherectomy (13, 36.1%) and lobectomy (12, 33.3%). The mean duration of rehabilitation was 16.2 days (SD 9.2, range 6–42). WeeFIMR scores improved after rehabilitation (65.6 vs. 49.3, p 0.05), and procedure type (p

OBJECTIVEUncontrolled epilepsy is associated with serious deleterious effects on the neurological development of infants and has been described as “catastrophic epilepsy.” Recently, there has been increased emphasis on early surgical interventions to preserve or rescue neurodevelopmental outcomes in infants with early intractable epilepsy. The enthusiasm for early treatments is often tempered by concerns regarding the morbidity of neurosurgical procedures in very young patients. Here, the authors report outcomes following the surgical management of infants (younger than 1 year).METHODSThe authors performed a retrospective review of patients younger than 1 year of age who underwent surgery for epilepsy at Miami (Nicklaus) Children’s Hospital and Jackson Memorial Hospital between 1994 and 2018. Patient demographics, including the type of interventions, were recorded. Seizure outcomes (at last follow-up and at 1 year postoperatively) as well as complications are reported.RESULTSThirty-eight infants (median age 5.9 months) underwent a spectrum of surgical interventions, including hemispherectomy (n = 17), focal resection (n = 13), and multilobe resections (n = 8), with a mean follow-up duration of 9.1 years. Hemimegalencephaly and cortical dysplasia were the most commonly encountered pathologies. Surgery for catastrophic epilepsy resulted in complete resolution of seizures in 68% (n = 26) of patients, and 76% (n = 29) had a greater than 90% reduction in seizure frequency. Overall mortality and morbidity were 0% and 10%, respectively. The latter included infections (n = 2), infarct (n = 1), and immediate reoperation for seizures (n = 1).CONCLUSIONSSurgical intervention for catastrophic epilepsy in infants remains safe, efficacious, and durable. The authors’ work provides the longest follow-up of such a series on infants to date and compares favorably with previously published series.

Hemispheric disconnection in the form of hemispherectomy or hemispherotomy is the most effective way of treating intractable hemispheric epilepsy. Anatomical hemispherectomy approaches have largely been abandoned in most cases due to a higher risk of superficial hemosiderosis, intraoperative blood loss, hydrocephalus, prolonged hospital stay, and mortality compared to the variety of tissue-sparing hemispherotomy techniques. Disconnective hemispherotomy approaches utilize the lateral ventricle as a key component of the surgical corridor. Without a lateral ventricle, disconnective surgery becomes significantly challenging, typically leading to a hemispherectomy. The authors present the case of a patient with severe hemispheric dysplasia without a lateral ventricle on the pathologic side and detail a novel surgical technique for a prone, occipital interhemispheric, tissue-sparing, purely disconnective aventricular hemispherotomy with an excellent surgical outcome.

OBJECTIVEAlthough hemispherectomy is an effective treatment for children with intractable hemispheric epilepsy syndromes, as many as 40% of patients eventually develop seizure recurrence. The causes of seizure recurrence in these patients are incompletely understood. The authors sought to evaluate the efficacy of hemispherectomy at their center and determine whether contralateral MRI abnormalities can predict seizure recurrence.METHODSA retrospective review of consecutive hemispherectomies performed at Miami Children’s Hospital between January 2000 and June 2014 was performed. Time-to-event analysis was performed. The “event” was defined as any seizures following resective epilepsy surgery (not including seizures in the first postoperative week and auras). Several preoperative variables were analyzed to determine their suitability to predict seizure recurrence following surgery.RESULTSSixty-nine patients (44 boys) with a mean age of 8.2 ± 5.9 years (range 0.1–20.8 years) underwent 72 hemispherectomies; 67 of these were functional hemispherectomies, while another 5 were completion of a previous functional hemispherectomy (2 completions of functional hemispherectomies, 3 anatomical hemispherectomies). The duration of epilepsy was 5.8 ± 5.5 years with 66 cases (91.7%) having daily seizures. Etiology included stroke (n = 28), malformation of cortical development (n = 11), hemimegalencephaly (n = 11), encephalitis (n = 13), and other (n = 7). Engel class I outcome was achieved in 59 (86%) and 56 (81%) patients at 1 and 2 years of follow-up, respectively. The mean time to seizure recurrence was 33.5 ± 31.1 months. In univariate analyses, the absence of contralateral abnormalities on MRI (HR 4.09, 95% CI 1.41–11.89, p = 0.009) was associated with a longer duration of seizure freedom. The presence of contralateral MRI abnormalities was associated with contralateral ictal seizures on preoperative scalp EEG (p = 0.002). Fifteen patients experienced 20 complications (20/72, 27.8%), including the development of hydrocephalus necessitating CSF diversion in 9 cases (13%), hygroma in 1, hemispheric edema in 1, aseptic meningitis in 2, postoperative hemorrhage in 2, infection in 2, ischemic stroke in 2, and blood transfusion–contracted hepatitis C in 1 case.CONCLUSIONSPatients with bihemispheric abnormalities, as evidenced by contralateral MRI abnormalities, have a higher risk of earlier seizure recurrence following functional hemispherectomy.

Corpus callosotomy is a palliative surgical option for patients with refractory epilepsy and frequent drop attacks, decreasing seizure frequency and severity by disconnecting the cerebral hemispheres. Though often successful, open surgery is not without risk. Corpus callosotomy by MRI-guided laser interstitial thermal therapy (MRgLITT) is a minimally invasive alternative to the standard open procedure. This report aims to present an illustrative case and systematically review the current literature on the surgical technique. A systematic review of the English literature through January 2019 was performed. Articles were searched by title utilizing the following key word combinations: “laser” and “callosotomy”, “callosotomy” and “ablation”, “laser” and “corpus”, “callosotomy” and “thermal”, and “stereotactic” and callosotomy”. The articles recovered were then classified by level of evidence and summarized. Fifteen papers were reviewed, of which 6 met inclusion and exclusion criteria. All included studies were classified as level IV evidence. There was a total of 13 patients ranging from 13 months to 44 years old (mean 23.5 years old). The number of laser fibers utilized ranged from 1 to 3. Engel class I was achieved in 5 patients, II in 4, III in 2, IV in 1. Reported patient follow up was 4–39.7 months (mean 15.43). Corpus callosotomy utilizing MRI-guided laser interstitial thermal therapy results in improvement in seizure frequency and severity with minimal complications. Prospective trials are needed to compare its seizure control and long-term outcomes to that of standard open callosotomy.

