Periventricular nodular heterotopia and childhood absence epilepsy.

A young female presented with an epileptic syndrome resembling childhood absence epilepsy, a normal neurologic examination, generalized 3-Hz spike-and-wave discharges, and clinical absences. Her seizures responded to treatment with valproic acid. Other abnormalities in her electroencephalogram prompted neuroimaging studies, which demonstrated periventricular nodular heterotopia. Review of published reports confirmed this presentation to be atypical of this developmental lesion. The authors describe their patient and discuss this unexpected association and the relevant reports briefly.     

Periventricular nodular heterotopia: A challenge for epilepsy surgery.

Pharmacoresistant focal epilepsies due to periventricular nodular heterotopia are a diagnostic and therapeutic challenge because of the need of invasive presurgical diagnostics and the selection of an optimal surgical approach. Invasive investigations in previous studies showed that focal epileptic activity can be correlated predominantly either with one of the nodular heterotopia or with neocortical epileptogenic zones distant to the periventricular nodules. Up to now, invasive recordings were required for localization of epileptic activity and its correlation to heterotopia. The following case presentation reports on a non-invasive approach using magnetic source imaging (MSI) combined with intraoperative ECoG. MSI combines preoperative data from magnetic resonance imaging (MRI) with magnetoencephalography (MEG). The MSI data for definition of the localization of the epileptic activity and functional important areas were coregistered with the intraoperative high-field-MRI and diffusion tensor imaging-based fiber tracking (DTI) of the visual pathway using a neuronavigational system. A neuronavigation-guided surgical resection of the epileptogenic area was performed leaving the heterotopia and the visual tract fibers intact. Postoperatively preservation of the visual fields was documented and the frequency of seizures was markedly reduced.     

Hyperkinetic seizures in patients with temporal lobe epilepsy: clinical features and outcome after temporal lobe resection

Purpose: Temporal lobe epilepsy (TLE) is usually associated with automatisms. Hyperkinetic seizures are supposed to be unusual. Because we witnessed several patients with TLE and ictal hyperkinetic symptoms, we retrospectively assessed the number, clinical findings, and seizure outcome in such patients who had undergone temporal lobe resection. Methods: We reviewed medical history, video–electroencephalography (EEG) recording and neuroimaging of adult patients who underwent epilepsy surgery for TLE at the Kork Epilepsy Center over the last 20 years with a minimum postoperative follow‐up of 12 months. Key Findings: Among 294 patients who were resected exclusively in the temporal region, we identified 17 (6%) who presented with hyperkinetic semiology such as violent vocalization, complex movements of the proximal segments of the limbs, rotation of the trunk, pelvic thrusting, or early tonic or dystonic posturing. Most of the patients had a preceding aura. Ictal EEG activity was located in the corresponding temporal region, usually with a wide distribution over temporal electrodes with fast spread to unilateral frontal electrodes and to the contralateral side. Neuroimaging revealed extended lesions in the temporal lobe involving mesial and neocortical structures. Most of the patients underwent classical anterior temporal lobe resection including amygdalo‐hippocampectomy. Fourteen patients (82%) became completely seizure‐free (Engel class Ia). Histopathology showed mainly focal cortical dysplasia plus hippocampal sclerosis. Significance: Hyperkinetic seizure semiology may occasionally occur in patients with TLE and is, therefore, no contradiction to the hypothesis of TLE if scalp EEG patterns and neuroimaging findings correspond. The postoperative seizure outcome is favorable in such patients and not different from outcome data in classical TLE.     

