Outcome and long term follow-up after corpus callosotomy in childhood onset intractable epilepsy

Introduction Epilepsy surgery is a standard of care in the treatment of medically intractable epilepsy. Twenty five percent of patients with intractable epilepsy in childhood can be candidates for epilepsy surgery. Corpus callosotomy is a surgical treatment option for patients with potentially injurious drop attacks and disabling generalized seizures. Postoperative improvement of cognition and speech are important gains after epilepsy surgery particularly during childhood. The aim of this study is to evaluate the outcome of corpus callosotomy for the treatment of childhood onset medically intractable epilepsy in a developing pediatric epilepsy surgery center.Method We report 16 patients who underwent two thirds anterior corpus callosotomy for treatment of refractory seizures in childhood.Results All patients had drop attacks or multiple types of seizures, yet some showed focal onset with secondary generalization on electroencephalogram (EEG). One patient was seizure free (class 1 outcome), five had class 2A outcome, five had class 2B outcome, and five had class 3 outcome. Overall 11/16 (69%) of our patients improved significantly after anterior callosotomy.Conclusion Corpus callosotomy remains to be a fairly good choice of surgical treatment for childhood onset medically intractable epilepsy in selected patients.     

Corpus Callosotomy for Intractable Epilepsy: Seizure Outcome and Prognostic Factors

We reviewed the outcome of corpus callosal section in 64 adult and pediatric patients to identify factors associated with a good outcome: 48% of patients had a favorable outcome for overall seizure frequency. Improvement was noted in several seizure types and was most likely for drop attacks, particularly in the setting of a unilateral focal cerebral lesion or a true generalized epilepsy of Lennox-Gastaut type. Poor outcomes for drop attacks were more likely if there was associated severe intellectual handicap or bilateral independent spikes on interictal EEG. Complex partial seizures (CPS), most commonly of frontal lobe origin, also responded favorably. The complications of callosal section were usually mild and transient. New focal seizures occurred in only 2 patients and were not as frequent or disabling as preoperative seizure types. A worthwhile improvement in seizure outcome was achieved by completion of the callosotomy in 6 of 10 patients with unsatisfactory results from anterior callosotomy.     

Corpus callosotomy: a palliative therapeutic technique may help identify resectable epileptogenic foci.

Corpus callosotomy has a long history as a palliative treatment for intractable epilepsy. Identification of a single epileptogenic zone is critical to performing successful resective surgery. We describe three patients in which corpus callosotomy allowed recognition of unapparent seizure foci, leading to subsequent successful resection. We retrospectively reviewed our epilepsy surgery database from 2003 to 2005 for children who had a prior callosotomy and were candidates for focal resection. All underwent magnetic resonance imaging and scalp video electroencephalograph monitoring, and two had magnetoencephalography, electrocorticography and/or intracranial video electroencephalograph monitoring. The children were 8 and 9 years old, and seizure onset varied from early infancy to early childhood. One child had a history of head trauma preceding seizure onset, one had a large intracerebral infarct and dysplastic cortex in the contralateral frontal lobe, and the other had an anterior temporal lobe resection without improvement in seizure frequency. After medical management failed, callosotomy was performed with the expectation of decreasing the seizure types affecting both hemispheres. Following transection of the callosal fibers, a single focus was recognized and resected, with resultant dramatic improvement in seizure control. In medically refractory epilepsy, where rapid secondary bisynchrony is suspected but the electroencephalograph is non-localizing, callosotomy should be considered as a means of treating generalized seizure types, but may also assist in identifying potentially operable seizure foci. Study limitations include its retrospective nature and cohort size. The findings, however, suggest the need for prospective, systematic, well-controlled studies of the use of corpus callostomy in this intractable patient population.     