Rasmussen's encephalitis is a rare drug-resistant focal epilepsy characterized by progressive hemiparesis, hemianopia, and cognitive decline. Hemispherectomy is currently the only known treatment that can be curative, though expected to cause postoperative motor and visual deficits in children and adolescents. To date, medical treatment with antiseizure medications and immunosuppressive agents can only offer partial, delayed, or temporary alleviation of symptoms. Hence, patients and families are often faced with the difficult decision to consider the possibility of seizure freedom at the cost of incurring permanent deficits. Here, we discussed the unique ethical issues when faced with a cure that can cause harm, and also discussed a shared decision-making approach guided by informed consent, principles of autonomy, and patient-centered values.

Background Hemispherectomy has been shown to be successful in treating medically intractable epilepsy, with favorable seizure-free outcomes. However, the procedure is technically challenging with high rates of in-hospital complications. We present a unique case of functional hemispherectomy complicated by diffuse cerebral vasospasm and subsequent death in a patient with COL4A1 gene mutation. Case Description A 17-year-old boy presented with right hemispheric epilepsy and a previously diagnosed autosomal dominant heterozygous COL4A1 gene mutation (c.4380T>G;p.Cys1460Trp). Functional hemispherectomy was performed without complications. On postoperative day 8, he developed an acute decline in neurologic status requiring urgent intubation for airway protection. Magnetic resonance imaging revealed areas of restricted diffusion throughout bilateral hemispheres that was explained by severe vasospasm and minimal cerebral blood flow seen on cerebral angiography. Intra-arterial calcium channel blocker infusion and balloon angioplasty were attempted without improvement in perfusion. With a worsening clinical picture, he was transitioned to comfort care and died. Conclusions This is the first report in the literature describing global vasospasm and delayed cerebral ischemia following hemispherectomy in a patient carrying COL4A1 gene mutation. We postulate that his COL4A1 gene mutation might have resulted in this exaggerated vasospasm despite minimal residual postoperative subarachnoid hemorrhage burden. This hypothesis needs to be studied in animal models of this genetic disorder.

OBJECTIVEThe objective of this study was to perform an individual participant data meta-analysis to identify preoperative factors associated with a good seizure outcome in children with Rasmussen’s encephalitis (RE) undergoing resective or hemispheric epilepsy surgery.METHODSElectronic databases (PubMed, Web of Science, CINAHL) were searched with no language or date restrictions to identify cohort studies of consecutive participants undergoing resective surgery that reported seizure outcomes. The authors recorded all preoperative factors that could plausibly be associated with seizure outcomes and used Cox regression analysis to identify which of these variables were associated with seizure freedom (i.e., Engel class I).RESULTSOf 720 citations, 19 articles reporting on 187 participants were eligible. Seizure freedom (Engel class I) was observed in 113 participants (60.4%). On univariate analyses, younger age at disease onset (hazard ratio [HR] 0.906, p = 0.001), younger age at surgery (HR 0.928, p < 0.001), shorter time to surgery (HR 0.921, p = 0.001), and hemispherectomy (HR 0.283, p < 0.001) were all associated with longer time to postoperative seizure recurrence. Additionally, multivariable analysis including the aforementioned variables showed that younger age at surgery (HR 0.946, p = 0.043) and hemispherectomy (HR 0.297, p < 0.001) were independently and significantly associated with a greater time to seizure recurrence and longer duration of seizure freedom.CONCLUSIONSThe majority of pediatric patients undergoing resective or hemispheric surgery for RE achieve good seizure outcome. Although small retrospective cohort studies are inherently prone to bias, the best available evidence utilizing individual participant data suggests hemispheric surgery and younger age at surgery are associated with good seizure outcomes following epilepsy surgery. Large, multicenter observational studies with long-term follow-up are required to evaluate the risk factors identified in this review.

Treatment of intracranial arteriovenous malformations is complex and multidisciplinary. This article presents the treatment model utilized in Christchurch, New Zealand which provides cerebrovascular surgery and interventional neuroradiology to the entire south island (approximate population of 1.1 million). A total of 40 patients treated over a 10 year period (2004–2014) are analysed here. Nine patients were managed surgically and complete resection was achieved in 100% of cases. Permanent mortality was 0% and permanent morbidity was 22% however median mRS improved from 3.0 preoperatively to 1.0 at follow up. Embolisation was utilized in 31 patients (mean age 40), of which 45% presented with haemorrhage, 39% with seizures, 10% with a headache only, and 6% with a deficit. None were found incidentally. The Spetzler-Martin grade 1 cases accounted for 10% of the cohort, 23% were grade II, 42% grade III, 23% grade IV and 3% grade V. A single aneurysm was present in 42% of cases, and multiple in 13%. The nidus was obliterated in 9.6% of cases with a morbidity rate of 6.5% and mortality rate of 3%. Modified Rankin scale improved marginally from 0.9 at diagnosis to 0.88 at final follow up (mean 22 months). There were no cases of recanalization. The total nidus obliteration rate using our algorithm of surgery alone for small accessible lesions, then staged embolization for larger lesions with adjuvant radiosurgery reserved for cases with residual nidus, was 50%.

Drug-resistant seizures due to hemimegalencephaly in neonates and infants are a unique surgical and anesthesia challenge. While early surgery in these patients may predict a better seizure control, a lower body weight, limited blood volume, and surgical blood loss may make hemispherectomy prohibitive. Two infants (weight, 8.7 kg and 3.7 kg) underwent interhemispheric vertical hemispherotomy with endoscope assistance. In the first case, during the lateral disconnection, excessive bleeding prompted the surgeon to coagulate the lenticulostriate arteries at the origin from the middle cerebral artery to reduce bleeding. In the second infant, the lenticulostriate arteries were coagulated before initiating the lateral disconnection. In both infants, the blood loss from lateral dissection was reduced by coagulation of lenticulostriate arteries. The authors suggest that early coagulation of the lenticulostriate arteries is a useful strategy to minimize blood loss in low-weight infants undergoing hemispherotomy.

