Depression in temporal lobe epilepsy before epilepsy surgery

PURPOSE: This study examined the association of depression with laterality of epilepsy surgery in patients with temporal lobe epilepsy before standard lobectomy. METHODS: Forty-nine patients presented for EEG telemetry for localization of epilepsy and eventual temporal lobectomy. Patients underwent routine neuropsychiatric evaluation blinded for epileptic focus, including ratings on depression. Patients were grouped according to right (n = 25, M = 10/F = 15) and left (n = 24, M = 13/F = 11) temporal lobectomy. Analysis of variance included side of surgery as grouping variable and sex, general depressive, cognitive depressive, and vegetative depressive symptoms as dependent variables. Chi2 analyses included categoric variables of sex, handedness, education, neuropathologic findings, and current affective disorders. t Tests were performed on variables of age, epilepsy duration, and cognitive function. RESULTS: Right and left temporal epilepsy groups did not differ with regard to sex, handedness, age, duration of epilepsy, education, cognitive function, and neuropathology. Patients with right temporal epilepsy rated higher on general, cognitive. and vegetative depression scores. Women scored higher on general, cognitive, and vegetative depression scores. Current affective disorders were more common in the right temporal epilepsy group. CONCLUSIONS: Depression ratings and diagnoses were more prominent in patients with right temporal lobe epilepsy and in women in particular. The strength of this laterality finding lies in the selection of patients, as all underwent epilepsy surgery. The finding on gender difference partly reflects the higher incidence of depression in women and needs further exploration. The laterality finding contrasts with recent findings in epilepsy, stroke, and trauma that associate depression with left hemispheric lesions. However, our results are consistent with findings in electrically hyperactive lesions such as gelastic and dacrystic epilepsy.     

Depression in temporal lobe epilepsy surgery patients: an FDG-PET study

PURPOSE: Depression is common in temporal lobe epilepsy (TLE) and after temporal lobectomy, and its etiology is obscure. In nonepileptic depression (including depression associated with other neurologic disorders), a consistent PET imaging finding is frontal lobe hypometabolism. Many TLE patients have hypometabolism involving frontal regions. Thus in data available from routine clinical assessments in an epilepsy surgery unit, we tested the hypothesis that the pattern of hypometabolism, particularly in the frontal lobe, may be associated with the depression seen in patients with TLE and TLE surgery. METHODS: We studied 23 medically refractory TLE patients who underwent anterior temporal lobectomy and who had preoperative FDG-PET scanning. All patients had pre- and postoperative psychiatric assessment. By using statistical parametric mapping (SPM-99), patterns of hypometabolism were compared between patients who had a preoperative history of depression (n=9) versus those who did not (n=14) and between those in whom postoperative depression developed (n=13) versus those in whom it did not (n=10). A significant region of hypometabolism was set at p<0.001 for a cluster of >or=20 contiguous voxels. RESULTS: Patients with a history of depression at any time preoperatively showed focal hypometabolism in ipsilateral orbitofrontal cortex compared with those who did not (t=4.64; p<0.001). Patients in whom depression developed postoperatively also showed hypometabolism in the ipsilateral orbitofrontal region (t=5.10; p<0.001). CONCLUSIONS: Although this study is methodologically limited, and other explanations merit consideration, orbitofrontal cortex dysfunction, already implicated in the pathophysiology of nonepileptic depression, may also be relevant to the depression of TLE and temporal lobectomy.     

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.     

Drug-resistant temporal lobe epilepsy is associated with postural control abnormalities

Epilepsy is responsible for falls that are not systematically associated with seizures and that therefore suggest postural impairment. There are very few studies of postural control in patients with epilepsy and none of them focus on temporal lobe epilepsy (TLE), although part of the vestibular cortex is located in the temporal cortex. The aim of this study was to evaluate the characteristics of postural control in a homogeneous population of patients with complex partial TLE. Twenty-six patients with epilepsy and 26 age-matched healthy controls underwent a sensory organization test combining six conditions, with and without sensory conflicting situations. Patients with epilepsy displayed poorer postural control, especially in situations where vestibular information is necessary to control balance. In addition to potential antiepileptic drug side effects, vestibular dysfunction could be related to the temporal pathology. Our study allows for a better understanding of the mechanism underlying falls in this population of patients.     