Interictal PET and ictal subtraction SPECT: Sensitivity in the detection of seizure foci in patients with medically intractable epilepsy

Purpose: Interictal positron emission tomography (PET) and ictal subtraction single photon emission computed tomography (SPECT) of the brain have been shown to be valuable tests in the presurgical evaluation of epilepsy. To determine the relative utility of these methods in the localization of seizure foci, we compared interictal PET and ictal subtraction SPECT to subdural and depth electrode recordings in patients with medically intractable epilepsy. Methods: Between 2003 and 2009, clinical information on all patients at our institution undergoing intracranial electroencephalography (EEG) monitoring was charted in a prospectively recorded database. Patients who underwent preoperative interictal PET and ictal subtraction SPECT were selected from this database. Patient characteristics and the findings on preoperative interictal PET and ictal subtraction SPECT were analyzed. Sensitivity of detection of seizure foci for each modality, as compared to intracranial EEG monitoring, was calculated. Key Findings: Fifty‐three patients underwent intracranial EEG monitoring with preoperative interictal PET and ictal subtraction SPECT scans. The average patient age was 32.7 years (median 32 years, range 1–60 years). Twenty‐seven patients had findings of reduced metabolism on interictal PET scan, whereas all 53 patients studied demonstrated a region of relative hyperperfusion on ictal subtraction SPECT suggestive of an epileptogenic zone. Intracranial EEG monitoring identified a single seizure focus in 45 patients, with 39 eventually undergoing resective surgery. Of the 45 patients in whom a seizure focus was localized, PET scan identified the same region in 25 cases (56% sensitivity) and SPECT in 39 cases (87% sensitivity). Intracranial EEG was concordant with at least one study in 41 cases (91%) and both studies in 23 cases (51%). In 16 (80%) of 20 cases where PET did not correlate with intracranial EEG, the SPECT study was concordant. Conversely, PET and intracranial EEG were concordant in two (33%) of the six cases where the SPECT did not demonstrate the seizure focus outlined by intracranial EEG. Thirty‐three patients had surgical resection and >2 years of follow‐up, and 21 of these (64%) had Engel class 1 outcome. No significant effect of imaging concordance on seizure outcome was seen. Significance: Interictal PET and ictal subtraction SPECT studies can provide important information in the preoperative evaluation of medically intractable epilepsy. Of the two studies, ictal subtraction SPECT appears to be the more sensitive. When both studies are used together, however, they can provide complementary information.     

Outcome after corpus callosotomy in children with injurious drop attacks and severe mental retardation

Wide variability in patient selection, extent of callosal section and definition of successful outcome between studies make impact of corpus callosotomy on patients with medically refractory epilepsies difficult to interpret. Severe mental retardation is considered to be predictive of unfavorable seizure outcome after callosotomy. Very little attention has been paid on the influence of callosotomy on the psychosocial burden on the patients' families. We evaluated the seizure outcome, and parental perception about change in cognition and behavior of 17 children (median age 9.5 years, range 3.5-18 years) with severe mental retardation (IQ<30 in all, except one) and injurious drop attacks, who have completed >or=1-year postoperative follow-up after callosotomy. Nearly two-thirds of our patients had >or=90% reduction in drop attacks and generalized tonic-clonic seizures. In the one-stage total callosotomy group, 9 of 11 (82%) patients had favorable outcome, compared to 2 of the 6 (33%) in the partial callosotomy group. Absence of generalized epileptiform discharges on the 1-year postoperative EEG was significantly associated with a favorable seizure outcome. The mean duration of epilepsy prior to callosotomy tended to be shorter among patients with favorable seizure outcome. Postoperative complications were trivial and transient. Nearly three-fourths of the parents appreciated improvements in behavior and attentiveness of their children and were satisfied with the outcome. We conclude that, in children with severe mental retardation and injurious drop attacks, total callosotomy can be undertaken as a one-stage procedure with insignificant morbidity and results in highly favorable seizure outcome.     

