[Functional hemispherectomy: long-term follow-up in a series of five patients]. / Hemisferectomia funcional: seguimiento a largo plazo en una serie de cinco casos.

INTRODUCTION: Functional hemispherectomy consists in palliative epilepsy surgical procedure usually performed in patients with pharmaco-resistant epilepsy and hemispheric syndromes. It is based on the neural disconnection of the affected hemisphere with preservation of the vascular supply. AIM: To analyze long-term prognosis and safety of the hemispherectomies performed in our institution. PATIENTS AND METHODS: Retrospective analysis collecting the following variables: age, gender, age of epilepsy onset, type of seizures, etiology, age of epilepsy surgery, prognosis and potential surgical complications. All patients had a minimum of five years of follow up. RESULTS: Five patients (60% females) underwent hemispherotomy between 1999 and 2010. Age of epilepsy onset was 36 months and time of evolution until surgery was 7 years. The most frequent type of seizures were simple motor seizures with secondary generalization (n = 5). Three patients remained seizure free persistently after surgery and another patient had a more than 90% improvement. Time of follow up was 13 years. One patient suffered a bacterial meningitis without sequelae. Six years after surgery a patient suffered hydrocephalous requiring ventriculoperitoneal shunt. CONCLUSIONS: Functional hemispherectomy constitutes an effective method to treat patients with pharmaco-resistant epilepsy, extensive unihemispheric pathology and seizures limited to that hemisphere. Late complications may occur thus long-term follow-up is needed.

TITLE: Hemisferectomia funcional: seguimiento a largo plazo en una serie de cinco casos.Introduccion. La hemisferectomia funcional es una de las tecnicas quirurgicas con intencion paliativa que se pueden realizar en pacientes con epilepsia farmacorresistente y sindromes hemisfericos. Se basa en la desconexion neuronal del hemisferio afectado preservando el arbol vascular. Objetivo. Analizar el pronostico y la seguridad a largo plazo de las hemisferectomias realizadas en nuestro centro. Pacientes y metodos. Revision retrospectiva de los casos intervenidos, recogiendo las siguientes variables clinicas: edad, sexo, edad de inicio de la epilepsia, tipo de crisis, etiologia de la epilepsia, edad de intervencion, pronostico posquirurgico y posibles complicaciones. El seguimiento minimo fue de cinco años. Resultados. Cinco pacientes (60% mujeres) fueron intervenidos entre 1999 y 2010. La edad de inicio de la epilepsia fue de 36 meses, y el tiempo de evolucion hasta la cirugia, de 7 años. El tipo de crisis mas habitual fueron las crisis parciales simples motoras con generalizacion secundaria (n = 5). Tres pacientes permanecieron libres de crisis tras la cirugia, y otro paciente mejoro mas de un 90%. El tiempo medio de seguimiento fue de 13 años. Como complicaciones, una paciente sufrio una meningitis bacteriana sin secuelas posteriores. A los seis años de la cirugia, un paciente presento una hidrocefalia que requirio la implantacion de una valvula de derivacion ventriculoperitoneal. Conclusiones. La hemisferectomia funcional constituye un procedimiento quirurgico eficaz para el tratamiento de pacientes con epilepsia farmacorresistente, patologia hemisferica extensa y crisis limitadas a ese hemisferio. Hay complicaciones que pueden aparecer tardiamente, por lo que se aconseja un seguimiento a largo plazo de estos pacientes.

Seizure Outcome after Anterior versus Complete Corpus Callosotomy in Children: A Systematic Review with Meta-Analysis / Controle das crises epilépticas após calosotomia anterior versus completa em crianças: uma revisão sistemática com metanálise

Introduction Refractory epilepsy is a debilitating and challenging condition to manage. Corpus callosotomy (CC) seems to be an effective treatment option for patients with seizures not amenable to focal resection. The aim of the present study is to compare seizure outcome of pediatric patients following anterior CC, compared with complete CC. Method The authors performed a systematic review and meta-analysis of the English literature involving comparative studies. Results The present investigation includes four retrospective case-controlled studies and authors perform a pooled analysis of the surgical results. Seizure outcome presented favorable results in patients who underwent complete CC (Odds Ratio, M-H, Fixed, 95% CI: 3.02 [1.43, 6.387], p-value: 0.005). Clinical and neurological complications occurred independently when a complete or anterior CC was performed. Conclusion Complete CC seems to be the most effective treatment option to control intractable seizure in children not amenable to focal resection.