ObjectiveThe authors sought to analyze the residual connections formed by the temporal stem as a cause for seizure recurrence following endoscopic vertical interhemispheric hemispherotomy and to review and compare lateral approach (perisylvian) with vertical approach surgical techniques to highlight the anatomical factors responsible for residual connections.METHODSThis study was a retrospective analysis of patients who underwent endoscopic hemispherotomy for drug-resistant epilepsy. Postoperative MR images were analyzed. Specific attention was given to anatomical 3D-acquired thin-section T1 images to assess the extent of disconnection, which was confirmed with a diffusion tensor imaging sequence. Cadaver brain dissection was done to analyze the anatomical factors responsible for persistent connections.RESULTSOf 39 patients who underwent surgery, 80% (31/39) were seizure free (follow-up of 23.61 ± 8.25 months) following the first surgery. Thirty patients underwent postoperative MRI studies, which revealed persistent connections in 14 patients (11 temporal stem only; 3 temporal stem + amygdala + splenium). Eight of these 14 patients had persistent seizures. In 4 of these 8 patients, investigations revealed good concordance with the affected hemisphere, and repeat endoscopic disconnection of the residual connection was performed. Two of the 8 patients were lost to follow-up, and 2 had bihemispheric seizure onset. The 4 patients who underwent repeat endoscopic disconnection had seizure-free outcomes following the second surgery, increasing the good outcome total among all patients to 90% (35/39). Cadaveric brain dissection analysis revealed the anatomical factors responsible for the persistence of residual connections.CONCLUSIONSIn endoscopic vertical approach interhemispheric hemispherotomy (and also vertical approach parasagittal hemispherotomy) the temporal stem, which lies deep and parallel to the plane of disconnection, is prone to be missed, which might lead to persistent or recurrent seizures. The recognition of this limitation can lead to improved seizure outcome. The amygdala and splenium are areas less commonly prone to be missed during surgery.

Background: Epilepsy is a disease of the brain defined by any of the following conditions: At least 2 unprovoked (or reflex) seizures occurring more than 24 hours apart; One unprovoked (or reflex) seizure with relatively high recurrence risk (i.e., ≥60% (, occurring over the next 10 years; or Diagnosis of an Epilepsy syndrome. Objectives: This work aims to review surgical outcome for drug resistant epilepsy of different causes to identify which patient would get the most benefit. Patients and Methods: Prospective and retrospective study on 20 cases with drug resistant epilepsy at Al-Azhar university hospitals.surgical techniques:Lesionectomy Surgery, corpus Callosotomy Conclusion: The objective of epilepsy surgery is complete seizure control without any resulting post-surgical functional deficits, so presurgical evaluation is to determine whether or not epilepsy surgery can be done and to define its chances of risk and benefit. Surgery can be classified to curative procedures which are performed when tests consistently point to a specific area of the brain where the seizures begin, as the Temporal lobectomy which is the most common type of surgery, Cortical excision, Hemispherectomy and Palliative procedures are performed when a specific area in the brain can’t be determined or when the seizure focus overlaps brain areas critical for movement as Vagus nerve stimulation. Not all people who have done epilepsy surgery are seizure free following surgery, but there is usually a significant decrease in seizures. Some people may have some seizures immediately after surgery but this doesn’t mean that the surgery wasn’t successful.

ObjectiveThis study was undertaken to determine whether the vertical parasagittal approach or the lateral peri-insular/peri-Sylvian approach to hemispheric surgery is the superior technique in achieving long-term seizure freedom.MethodsWe conducted a post hoc subgroup analysis of the HOPS (Hemispheric Surgery Outcome Prediction Scale) study, an international, multicenter, retrospective cohort study that identified predictors of seizure freedom through logistic regression modeling. Only patients undergoing vertical parasagittal, lateral peri-insular/peri-Sylvian, or lateral trans-Sylvian hemispherotomy were included in this post hoc analysis. Differences in seizure freedom rates were assessed using a time-to-eventmethod andcalculated using the Kaplan-Meier survival method.ResultsData for 672 participants across 23 centers were collected on the specific hemispherotomy approach. Of these, 72 (10.7%) underwent vertical parasagittalhemispherotomy and 600 (89.3%) underwent lateral peri-insular/peri-Sylvian or trans-Sylvian hemispherotomy. Seizure freedom was obtained in 62.4% (95% confidence interval [CI]=53.5%-70.2%) of the entire cohort at 10-year follow-up. Seizure freedom was 88.8% (95% CI=78.9%-94.3%) at 1-year follow-up and persisted at 85.5% (95% CI=74.7%-92.0%) across 5- and 10-year follow-up in the vertical subgroup. In contrast, seizure freedom decreased from 89.2% (95% CI=86.3%-91.5%) at 1-year to 72.1% (95% CI=66.9%-76.7%) at 5-year to 57.2% (95% CI=46.6%-66.4%) at 10-year follow-up for the lateral subgroup. Log-rank test found that vertical hemispherotomy was associated with durable seizure-free progression compared to the lateral approach (p=.01). Patients undergoing the lateral hemispherotomy technique had a shorter time-to-seizure recurrence (hazard ratio=2.56, 95% CI=1.08-6.04, p=.03) and increased seizure recurrence odds (odds ratio=3.67, 95% CI=1.05-12.86, p=.04) compared to those undergoing the vertical hemispherotomy technique.SignificanceThis pilot study demonstrated more durable seizure freedom of the vertical technique compared to lateral hemispherotomy techniques. Further studies, such as prospective expertise-based observational studies or arandomized clinical trial, are required to determine whether a vertical approach to hemispheric surgery provides superior long-term seizure outcomes.