Somatosensory auras in refractory temporal lobe epilepsy

PURPOSE: To determine the prevalence, manifestations, lateralizing value, and surgical prognostic value of somatosensory auras (SSAs) in patients with refractory temporal lobe epilepsy (TLE). METHODS: Eighty-one consecutive patients undergoing temporal lobectomy for refractory complex-partial seizures were screened for SSAs. The characteristics of the somatosensory phenomena, occurrence of other aura types, seizure semiology, findings of EEG and imaging studies, temporal lobe neuropathology, and postoperative seizure outcome were determined in each patient with SSAs. RESULTS: Nine (11%) of 81 patients with refractory temporal lobe seizures reported distinct SSAs as part of their habitual seizures. The most common manifestation of SSAs was tingling (eight of nine, 89%), but sensory loss (one of nine, 11%) and pain (one of nine, 11%) also were reported. Five patients had unilateral somatosensory symptoms, and four patients had bilateral somatosensory symptoms. Seizure origin was in the contralateral temporal lobe in four (80%) of five patients with unilateral SSAs, including all patients with unilateral SSAs affecting a limb. Partial temporal lobe resection produced complete seizure remission in all nine (100%) patients 1 year after surgery and in seven (78%) of nine patients 2 years after surgery. CONCLUSIONS: SSAs occur more frequently than previously appreciated in patients with refractory temporal lobe seizures and usually manifest as either unilateral or bilateral tingling. In patients with temporal lobe seizures, unilateral SSAs involving a limb suggest a seizure origin in the contralateral temporal lobe. The surgical outcome of TLE patients with SSAs is favorable. Thus the presence of SSAs should not serve as a deterrent to temporal lobe resection in patients with clearly defined TLE.     

影响颞叶癫痫预后相关因素分析

目的研究颞叶癫痫患者病史、脑电图、头颅影像学资料等与其预后的关系。方法回顾分析我院确诊的99例颞叶癫痫患者病史、头颅影像学资料、发作间期脑电图资料、药物疗效,依据药物疗效分为难治性癫痫组46例,非难治性癫痫组53例,比较两组间差异。结果比较两组间差异发现:头颅MRI异常(χ2=7.55,P<0.01)、发作间期脑电图(electroencephalogram,EEG)反复异常(χ2=8.21,P<0.01)、初发年龄小(Z=-3.81,P<0.01)、病程长(Z=-4.41,P<0.01)与难治性颞叶癫痫有关。结论头颅MRI异常、发作间期EEG反复异常、初发年龄小、病程长为颞叶癫痫预后的不良因素。     

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.     

Prognosis after temporal lobe epilepsy surgery: the value of combining predictors

Purpose: Although several independent predictors of seizure freedom after temporal lobe epilepsy surgery have been identified, their combined predictive value is largely unknown. Using a large database of operated patients, we assessed the combined predictive value of previously reported predictors included in a single multivariable model.
Methods: The database comprised a cohort of 484 patients who underwent temporal lobe surgery for drug-resistant epilepsy. Good outcome was defined as Engel class 1, one year after surgery. Previously reported independent predictors were tested in this cohort. To be included in our final prediction model, predictors had to show a multivariable p-value of <0.20.
Results: The final multivariable model included predictors obtained from the patient's history (absence of tonic–clonic seizures, absence of status epilepticus), magnetic resonance imaging [MRI; ipsilateral mesial temporal sclerosis (MTS), space occupying lesion], video electroencephalography (EEG; absence of ictal dystonic posturing, concordance between MRI and ictal EEG), and fluorodeoxyglucose positron emission tomography (FDG-PET; unilateral temporal abnormalities), that were related to seizure freedom in our data. The model showed an expected receiver-operating characteristic curve (ROC) area of 0.63 [95% confidence interval (CI) 0.57–0.68] for new patient populations. Intracranial monitoring and surgery-related parameters (including histology) were not important predictors of seizure freedom. Among patients with a high probability of seizure freedom, 85% were seizure-free one year after surgery; however, among patients with a high risk of not becoming seizure-free, still 40% were seizure-free one year after surgery.
Conclusion: We could only moderately predict seizure freedom after temporal lobe epilepsy surgery. It is particularly difficult to predict who will not become seizure-free after surgery.     

