Executive functioning in children with intractable frontal lobe or temporal lobe epilepsy

The aim of the present study was to shed light on the executive functioning deficits that might differentiate children with frontal lobe epilepsy (FLE) from children with temporal lobe epilepsy (TLE). Participants included 19 youth with intractable FLE and 47 youth with intractable TLE. Participants completed the Wisconsin Card Sorting Test (WCST), verbal fluency, Trail Making Test (Trails A and B), Digit Span Forward (DSF), and Digit Span Backward (DSB). When compared to the normative sample, the FLE group performed significantly worse on DSF, DSB, Trails B, and the WCST. Similarly, the TLE group performed significantly worse on DSF and DSB compared to the normative sample. Youth with FLE had significantly greater difficulty on the WCST compared to the TLE group. Overall, the results indicated that youth with FLE had significantly greater difficulty with concept formation compared to children with TLE. No differences between groups emerged on tasks assessing attention, working memory, mental flexibility, or rapid word retrieval. Both groups performed significantly below the normative sample levels on attention and working memory tasks. As a whole, it appears that some, although not all, executive dysfunction is specific to FLE.     

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.     

额叶离断术治疗无影像学异常的难治性额叶癫痫

目的 探讨额叶离断术治疗无影像学异常的难治性额叶癫痫的可行性、有效性、并发症及适应证.方法 2006年6月至2012年1月解放军第153医院全军神经外科中心对12例无影像学异常的难治性额叶癫痫患者,采用额叶离断术治疗,对手术适应证的选择、手术方法、离断范围、额叶功能区的保护方法、手术效果以及并发症进行总结分析.12例患者中,10例行单纯额叶离断,2例一侧额叶离断后皮质脑电图(ECoG)监测发现离断部位后缘仍有癫痫波,加行胼胝体前部切开术.结果 5例术后出现短暂精神、记忆及性格改变,2例出现一侧肢体轻度偏瘫,均于1个月内恢复正常.无颅内出血、感染及严重并发症.随访1.0～5.5年,Engel Ⅰ级9例,Ⅱ级3例.结论 在术中直接皮层电刺激技术及ECoG监测下,采用额叶离断术治疗无影像学异常的难治性额叶癫痫,是一种安全有效的手术方法.     

Periventricular nodular heterotopia and intractable temporal lobe epilepsy: Poor outcome after temporal lobe resection

We describe 5 women and 5 men with periventricular nodular heterotopia and electroclinical features suggestive of temporal lobe epilepsy, who were surgically treated for control of medically refractory seizures. Magnetic resonance imaging revealed bilateral periventricular nodular heterotopia in 7 of the 10 patients. Because of the lack of clear localization, 6 patients were studied with intracranial depth electrode recordings. Seizures were of hippocampal onset (3 patients), regional temporal lobe onset (2 patients), or occipital-temporal onset (1 patient). Anterior temporal lobectomy was performed in 6 patients; selective amygdalohippocampectomy, in 1; and anterior temporal lobectomy plus resection of the heterotopic tissue, in 3. None of the 9 patients followed for more than 12 months postoperatively were seizure free. Two patients were initially seizure free for approximately 18 months, but then seizures recurred. One patient had a major reduction in seizure frequency at a 39-month follow-up after most of the unilateral heterotopic tissue was included in the temporal resection. Temporal resection did not lead to a long-term favorable outcome in this group of patients with periventricular nodular heterotopia and epileptogenic discharges involving the temporal lobe. This sugests a more widespread disorder with epileptogenic activity possibly originating in or near the heterotopic tissue. The clinical and electrographic features of periventricular nodular heterotopia pointing to temporal lobe origin are misleading and temporal resection does not result in long-term cessation of seizures.     

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.     

Cephalic aura after frontal lobe resection

A cephalic aura is a common sensory aura typically seen in frontal lobe epilepsy. The generation mechanism of cephalic aura is not fully understood. It is hypothesized that to generate a cephalic aura extensive cortical areas need to be excited. We report a patient who started to have cephalic aura after right frontal lobe resection. Magnetoencephalography (MEG) showed interictal spike and ictal change during cephalic aura, both of which were distributed in the right frontal region, and the latter involved much more widespread areas than the former on MEG sensors. The peculiar seizure onset pattern may indicate that surgical modification of the epileptic network was related to the appearance of cephalic aura. We hypothesize that generation of cephalic aura may be associated with more extensive cortical involvement of epileptic activity than that of interictal activity, in at least a subset of cases.     

