Callosotomía posterior: un nuevo abordaje en Cirugía de Epilepsia / Posterior callosotomy: a new approach in Epilepsy Surgery

Objetivo: describir la nueva técnica de callosotomía posterior utilizada en cirugía de epilepsia, junto a sus indicaciones, ventajas comparativas y sus resultados. Métodos: se muestran en secuencias de video dos casos de callosotomía posterior, en pacientes con epilepsia refractaria severa, con crisis tipo "drop attacks" (pérdida súbita del tono postural), presentando traumatismos a repetición, con potencial riesgo de vida. Ambos pacientes, una mujer de 35 años y un varón de 24 años de edad, presentaban una malformación congénita del desarrollo cortical denominada doble corteza. Un caso fue operado en posición semisentada, con abordaje parafalcino derecho, el segundo en decúbito ventral, con abordaje parafalcino izquierdo. Se realizó una incisión vertical parasagital de 7cm, a 2 cm de la línea media, con límite inferior en el inion y superior en la unión de la sutura sagital y lambdoidea. Se realizó una craneotomía de 5 x 5cm, exponiendo el seno longitudinal superior. La anatomía venosa de la región permite sin inconvenientes el desplazamiento lateral occipito-parietal. Se realizó una callosotomía que incluyó esplenio y cuerpo llegando anteriormente al sector que une ambas áreas motoras suplementarias. Resultados: no se presentaron complicaciones postoperatorias. El síndrome de desconexión apareció en un caso, desapareciendo en un periodo de 2 semanas. Se obtuvo una reducción del 90% de crisis, mejorando la calidad de vida y otorgando un mayor grado de independencia a ambos pacientes. Conclusión: la callosotomía posterior es un procedimiento seguro, poco invasivo y altamente efectivo contra las crisis de drop attacks en epilepsias refractarias

Objective: to describe the new technique of posterior callosotomy applied to epilepsy surgery, including its indication, comparative advantages and results. Methods: two surgical cases are presented on video sequences, including patients with refractory epilepsy, with "drop attack" type seizures (loss of postural tone), presenting with recurring trauma and a potential life risk. Both patients, a 35 years-old woman and a 24 years-old man suffered from a congenital malformation of cortical development known as double cortex. One of the cases was operated in a semi-sitting position, trough a right parafalcine approach, and the other one in a prone position trough a left parafalcine approach. A 7cm parasagittal vertical incision, 2cm lateral to midline was performed, considering its upper limit at the union of the lambdoid and parasagittal suture, and its lower limit at the inion. A craniotomy of 4 by 4cm was performed, exposing the superior sagittal sinus. The venous regional anatomy allows an easy parieto-occipital lateral retraction. The callosotomy included the splenium and the body reaching anteriorly up to the region where we find both supplementary motor areas. Results: no postoperative complications were found. One case presented with a disconnection syndrome, resolving in 2 weeks. A 90% reduction of the seizure frequency was achieved, improving the quality of life and the degree of Independence of the patients. Conclusions: posterior callosotomy is a safe, less invasive and highly effective procedure against drop attack type seizures in refractory Epilepsy

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.

Resultados de callosotomía en adultos con diagnóstico de epilepsia refractaria y drop-attack / Callosotomy results in adults with diagnosis of refractory epilepsy and drop-attack

Introduction: For patients with refractory epilepsy patients, the sub-group characterized for seizures involving falls or drop-attack, the technique of callosotomy, as a palliative measure has been validated and used to control this type of seizures. Method: Group of 16 patients operated during period of four years, evaluated by protocol, which was performed as a palliative callosotomy crisis management technique was evaluated. Results: The observed group, 10 were males and 6 females, mean age 30 years, range between 19-46 years. Average evolution of epilepsy in 20.8 years, 14 cases crisis was starting before age 14. Major crises were TCG (generalized tonic clonic) and a tonic seizures were being 62.5 percent daily and 37.5 percent monthly, 100 percent had a history of TEC (brain trauma) and 56 percent history of status epilepticus. Was performed anterior callosotomy two thirds in 8 patients (mean follow-up 23.8 months), 6 patients complete callosotomy (average follow-up 15.5 months), and in 2 cases, two anterior thirds and then total callosotomy (1 case 22 months, and another 1 month follow-up). Seizures management fall > 50 percent in 75 percent of patients (3 cases without seizures of fall with anterior callosotomy two thirds), and for complete callosotomy, 100 percent control crisis in > 80 percent of patients (3 cases without seizures of fall was found in this group). Conclusion: The technique callosotomy as a palliative measure in the context of drop-attack or crises involving falls, in our experience with adult patients, has been a good tool in controlling this type of seizures.