Objective Hemispheric surgeries are an effective treatment option to control seizures for children with hemimegalencephaly (HME); however, not enough is known about their cognitive outcomes. This study aimed to delineate the cognitive and language outcomes after hemispherectomy for HME and identify the clinical characteristics associated with cognition and language. Methods Data came from the Global Pediatric Epilepsy Surgery Registry, a patient-driven web-based registry for epilepsy surgery. We focused on children's functional status, assessed through parent-reports of cognitive and language skills. Parents also reported on their satisfaction with surgery, their child's quality of life, and various demographic, clinical, and surgery characteristics. Results Parents of 45 children (40% female) participated. Children were aged 2.6 (SD 6.5) months at seizure onset, 10.8 (SD 12.7) months at hemispherectomy, and 8.7 (SD 4.8) years at follow-up, at which point 68% were seizure-free. We found that at follow-up, 43% had average or mildly impaired cognition, 26% could speak age appropriately, and 21% had satisfactory reading skills. A total of 55%, 43%, and 17% of children first babbled, spoke their first words, and started speaking in sentences at an age-appropriate period, respectively. Children who had undergone a right hemisphere resection and those who were older at epilepsy onset were more likely to have better cognitive and language outcomes. Significance Children with HME have delayed language milestones and continue to require significant language and literacy support long-term after cerebral hemispherectomy.

Background: Hemispheric disconnection represents a challenging and major epilepsy surgical procedure. This procedure in experienced hands offers excellent results in terms of seizure outcomes, especially for hemispheric pathologies such as Rasmussen's encephalitis, hemispheric dysplasias, hemimegalencephaly. The technique of hemispherotomy has witnessed various modifications over the years, beginning from anatomical hemispherectomy to the current era of minimally invasive functional hemispheric disconnections. Objective: This study aimed to describe the technique of performing endoscopic vertical hemispherotomy using interhemispheric corridor developed by the senior author. Materials and Methods: A 12-year-old girl with seizure onset at the age of 10 years presented with an aura of fear and nausea followed by tonic deviation of eyes to the right and blinking with speech arrest. There were tonic–clonic movements of the right-sided limbs along with ictal spitting and occasional deviation of the angle of mouth to the right. The patient had loss of awareness for the event along with postictal confusion lasting few minutes. Results: Video electroencephalography (VEEG) revealed left parietocentral and left temporal localization. Serial magnetic resonance imaging (MRI) brain over 3 years revealed progressive left hemispheric changes suggestive of Rasmussen's encephalitis. The patient underwent left-sided endoscopic hemispherotomy. At 2 years follow-up, the patient is seizure-free (ILAE [International League Against Epilepsy] Class 1). Conclusion: Endoscopic hemispherotomy using the interhemispheric approach is an elegant, minimally invasive, reproducible, safe, and efficacious technique.

Rasmussen encephalitis is a rare disease consisting of a chronic, slowly progressive inflammatory reaction of brain tissues. The objective of this study was to describe the case of an 18-year-old female patient, studying on the fourth grade of elementary school, and right-handed, who underwent left hemispherectomy in a neurological rehabilitation program. Her seizures began at 10 years of age and were unresponsive to drug treatment, with functional repercussions. She underwent hemispherectomy in March 2019, with 7 years of ongoing disease, and was admitted for the rehabilitation program with a multidisciplinary team in June 2020. The quality-of-life questionnaire (WHOQOL-BREF) was applied as a comparison measure before and after the rehabilitation program, along with measures of participation on the program activities. Despite the patient’s short time in a rehabilitation program, data show the importance of an interdisciplinary intervention through the establishment of specific and contextualized objectives in chronic patients. RESUMO A encefalite de Rasmussen representa uma doença rara, que consiste em uma reação inflamatória dos tecidos cerebrais, de modo crônico e lentamente progressivo. O objetivo deste estudo foi descrever o caso de uma paciente, submetida à hemisferectomia à esquerda, em março de 2019, em programa de reabilitação neurológica. Paciente do sexo feminino, 18 anos de idade, 4ª série do ensino fundamental, destra, que participou de programa de reabilitação neurológica interdisciplinar após hemisferectomia. Início das crises convulsivas aos 10 anos de idade, refratárias ao tratamento medicamentoso, com repercussão funcional. Foi submetida à hemisferectomia em março de 2019, com sete anos de doença em curso. Foi internada para programa de reabilitação, com equipe multiprofissional, em junho de 2020. Aplicou-se o questionário de qualidade de vida (WHOQOL-BREF), como medida de comparação antes e após o programa de reabilitação, além de medidas de participação nas atividades do programa. Os dados, apesar do pouco tempo da paciente em programa de reabilitação, mostram a importância da intervenção interdisciplinar, por meio do estabelecimento de objetivos realísticos e contextualizados.

Rasmussen encephalitis (RE) is a rare disease of unknown etiology that causes severe chronic unihemispheric inflammatory disease of the central nervous system mainly in children. It leads to intractable seizures, cognitive decline and progressive neurological deficits in the affected hemisphere. We report two cases of RE, as defined by fulfillment of the 2005 Bien criteria. The diagnostic challenge of characterizing this rare disease will be highlighted by the extensive serum, CSF, MR imaging and EEG data in the two patients. In addition, we will review the various forms of therapy attempted in these two patients, namely anti-epileptic drug therapy and immunomodulatory therapy. Hemispherectomy was done for the second patient with favorable outcomes of controlling seizures, but unfortunately, he died because of meningitis. Until the causes of Rasmussen's encephalitis are known, it is difficult to anticipate how treatments will improve. Such a situation creates a therapeutic dilemma; hemispherectomy is not favored because of the inevitable postoperative functional deficits, but a real risk exists that treatments used to delay progression of the disease will defer definitive surgical treatment beyond the time when an optimum post-hemispherectomy outcome could be expected., Highlights • Rasmussen encephalitis (RE) causes severe chronic unihemispheric inflammatory disease. • RE should be suspected in any patient with refractory seizures. • Its recognition is important because early intervention with surgery can improve outcomes.