Executive functions in children with frontal and temporal lobe epilepsy.

Even though frontal lobe epilepsy (FLE) is a relatively common seizure type, no formal psychometric studies of children with FLE have been reported. We compared 12 children with FLE and 15 children with temporal lobe epilepsy (TLE) on neuropsychological tests of attention, memory, executive functioning, and adaptive functioning. The results of these tests indicated that the children with FLE had deficits in planning and executive functions, whereas their verbal and nonverbal memory was intact. The opposite pattern was observed in children with TLE. Measures of executive functioning and impulse control were the best predictors of adaptive functioning. The findings suggest that children with FLE have a pattern of cognitive deficits that differs markedly from the pattern seen in children with TLE. Children with FLE have prominent deficits in executive functioning that appear to be related to poor behavioral adaptation.     

Neurocognitive and behavioral functioning in frontal lobe epilepsy: a review

Frontal lobe epilepsy (FLE) is a seizure disorder with a lower prevalence than temporal lobe epilepsy (TLE). Despite its consequences on cognitive and emotional well-being, the neuropsychology of FLE has not been well studied. By contrast, TLE has been studied meticulously, leading to a relevant understanding of memory and the functional characteristics of the temporal and limbic circuits. The neuropsychological studies on FLE report deficits in motor coordination and planning, reduced attention span, and difficulties in response inhibition in complex cognitive tasks. This review aims to illustrate the most relevant neurocognitive dimensions, psychiatric comorbidity, and postoperative neuropsychological outcome of FLE. Methodological suggestions for future research are also included by critically reviewing the existing literature.     

Impact of depressed mood on neuropsychological status in temporal lobe epilepsy

OBJECTIVES: Depression is a common psychiatric complication of temporal lobe epilepsy. This study examined the effect of depressed mood on neuropsychological performance among patients with chronic temporal lobe epilepsy. METHODS: Seventy consecutive surgery candidates for medication resistant complex partial seizures of unilateral temporal lobe origin were assessed for psychiatric symptoms and underwent comprehensive neuropsychological assessment. RESULTS: Standardised psychiatric interview disclosed that 34% of the patient sample exhibited significant depression. Controlling for seizure frequency, patients with comorbid depression at the time of neuropsychological assessment exhibited significantly poorer performance on measures of intelligence, language, visuoperceptual ability, memory, and executive function. Within lateralised temporal lobe epilepsy groups, the adverse effects of depression on cognitive function were greater in patients with left temporal lobe compared with those with right temporal lobe epilepsy. In addition, depression seemed to be underrecognised and undertreated as none of the patients with epilepsy and comorbid depression were treated for their psychiatric condition at the time of admission for monitoring. CONCLUSIONS: Depression, a common psychiatric comorbidity among patients with chronic temporal lobe epilepsy, seems to be undertreated and to have adverse effects on cognitive functioning.     

Patterns of verbal learning and memory in children with intractable temporal lobe or frontal lobe epilepsy

PurposeThe objective of this study was to provide a better understanding of the verbal learning and memory (VLM) patterns that might differentiate children with frontal lobe epilepsy (FLE) from children with temporal lobe epilepsy (TLE) and to examine the impact of variables thought to influence outcomes (seizure laterality, age at seizure onset, age at assessment, epilepsy duration, number of antiepileptic drugs).MethodsRetrospective analyses were carried out for children with intractable unilateral TLE (n = 100) and FLE (n = 27) who completed standardized measures of VLM entailing lists of single words or lists of word pairs.ResultsMean intelligent quotients and VLM scores on single words fell within the average range for both groups, whereas scores fell within the low average to borderline range on word pairs. No significant overall differences in VLM were found between the group with TLE and the group with FLE.Older age at assessment and older age at seizure onset were generally associated with better VLM in both groups but were related to better performance in a number of indices in the group with TLE and only fewer intrusions in the group with FLE.ConclusionsThe VLM profiles of children with TLE and FLE are generally similar. Older age at assessment and older age at seizure onset have a favorable impact on both groups but are related to better encoding, retrieval, and monitoring processes for the group with TLE and improved memory monitoring (i.e., as indicated by fewer intrusions) in the group with FLE.     