Introducción: Dentro del grupo de pacientes refractarios en epilepsia, el sub-grupo caracterizado por crisis que involucran caídas o drop-attack, la técnica de callosotomía, como medida paliativa, ha sido validada y utilizada para el control de este tipo de crisis. Método: Se evaluó grupo de 16 pacientes adultos operados durante período de 4 años, evaluados por protocolo, donde se realizó callosotomía como técnica paliativa de control de crisis. Resultados: Del grupo observado, 10 fueron varones, 6 mujeres, promedio de edad 30 años, rango entre 19 a 46 años. Promedio de evolución de epilepsia de 20,8 años. En 14 casos el inicio de crisis fue antes de los 14 años. Principales crisis fueron TCG (tónico clónico generalizada) y atónicas, siendo en el 62,5 por ceinto diarias y en el 37,5 por ciento mensuales, el 100 por ceinto tenía antecedente de TEC (trauma encéfalo craneano) y en el 56 por ciento antecedente de status epiléptico. Se realizó callosotomía dos tercios anterior en 8 pacientes (seguimiento 23,8 meses promedio), 6 pacientes callosotomía total (seguimiento 15,5 meses promedio), y en 2 casos, dos tercios anterior y luego callosotomía total (1 caso 22 meses, y otro, 1 mes de seguimiento). Se encontró control de crisis de caídas > 50 por ciento en el 75 por ciento (3 casos sin crisis) de casos con callosotomía dos tercios anterior, para callosotomía completa, 100 por ciento control de crisis en > 80 por ciento (3 casos sin crisis) de este grupo. Conclusión: La técnica de callosotomía como medida paliativa en el contexto de drop-attack o crisis que involucren caídas, en nuestra experiencia en pacientes adultos, ha sido una herramienta útil en el control de este tipo de crisis.

Estimulador de nervo vago em paciente com síndrome de Lennox-Gastaut: relato de caso / Vagus nerve stimulator in a patient with Lennox-Gastaut syndrome: case report

A Síndrome de Lennox-Gastaut (SLG) é uma encefalopatia epiléptica grave da infância caracterizada por múltiplos tipos de crises intratáveis, anormalidades cognitivas e comportamentais e alterações eletroencefalográficas características. Na grande maioria dos casos as crises se tornam refratárias mesmo com politerapia, sendo indicado tratamentos alternativos. O uso de calosotomia é descrito para ajudar no controle das crises, entretanto novas terapias como o estimulador de nervo vago (ENV) começaram a ser utilizadas. Neste caso, relatamos um paciente com SLG, que apesar das drogas antiepilépticas apresentava crises diárias, que foi submetido a ENV, com redução das crises. Discutimos o tratamento não farmacológico da SLG, comparando a calosotomia com ENV...

The Lennox-Gastaut Syndrome (LGS) is a severe childhood epileptic encephalopathy characterized by multiple types of intractable seizures, cognitive and behavioral abnormalities and specific electroencephalographic features. Most patients are refractory even with polytherapy, so alternative treatment is indicated. Callosotomy is indicated in these cases, however vagus nerve stimulator (VNS) is a less invasive option. This is a case report of a patient with LGS, which despite antiepileptic drugs had daily seizures, who underwent VNS, with reduction of seizures. We discuss the nonpharmacological treatment of LGS, comparing the callosotomy with VNS...