难治性颞叶癫(癎)的相关基因表达谱

目的 筛选难治性颞叶癫(癎)相关基因表达谱,并通过对表达谱筛选所发现的差异基因进行验证,从分子水平探讨颞叶癫(癎)可能的发病机制.方法 在利用基因芯片对难治性颞叶癫(癎)患者手术切除颞叶组织与对照间行基因表达谱分析研究的基础上,扩大样本量,应用RT.PCR方法,验证SH3GL2、BTN2A2、KCNJ4基因的mRNA在颞叶癫(癎)患者脑内的表达差异.结果 芯片研究结果显示,颞叶癫(癎)脑组织标本与对照组相比,表达趋势一致的已知基因包括:免疫相关因子、离子通道相关因子、信号转导相关基因、细胞增殖周期因子、细胞凋亡相关基因等;经RT.PCR证实,颞叶癫(癎)组突触重建调控因子SH3GL2的mRNA表达水平(1.022±0.547)明显高于对照组(0.446±0.171,t=-3.181),免疫调控基因BTN2A2的mRNA表达在颞叶癫(癎)组(0.481±0.196)同样高于对照组(0.243±0.111,t=3.351),而编码内向整流钾通道亚单位基因KCNJ4 mRNA的表达水平在颞叶癫疴组(0.438±0.178)则明显低于对照组(0.795±0.112),差异均有统计学意义(P<0.05).结论 在颞叶癫(癎)发生发展各个阶段均有基因的参与,是一个复杂的调控过程;芯片试验结果对进一步探讨疾病可能的发病机制以及为探求疾病治疗的新靶点提供了依据.     

难治性颞叶癫(癎)的手术治疗

目的 探讨难治性颞叶癫(癎)的手术疗效.方法 回顾性分析2003年7月至2007年2月我科手术治疗的72例难治性颞叶癫(癎)患者临床资料.结果 按我国谭氏标准,满意:59例;显著改善:2例;良好:3例;效差:2例;无改善:5例;死亡:1例.结论 手术治疗难治性颞叶癫(癎)疗效确切可靠,在有条件的医院可推广.     

Periventricular nodular heterotopia: report of a pediatric series

Periventricular nodular heterotopia is a malformation that occurs in both males and females and is associated with a variety of clinical and neuroradiologic signs. A gene called filamin-1 (FLN-1) has recently been identified. We review the clinical and imaging findings from a series of pediatric patients with periventricular nodular heterotopia. Five patients (three males and two females; age range = 4-18 years) were investigated. In our series, periventricular nodular heterotopia can be the common denominator in different conditions. Periventricular nodular heterotopia can occur alone or be associated with cortical malformations. Epilepsy was present in three of the five patients and was resistant to drugs in one female. Mental retardation was present in three of the five patients. Two male patients had normal intelligence, with no cortical anomalies; patient 3 had unilateral periventricular nodular heterotopia. The associated malformations were more severe in the female patients and slight only in patient 1. The two females showed anomalies rarely reported in association with bilateral periventricular nodular heterotopia. We believe that other genes can be involved in children with atypical neuroradiologic periventricular nodular heterotopia. No mutations were detected in 6 of the 48 exons of the FLN-1 gene, although this does not allow any definitive conclusions to be reached. We conclude that our series of patients with periventricular nodular heterotopia clearly highlights the complexity of the clinical, neurologic, and neuroradiologic characteristics associated with this malformation.     

Antiepileptic drug withdrawal after successful surgery for intractable temporal lobe epilepsy

PURPOSE: To investigate the prognosis related to antiepileptic drug (AED) discontinuation after successful surgery for intractable temporal lobe epilepsy. METHODS: The clinical courses after temporal lobectomies (TLs) were retrospectively analyzed in 88 consecutive patients. All the patients had TLs as the only surgical procedure, and they had been followed up for longer than 3 years. AED discontinuation was attempted if the patient had been seizure free without aura for >or=1 year during the follow-up period. RESULTS: Sixty-six (75%) patients achieved complete seizure freedom for >or=1 year; 28 patients were seizure free immediately after surgery (immediate success); and 38 patients became seizure free after some period of recurrent seizures (delayed success). AED discontinuation was attempted in 60 (91%) of 66 patients with a successful outcome. In 13 (22%) patients, seizure relapse developed during AED reduction (n=60), and in seven (12%) patients after discontinuation of AEDs (n=38). The seizure recurrence rate was not different between the immediate-and delayed-success groups. Among 20 patients with seizure relapse related to AED tapering, nine (45%) of them regained seizure freedom after reinstitution of AED treatment, and AEDs were eventually discontinued in six of them. Seizures that recurred after complete AED discontinuation had a better prognosis than did the seizures that recurred during AED reduction (seizure freedom in 86% vs. 23%). At the final assessment, 54 (61%) patients had been seizure free >or=1 year; 37 without AEDs and 17 with AEDs. The successful discontinuation of AEDs was more frequent for patients with a younger age at the time of surgery and for those patients with shorter disease duration. CONCLUSIONS: Our results suggest that seizure freedom without aura at >or=1 year is a reasonable indication for the attempt at AED discontinuation. The subsequent control of recurrent seizures was excellent, especially if seizures relapsed after the complete discontinuation of AEDs. Younger age at the time of surgery and a shorter disease duration seem to affect successful AED discontinuation for a long-term period.     