The effect of surgery in encephalopathy with electrical status epilepticus during sleep

Purpose: We analyzed clinical and electroencephalography (EEG) outcomes of 13 patients with pharmacoresistant encephalopathy with electrical status epilepticus during sleep (ESES) following epilepsy surgery. Methods: All patients had symptomatic etiology of ESES and preoperative neuropsychological deterioration. Ten patients had daily atypical absences. Clinical outcome was assessed at 6 months and at 2 years after surgery. Clinical and EEG data were reviewed retrospectively. The spike propagation pattern and area and source strength in source montage were analyzed from preoperative and postoperative EEG studies. Key Findings: Preoperative sleep EEG showed electrical status epilepticus during sleep (SES) with one‐way interhemispheric propagation in nine patients and with two‐way interhemispheric propagation in four. The age of the patients at the time of surgery ranged from 3.6–9.9 years. Focal resection (two patients) or hemispherotomy (one patient with postoperative EEG) either terminated SES or restricted the discharge to one region. Either reduced SES propagation area or source strength was found in four of eight callosotomy patients with postoperative EEG. Of patients who had seizures preoperatively, Engel class I–II seizure outcome was observed in two of three children after focal resection or hemispherotomy and in two of eight children after callosotomy. None of these patients with Engel class I–II outcome had SES with two‐way interhemispheric propagation on preoperative EEG. Cognitive deterioration was halted postoperatively in all except one patient. Cognitive catch‐up of more than 10 IQ points was seen in three patients, all of whom had shown a first measured IQ of >75. Significance: Patients with pharmacoresistant ESES based on symptomatic etiology may benefit from resective surgery or corpus callosotomy regarding both seizure outcome and cognitive prognosis.     

Medically intractable, localization-related epilepsy with normal MRI: presurgical evaluation and surgical outcome in 43 patients

PURPOSE: High-resolution magnetic resonance imaging (MRI) plays a crucial role in the presurgical evaluation of patients with medically refractory partial epilepsy. Although MRI detects a morphologic abnormality as the cause of the epilepsy in the majority of patients, some patients have a normal MRI. This study was undertaken to explore the hypothesis that in patients with normal MRI, invasive monitoring can lead to localization of the seizure-onset zone and successful epilepsy surgery. METHODS: A series of 115 patients with partial epilepsy who had undergone intracranial electrode evaluation (subdural strip, subdural grid, and/or depth electrodes) between February 1992 and February 1999 was analyzed retrospectively. Of these, 43 patients (37%) had a normal MRI. RESULTS: Invasive monitoring detected a focal seizure onset in 25 (58%) patients, multifocal seizure origin in 12 (28%) patients, and in six patients, no focal seizure origin was found. Of the 25 patients with a focal seizure origin, cortical resection was performed in 24, of whom 20 (83%) had a good surgical outcome with respect to seizure control. Six of the 12 patients with multifocal seizure origin underwent other forms of epilepsy surgery (palliative cortical resection in two, anterior callosotomy in two, and vagal nerve stimulator placement in two). CONCLUSIONS: Successful epilepsy surgery is possible in patients with normal MRIs, but appropriate presurgical evaluations are necessary. In patients with evidence of multifocal seizure origin during noninvasive evaluation, invasive monitoring should generally be avoided.     