Callosotomía en el tratamiento de epilepsia resistente / Callosotomy in the management of refractory epilepsy

La callosotomía es una técnica aunque antigua aun hoy en día sigue vigente como opción terapéutica quirúrgica en pacientes con epilepsia refractaria, en especial pacientes con epilepsia multifocal, crisis tónicas, atónicas y drops attacks, es una cirugía segura con baja morbilidad y mortalidad siendo la mayoría de las vecescomplicaciones transitorias...

Corpus callosotomy is a technique old today it is still a therapeutic option in patients with refractory epilepsy, especially patients with multifocal epilepsy, Tonic seizures, atonic and drops attacks, is a safe surgery with low morbidity and mortality to be mostoften transient complications...

Corpus Callosotomy in Lennox-Gastaut Syndrome / 대한간질학회지

PURPOSE: Lennox-Gastaut syndrome (LGS) is one of the most devastating pediatric epileptic syndromes characterized by various disabling seizures, generalized forms of abnormal epileptiform EEG features and progressive psychomotor retardation. Corpus callosotomy is one of treatment options in patients with intractable LGS without definitive focal cortical pathology. This study was designed to evaluate efficacy and safety of corpus callosotomy in patients with LGS. PATIENTS AND METHODS: Thirty patients (21 boys, 9 girls) with LGS who had corpus callosotomy at Severance Children's Hospital from October 2003 to January 2007, were enrolled with mean follow-up of 34.6+/-14.0 months. We retrospectively reviewed medical records, video-EEG monitoring, MRI, seizure outcome and postoperative complications. RESULTS: Mean age of corpus callosotomy was 100.7+/-56.4 months. Twenty-four patient (80.0%) underwent total corpus callosotomy and 6 (20.0%) underwent resection of the anterior 4/5 of corpus callosum. Seizure outcomes were as follows: 5 patients (16.7%) were Engel class I, 9 (30.0%) were class II, 6 (20.0%) were class III and 10 (33.3%) were class IV. Postoperative complications were seen in 4 patients (13.3%), such as hemorrhage (2 patients), involuntary movement (1 patient) and transient ataxia (1 patient), but all were recovered completely. Subsequent resective surgery was performed in 5 patients of Engel class III and IV, whose EEG features became lateralized without complete seizure control. Satisfactory surgical outcomes (class I and II) were achieved in 46.7% of total patients. CONCLUSIONS: Corpus callosotomy could be effective and safe treatment in medically intractable LGS without focal pathology.

Calosotomia em paciente com epilepsia generalizada primária e crises tônico-clônicas generalizadas refratárias: relato de caso / Callosotomy in patients with primary generalized epilepsy and generalized tonic-clonic seizures: case report

INTRODUÇÃO: Pacientes com epilepsia generalizada primária (idiopática) podem, raramente, não responder ao tratamento medicamentoso e assim apresentar crises tônico-clônicas generalizadas (CTCG) recorrentes, incapacitantes e que colocam o paciente em risco de complicações graves. OBJETIVO: Nesse artigo é relatado o caso de um paciente com epilepsia generalizada primária e CTCG semanais, refratárias a diversos esquemas medicamentosos, que foi submetido a uma calosotomia. RESULTADO: No curto espaço de 3 meses de seguimento pós-operatório, o paciente não mais apresentou CTCG. CONCLUSÃO: A calosotomia pode ser um procedimento útil na redução da freqüência de CTCG refratárias, mesmo em pacientes com epilepsia generalizada primária.

INTRODUCTION: Patients with idiophatic generalized epilepsy (IGE) may occasionally have frequent generalized tonic-clonic seizures (GTCS) which are not adequantely controlled by antiepileptic drugs. Frequent GTCS pose a significant risk of injury and other complications. In symptomatic generalized epilepsies, corpus callosotomy (CC) has been shown to be effective in reducing the number of generalized seizures. OBJECTIVE: We report a patient with refractory, weekly GTCS in the context of a primary generalized epilepsy syndrome who underwent subtotal CC. RESULT: In the 3 months since operation, no GTCS occurred. CONCLUSION: Corpus callosotomy can be helpful in reducing medically-refractory GTCS, even in patients with primary generalized epilepsies.