Predictors of outcome after temporal lobectomy for refractory temporal lobe epilepsy

Objective – To identify predictors of outcome after epilepsy surgery in patients with temporal lobe epilepsy (TLE). Methods – Seventy‐six patients with normal magnetic resonance imaging (MRI) or hippocampal sclerosis on MRI who underwent anterior temporal lobe resections were included. Outcome 2 years after surgery was classified as good (Engel I and II) or poor (Engel III and IV). Gender, age at onset and duration of epilepsy, history of febrile convulsions, auras, right‐ or left‐sided TLE, memory ipsilateral to seizure onset (Wada test), hippocampal asymmetry (HA) and T2 relaxation time, amygdala, temporal lobe and hemispheral volume were tested for associations with outcome. Results – Sixty‐seven percent had a good outcome. Of all parameters tested, only a history of febrile convulsions and HA on quantitative MRI were significantly associated with a good seizure outcome. The absence of these parameters did not exclude a good outcome, but only five of 18 patients (28%) without HA and without a history of febrile convulsions had a good outcome. Conclusion – Febrile convulsions and HA were predictors of outcome after epilepsy surgery in TLE. Subtle volume loss in amygdala, temporal lobe or hemispheres and the memory ipsilateral to the side of resection were not associated with outcome.     

The duration of temporal lobe epilepsy and seizure outcome after epilepsy surgery

To assess the effect of the duration of epilepsy on the outcome of epilepsy surgery in non-lesional medically refractory temporal lobe epilepsy we reviewed the outcome of 76 patients.MethodsAll patients had anterior temporal resections for “non-lesional” temporal epilepsy (excluding any patient with tumours or vascular malformations but including patients with hippocampal sclerosis). Outcome at one year was assessed using Engel's scale.Results67% had a good outcome (Engel I or II). The mean duration of epilepsy was 23.0 years (range 2.9–46.9 years). Overall, there was no significant difference between patients with good outcome (mean duration 22.4 years) and poor outcome (mean duration 24.2 years) (p = 0.49). The proportion of patients with good outcome was slightly higher in the shorter duration groups. (Duration less than 10 years 75%, 10–19 years 71%, 20–29 years 65%, 30–39 years 62%, and 40–49 years 60% good outcome, p = 0.95).ConclusionWe found no significant associations between outcome and duration of epilepsy.     

Predictors of seizure outcome after temporal lobectomy for intractable epilepsy

OBJECTIVES: To assess predictors of outcome of temporal lobectomy for intractable epilepsy. MATERIAL AND METHODS: In 63 adult patients operated with anterior temporal lobectomy during 198892, we used logistic regression analysis to assess predictors of being seizure-free (Engel's class I) 2 years after surgery. As potential predictors, we included the following variables: gender, age at operation, age at onset of seizures, epilepsy duration, etiology, generalized vs not generalized seizures, seizure frequency, intelligence quotient, ictal electroencephalography, magnetic resonance imaging (MRI), single-photon emission computed tomography (SPECT), side of resection, and extent of the resection. RESULTS: About 44% of the surgery patients were seizure-free (Engel's class I) 2 years after surgery. In multivariate analysis (n = 55), MRI pathology defined as atrophy in the temporal lobe, angioma, tumor or mesial temporal sclerosis (odds ratio, OR 7.4, 95%CI: 1.7-32.9) and extent of the hippocampal resection (increase of 1 cm) (OR 2.2, 95%CI: 1.1-4.6) predicted being seizure-free. CONCLUSION: Focal pathology in preoperative MRI and the extent of the hippocampal resection were the only significant predictors of being seizure-free after 2 years.     