多种手术结合治疗顽固性癫痫

目的：对部分复杂的顽固性癫痫病人，将几种手术结合使用，并对其临床效果进行评价。方法：北京天坛医院手术治疗顽固性癫痫230例，其中对15例顽固性癫痫病人采用几种术式结合的方法。病人年龄9-43岁，平均18岁。病程4-40年，平均13年。发作形式为强直阵挛性发作、复杂部分性发作及失神，其中有8例存在两种发作形式。术前均服过抗癫痫药，病程后期同时服用2-3种抗癫痫药。这15例病人术前均行头皮脑电视频连续监测及头MRI检查，其中5例行头PET检查。手术在皮层脑电及深部电极监测下进行。13例行额颞开颅，胼胝体前部切开 颞前叶及海马切除 皮层热灼术；1例行额颞顶枕开颅，枕叶萎缩皮层切除 胼胝体前部切开 选择性海马切除 皮层热灼术；1全先行左额颞开颅，脚间池错构瘤及颞前叶及海马切除 皮层热灼术，术后癫痫减轻但仍发作且术后头皮脑电显示右额棘波明显，故又右额颞开颅，胼胝体前部切开 皮层热灼术。结果：术后无死亡及并发症。术手抗癫痫药物减少，术后12例服用一种抗癫痫药，3例服用两种抗癫痫药。术后随访3-12个月，14例无癫痫发作，1例癫痫发作两次（术前每天发作5-8次）。结论：多种手术结合治疗顽固性癫痫病人安全有效。     

EEG and Seizure Outcome After Epilepsy Surgery

Summary: The significance of the EEG after epilepsy surgery is not fully understood. We investigated the as- sociation between postoperative EEG abnormalities and persistent seizures after epilepsy surgery as they relate to pathologic lesions. Among 254 patients who underwent epilepsy surgery between 1987 and 1991, we identified 78 patients who had mesiotemporal sclerosis (MTS) and 47 patients who had low-grade brain tumors, all of whom had 6-to 18-month postoperative follow-up including EEG. Patients who had other pathology, multiple operations, callosotomy, or hemispherectomy, or who were aged <18 years or who had insufficient EEG data, were excluded. Patients were classified as having persistent seizures or being seizure-free since operation. EEG abnormalities were abstracted from EEG reports 6–18 months postoperatively. Seizures persisted in 24% of the MTS group and in 27% of the tumor group. Of those with normal EEGs, none of the MTS patients and only 1 of the tumor patients had persistent seizures (p = 0.03 for MTS and p = 0.42 for tumor). Epileptiform discharges and focal slowing were associated with seizure persistence in both groups, but to a significant extent only in the MTS group. In the MTS group, patients who had both epileptiform discharges and focal slowing were more likely to have persistent seizures than were those with either abnormality alone.     

Outcome following corpus callosotomy

Although corpus callosotomy has been performed since 1940 to treat severe medically intractable seizures, there remains controversy as to when, or even if, the surgery should be done. Unlike most surgical therapies for epilepsy where the epileptic focus is removed, corpus callosotomy interrupts the propagation of epileptic discharges. The procedure is primarily used in patients with secondarily generalized seizures with or without drop attacks in whom focal resection is not possible. The goal of this surgery is to improve functioning and well-being. In this study, we retrospectively reviewed records from 28 patients undergoing corpus callosotomy to assess improvement following surgery. Parents and patients were also sent a questionnaire to assess quality of life. While surgery reduced the frequency of seizures, definite improvements in quality of life were limited only to patients with frequent daily drop attacks preoperatively. We believe corpus callosotomy offers a significant improvement of both seizure control and quality of life in children with frequent drop attacks of tonic, myoclonic, or atonic origin.     

胼胝体切开术治疗儿童药物难治性癫(癎)

目的 探讨胼胝体切开术治疗无法行局灶性切除的儿童药物难治性癫(癎)的安全性及有效性.方法 回顾性分析113例儿童药物难治性癫(癎)病人的临床资料,均行胼胝体切开术.结果 术后发作完全消失77例(68.1％),发作减少90％以上21例(18.6％),其中失张力性发作病人术后发作完全消失和发作减少90％以上者分别占94.1％和5.9％,而全身强直性发作病人为8.3％和75.0％.术后出现短暂的主动性语言减少3例,并在术后6-8d内恢复.随访113例,时间12个月～5年,病人精神发育状态均有不同程度的改善,无发作加重病例.结论 胼胝体切开术是治疗儿童药物难治性癫(癎)的一种安全有效的方法,特别是对失张力性发作和全身强直性发作效果更佳.     