Introdução Epilepsia refratária é uma condição debilitante e desaadora para lidar. Calosotomia parece ser uma opção de tratamento ecaz para pacientes com convulsões não passíveis de ressecção focal. O objetivo do presente estudo é comparar o resultado de convulsões em pacientes pediátricos de acordo com calosotomia anterior e completa. Métodos Uma revisão sistemática e metanálise da literatura médica em inglês envolvendo estudos comparativos. Resultados Quatro casos retrospectivos foram incluídos na presente investigação e uma análise dos resultados cirúrgicos foi realizada. Convulsões decorrentes tiveram resultados favoráveis em pacientes submetidos a calosotomia complete (odds ratio, M-H, xo, 95% IC: 3,02 [1,43; 6,387], valor de p: 0,005). Complicações clínicas e neurológicas ocorreram independentemente de se calosotomia complete ou anterior. Conclusão Calosotomia completa parece ser a opção de tratamento mais ecaz para controlar convulsões não rastreáveis e não passíveis de ressecção focal em crianças.

Trends in outcomes, complications, and hospitalization costs for hemispherectomy in the United States for the years 2000-2009.

OBJECTIVE: Hemispherectomy is an established surgical treatment for carefully selected pediatric patients with intractable epilepsy. Published perioperative data report low mortality rates and seizure reduction rates of 50-89%. This study investigates trends in the demographics, hospital utilization, and in-hospital complication rates of patients undergoing hemispherectomy over the past decade in the United States, using the nationally representative Kids' Inpatient Database (KID). METHODS: The KID was queried for all discharges with the International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) procedure code for hemispherectomy in the years 2000, 2003, 2006, and 2009. The patient cohorts from these four time points were compared, analyzing differences in demographic data, insurance and payer status, total cost, length of stay, in-hospital mortality, and complications. National estimates and 95% confidence intervals are reported given the weighted sample design of KID. RESULTS: This study identified an estimated total of 552 hospital admissions for hemispherectomy surgery during the years studied in this cohort. The incidence of this procedure increased from 1.2/100,000 admissions in 2000 to 2.2/100,000 in 2009 (p=0.05). Mean age was 6.7 years (range 0-20). There were no significant changes in demographics (age, gender, or race), hospital descriptors (size or type), insurance type, or zip code income quartile. There was a significant increase in total cost, from $42,807 in 2003 to $57,443 in 2009 (p=0.015) (adjusted to 2009 dollars). There were no trends in postoperative complications. In-hospital mortality occurred in five subjects (0.9%). Ventricular shunt placement during hemispherectomy hospitalizations increased over time from 6.7% to 16.5% (p=0.056). Hospitals that performed two or more hemispherectomies yearly had a significantly decreased incidence of in-hospital mortality (odds ratio [OR] 0.08, p=0.04) and an increased incidence of blood transfusion (OR 3.7, p=0.01) compared to hospitals that performed 0-1 procedures a year. SIGNIFICANCE: Hemispherectomy procedures increased slightly in frequency over the past decade, with no change in demographic characteristics of the patients over time. Rates of mortality and perioperative complications remained low. Total costs have increased significantly over time. In-hospital mortality was lower in higher volume hospitals.

[Seizure outcomes of cerebral hemispherectomy in adults: A systematic review and individual patient data meta-analysis]. / Control de las crisis epilépticas con la hemisferectomía cerebral en adultos: revisión sistemática y metaanálisis con datos de pacientes individuales.

OBJECTIVE: The objective of our study was to determine the seizure control rate of cerebral hemispherectomies in adult patients with drug-resistant epilepsy. MATERIALS AND METHODS: A systematic review and individual patient data meta-analysis was carried out. Seven international databases and scientific meeting proceedings were reviewed. Individual patient data were analysed to establish potential factors associated with postoperative seizure control. RESULTS: Eight articles that satisfied the pre-established selection criteria were identified. After a median follow-up of 70 months (interquartile range, 29-175.5), 79.4% of patients remained seizure-free. There were no statistically significant differences in age at onset of epilepsy, duration of epilepsy, age at surgery, time of follow-up, gender, surgical-laterality, aetiology and ictal EEG abnormalities between seizure-free patients and those with recurrences. CONCLUSIONS: Cerebral hemispherectomy has a high seizure control rate in adult patients with drug-resistant epilepsy. None of the variables analysed in the present study were associated with surgical success.

Anatomic hemispherectomy: historical perspective.