Factors underlying scalp-EEG interictal epileptiform discharges in intractable frontal lobe epilepsy.

AIMS: Scalp-EEG interictal epileptiform discharges (IEDs) may be less predictive of the outcome of frontal lobe epilepsy surgery than of temporal lobe epilepsy surgery. We identified factors associated with the location of scalp-EEG IEDs in intractable frontal lobe epilepsy. METHODS: Ten factors were assessed in a retrospective review of 53 patients with either concordant (frontal lobe seizure focus) or discordant (generalized or outside frontal seizure focus) IED or both, who had excellent surgical outcomes. The Fisher exact test and the Wilcoxon rank sum test determined statistically significant associations. RESULTS: Thirty-six patients (68%) had concordant IED, 24 (45%) discordant IED, and 17 (32%) both. Younger age at onset was significantly associated with discordant IED (mean, 7.5 years versus 17 years for patients without discordant IED; P < 0.01), whereas duration of epilepsy was not. Seizure foci at the frontal convexity were associated with concordant IED. About 72% of patients with a convexity seizure focus had concordant IED, compared with only 33% of patients with mesial frontal foci having concordant IED (P = 0.06). CONCLUSIONS: Early seizure onset in intractable frontal lobe epilepsy is associated with IEDs discordant with seizure focus. Frontal convexity seizure foci are more likely than mesial frontal seizure foci to be associated with concordant discharges.     

顽固性额叶癫痫的临床特点及术后影响因素分析

目前越来越多的顽固性癫痫患者接受外科治疗，但额叶癫痫患者的临床特点和影响手术预后的因素报道不多，现对2001年9月到2003年3月接受手术方法治疗的66例额叶癫痫患者进行回顾性总结，分析预后影响因素。     

额叶癫痫的手术治疗

目的总结并分析顽固性额叶癫痫患者手术治疗的效果、手术方式和经验。方法回顾性分析2003年3月至2009年4月在我院接受手术治疗的116例顽固性额叶癫痫患者的临床及脑电图特征、手术方式和疗效。结果随访1～6年,平均2.6年。疗效根据Engel的标准进行评定,其中I级（癫痫发作消失）49例（42.2%）;Ⅱ级（癫痫发作频率减少≥90%）36例（31.0%）;Ⅲ级（癫痫发作频率减少≥75%）19例（16.4%）;Ⅳ级（癫痫发作频率减少〈75%或与术前相近）12例（10.3%）。本组总有效（Ⅰ、Ⅱ、Ⅲ级）率为89.7%;效果优良（Ⅰ、Ⅱ级）率为73.3%。此外,患者术前所伴有的精神和行为异常在术后多数患者有所改善。术后无严重并发症及手术死亡。结论对于顽固性额叶癫痫,准确定位原发致痫灶并采用合理的手术方式彻底处理痫灶是手术成功的关键。必要时应采用颅内埋藏电极来寻找原发致痫灶。     

Up-regulation of major vault protein in the frontal cortex of patients with intractable frontal lobe epilepsy

Major vault protein (MVP) is a vesicular drug transporter and may participate in multidrug resistance (MDR). The aim of this study was to determine the expression and cellular localization of MVP in refractory frontal lobe epilepsy (FLE). We detected MVP expression in tissue samples from the refractory frontal cortex of 30 patients who had been surgically treated for refractory epilepsy. We compared these tissues with twelve histologically normal frontal lobe samples from controls. In the control group, the expression of MVP was faint in the cortex. The expression of MVP protein increased dramatically in the refractory epilepsy group; MVP immunoreactivity (IR) was observed in the cytoplasm of neurons. Thus, MVP protein was increased in the frontal cortex of patients with refractory epilepsy. Further research is necessary to determine whether or not MVP plays a role in the mechanisms underlying drug resistance in refractory FLE.