Time-varying inter-hemispheric coherence during corpus callosotomy

Objective

Corpus callosotomy limits the bilateral synchrony of epileptic discharges. However, the instantaneous changes in bilateral synchrony during corpus callosotomy are unclear. The present study investigated how and when bilateral synchrony is suppressed in the anterior and then posterior steps of corpus callosotomy.

Methods

Intra-operative scalp electroencephalography (EEG) was recorded simultaneously with surgical video for six patients who underwent total corpus callosotomy for medically intractable drop attacks. The time-varying EEG inter-hemispheric coherence was quantified by wavelet transform coherence and trend analysis.

Results

The 4–13 Hz coherence decreased after corpus callosotomy in five patients. Significant decrease in coherence was observed only during the posterior step of callosal sectioning in three patients, but throughout both steps in two patients.

Conclusions

Decrease in inter-hemispheric coherence is not always correlated with the stages of callosal sectioning. Inter-hemispheric coherence is decreased during the final stage of corpus callosotomy and the effect is maximized after sectioning is completed.

Significance

Various patterns of coherence decrease suggest individual variations in the participation of the corpus callosum in the genesis of bilateral synchrony. Time-varying inter-hemispheric EEG coherence is useful to monitor the physiological completeness of corpus callosotomy.     

Ictal EEG Changes with Corpus Callosum Section

Summary: Corpus collosum section diminishes but does not completely abolish secondary bilaterally synchronous interictal EEG discharges, yet often causes cessation of generalized seizures. The effects of corpus callosum section on ictal EEG patterns have not been described. We contrasted ictal EEG patterns before and after anterior callosotomy in 18 patients and before and after total callosotomy in 10 patients. Bilaterally synchronous seizure onset was disrupted in 5 of 11 anterior section patients and 5 of 5 total section patients. Seven of 18 anterior section patients and 5 of 10 total section patients had more localized seizure onset after the procedure; localization to the frontal lobe was observed after anterior or total section, but only total section patients had newly demonstrated posterior locations of seizure onset. These data suggest that the mechanisms by which bilaterally synchronous interictal and ictal discharges are generated differ. Although brainstem or diencephalic structures may contribute to formation of interictal bilateral synchrony, the corpus callosum may be the only pathway used in producing apparent bilateral synchronous seizure onset in patients with secondarily generalized seizures.     

经纵裂-透明隔间腔入路胼胝体切开术治疗难治性癫痫的手术方法及临床疗效

目的探讨经纵裂-透明隔间腔入路胼胝体切开术治疗药物难治性癫痫的手术方法和临床疗效。方法回顾性分析2014年1月至2019年1月上海交通大学医学院附属仁济医院功能神经外科收治的23例难治性癫痫患者的临床资料。患者均采用梯形小骨窗开颅,分别经纵裂-透明隔间腔入路行胼胝体前2/3切开术或一期胼胝体全节段切开术。术前行磁共振静脉成像(MRV)和图像三维重建辅助设计切口和骨窗。术后定期行影像学随访,采用Montreal神经研究所和医院Oguni等胼胝体切开术后疗效分级标准评估疗效。结果23例患者均顺利完成胼胝体切开手术,其中11例行胼胝体前2/3切开术,12例行一期胼胝体全节段切开术。23例患者中,22例沿中线切开胼胝体至透明隔腔,仅1例患者因脑发育畸形,术中探查透明隔腔缺失,改用经侧脑室入路切开胼胝体。患者术后均无颅内出血、脑积水和感染,无遗留长期神经功能障碍和并发症。MRI或弥散张量成像复查证实胼胝体切开范围达到要求。所有患者的中位随访时间为1.8年(0.5~5.2年)。术后疗效分级结果:A级4例、B级6例、C级6例、D级7例、E级0例,总有效率为69.6%(16/23)。结论经纵裂-透明隔间腔入路行胼胝体切开术可保持正中的手术路径,从而减少副损伤和并发症的发生,提高手术疗效。     