This is a case series of six children with unilateral cerebral palsy and hemispheric encephaloclastic lesions who were evaluated for epilepsy surgery. Seizure onset was in the neonatal period in three children, at 17 months in two, and at 5 years in one. Their ictal and interictal electroencephalogram (EEG) abnormalities showed paradoxical lateralization to the incorrect/'normal' hemisphere or showed bilateral abnormalities. After cautious discussion regarding the discordant electroclinical profile and implications for outcome, they proceeded to a functional hemispherectomy (between ages 4-11y) with good outcomes (at 1-10y follow-up). Their clinical details, EEG findings, electrocorticography, neuroimaging, and histology are reported. Possible surgical candidacy should be evaluated early in children with refractory epilepsy, even those with complex profiles and discordant data from the different investigations. Contralateral or bilateral EEG abnormalities should not preclude consideration of hemispherectomy in children with refractory epilepsy, hemiparesis, and uniclastic lesions.

Social cognition and emotion are ubiquitous human processes that recruit a reliable set of brain networks in healthy individuals. These brain networks typically comprise midline (e.g., medial prefrontal cortex) as well as lateral regions of the brain including homotopic regions in both hemispheres (e.g., left and right temporo-parietal junction). Yet the necessary roles of these networks, and the broader roles of the left and right cerebral hemispheres in socioemotional functioning, remains debated. Here, we investigated these questions in four rare adults whose right (three cases) or left (one case) cerebral hemisphere had been surgically removed (to a large extent) to treat epilepsy. We studied four closely matched healthy comparison participants, and also compared the patient findings to data from a previously published larger healthy comparison sample (n = 33). Participants completed standardized socioemotional and cognitive assessments to investigate social cognition. Functional magnetic resonance imaging (fMRI) data were obtained during passive viewing of a short, animated movie that distinctively recruits two social brain networks: one engaged when thinking about other agents’ internal mental states (e.g., beliefs, desires, emotions, so-called Theory of Mind or ToM network), and the second engaged when thinking about bodily states (e.g., pain, hunger, so-called PAIN network). Behavioral assessments demonstrated remarkably intact general cognitive functioning in all individuals with hemispherectomy. Social-emotional functioning was somewhat variable in the hemispherectomy participants, but strikingly, none of these individuals had consistently impaired social-emotional processing and none of the assessment scores were consistent with a psychiatric disorder. Using inter-region correlation analyses, we also found surprisingly typical ToM and PAIN networks, as well as typical differentiation of the two networks (in the intact hemisphere of patients with either right or left hemispherectomy), based on idiosyncratic reorganization of cortical activation. The findings argue that compensatory brain networks can process social and emotional information following hemispherectomy across different age levels (from 3 months to 20 years old), and suggest that social brain networks typically distributed across midline and lateral brain regions in this domain can be reorganized, to a substantial degree.

Introduction: Refractory epilepsy can be defined as a failure of adequate trials of antiepileptic drug programs tolerated and appropriately chosen and used (either as monotherapy or in combination) to achieve sustained freedom from seizures. Surgical procedures for the control of epileptic seizures have spread throughout the world, however, large medical centers have mainly focused on studying and analyzing the clinical results of their surgical interventions. For this reason, this study aims to analyze the cost of pre and post-surgical anticonvulsant medications in patients. Objective: To analyze the relationship between preoperative cost / postoperative cost of antiepileptic drugs in patients undergoing hemispherectomy or temporary lobectomy at the National Children’s Hospital (Hospital Nacional de Niños-HNN). Materials and methods: This study is a retrospective, descriptive, quantitative and longitudinal type of a series of patients who were operated in the Epilepsy Monitoring and Surgery Unit (UMCE) of Costa Rica, between November 2000 and December 2018. Information on the history of medications is obtained from patients before and after having undergone hemispherectomy or temporal lobectomy to assess whether or not there is an economic saving in this aspect when comparing both periods of time. Results: 69 patients have undergone hemispherectomy and temporal lobectomy since the creation of the UMCE in November 2000. Of these, 18 (26%) underwent hemispherectomy and 51 (74%) underwent temporary lobectomy. A sample of 31 patients (45%) were obtained, which met the inclusion criteria. The average age of initiation of treatment at the HNN was 5.5 years old (66 months) and the average age at which they underwent surgery was 10.8 years old (130 months). There was one patient in the sample who received 9 anticonvulsant medications before undergoing the surgical procedure and the average number of medications used pre-surgically was 4.45 anticovulsivants per patient. The average postoperative medication was 2.35 anticonvulsivants per patient. The average monthly preoperative cost was $50.17, while the postoperative period was $31.26, with a difference of $18.91. A total of 9 patients in the sample increased the monthly postoperative cost. The total savings per month in the patients included in the sample was $586.36 and extrapolated to the population of 69 patients resulting in a saving of $1,305.14 per month. The projection according to the life expectancy of the patients in the sample translates into a saving of $409,188.59 while the projection to the 69 patients would result in a saving of $910,774.60 for the Caja Costarricense del Seguro Social (CCSS - Costa Rican Social Security Fund). Discussion: The effectiveness of these two surgeries in suitably selected patients is reflected in the economic savings represented by antiepileptic drugs administered after these surgical procedures. Conclusion: we consider that in this center the patients who have been operated have meant a saving for the Caja Costarricense del Seguro Social (CCSS) since they have diminished or completely eliminated the anti-epileptic medical treatment

OBJECTIVE: To examine longitudinal seizure and functional outcomes after hemispherectomy in adults and adolescents. METHODS: We reviewed 47 consecutive patients older than 16 years of age who underwent hemispherectomy between 1996 and 2016 at our center. Clinical, EEG, imaging, neuropsychological, surgical, and functional status data were analyzed. RESULTS: Thirty-six patients were aged 18 or older at surgery; 11 were aged between 16 and 18 years. Brain injury that lead to hemispheric epilepsy occurred before 10 years of age in 41 (87%) patients. At a mean follow up of 5.3 postoperative years (median 2.9 years), 36 (77%) had Engel class I outcome. Longitudinal outcome analysis showed 84% seizure freedom (Engel IA) at 6 months, 76% at 2 years, and 76% at 5 years and beyond with stable longitudinal outcomes up to 12 years from surgery. Multivariate analysis demonstrated that acute post-operative seizures and contralateral interictal spikes at 6 month follow-up EEG were associated with seizure recurrence. Patients who could walk unaided pre-operatively and had no cerebral peduncle atrophy on brain MRI were more likely to experience worsening of motor function post-operatively. Otherwise, post-operative ambulatory status and hand function were unchanged. Of the 19 patients who completed neuropsychological testing, 17 demonstrated stable or improved post-operative outcomes.