Serotonin 1A receptors, depression, and memory in temporal lobe epilepsy

Purpose: Memory deficits and depression are common in patients with temporal lobe epilepsy (TLE). Previous positron emission tomography (PET) studies have shown reduced mesial temporal 5HT1A‐receptor binding in these patients. We examined the relationships among verbal memory performance, depression, and 5HT1A‐receptor binding measured with 18F‐trans‐4‐fluoro‐N‐2‐[4‐(2‐methoxyphenyl)piperazin‐1‐yl]ethyl‐N‐(2‐pyridyl) cyclohexane carboxamide (18FCWAY) PET in a cross‐sectional study. Methods: We studied 40 patients (24 male; mean age 34.5 ± 10.7 years) with TLE. Seizure diagnosis and focus localization were based on ictal video–electroencephalography (EEG) recording. Patients had neuropsychological testing with Wechsler Adult Intelligence Score III (WAIS III) and Wechsler Memory Score III (WMS III) on stable antiepileptic drug (AED) regimens at least 24 h since the last seizure. Beck Depression Inventory (BDI) scores were obtained. We performed interictal PET with 18FCWAY, a fluorinated derivative of WAY 100635, a highly specific 5HT1A ligand, and structural magnetic resonance imaging (MRI) scans to estimate partial volume and plasma free fraction corrected 18FCWAY volume of distribution (V/f1). Key Findings: Hippocampal V/f1 was significantly lower in area ipsilateral than contralateral to the epileptic focus (73.7 ± 27.3 vs. 95.4 ± 28.4; p < 0.001). We found a significant relation between both left hippocampal 18FCWAY V/f1 (r = 0.41; p < 0.02) and left hippocampal volume (r = 0.36; p < 0.03) and delayed auditory memory score. On multiple regression, there was a significant effect of the interaction of left hippocampal 18FCWAY V/f1 and left hippocampal volume on delayed auditory memory, but not of either alone. High collinearity was present. In an analysis of variance including the side of the seizure focus, the effect of left hippocampal 18FCWAY V/f1 but not focus laterality retained significance. Mean BDI was 8.3 ± 7.0. There was a significant inverse relation between BDI and 18FCWAY V/f1 ipsilateral to the patient’s epileptic focus (r = 0.38 p < 0.02). There was no difference between patients with a right or left temporal focus. There was no relation between BDI and immediate or delayed auditory memory. Significance: Our study suggests that reduced left hippocampal 5HT1A‐receptor binding may play a role in memory impairment in patients with TLE.     

Multifactorial etiology of interictal behavior in frontal and temporal lobe epilepsy

Purpose: Based on discussions on the so called “epileptic personality” in patients with epilepsy, interictal behavioral impairments in frontal and temporal lobe epilepsies were examined in a multivariate approach that took demographic, clinical, and neuropsychological determinants into consideration. Methods: A total of 428 patients with epilepsies originating from the temporal (TLE; 84%) or frontal (FLE; 16%) lobes were examined in regard to personality (Fragebogen zur Persönlichkeit bei zerebralen Erkrankungen [FPZ], a clinical personality questionnaire) and mood (Beck Depression Inventory [BDI I]). Prevalence of impaired behavioral domains was determined. Etiologically relevant determinants of behavioral problems were identified via multiple regression analyses. Key Findings: Elevated depression scores (BDI) were evident in 42% of the patients, and not different in TLE and FLE. In regard to personality, introversion together with low mood, sociability, and self‐determination, as well as problems with interpersonal communication were frequent. The TLE group tended to show greater neuroticism and introversion, while FLE appeared more associated with behavioral aspects of an organic psychosyndrome. Multivariate analyses revealed demographic characteristics (age, gender, education), clinical aspects (psychiatric history, affected hemisphere, mesial pathology, seizure frequency, cognitive functions), and treatment (antiepileptic drug treatment) as relevant determinants, explaining up to 30% of the behavior. Significance: Behavioral abnormalities in patients with frontal or temporal lobe epilepsy are common but on the average mostly mild. Within a multivariate etiological model, localization (mesial yes/no) and lateralization (left > right) dependent behavioral problems in TLE and FLE seem to be overshadowed by other variables, of which patients’ and their families’ psychiatric history, patient characteristics and pharmacological treatment appear of major importance. Better education and cognitive capabilities may be discussed as protective features.     