Corpus callosotomy

Corpus callosotomy is a palliative surgical procedure that is suitable for some patients with intractable seizures who are not candidates for focal resective surgery. The rationale for this procedure is based on the hypothesis that the corpus callosum is a critical pathway for interhemispheric spread of epileptic activity. Efficacy and relatively low permanent morbidity in corpus callosotomy for medically intractable epilepsy have been demonstrated by more than six decades of experience. Callosotomy best ameliorates drop attacks (tonic and atonic seizures), though tonic-clonic, absence, and frontal lobe complex partial seizures often respond as well. In addition to seizure reduction, behavior and quality of life may improve. Hence, callosotomy is justified as a therapy for appropriate patients with intractable epilepsy.     

中央区纵裂癫痫的手术治疗

目的 探讨中央区纵裂癫痫的诊断及手术治疗方法. 方法 选择自2007年6月至2008年4月在河北省人民医院功能神经外科就诊并接受手术治疗的6例中央区纵裂癫痫患者,常规术前评估(包括MRI、头皮脑电图、MEG、加密头皮脑电图、颅内埋藏电极及皮层电刺激联合定位致痫灶和功能区)后在皮层脑电临测下行手术切除,切除组织进行病理检查,术后随访发作情况、腩电图和并发症. 结果 经术前评估致痫灶均位于中央区纵裂区,经手术治疗后5例患者术后无发作,达到Engle Ⅰ级;1例EngleⅡ级,发作明显减少.术后病理结果显示,6例患者中局灶性皮层发育不良3例,胶质增生、脂肪瘤和海绵状血管瘤各1例.术后脑电图显示,大致正常脑电图3例,少量慢波3例. 结论 中央区纵裂癫痫在精确定位下可行手术切除,手术效果良好,无严重并发症.     

Identifying potential surgical candidates in patients with evidence of bitemporal epilepsy

PURPOSE: To determine which patients with evidence of medically refractory bitemporal epilepsy are potentially good candidates for surgical therapy. METHODS: We reviewed 42 adults with intractable seizures who were found to have bitemporal ictal onsets, based on scalp video-EEG long-term monitoring (LTM). All underwent invasive LTM before surgery. Surgical outcomes were classified as seizure free, >75% reduction in seizures, or <75% reduction in seizures, >or=1 year after resection. We related the following factors to outcome: (a). >75% preponderance of interictal scalp EEG discharges to one temporal region; (b). magnetic resonance imaging (MRI) findings; (c). lateralizing deficits on verbal or visual reproduction memory testing; and (d). memory failure with injection contralateral to side of surgery on Wada testing. RESULTS: Twenty-six (62%) of 42 patients had unilateral ictal onsets based on intracranial studies. Seizure freedom (occurring in 64% of this group), or >75% seizure reduction (found in 12% of subjects) occurred only when at least one of the following three factors was concordant with the side of surgery: preponderance of interictal scalp EEG discharges, unilateral temporal lesion on MRI, or lateralizing verbal or visual reproduction memory deficits on neuropsychological tests (p = 0.004). Seven subjects with bilateral ictal onsets based on intracranial studies had resections based on preponderance of seizures to one side, or other lateralizing noninvasive abnormality. Five of these (all of whom had >or=80% of seizures originating from one side) had >75% reduction in seizures. CONCLUSIONS: Invasive monitoring to pursue possible surgical therapy for patients with surface EEG evidence of bitemporal epilepsy may be justified only when some lateralizing feature is found in other noninvasive assessments.     

Posterior cortex epilepsy secondary to ulegyria: Is it a surgically remediable syndrome?