Rasmussen's encephalitis (RE) is a chronic neurological disorder characterized by unilateral inflammation of the cerebral cortex leading to severe focal seizures, progressive loss of cognition, and neurological deficits in the affected hemisphere. We present a rare case of RE in a child with global developmental delay and cerebral atrophy. Neuroimaging helped in clinching the diagnosis of the disease. Immunomodulators may slow the progression of the disease; hence, it needs to be identified early and treated promptly. Functional cerebral hemispherectomy is the only treatment for drug-resistant seizures, but it has its functional compromise.

Background When the epileptogenic foci skip the motor area, the epilepsy can be cured by surgery while preserving the motor function. This surgery has been reported as subtotal hemispherectomy. The disconnective variant of this surgery, subtotal hemispherotomy, is described. Objective To demonstrate each step clearly, a cadaveric brain, 3-dimensional reconstruction and simulation model, and intraoperative photographs were used. Methods A formalin-fixed cadaveric brain was dissected to show each step of this surgery. For the 3-dimensional model, several brain structures were reconstructed from preoperative images, and the surgery was simulated. Intraoperative photographs and postoperative magnetic resonance images were taken from the representative cases. Results Temporo-parieto-occipital disconnection is performed to disconnect these lobes and the insula, limbic system, and splenium of the corpus callosum. The postcentral sulcus is the anterior border of the disconnection. Next, prefrontal disconnection is performed to disconnect the frontal lobe and the insula, frontal lobe and basal ganglia, and the anterior part of the corpus callosum. The precentral sulcus is the posterior border of the disconnection. Finally, corpus callosotomy of the central part is performed. After these steps, subtotal hemispherotomy, with preservation of the pre- and postcentral gyrus, is achieved. The 3-dimensional model clearly shows the anatomic relationships between deep brain structures. In the representative cases, postoperative motor deterioration was transient or none, and seizure-free status was achieved after surgery. Conclusion Subtotal hemispherotomy is generally difficult because of the complicated anatomy and narrow and deep surgical corridors. Combined use of these methods facilitates a clearer understanding of this surgery.

Hemispherectomy in Adults and Adolescents: Seizure and Functional Outcomes in 47 Patients McGovern RA, NV Moosa A, Jehi L, Busch R, Ferguson L, Gupta A, et al. Epilepsia. 2019;60(12):2416-2427. http://doi.org/10.1111/epi.16378.Objective:To examine longitudinal seizure and functional outcomes after hemispherectomy in adults and adolescents.Methods:We reviewed 47 consecutive patients older than 16 years who underwent hemispherectomy between 1996 and 2016 at our center. Clinical, electroencephalographic (EEG), imaging, neuropsychological, surgical, and functional status data were analyzed.Results:Thirty-six patients were 18 years or older at surgery; 11 were aged between 16 and 18 years. Brain injury leading to hemispheric epilepsy occurred before 10 years of age in 41 (87%) patients. At a mean follow-up of 5.3 postoperative years (median = 2.9 years), 36 (77%) had Engel class I outcome. Longitudinal outcome analysis showed 84% seizure freedom (Engel IA) at 6 months, 76% at 2 years, and 76% at 5 years and beyond, with stable longitudinal outcomes up to 12 years from surgery. Multivariate analysis demonstrated that acute postoperative seizures and contralateral interictal spikes at 6-month follow-up EEG were associated with seizure recurrence. Patients who could walk unaided preoperatively and had no cerebral peduncle atrophy on brain magnetic resonance imaging were more likely to experience worsening of motor function postoperatively. Otherwise, postoperative ambulatory status and hand function were unchanged. Of the 19 patients who completed neuropsychological testing, 17 demonstrated stable or improved postoperative outcomes.Significance:Hemispherectomy in adults is a safe and effective procedure, with seizure freedom rates and functional outcome similar to those observed in children.

Introducción: A hemisferectomía es un procedimiento valioso en el tratamiento de trastornos convulsivos causados por desordenes hemisféricos unilaterales. El hemisferectomía anatómica se ha utilizado para este fin desde 1938, sin embargo, se abandonó este procedimiento después de informes de complicaciones postoperatorias causadas por hemosiderosis superficial, ependimitis e hidrocefalia obstructiva. Así que, se ha mostrado en la literatura modificaciones en las indicaciones y técnicas de hemisferectomía anatómica cuya finalidad es la de reducir la incidencia de esta complicación sin dejar de lograr control de las convulsiones. Sobre la base de la literatura, la hemisferectomía mejora la calidad de vida de los pacientes que tiene la indicación para realizar este procedimiento, ya que permite reducir la frecuencia de las convulsiones, si tónica o átona, tónico-clónicas Objetivo: El objetivo de esta revisión de la literatura es discutir los detalles técnicos, modalidades, riesgos, complicaciones, resultados y de pronóstico de hemisferectomía basado en la revisión crítica de la literatura. Casuística y Métodos: Se realizó la consulta bibliográfica, utilizando la base de datos MEDLINE, LILACS, SciELO, que utiliza el lenguaje como criterios de selección, la elección de los artículos recientes preferiblemente en portugués, español o inglés. Conclusión: Según las referencias, hemisferectomía es un procedimiento con buen resultado para las personas con convulsiones derivadas cuando está indicado para casos seleccionados y la tasa de éxito no es proporcional a la extensión de la reseccióndel tejido neuronal. A mayor resección puede o no reducir la frecuencia de las crisis, sin embargo, la incidencia de la morbilidad puede ser mayor.