The history of surgical treatment for hemispheric epilepsy is rich with colorful twists and turns. The authors trace the evolution of the surgical treatment of hemispheric epilepsy from radical anatomic resections to current less invasive disconnection procedures. Anatomic hemispherectomy (AH) was first described by Dandy in 1928 as a treatment for gliomas. The first report of this technique to control seizures was by McKenzie in 1938. AH gained wide popularity but began to fall out of favor after the description of superficial cerebral hemosiderosis in 1966. To reduce the morbidity and mortality associated with AH, Rasmussen introduced functional hemispherectomy in 1974. The technique of hemispherotomy was introduced in the 1990 s to minimize the extent of brain removal while maximizing the white matter disconnections. Thus, surgery for hemispheric epilepsy has undergone dramatic transformation since the technique was first introduced. Less invasive techniques have been developed to reduce surgical morbidity. Although optimal seizure control is best achieved with radical AH, the newer less invasive disconnection techniques appear to achieve near-comparable postoperative seizure control with a significantly lower rate of complications.

Epilepsy surgery in children compared to adults.

AIM: The purpose of this study was to compare the frequency of various surgical techniques and surgical outcome between pediatric and adult populations that underwent epilepsy surgery by the same team. METHODS: All patients who underwent epilepsy surgery at the Tel Aviv Medical Center between 1997 and 2006 and had been followed up for >2 years were eligible for this study. The majority (90%) of all epilepsy surgeries carried out in Israel were performed in this institution and by a single neurosurgeon. Only patients that underwent video-EEG monitoring as part of the presurgical evaluation were included in the study. RESULTS: A total of 186 patients (131 adults and 55 children) underwent epilepsy surgery in our institute during the study period, and follow-up was available for 177 patients (95%). While the adults underwent significantly more temporal lobe resections (51 vs. 20%, p < 0.0001), the children had significantly more extra-temporal non-lesional resections (18 vs. 1%, p < 0.0001) and hemispherectomies (5 vs. 1%, p = 0.002). Over one half (54%) of all the patients had a postoperative reduction in seizures of >90%, and 72% had a reduction of >50%, with no group difference in surgical success. Among the lesionectomies, the outcome was better for tumors, especially those in the temporal lobe. Only 1% of the patients had a long-term neurological deficit. CONCLUSIONS: Children comprised 30% of the epilepsy surgical cases during the study period. Children underwent more non-lesional resections and hemispherectomies, while adults underwent more temporal lobe resections. There was no age-related difference in surgical outcome.

[Functional hemispherectomy in adult patients with catastrophic epilepsy: a new therapeutic indication?]. / La hemisferectomía funcional también es eficaz en pacientes adultos con epilepsia catastrófica: ¿una nueva indicación terapéutica?

Functional hemispherectomy was reported in 1983 for the treatment of catastrophic refractory epilepsies in order to reduce the complications derived by the anatomical hemispherectomy. A series of variants of the functional hemisphectomy have been reported. They include peri-insular hemispherectomy, modified lateral hemispherectomy, vertical parasagital hemispherectomy. The functional hemispherectomy has been used mainly in the treatment of catastrophic epilepsies in children, in which extensive hemispheric lesions are associated with pharmacoresistant epileptic seizures and focal neurological deficit such as: Rasmussen's encephalitis, hemimegalencephaly, Sturge-Weber syndrome, and extensive hemispheric cortical dysplasias, etc. Recently, two series of adults patients with catastrophic epilepsies with excellent control of the episodes (above 75 %) and without mortality have been reported. Thus, functional hemispherectomy may be an effective procedure in appropriately selected adult patients, although more studies with larger series are still needed to evaluate the long-term prognosis.

[Successful functional hemispherectomy in adult patients with refractory epilepsy]. / La hemisferectomía funcional también es eficaz en pacientes adultos con epilepsia catastrófica.

INTRODUCTION: Functional hemispherectomy is a surgical technique used to treat refractory epilepsies in the setting of extensive unilateral hemispheric lesions. Most series of hemispherectomies include mainly pediatric patients. METHODS: We report our series of four adult patients that have undergone functional hemispherectomy for their refractory epilepsy. Each one had a complete presurgical evaluation including video EEG, neuropsychological testing and anatomical and functional neuroimaging. In three of them, the epilepsy was secondary to a middle cerebral artery infarction. One patient had Rasmussen encephalitis. RESULTS: After surgery, three patents have become completely seizure free (follow up 13-26 months). The fourth patient has had more than 75% reduction in seizure frequency. All of them have had significant improvement in their quality of life. Early complications included an isolated tonic-clonic generalized seizure (one patient), and status epilepticus in another patients related to infection and use of meropenem. Only one patient has presented hemianopia as a permanent neurological deficit after surgery. CONCLUSIONS: Functional hemispherectomy is a good surgical option in the setting of large unilateral hemispheric lesions causing hemiparesis and intractable seizures, even in adult patients.