Purpose: To examine whether surgery is indicated for posterior cortex epilepsy secondary to ulegyria. Patients and methods: Ten patients who underwent surgery for posterior cortex epilepsy with ulegyria and were followed for more than 2 years were included. All patients underwent comprehensive presurgical evaluations. Five patients underwent intracranial electroencephalography (EEG) studies. The posterior cortex including the magnetic resonance imaging (MRI) lesion was resected in all patients. Postoperative follow‐up period was 2–12 (mean 6) years. Results: Nine patients had a history of perinatal distress including asphyxia and prolonged labor. Age at seizure onset was 5–11 years, except one patient. Three patients had visual field defects preoperatively. Ulegyria was unilateral in four patients and bilateral but unilateral‐predominant in six patients. In most of the cases, the lesions were in the posterior cerebral artery area or the watershed area between middle cerebral and posterior cerebral arteries. In four of five patients who underwent intracranial EEG, seizure onset zones extended outside the lesions. Postoperative seizure outcome was Engel's class I in seven cases, and class III in three cases. Three of four patients whose seizure onset zones were not completely resected achieved class I outcome. Four of six patients with bilateral lesions achieved class I outcome. Conclusion: Ulegyria due to perinatal distress is considered to be a major cause of posterior cortex epilepsy. Long‐term postoperative seizure outcome is favorable. Resection of MRI lesion is important for seizure relief. Bilateral lesions should not be excluded from surgical indication. The usefulness of intracranial EEG may be limited.     

长程颅内电极监测定位技术在癫痫外科中的应用(附19例临床分析)

目的分析长程颅内电极对难治性癫痫患者的癫痫发作起源区定位作用,评估采用这一技术后的癫痫发作控制以及手术并发症的发生情况。方法19例难治性癫痫患者,采用常规脑电图及其它检查不能明确癫痫发作起源区位置,或癫痫发作起源区与重要功能区关系密切,对怀疑脑区进行颅内电极埋置术,术后进行长程颅内脑电监测,根据脑电情况,确定发作起源区,明确与功能区的部位后,进行切除术或多处软膜下横切术。结果19例患者中,核磁共振有双侧病变者5例,单侧病变9例,核磁共振阴性的患者5例。非侵袭性的术前评估方法结论不一致的有11例。手术后15例患者发作消失,3例患者发作频率减少90%以上,1例癫痫发作控制无效。1例患者发生永久性局限视野缺损,缺损为左上视野区,1例患者电极埋置术后出现一过性失语,切除术后未发生失语。结论对于采用常规脑电图及其它检查不能明确癫痫发作起源区位置,或癫痫发作起源区与重要功能区关系密切的患者,长程颅内脑电图监测能够准确定位发作起源区位置,回避功能皮质区,有效降低并发症的发生率。     

Refractory generalized seizures: response to corpus callosotomy and vagal nerve stimulation

PURPOSE: The vagal nerve stimulator (VNS) and corpus callosotomy can reduce seizure frequency when seizures are refractory to medications. However, the efficacy and safety of these two procedures have not been compared. This study evaluates the two procedures for generalized seizures. METHODS: All patients with refractory generalized seizures (generalized tonic-clonic, tonic, or atonic) who underwent a corpus callosotomy (anterior or complete) (n = 53) without other forms of epilepsy surgery and those who underwent VNS placement (n = 25) were evaluated for this study. Seizure response and procedure complications were evaluated. RESULTS: For those with a corpus callosotomy and generalized tonic-clonic seizures (n = 50), 79.5% had >or=50% decrease in the frequency of generalized tonic-clonic seizures, and 60% had >or=80% seizure reduction. For those with a VNS and generalized tonic-clonic seizures (n = 21), 50% had >or=50% seizure reduction, and 33% had >or=80% seizure reduction. Tonic and atonic seizures decreased after either VNS or a corpus callosotomy. The complication rate for corpus callosotomy was higher (21% all complications, 3.8% permanent) than that for VNS (8%; none permanent), but complications for both corpus callosotomy and VNS were rarely permanent. CONCLUSIONS: Both corpus callosotomy and VNS are effective in reducing generalized seizures. Corpus callosotomy is associated with greater efficacy but higher risk for complications, although these were generally transient.