Mortality after temporal lobe epilepsy surgery

Purpose: To report mortality, after a longer interval, in a cohort of patients with drug‐resistant epilepsy treated by temporal lobe surgery between 1975 and 1995. A previous audit of these patients ending December 1, 1997 observed a standardized mortality ratio (SMR) of 4.5. Methods: We analyzed mortality in a cohort of 306 patients with temporal lobe epilepsy (TLE) who underwent temporal lobe resections between December 1, 1975 and December 1, 1995. Deaths occurring after December 1,1997 and until December 1, 2009 were evaluated. Medical records, death certificates, postmortem examination reports, coroner officer’s reports, and coroner’s inquest reports were sought, and causes of death were ascertained. Sudden unexpected death in epilepsy (SUDEP) cases were identified. Key Findings: In 3,569 person‐years of follow‐up 19 deaths occurred, [SMR 2.00, 95% confidence interval (CI) 1.27–3.13], 14 men (SMR 2.01, 95% CI 1.19–3.39) and 5 women (SMR 1.68, 95% CI 0.70–4.03). On analysis of subgroups, SMRs were significantly elevated in patients with mesial temporal sclerosis (MTS) (SMR 2.50, 95% CI 1.38–4.51), men with MTS (SMR 3.12, 95% CI 1.56–6.25), men with nonspecific lesions (SMR 2.68, 95% CI 1.00–7.09), and right‐sided resections in MTS (SMR 3.33, 95% CI 1.39–8.00). During follow‐up, six SUDEP cases were observed with a rate of 1/595 person‐years. Significance: In this cohort, the risk for premature death in patients undergoing TLE surgery decreased over time but remained above the standard population. Men had a slightly higher risk than women, as did right‐sided resections in MTS, confirming this observation in the original cohort. Although lower, the risk of SUDEP remained. Without up‐to‐date information on seizure outcome, we were unable to directly relate this to mortality.     

Antiepileptic drug withdrawal in patients with temporal lobe epilepsy undergoing presurgical video-EEG monitoring

PURPOSE: To investigate antiepileptic drug (AED) withdrawal during video-EEG monitoring in adult patients with temporal lobe epilepsy (TLE). METHODS: Between 1995 and 1997, 102 consecutive patients with refractory TLE were admitted to the epilepsy monitoring unit for presurgical evaluation. Patients were monitored with ongoing AEDs being rapidly decreased and discontinued in 4-6 days. The monitoring was continued until sufficient numbers of seizures were recorded. Serum AED levels were checked at admission and after the first complex partial seizure (CPS). RESULTS: In all, 89 patients had 429 CPSs (mean, 4.8 per patient), including 156 (36.4%) secondarily generalized. A mean of 153.8 h (16-451 h) was required for completing the monitoring in each patient. Forty-three (48.3%) patients experienced seizure clusters, and eight (9.0%) had generalized seizures that had never occurred or had been absent for years. However, none evolved to status epilepticus. Carbamazepine was the most commonly used AED in 71.9% of patients, followed by valproate and phenytoin. When the first CPS occurred, mean 77.2 h since the beginning of the monitoring, serum levels of these three AEDs were mostly subtherapeutic rather than minimal. CONCLUSIONS: Acute AED withdrawal effectively provoked seizures in TLE patients undergoing presurgical video-EEG monitoring. However, nearly 50% of patients had seizure clusters or secondarily generalized seizures. Serum AED levels were mostly subtherapeutic when the first CPS occurred.     