Epilepsy Surgery II

Epilepsy surgery is classified into two types: curative epilepsy surgery and palliative surgery. The most frequently performed curative epilepsy surgery is an anterior temporal lobectomy with amygdalohippocampectomy (ATL with AH). ATL with AH includes the resection of epileptic hippocampus/amygdala and anterior temporal lobe (3~4cm from temporal pole) and is performed for treating drug refractory mesial temporal lobe epilepsy. A literature reports that more resection of epileptic hippocampus had a better surgical outcome. However, a surgery should be planned to prevent or minimize a postsurgical memory decline especially in resection of a dominant temporal lobe. Cortisectomy is a resection of localized epileptic focus in patients with neocortical epilepsy such as frontal, parietal, occipital, and lateral temporal lobe epilepsies. Most of neocortical epilepsy patients need an intracranial electrode implantation for determination of resection margin and a brain stimulation on intracranial electrodes for functional mapping. For a successful cortisectomy, an epilepsy surgery team should have a good amount of knowledge and experiences in intracranial EEG monitoring for intractable epilepsy patients. It is very important to place the intracranial electrodes at a brain region where epileptic focus is located because a wrong placement of intracranial electrodes results in failure of surgery. The surgical principles of functional hemispherectomy (FH) aim at disconnecting the hemisphere while leaving as much of the ipsilateral brain as possible intracranially; it has been characterized as anatomically subtotal but physiologically complete hemispherectomy. The original technique consists of a large central tissue removal, complete callosotomy, frontal and parieto-occipital disconnection, temporal lobectomy and insular corticectomy. The candidates of FH are drug refractory partial epilepsy patients who have unilateral epileptic focus and severe brain damage in ipsilateral hemisphere with loss of finger movements of contralateral hand. Corpus callosotomy is a surgical technique severing the corpus callosum so that communication between the cerebral hemispheres is interrupted. In contrast with lobectomy, corpus callosotomy does not involve removing any brain tissue. Instead, it usually involves cutting the front two-thirds of this bundle (anterior callosotomy). Sometimes the other one-third is cut later (complete callosotomy). Corpus callosotomy is most effective for atonic seizures ("drop attacks"), less effective for tonic-clonic seizures and tonic seizures. Additionally, multiple subpial transection and neurostimulation techniques are described.

The Outcome of Corpus Callosotomy for Intractable Epilepsy: 10 Years Experience of Corpus Callosotomy

OBJECTIVE: The purpose of this study is to evaluate the effect of the corpus callosotomy and to elucidate possible prognostic factors. METHODS: The cases of 39 patients who underwent corpus callosotomy were reviewed retrospectively. Clinical outcomes were analyzed using Engel's classification, with consideration of various presurgical conditions and the extent of the callosal resection during follow-up more than one year. RESULTS: Satisfactory outcome (Engel's class I, II) was obtained in 20 patients (51%) of 39 patients. In 36 cases with drop attack seizures, the class I, II outcomes were 22 patients (61%). When the patients were grouped according to the extent of callosal resection, the class I, II outcomes were 50% of the patients with anterior 1/2 or 2/3, 50% of those with anterior 4/5 callosotomy, and 57% of those with total callosotomy, respectively. The mean follow-up period was 34 months (24 to 58 months). CONCLUSION: Although it is not statistically significant, the patients who had underwent total callosotomy show better outcomes than those with partial callosotomy. Corpus callosotomy is efficacious in controlling medically intractable epilepsy in appropriately selected patients.