小儿顽固性颞叶癫痫的病理特点研究

目的 研究小儿顽固性颞叶癫痫的临床病理学表现.方法 80例小儿顽固性颞叶癫痫患者行标准前颞叶切除术,切除组织送病理学检查.术后随访1-5年,根据Engel分级评估手术效果.结果 切除组织病理学表现以单纯海马硬化(26例)、良性肿瘤(20例)、局灶性皮层发育不良(10例)和海马硬化合并颞叶其他病变(9例)四大类型为主.癫痫发作控制结果提示EngelⅠ级58例,Ⅱ级11例,Ⅲ级6例,Ⅳ级5例.结论 小儿顽固性颞叶癫痫病理表现多样,以海马硬化、良性肿瘤和局灶性皮层发育不良最常见;颞叶切除疗效肯定;病理类型与手术效果之间的关系仍待更多研究.     

Psychopathology in children with epilepsy before and after temporal lobe resection

The aim of this study was to establish the rate and spectrum of psychiatric disorder among children before and after temporal lobe surgery for epilepsy. Data were examined for associations between psychopathology and seizure outcome following surgery, or association between psychopathology and other variables, such as laterality of lesion, sex, cognitive level, and underlying pathology. Participants were 60 children (35 males, 25 females) who had focal seizures of temporal lobe origin and who had undergone temporal lobe resection between 1992 and 1998; mean age at time of operation 10 y 7 mo, (SD 4 y 11 mo) range 7 mo to 17 y 11 mo. Mean length of follow-up was 5.1 years (SD 2.3, range 2 to 10 y). Twenty-eight (47%) children had undergone right temporal lobectomy. Diagnosis of a psychiatric disorder was present in 50/60 (83%) children at some point, with high rates of psychiatric comorbidity. Common childhood psychiatric disorders of attention-deficit-hyperactivity disorder, oppositional defiant disorder/conduct disorder, and emotional disorders were present in about 25% of children. Disorders rarely seen in the general child population were over-represented: disruptive behaviour disorder--not otherwise specified (30/60 [50%]), and pervasive developmental disorder (autistic spectrum disorder; 23/60 [38%]). there was no significant relationship between pathology, sex, seizure frequency, or postoperative seizure outcome and psychiatric disorder, other than for pervasive developmental disorder. The same proportion of children had psychiatric diagnoses pre- and postoperatively (43/60 [72%] and 41/57 [72%] respectively). Although mental health problems are common in children undergoing temporal lobe resection, there are few predictors of psychiatric outcome following epilepsy surgery. Parents require counselling on these issues in the preoperative work-up.     

Absence epilepsy and periventricular nodular heterotopia

We report a case of a girl who presented with typical absence seizures at age of 4.5 years. EEG showed absence seizures of sudden onset with 3 Hz spike-and-waves that also correlated with the clinical absences. The seizure semiology included subtle deviation of the eyes which prompted MRI investigation of the brain. This showed a periventricular nodular heterotopia in the mid to anterior horn of the right lateral ventricle. Although possibly coincidental, periventricular heterotopia are considered to be epileptogenic and this association has been reported once before. Migration disorders, such as in the periventricular heterotopia of our patient, may influence the formation and excitability of the striato–thalamo–cortical network involved in the generation of 3 Hz spike-waves.     

Acute postoperative seizures after frontal lobe cortical resection for intractable partial epilepsy

PURPOSE: To evaluate the incidence and prognostic importance of acute postoperative seizures (APOSs) occurring in the first week after a focal corticectomy in patients with partial epilepsy of frontal lobe origin. METHODS: We retrospectively evaluated 65 patients who underwent a frontal lobe cortical resection for intractable partial epilepsy between April 1987 and December 2000. All patients were followed up for a minimum of 1 year after surgery. RESULTS: APOSs occurred in 17 (26%) patients. None of the following factors was shown to be significantly associated with the occurrence of APOSs: gender, duration of epilepsy, etiology for seizure disorder, use of subdural or depth electrodes, surgical pathology, or postoperative risk factor for seizures. Patients with APOSs were older at seizure onset and at the time of surgery (p = 0.003 and p = 0.05, respectively). At last follow-up, patients who had APOSs had a seizure-free outcome similar to that of individuals without APOSs (47.1% vs. 50.0%; p = 0.77). Patients with APOSs appeared less likely to have a favorable outcome [i.e., fewer than three seizures per year and >95% decrease in seizure activity (58.8 vs. 70.8%; p = 0.35)]. This result may not have reached statistical significance because of the sample size. No evidence suggested that precipitating factors or the timing of APOSs was an important prognostic factor. CONCLUSIONS: The presence of APOSs after frontal lobe surgery for intractable epilepsy does not preclude a significant reduction in seizure tendency. These findings may be useful in counseling patients who undergo surgical treatment for frontal lobe epilepsy.     