Thalamo-cortical network dysfunction in temporal lobe epilepsy

ObjectivesImaging and neurophysiological data shows that the cortical disfunction caused by focal epilepsy is not limited to the epileptic focus, thus raising the modern vision of focal epilepsy as a network disorder. The involvement of deep thalamo-cortical projections in temporal lobe epilepsy is a clear example. We aimed at demonstrating the interictal functional impairment of thalamo-cortical network in drug-naïve TLE patients through the study of high frequency oscillations of somatosensory evoked potentials (HF-SEP).MethodsTwelve healthy controls (HC; 8 females, 52.2 ± 17.3 years-old) and 12 drug-naïve TLE patients (8 females, 55.5 ± 21.5 years-old) underwent bilateral median HF-SEP, recorded by scalp electrodes. Cp3′-Fz and Cp4′-Fz traces were filtered (400–800 Hz) to evidence HF-SEP.ResultsHF-SEP duration in the affected hemisphere was significantly longer when compared to that of both the unaffected hemisphere and HC hemispheres. No significant inter-hemispheric differences were found in areas, powers and latencies of HF-SEP wavelets.ConclusionOur results demonstrate that TLE induces early interictal functional impairments of the thalamo-cortical network.SignificanceOur data strongly corroborates the vision of focal epilepsy as a network disorder and offers a new neurophysiological tool to test pharmacological, surgical and neuromodulatory therapies.     

Mitochondrial involvement in temporal lobe epilepsy

Mitochondrial dysfunction has been identified as a potential cause of epileptic seizures and therapy-resistant forms of severe epilepsy. Thus, a broad variety of mutation in mitochondrial DNA or nuclear genes leading to the impairment of mitochondrial respiratory chain or of mitochondrial ATP synthesis has been associated with epileptic phenotypes. Additionally, with a variety of different methods impaired mitochondrial function has been reported for the seizure focus of patients with temporal lobe epilepsy and Ammon's horn sclerosis and of animal models of temporal lobe epilepsy. Since mitochondrial oxidative phosphorylation provides the major source of ATP in neurons and mitochondria participate in cellular Ca²⁺ homeostasis, their dysfunction strongly affects neuronal excitability and synaptic transmission, which is proposed to be highly relevant for seizure generation. Additionally, mitochondrial dysfunction is known to trigger neuronal cell death, which is a prominent feature of therapy-resistant temporal lobe epilepsy. Therefore, mitochondria have to be considered as promising targets for neuroprotective strategies in epilepsy.     

Memory functions following surgery for temporal lobe epilepsy in children

Surgical treatment appears to improve the cognitive prognosis in children undergoing surgery for temporal lobe epilepsy (TLE). The beneficial effects of surgery on memory functions, particularly on material-specific memory, are more difficult to assess because of potentially interacting factors such as age range, intellectual level, left-handedness, type of surgery and seizure outcome. This study investigated memory functions in 20 right-handed children who had left or right-temporal lobe surgery - including hippocampectomy - and became seizure-free. The neuropsychological evaluation included tests measuring verbally and visually mediated episodic memory, everyday memory as well as attention/working memory and language/semantic memory. We also assessed the relationships between age of seizure onset, general cognitive ability and memory functions. Children with TLE showed poor memory efficiency before surgery that tended to improve about 1 year after surgery. We found a material-specific memory effect, especially after surgery-9 (out of 12) children with left TLE had worse verbal memory results while 5 (out of 8) with right TLE had worse visual memory results. Post-operatively, most children had poor everyday memory performance on the Rivermead Behavioural Memory Test. No significant relationship was observed between episodic memory scores and age of epilepsy onset but children with early onset remained with lower Performance IQ values, Rey's figure copy scores and naming performances after surgery. Surgery significantly improved all the attention/working memory scores, some verbal episodic memory tasks and naming test performances. A different pattern of episodic and semantic memory limitations related to left or right TLE was observed.     

Surgery for temporal lobe epilepsy after cerebral malaria

The most common indication for epilepsy surgery is temporal lobe epilepsy (TLE) which usually is divided into two categories, mesial and lateral TLE. The commonest pathology underlying mesial temporal lobe epilepsy (MTLE) is mesial temporal sclerosis (MTS); we report on a 50-year-old male patient, who contracted cerebral malaria and developed MTLE shortly thereafter. Magnetic resonance imaging (MRI) showed MTS. Surgical treatment was an anteromedial temporal lobe resection with amygdalohippocampectomy. The patient is seizure free, 36 months after surgical treatment. This is the first report describing MTLE-onset subsequent to cerebral malaria and discussing the potential pathophysiological relationship between cerebral malaria and MTS.     