Epilepsy Surgery I

Epilepsy is a chronic neurological disorder manifesting recurrent unprovoked epileptic seizures. About 20~30% of epilepsy patients are resistant to antiepileptic medications. These patients suffer from high risk of physical injury, unemployment, marital problem, and psychological stress. Epilepsy surgery is the firstly recommended treatment modality for the patients with medically intractable epilepsy. Presurgical evaluation is the most important process for performing epilepsy surgery. The ultimate goal of the presurgical evaluation in patients with medically refractory partial seizures is the localization of the epileptogenic zone and the resection of which is also both necessary and sufficient to render the patient seizure-free. The localization of the epileptogenic zone derives from a hierarchical synthesis of localizing data independently obtained from clinical, electrographic, neuroimaging, and neuropsychological examination. In addition, closely related to the goal of localizing the epileptogenic zone is the significant need for anticipating the risks of functional deficits that could derive from the surgical resection. Mesial temporal lobe epilepsy (TLE) is the best candidate for epilepsy surgery. Anterior temporal lobectomy with amygdalohippocampectomy is a surgical treatment method for mesial TLE and its seizure-free rate (SFR) is 60~90%, whereas one-year SFR of antiepileptic drug treatment for mesial TLE is 10~20%. Cortisectomy is a surgical method for extratemporal epilepsy and its SFR is about 40~70%. Corpus callosotomy is a partial or complete division of corpus callosum for preventing seizure propagations between right and left hemispheres and is effective for controlling atonic seizures. The variation of postsurgical seizure outcomes is related to the qualities of epilepsy surgery program, presurgical evaluation and surgical techniques. For the good surgical outcome, the epilepsy surgery program should include neurologist, neurosurgeon, neuropsychologist, neuro-radiologist and neuro-nuclear medicine specialist for a comprehensive team approach.

The Results of One stage Total Callosotomy in Pediatric Epilepsy / 대한간질학회지

PURPOSE: In the pediatric patients who have medically intractable epilepsy the callosotomy is useful to prevent the propagation of seizure from one hemisphere to the other. The indications of callosotomy are drop attack, life threatening primarily or secondarily generalized seizure, medically refractory mixed seizure types such as Lennox-Gastaut syndrome. In addition, the retarded children are not contraindicated. The anterior callosotomy is used to perform to control medically intractable epilepsy which is believed to have some advantages to total callosotomy. But, we propose that the anterior callosotomy does not seem to be superior to total callosotomy for the prevention of the propagation of seizure or complication. We describe a series of 21 patients with medically intractable epilepsy who underwent total callosotomy in one stage. METHODS: The diagnoses in these patients included Lennox-Gastaut syndrome, atonic seizure, infantile hemiplegia, and no obvious solitary seizure focus on chronic video/EEG monitoring to characterize seizures, electrographic activity, and postictal behaviors. Preoperatively 16 patients suffered from disabling drop attacks or intense head drop seizures which caused frequent physical injuries. Other types of seizures are 12 generalized tonic-clonic seizures, 7 complex partial seizures, 1 absence seizure, and 7 myoclonic seizures. Male:Female=14:7, Age: 2-22 years (Mean: 9.4 years). The follow-up period ranged from 0.8 to 3.8 years (median 2.4 years). Seizure outcome, parental assessment of daily function, and parental satisfaction with outcome were assessed postoperatively. RESULTS: Drop attacks disappeared completely during the entire follow-up period in 13 patients and decreased to less than 10% of baseline in five. The corpus callosum of the one patient were not completely sectioned in Diffusion Tensor Image, tractography. Other types of seizures resolved completely in 14 patients and decreased in 7. 2 patients experienced a transient disconnection syndrome, but completely resolved within four weeks. Overall daily function improved and parents were satisfied with the surgical outcome in all patients except three who experienced recurrent of drop attacks after operation. There was no sign of significant and persistent neurological deficits in any case. CONCLUSION: Results of total callosotomy in patients with medically intractable epilepsy with diffuse epileptic foci were favorable in most cases. The procedure was particularly effective against drop attacks causing physical injuries and impaired quality of life in these patients.

The Surgical Effect of Callosotomy in the Treatment of Intractable Seizure

We evaluated the surgical effects of the callosotomy, particularly with respect to the effect of callosotomy in some seizure types and the extent of surgery. Twenty-one patients with a minimum follow-up of two year were enrolled. The most significant effect of callosotomy was the complete suppression of the generalized seizures associated with drop attack in 12 of 21 patients and seizure reduction of more than 75% in 6 of 21 patients. The surgical effect on the partial seizures was very variable. Transient disconnection syndrome appeared in 4 patients after anterior callosotomy. Total callosotomy by staged operation significantly suppressed generalized seizures associated with drop attack without any disconnection syndrome. Our data show that callosotomy is quite a good approach to the surgical treatment of drop attacks accompanied by disabling generalized seizures.