Background Vertical perithalamic hemispherotomy was introduced by Olivier Delalande in 1992 as an alternative concept of functional hemispherectomy. Objective To provide a step-by-step illustration of the surgical anatomy of this procedure. Methods The descriptions in this manuscript are based on an experience of 52 hemispherotomies performed with the same technique by a single surgeon. Results Our illustrations of the surgical anatomy and the descriptions of the surgical nuances facilitate a deep understanding for the surgical concept of Delalande's vertical hemispherotomy technique. They highlight the advantages (ie, reduced risk of inadvertent damage to the contralateral hemisphere and a clear orientation by defined anatomical landmarks) over the recently suggested modifications to this original technique. Conclusion Olivier Delalande's original technique remains the most appealing concept of vertical hemispherotomy to us.

The safety of hemispherectomy between staged cardiac procedures is unknown and not previously reported. Retrospective review of a case with drug-resistant epilepsy due to stroke following bidirectional cavopulmonary connection (BDCPC). This report describes the first case of a successful pediatric peri-insular functional hemispherectomy in the setting of a BDCPC. A discussion of the complex preoperative planning from both a cardiac and neurological perspective is presented. Considerations regarding hemispherectomy and its effects on the cardiac physiology, and perioperative considerations are emphasized in clinical decision making. A multidisciplinary approach was critical in this child which led to a successful outcome.

The paper addresses the relatively rare inherited neurodermal disorder – Sturge-Weber syndrome that can manifest in epileptic seizures. We describe updated concepts, epidemiology, etiology, pathogenesis, clinical manifestations, and surgical treatment of the disease. We examined medical records of 21 patients (aged from 1 to 11 years) with Sturge-Weber syndrome treated over the period of 1996-2016. After surgical treatment of 10 patients (five cases with hemispheretomy and five – with multifocal resection), positive outcomes (Engel class I, II) were found in 70% of cases, and negative (Engel class III, IV) – in 20% of cases. Оne child suddenly died during epileptic seizures. In non-operated children (age from 2 to 5 years) under our observation, an improvement was noted in six cases, no changes – in three cases, and a further progression of the disease – in three cases. In this article, we analyze two of these cases in detail.

OBJECTIVEThe objective of this study was to describe a new experimental model of hemispherotomy performed on laboratory animals.METHODSTwenty-six male young adult Wistar rats were distributed into two groups (surgery and control). The nonfluorescent anterograde neurotracer biotinylated dextran amine (BDA; 10,000 MW) was microinjected into the motor cortex area (M1) according to The Rat Brain in Stereotaxic Coordinates atlas to identify pathways and fibers disconnected after the experimental hemispherectomy. SPECT tomographic images of 99mTc hexamethylpropyleneamine oxime were obtained to verify perfusion in functioning areas of the disconnected and intact brain. A reproducible and validated surgical procedure is described in detail, including exact measurements and anatomical relationships. An additional 30 rodents (n = 10 rats per group) were divided into naïve, sham, and hemispherotomy groups and underwent the rotarod test.RESULTSCortico-cortical neural pathways were identified crossing the midline and contacting neuronal perikarya in the contralateral brain hemisphere in controls, but not in animals undergoing hemispherotomy. There was an absence of perfusion in the left side of the brain of the animals undergoing hemispherotomy. Motor performance was significantly affected by brain injuries, increasing the number of attempts to maintain balance on the moving cylinder in the rotarod test at 10 and 30 days after the hemispherotomy, with a tendency to minimize the motor performance deficit over time.CONCLUSIONSThe present findings show that the technique reproduced neural disconnection with minimal resection of brain parenchyma in young adult rats, thereby duplicating the hemispherotomy procedures in human patients.

Corpus callosotomy has been used as a form of surgical palliation for patients suffering from medically refractory generalized seizures, including drop attacks. Callosotomy has traditionally been described as involving a craniotomy with microdissection. MR-guided laser interstitial thermal therapy (MRg-LITT) has recently been used as a minimally invasive method for performing surgical ablation of epileptogenic foci and corpus callosotomy. The authors present 3 cases in which MRg-LITT was used to perform a corpus callosotomy as part of a staged surgical procedure for a patient with multiple seizure types and in instances when further ablation of residual corpus callosum is necessary after a prior open surgical procedure. To the authors’ knowledge, this is the first case series of corpus callosotomy performed using the MRg-LITT system with a 3.3-year average follow-up. Although MRg-LITT is not expected to replace the traditional corpus callosotomy in all cases, it is a safe, effective, and durable alternative to the traditional open corpus callosotomy, particularly in the setting of a prior craniotomy.

OBJECTIVEAppropriately chosen candidates with medically refractory epilepsy may benefit from hemispheric disconnection. Traditionally, this involves a large surgical exposure with significant associated morbidity. Minimally invasive approaches using endoscopic assistance have been described by only a few centers. Here, the authors report on the feasibility of endoscope-assisted functional hemispherotomy in a cadaver model and its first translation into clinical practice in appropriately selected patients.METHODSThree silicone-injected, formalin-fixed cadaver heads were used to establish the steps of the procedure in the laboratory. The steps of disconnection were performed using standard surgical instruments and a straight endoscope. The technique was then applied in two patients who had been referred for hemispherectomy and had favorable anatomy for an endoscope-assisted approach.RESULTSAll disconnections were performed in the cadaver model via a 4 × 2–cm paramedian keyhole craniotomy using endoscopic assistance. An additional temporal burr hole approach was marked in case the authors were unable to completely visualize the frontobasal and insular cuts from the paramedian vertical view. Their protocol was subsequently used successfully in two pediatric patients. Full disconnection was verified with postoperative tractography.CONCLUSIONSFull hemispheric disconnection can be accomplished with minimally invasive endoscope-assisted functional hemispherotomy. The procedure is technically feasible and can be safely applied in patients with favorable anatomy and pathology; it may lead to less surgical morbidity and faster recovery.

We describe a 23-year-old woman with previous right temporal lobe surgeries for underlying cortical dysplasia, presenting with drug-resistant right hemispheric seizures and epilepsia partialis continua (EPC). After anti-seizure medication adjustments, she developed focal status epilepticus with progressive EEG and neuroimaging changes. Cerebrospinal fluid and serum autoimmune panels were negative except for an elevated serum acetylcholine-receptor antibody titer, but she underwent immunosuppressive therapy. Stereotactic-EEG evaluation demonstrated multifocal independent ictal patterns in the right hemisphere. Rasmussen's Syndrome was confirmed by brain biopsy, and a hemispherectomy was performed. This patient demonstrates the rare association of adult-onset EPC with cortical dysplasia, precipitously evolving into Rasmussen's Syndrome., Highlights • Rasmussen's Syndrome (RS) can be associated with focal cortical dysplasia. • Autoimmunity underlies evolution of new-onset EPC in the setting of chronic focal epilepsy, and support a diagnosis of RS. • Hemispherectomy can be an effective intervention in adult-onset RS.