Outcomes of epilepsy surgery in adults and children.

Surgery is widely accepted as an effective therapy for selected individuals with medically refractory epilepsy. Numerous studies in the past 20 years have reported seizure freedom for at least 1 year in 53-84% of patients after anteromesial temporal lobe resections for mesial temporal lobe sclerosis, in 66-100% of patients with dual pathology, in 36-76% of patients with localised neocortical epilepsy, and in 43-79% of patients after hemispherectomies. Reported rates for non-resective surgery have been less impressive in terms of seizure freedom; however, the benefit is more apparent when reported in terms of significant seizure reductions. In this Review, we consider the outcomes of surgery in adults and children with epilepsy and review studies of neurological and cognitive sequelae, psychiatric and behavioural outcomes, and overall health-related quality of life.

Defining the spectrum of international practice in pediatric epilepsy surgery patients.

PURPOSE: The Pediatric Epilepsy Surgery Sub-commission of the International League Against Epilepsy conducted a survey to determine the frequency of epilepsy procedures and etiologies. METHODS: Data were gathered from 20 programs in the United States, Europe, and Australia on 543 patients (<18 years) for calendar year 2004. RESULTS: Age at seizure onset was 1 year or less in 46% of patients. Intracranial electrodes were used in 27% of patients. The most common final operation was lobar and focal resections of the frontal and temporal lobes (41%), followed by cerebral hemispherectomy (16%), vagus nerve stimulator (16%), and multilobar resections (13%). Multiple-subpial transections were uncommon procedures (0.6%). The most frequent etiologies were cortical dysplasia (42%), tumors (19%), and atrophic lesions and strokes (10%). Less common were vascular lesions (1.5%), Rasmussen encephalitis (3%), Sturge-Weber (3%), and operations for infantile spasms (4%), and Landau-Kleffner/ESES (<2%). Children <4 years generally presented with daily seizures from cortical dysplasia and underwent multilobar or hemispherectomy. Previous surgeries before 2004 were reported in 22%, and occurred more commonly in patients with tumors (40%), hypothalamic hamartomas (47%), and vascular lesions (67%). U.S. centers reported more vagus nerve stimulator procedures, operated more often on children with no or subtle MRI findings, and used intracranial electrodes and functional neuroimaging more frequently than programs in Europe and Australia. CONCLUSIONS: The results of this international survey show the feasibility of international collaborations in determining epilepsy etiologies and procedures in children, and suggest differences in clinical practice between regions of the world. These results can guide the design of future studies in producing guidelines for therapy-resistant pediatric epilepsy surgery patients.

Is epilepsy surgery on both hemispheres effective?

BACKGROUND: Patients with bilateral independent seizure foci are poor candidates for conventional resective epilepsy surgery. The authors have therefore used minimally invasive procedures to treat such patients. In this paper, the result of a large series of patients treated by this approach is examined to determine the effectiveness of this approach. MATERIALS AND METHODS: The series had 61 patients. The range of follow-up was 15-90 months. The mean follow-up was 41.5 months with a median of 37 months. Patients' ages at the time of surgery ranged from 3 to 54 years, with a mean of 11.3 and median of 6. Male to female ratio was 39/22. Fifty patients had complex partial seizures, 3 had Lennox-Gastaut syndrome, 4 had myotonic seizures, 2 had infantile spasm, and 2 had myoclonic seizures. Preoperative evaluation included: video electroencephalogram (EEG) monitoring using scalp electrodes, neuropsychological evaluation, magnetic resonance scans, positron emission topography and/or single photon emission computed tomography scans, magnetoencephalogram, Wada test and video EEG recording using subdural electrodes. Multiple subpial transection (MST) was the principle procedure. This procedure was supplemented (17 patients) with minimal cortical resection when intraoperative electroencephalogram indicated that an area failed to respond to MST. When an additional epileptogenic focus was present in the amygdala-hippocampus complex (5 patients), it was treated with stereotactic amygdala-hippocampotomy. The eloquent cortex was treated in 51 patients. The number of lobes treated was 2 in 5 patients, 3 in 5 patients, 4 in 10 patients, 5 in 2 patients, 6 in 38 patients and 8 in 1. RESULTS: Seizure outcome based on Engel's modified classification was as follows: 32 patients (52.45%) were class I, 5 (8.2%) were class II, 15 (24.59%) were class III, 3 (4.9%) were class IV and 6 (9.83%) were class V. There was no statistical difference between those who were operated on of the first half of the series and those who were operated on of the second half of the series (p = 0.1636). Similarly, there was no statistical difference between this series and two large series in which MST had been performed on one hemisphere (p values of 0.6863 and 0.7337). There was no statistical difference between those who had MST alone and those who had MST plus minimal cortical resection (p = 0.1698). There was no permanent neurological complication in this series. CONCLUSION: Patients with intractable epilepsy with independent seizure foci in both hemispheres can be safely treated with the approach described in this paper, and seizure control achieved by this approach is fairly satisfactory and similar to that reported in patients with surgery on one hemisphere.