Interictal depression, anxiety, personality traits, and psychological dissociation in patients with temporal lobe epilepsy (TLE) and extra-TLE

PURPOSE: This study was performed to investigate the relation between symptoms of interictal depression, anxiety, personality traits, and psychological dissociation with the localization and lateralization of the epileptogenic zone in patients with partial epilepsy. METHODS: All patients were diagnosed according to the localization-related concept of the 1989 International League Against Epilepsy (ILAE) Classification of Epilepsies and Epileptic Syndromes, and the localization and lateralization of the epileptogenic zone was established by using the clinical criteria for noninvasive presurgical evaluation. This resulted in 67 patients with temporal lobe epilepsy (TLE) and 64 patients with extra-TLE. All patients were assessed on the various aspects of psychopathology by using a comprehensive battery of standardized diagnostic instruments. RESULTS: We did not find the hypothesized excess of psychiatric symptoms in patients with (mesial) TLE in comparison with patients with extra-TLE. We also found no differences between patients with the lateralization of epilepsy in the left versus the right hemisphere. CONCLUSIONS: TLE per se cannot be considered a risk factor in developing more or more severe symptoms of psychopathology in patients with partial epilepsy. Concomitant factors, such as the duration of epilepsy, seizure frequency, and frontal lobe dysfunction may play an additional role. Our findings support the hypothesis of a multifactorial explanation for the psychiatric symptoms in patients with epilepsy.     

Efficacy of temporal lobe surgery for epilepsy in patients with negative MRI for mesial temporal lobe sclerosis

Epilepsy surgery is a successful treatment for refractory temporal lobe epilepsy (TLE). Reports suggest fewer seizure-free outcomes for patients with TLE and who have a negative brain MRI (nMRI) for mesial temporal sclerosis. Data were collected prospectively from patients with nMRI who underwent temporal lobe surgery for TLE characterized by unilateral ictal temporal lobe seizure onset based on a scalp video electroencephalogram or invasive subdural electrode recordings. A total of 86 patients were followed for at least 24 months after surgery. Outcome was evaluated using the Engel classification. Seizure control was obtained by 55% (47/86) of patients (Class [CL]-I), 27% (23/86) showed significant improvement (CL-II) and 19% (16/86) were deemed surgical failures. Shorter duration of epilepsy, later onset of seizures, and ictal theta rhythm (5-7 Hz) were the most significant predictors of postoperative seizure control. Although hypometabolism on positron emission tomography scan and significant memory disparity (>2.5/8) were not significant prognosticators independently, cumulatively they were predictors for favorable outcome.     

Surgical implications of neuromagnetic spike localization in temporal lobe epilepsy

PURPOSE: To investigate the clinical usefulness of magnetoencephalography (MEG) as a guide to the surgical treatment of temporal lobe epilepsy (TLE). METHODS: Preoperative spike localization by MEG was compared with seizure outcome and postoperative spike localization at 12 months after resective surgery in 16 patients with TLE. Spike localization was classified into anterior temporal (AT) and non-AT localization in 11 patients without neocortical lesion treated with anterior temporal lobectomy (ATL); and lesion and lobar localization in five patients with neocortical lesion treated with lesionectomy (n = 3) or lesionectomy with medial temporal resection (n = 2). RESULTS: All five patients with AT localization became seizure free and spike free after surgery. Among the six patients with non-AT localization, two became seizure free and spike free, two became seizure free with residual spikes, one had residual seizures but no spikes, and one had both residual seizures and spikes. All three patients with lesion localization and two with lobar localization had favorable seizure outcome and became spike free after surgery. CONCLUSIONS: MEG spike localization can identify neocortical sources remote from the presumed epileptogenic area. Favorable seizure outcome can be expected in patients with AT localization after ATL and patients with lesion localization after lesionectomy. In contrast, non-AT localization indicates either nonmedial TLE or spike propagation to the posterior and extratemporal neocortex. Similarly, lobar localization indicates spike propagation from an epileptogenic lesion or extensive epileptogenicity. Patients with non-AT localization or lobar localization should undergo intensive evaluations, such as intracranial EEG, for improved seizure outcome.