Outcome after Corpus Callosotomy in Intractable Epilepsy / 대한간질학회지

BACKGROUND: The authors present the results of a series of corpus callosotomies in 6 patients performed from 1998 to 2001 at the Samsung Medical Center. METHODS: Patients with medically intractable siezures, frequent drop attacks, poorly localized partial seizures with secondary generalization and generalized seizures were accepted as candidates (patients aged 14-29 years, 3 male and 3 female, with mean age at surgery of 18.6 years). Preoperatively, the frequency of seizures ranged from 2 to 600 per month. The standard microsurgical technique performed was a corpus callosotomy by the same surgeon under general anesthesia (anterior two-thirds corpus callosotomy was done in 4 cases, total callosotomy was done in 2 cases). In two cases, an additional cortical resection after electrocorticography using subdural electrode monitoring was carried out. The results were evaluated after a mean follow-up of 22 months (range, 4-34). We evaluated the effect of surgery according to the Engel classification. RESULTS: Complete freedom from seizures was noted in 2 cases (33%). More than 75% of reduction in seizure frequency was noted in 3 cases (50%). There was no significant reduction in frequency of seizure in one case. The highest rate of significant improvement was noted in the patients with drop attacks (75%(3/4)) and generalized tonic-clonic seizures (75%(3/4)). In one patient, pseudoaneurysm was complicated postoperatively but successful treatment was performed by endovascular procedure. Otherwise, there were no major postoperative complications except for brief mutism, slow activity and abnormal movement of one leg during the several weeks postoperatively. CONCLUSION: We conclude that corpus callosotomy is a safe alternative treatment for the medically intractable seizures, especially drop attack and generalized epilepsy.

Corpus Callosotomy for Intractable Epilepsy in Children: Seizure Outcome and Prognostic Factors / 대한간질학회지

PURPOSE: The therapeutic effectiveness of callosotomy in controlling medically intractable epilepsy has been discussed since first case reported. Nevertheless, patient selection, type of seizures and epileptic syndromes are now better determined. We reviewed the outcome of corpus callosotomy in 20 pediatric patients and tried to identify factors associated with good outcome. METHODS: The medical records of all pediatric patients who underwent corpus callosotomy at Asan medical center between 1996 and 2000 were retrospectively analyzed. RESULTS: At the time of last follow-up, four patients(20%) became seizure free, fifteen patients(75%) had significant improvement in seizure control, and two patients(10%) remained unchanged. No significant association was found between seizure outcome and age at operation, or duration of seizure, intracranial pathology, or extent of callosal section. Drop attacks are most likely to be benefited by callosotomy in view of the frequency of seizure. This was followed by generalized tonic-clonic and myoclonic seizures. Complex partial seizures had the worst response. CONCLUSIONS: Corpus callosotomy is valuable for controlling medically intractable generalized seizures in appropriate patients. Overall, drop attacks were one of the most frequent seizure pattern and they were also most likely to be benefited from corpus callosotomy. Though most patients do not become seizure-free after corpus callosotomy, worthwhile palliation of an otherwise intractable illness can be achieved. An analysis of prognostic factors should lead to better selection of patients for surgery.

The Effect of Corpus Callosotomy in the Lithium-Pilocarpine Induced Status Epileptic Rats