Periventricular nodular heterotopia functionally couples with the overlying hippocampus

Patients with periventricular nodular heterotopia (PVNH) often have severe epilepsy. However, it is unclear how the heterotopia contributes to epileptogenesis. Recently, electrophysiologic studies using intraoperative depth electrodes have indicated that interaction between the heterotopia and overlying cortex is crucial for seizure onset. We performed an in vitro physiologic study using slices of resected brain from a 22-year-old man with PVNH, who manifested medically refractory mesial temporal lobe epilepsy. Preoperative evaluation indicated that the right mesial temporal structure and PVNH were the epileptogenic focus. The resected tissue was immediately immersed in cold artificial cerebrospinal fluid, and then slices of the brain tissue including the heterotopic nodules and overlying hippocampus were prepared. We electrically stimulated the incubated slices, and the elicited neural activities were analyzed as changes in the flavoprotein fluorescence signals. When we stimulated either the heterotopic nodule or the overlying hippocampus, clear functional coupling of neural activities between these structures was observed. The coupling response evoked by stimulation of the subiculum and developing within the heterotopic nodule was enhanced by application of bicuculline. Therefore, activities of the hippocampus and the nodule are closely correlated.     

Seizure outcome after temporal lobectomy for temporal lobe epilepsy: a Kaplan-Meier survival analysis

OBJECTIVE: To determine seizure outcome and its predictors in patients with medically refractory temporal lobe epilepsy (TLE) after temporal lobectomy (TL). BACKGROUND: TL is the most common surgical procedure performed in adolescents and adults for the treatment of medically refractory TLE. Seizure outcome has been reported extensively during the first few postoperative years, but little is known beyond that time. METHODS: The authors analyzed seizure outcome in 79 patients who underwent TL for epilepsy at the Duke University Medical Center from 1962 through 1984. Patients with less than 2 years of follow-up and degenerative disorders were excluded. Predictors of seizure outcome were analyzed using Kaplan-Meier survival analyses. RESULTS: The mean follow-up was 14 years (range, 2.1 to 33.6 years). Using Engel's classification, 65% of patients were class I, 15% were class II, 11% were class III, and 9% were class IV. At least one postoperative seizure occurred in 55% of subjects. The majority of recurrences (86%) took place within 2 years of surgery. Later recurrences tended not to lead to medical intractability. Higher monthly preoperative seizure frequency was associated with poor seizure outcome. A seizure-free state at 2 years was found to be a better predictor of long-term outcome than the 6-, 12-, and 18-month landmarks. CONCLUSIONS: TL provides sustained, long-term benefit in patients with medically refractory TLE. Seizure-free status at 2 years from the time of surgery is predictive of long-term remission.     

Superselective anterior temporal resection in mesial temporal lobe epilepsy

We report the case of a patient with pharmacoresistant mesial temporal lobe epilepsy presenting psychomotor seizures with onset at early childhood. MRI showed a blurred internal structure of the right hippocampus and right mammillary body atrophy. Neuropsychological testing revealed deficits in selective attention and visual planning. Non-invasive recording was not sufficient to precisely detect the seizure onset zone. Invasive recording showed seizure onset in the temporo-polar neocortex, with spread to the amygdalum and hippocampus. A superselective resection of the temporal pole and amygdalum was performed with preservation of the hippocampus. Histology revealed the presence of focal cortical dysplasia (Palmini type Ib). Seizure frequency was reduced after surgery, and seizure freedom for two years was achieved with optimisation of the antiepileptic drug regime. Memory functions were preserved, and selective attention and visual planning improved following limited resection. This case suggests that, in selected cases, highly targeted resections with preservation of memory-relevant structures may be the best choice considering both seizure control and unimpaired cognitive functioning.