[Surgical treatment of epilepsy: outcome of various surgical procedures in adults and children]. / Evaluation des résultats de la chirurgie de l'épilepsie.

Surgical treatment of drug-resistant epilepsy is being performed in a growing number of adults and children. The objective of this report is to review and evaluate the published literature related to the outcome of epilepsy surgery. Surgical procedures were classified as "curative", which included temporal and extratemporal resections, as well as hemispherotomy and stereotactic radiosurgery, and as "palliative", which mainly included callosotomy and multiple subpial transections. Data obtained from the literature suggest that after temporal lobe surgery, 68 percent of the adult patients, on average, are seizure-free. This result may vary, according to the authors, from 50 to 93 percent. One randomized controlled study concludes that 58 percent of patients treated surgically become seizure-free, compared to only 8 percent in the group of patients who do not receive surgery. This suggests that temporal lobe surgery is an efficient treatment of drug-refractory temporal lobe surgery. Seizure outcome is similar in the pediatric population. Studies of frontal lobe surgery report that an average of 60 percent of patients are seizure-free after surgery, in adults as well as in children. These results may vary considerably, depending on how the seizure outcome is defined. Too few studies are available to allow for an evaluation of parietal or occipital lobe surgery. Hemispherotomy is mostly performed in the pediatric population. Studies of this procedure report that 60 percent of patients become seizure free after surgery, whereas 80 percent are improved in terms of seizure outcome and in terms of behavior. Stereotactic radiosurgery may be performed in case of hypothalamic hamartoma, and in some cases of temporal lobe epilepsy. In this later case, the reported results are similar to those obtained with temporal resections. Seizure outcome after corpus callosotomy is difficult to summarize, because of the many variations, according to the authors, of the definition of a good or poor seizure outcome. However, it can be stated that 65 to 85 percent of patients achieve a significant reduction in overall seizure frequency. The best reduction in seizure frequency is achieved in patients with atonic. Reported percentages of patients who benefit from multiple subpial transection, varies between 50 and 70 percent. In conclusion, our report shows that temporal resection is an efficient and scientifically validated treatment of drug-resistant temporal lobe epilepsy. Extra-temporal resections, hemispherotomy, and palliative surgery often allow cure of epilepsy, or a decrease of seizure frequency, however, prospective studies of these surgical procedures are needed.

Cerebral hemispherectomy: hospital course, seizure, developmental, language, and motor outcomes.

OBJECTIVE: To compare hemispherectomy patients with different pathologic substrates for hospital course, seizure, developmental, language, and motor outcomes. METHODS: The authors compared hemispherectomy patients (n = 115) with hemimegalencephaly (HME; n = 16), hemispheric cortical dysplasia (hemi CD; n = 39), Rasmussen encephalitis (RE; n = 21), infarct/ischemia (n = 27), and other/miscellaneous (n = 12) for differences in operative management, postsurgery seizure control, and antiepilepsy drug (AED) usage. In addition, Vineland Adaptive Behavior Scale (VABS) developmental quotients (DQ), language, and motor assessments were performed pre- or postsurgery, or both. RESULTS: Surgically, HME patients had the greatest perioperative blood loss, and the longest surgery time. Fewer HME patients were seizure free or not taking AEDs 1 to 5 years postsurgery, but the differences between pathologic groups were not significant. Postsurgery, 66% of HME patients had little or no language and worse motor scores in the paretic limbs. By contrast, 40 to 50% of hemi CD children showed near normal language and motor assessments, similar to RE and infarct/ischemia cases. VABS DQ scores showed +5 points or more improvement postsurgery in 57% of patients, and hemi CD (+12.7) and HME (+9.1) children showed the most progress compared with RE (+4.6) and infarct/ischemia (-0.6) cases. Postsurgery VABS DQ scores correlated with seizure duration, seizure control, and presurgery DQ scores. CONCLUSIONS: The pathologic substrate predicted pre- and postsurgery differences in outcomes, with hemimegalencephaly (but not hemispheric cortical dysplasia) patients doing worse in several domains. Furthermore, shorter seizure durations, seizure control, and greater presurgery developmental quotients predicted better postsurgery developmental quotients in all patients, irrespective of pathology.