Section of the corpus callosum(SCC) is a useful surgical therapy in selected types of epilepsy, i.e., tonic, atonic, and intractable generalized convulsive seizures. The object of this study was to determine effect of SCC on behaviors, electroencephalography(EEG) and Fos expression in the lithium-pilocarpine model of status epilepticus in the rat. A total of 40 Sprague-Dawley rats were used. They were divided into two groups: control and lesioned group, 20 rats for each. The control group had no callosal section and was injected with lithium-pilocarpine. The lesioned group had callosal section before lithium-pilocarpine injection. In each group, ten rats were used for behavior and EEG monitoring and other 10 were used for Fos expression. The results were as follows: 1) In the SCC group, four(40%) rats never developed status epilepticus, among them two(20%) never exhibited any seizure, while all of the control group developed seizure and status epilepticus. None of the SCC animals died until 24 hours after lithium-pilocarpine injection but 70% of the control animals died within 24 hours of status epilepticus. This difference was statistically significant(p<0.05). 2) The mean latency to the first seizure, status epilepticus and periodic epileptiform discharges after lithium-pilocarpine injection were 34.7+/-2.6min, 32.3+/-1.8min and 180.4+/-9.8min, respectively, in the SCC group, while was 21.0+/-2.0min, 58.2+/-6.9min and 215.6+/-7.2min, respectively, in the control group. These latencies were significantly longer than in the control group(p<0.05). 3) There was a massive Fos expression on the cerebral cortex in the control group at 4 hours after lithiumpi-locarpine injection , while it was less in the SCC group. This difference was statistically significant(p<0.05). In conclusion, complete corpus callosotomy had contributed to the protective effect on the development of status epilepticus in the lithium-pilocarpine model which was similar to that observed in humans. And result of Fos expression suggest that Fos immunohistochemisty may be useful in the study of seizure pathways as a metabolic marker in the lithium-pilocarpine model.

Surgical Treatment of Epilepsy: Extratemporal Operative Methods

The extratemporal operative approaches for intractable epilepsy are reviewed. Intracranial recordings are often necessary for extratemporal epilepsy to define the lateratization as well as the localization of epileptogenic regions and tailor the resection. The operative procedures include cortical resections, corpus callosotomy, and functional hemispherectomy. The author presents an overview of indications for surgery, oprative methods, and risks in the medically intractable epileptic patient with extratemporal focus.

Surgical Management of Medically Intractable Epilepsy

Since October, 1989, the authors underwent operations for 20 patients of medically intractable epilepsy. Eight patients with temporal lobe epilepsy were treated by temporal lobectomy. Four patients with extratemporal focus of seizure were treated with extratemporal cortisectomy, Eight patients with multiple types of seizure were treated with callosotomy. The presurgical evaluations of epileptic seizures were very important. The presurgical evaluations were standard EEG, CCTV-EEC morning, neuroimaging, neuropsychological test, Wade test and invasive study with intracranial electrodes. There were no serious complications after operation. The authors concluded that epilepsy surgery seemed to be safe and helpful method for the treatment of medically intractable epilepsy.

Preliminary Results of Epilepsy Surgery at Chonbuk National University Hospital Medical School

No abstract available.

Callosotomy for Intractable Epilepsy in Children

Four children with medically refractory multiform seizures were submitted for section of the corpus callosum for last 3 years. These patients had medically intractable generalized seizures diagnosed preoperatively as the Lennox-Gastaut syndrome characterized by a combination of seizure patterns, most frequently drop attack with generalized tonic-clonic, generalized tonic and atonic seizure. Guided by pre- and intra-operative electroencephalographic monitoring, the section was carried out in the anterior 2/3 or 4/5 part of callosum. Five to 28 months' postoperative follow-up suggests good results:Three patient showed no more drop attack except intermittent focal myoclonic seizures in 1 case and one patient had generalized seizures less in frequency than preoperative state. Corpus callosotomy seems to be an effective surgical approach for the intractable epilepsy with drop attack of multifocal origin, but longer follow-up is needed.

The Clinical Analysis of Surgical Treatment in the Medically Intractable Seizure

We performed callosotomy and amygdalo-hippocampectomy in medically intractable seizure patients. Symptom duration of these patients was over 2 years and seizure was not controlled with anticonvulsants in spite of high level in drug monitoring according to their seizure type. 7 patients with generalized epilepsy were treated by anterior callosotomy and 8 patients with temporal lobe epilepsy were treated by amygdalo-hippocampectomy. Anyone of these patients were not dead and discovered permanent complications. And so these methods, anterior callostomy and amygdalo-hippocampectomy seems to be relatively safety and effective methods in treatment of medically intractable seizure.