Objective Although hemidisconnection surgery may eliminate or reduce seizure activity in patients with epilepsy, there are visual, cognitive and motor deficits which affect patients’ function post-operatively, with varying severity and according to pathology. Consequently, there is a need to map microstructural changes over long time periods and develop/apply methods that work with legacy data. Methods In this study, we applied the novel single shell 3-Tissue method to data from a cohort of 4 patients who were scanned 20-years following childhood hemidisconnection surgery and presented with variable clinical outcomes. We have successfully reconstructed tractography of the whole visual pathway from single shell diffusion data with reduced number of gradient directions. Results All patients presented with degeneration of the visual system characterized by low fractional anisotropy and high mean diffusivity. There were no apparent microstructural differences between both optic nerves that could explain the different level of visual function across patients. However, we provide evidence suggesting an association between the level of visual function and DTI metrics within the remaining components of the visual system, particularly the optic tract, of the contralateral hemisphere post-surgery. Significance We believe this study suggests that diffusion MRI can be used to monitor the integrity of the visual system following hemispherectomy and if extended to larger cohorts and a greater number of time-points, including pre-surgically, can provide a clearer picture of the natural history of visual system degeneration. This knowledge may in turn help to identify patients at greatest risk of poor visual outcomes that might benefit from rehabilitation therapies.

In this review, we will discuss in four scenarios our challenges to offer possible solutions for the puzzle associated with the epilepsies and neuropsychiatric comorbidities. We need to recognize that (1) since quite old times, human wisdom was linked to the plural (distinct global places/cultures) perception of the Universe we are in, with deep respect for earth and nature. Plural ancestral knowledge was added with the scientific methods; however, their joint efforts are the ideal scenario; (2) human behavior is not different than animal behavior, in essence the product of Darwinian natural selection; knowledge of animal and human behavior are complementary; (3) the expression of human behavior follows the same rules that complex systems with emergent properties, therefore, we can measure events in human, clinical, neurobiological situations with complexity systems' tools; (4) we can use the semiology of epilepsies and comorbidities, their neural substrates, and potential treatments (including experimental/computational modeling, neurosurgical interventions), as a source and collection of integrated big data to predict with them (e.g.: machine/deep learning) diagnosis/prognosis, individualized solutions (precision medicine), basic underlying mechanisms and molecular targets. Once the group of symptoms/signals (with a myriad of changing definitions and interpretations over time) and their specific sequences are determined, in epileptology research and clinical settings, the use of modern and contemporary techniques such as neuroanatomical maps, surface electroencephalogram and stereoelectroencephalography (SEEG) and imaging (MRI, BOLD, DTI, SPECT/PET), neuropsychological testing, among others, are auxiliary in the determination of the best electroclinical hypothesis, and help design a specific treatment, usually as the first attempt, with available pharmacological resources. On top of ancient knowledge, currently known and potentially new antiepileptic drugs, alternative treatments and mechanisms are usually produced as a consequence of the hard, multidisciplinary, and integrated studies of clinicians, surgeons, and basic scientists, all over the world. The existence of pharmacoresistant patients, calls for search of other solutions, being along the decades the surgeries the most common interventions, such as resective procedures (i.e., selective or standard lobectomy, lesionectomy), callosotomy, hemispherectomy and hemispherotomy, added by vagus nerve stimulation (VNS), deep brain stimulation (DBS), neuromodulation, and more recently focal minimal or noninvasive ablation. What is critical when we consider the pharmacoresistance aspect with the potential solution through surgery, is still the pursuit of localization-dependent regions (e.g.: epileptogenic zone (EZ)), in order to decide, no matter how sophisticated are the brain mapping tools (EEG and MRI), the size and location of the tissue to be removed. Mimicking the semiology and studying potential neural mechanisms and molecular targets - by means of experimental and computational modeling - are fundamental steps of the whole process. Concluding, with the conjunction of ancient knowledge, coupled to critical and creative contemporary, scientific (not dogmatic) clinical/surgical, and experimental/computational contributions, a better world and of improved quality of life can be offered to the people with epilepsy and neuropsychiatric comorbidities, who are still waiting (as well as the scientists) for a paradigm shift in epileptology, both in the Basic Science, Computational, Clinical, and Neurosurgical Arenas. This article is part of the Special Issue "NEWroscience 2018".

Hemispheric surgery is an effective and cost-effective option for hemispheric epilepsy. Data specifically focusing on very early infancy are scant. In our study, we report the results of hemispheric surgery in children under three years of age, along with clinical, neuroradiological and EEG features, from two Italian epilepsy surgery centres. After reviewing our epilepsy surgery databases (2008-2018), we identified 14 patients (seven males) submitted to hemispheric surgery, under three years (range: 2-29 months), with a follow-up of at least 12 months. No deaths occurred, and surgical complications were observed in 3/17 procedures. At final follow-up visit (mean: 30.8 months; range: 12-90), 10/14 patients (71.4%) achieved Engel Class I (eight Class 1A, one Class 1B, and one Class 1C). Antiepileptic drugs were completely discontinued in three and reduced in eight, thus a significant decrease in drug regimen after surgery was achieved in 11/14 patients (78.6%). Before surgery, severe developmental delay was present in 10 patients, moderate in two and mild in two. At the last follow-up visit, the degree of developmental delay changed from severe to moderate in five patients, remained unchanged in six cases (four severe and two moderate), and changed from mild to moderate in two following surgery. In many cases, hemispheric surgery in children under three years is effective in achieving seizure freedom or reducing seizure frequency, with the possibility of simplifying complex drug regimens. Moreover, it appears to be a safe and well tolerated procedure, leading to improvement in cognition and posture.