Seizure outcome and its predictors after temporal lobe epilepsy surgery in patients with normal MRI

Purpose: To characterize seizure outcomes following temporal lobe epilepsy (TLE) surgery in patients with normal preoperative brain magnetic resonance imaging (MRI). Methods: We reviewed adult patients with pharmacoresistant epilepsy and normal MRI who underwent TLE surgery (1996–2009). Seizure outcomes were analyzed using survival and multivariate regression with Cox proportional hazard modeling. Two analyses were performed using two favorable outcome definitions: complete seizure freedom and Engel classification. Key Findings: Sixty‐four patients were analyzed (mean follow‐up 4.1 years; range 1–14.5 years). Most had a standard anterior temporal lobectomy (84%) and unremarkable pathology (45%). At 1 year, the chance of complete seizure freedom was 76% [95% confidence interval (CI) 71–81%] comparable to an 81% (95% CI 76–86%) chance of Engel score of 1. With longer follow‐up, a progressively broadening significant discrepancy between the two outcome measures was observed. The chance of complete seizure freedom was 66% (95% CI 61–71%) at 2 years, and 47% (95% CI 40–54%) at 7 years and beyond, whereas the respective chances of achieving an Engel 1 classification were 76% (95% CI 70–82%), and 69% (95% CI 63–75%) at similar time points. Seizure outcome as defined by either measure was worse in patients with higher baseline seizure frequency (adjusted risk‐ratio 2.7 when >12 seizures/month; p = 0.01) and with preoperative generalized tonic–clonic seizures (adjusted risk ratio 10.8; p = 0.0006). Memory measures declined with dominant hippocampus resections. Significance: A normal MRI should not prevent presurgical evaluations in patients with suspected TLE, as favorable long‐term postoperative seizure outcomes are possible. Proposed mechanisms of epileptogenicity and seizure recurrence in this group are discussed.     

When is a postoperative seizure equivalent to “epilepsy recurrence” after epilepsy surgery?

Purpose: Up to one‐half of epilepsy surgery patients will have at least one seizure after surgery. We aim to characterize the prognosis following a first postoperative seizure, and provide criteria allowing early identification of recurrent refractory epilepsy. Methods: Analyzing 915 epilepsy surgery patients operated on between 1990 and 2007, we studied 276 who had ≥1 seizure beyond the immediate postoperative period. The probability of subsequent seizures was calculated using survival analysis. Patients were divided into seizure‐free (no seizures for ≥1 year) and refractory (persistent seizures) and analyzed using multivariate regression analysis. Results: After a first seizure, 50% had a recurrence within 1 month and 77% within a year before the risk slowed down to additional 2–3% increments every two subsequent years. After a second seizure, 50% had a recurrence within 2 weeks, 78% within 2 months, and 83% within 6 months. Having both the first and second seizures within six postoperative months [odds ratio (OR) 4.04; 95% confidence interval (CI) 2.05–8.40; p = 0.0001], an unprovoked initial recurrence (OR 3.92; 95% CI 2.13–7.30; p < 0.0001), and ipsilateral spikes on a 6‐months postoperative electroencephalography (EEG) (OR 2.05; 95% CI 1.10–3.88; p = 0.025) predicted a poorer outcome, with 95% of patients who had all three risk factors becoming refractory. All patients with cryptogenic epilepsy and recurrent seizures developed refractoriness. Discussion: Seizures will recur in most patients who present with their first postoperative event, with one‐third eventually regaining seizure‐freedom. Etiology and early and unprovoked postoperative seizures with epileptiform activity on EEG at six postoperative months may predict recurrent medical refractoriness.     

Secondarily generalized seizures in temporal lobe epilepsy

Purpose: Secondarily generalized tonic–clonic seizure (SGTCS) may occur rarely in temporal lobe epilepsy (TLE), but SGTCS is the major risk factor for sudden death and for seizure‐related fatal injuries. Our aim was to investigate clinical factors associated with the occurrence of SGTCS in TLE by addressing two questions: (1) What clinical features differentiate patients with TLE who regularly had SGTCS from those who did not? (2) Is there an association of secondarily generalized seizures with preceding seizure elements and clinical data? Methods: We included 171 patients with TLE (mean age 34.4 ± 10) who participated in our presurgical evaluation program, which included continuous video–electroencephalography (EEG) and magnetic resonance imaging (MRI). Patients had a temporal lobectomy as a result of mesial or neocortical TLE. To reevaluate the archived seizures, we selected the consecutively recorded seizures of each patient. If the patient had more than three recorded seizures, then we reevaluated only the first three. Altogether video‐recorded seizures of 402 patients were reanalyzed. Key Findings: A positive association between the presence of hippocampal sclerosis on the MRI and SGTCS in the patient history was found, whereas ictal speech and pedal automatism showed a negative association with a SGTCS history. The age of patients showed a positive association, whereas patient’s reactivity before and during the seizure, oral/pedal automatisms, and vocalizations showed a negative association with secondary generalization of a focal‐onset seizure during video‐EEG monitoring. Significance: Clinical features associated with SGTCS may help clinicians during presurgical monitoring identify high‐risk patients for SGTCS. Our study may help in understanding the pathophysiology of secondary generalization.     

Seizure worsening and its predictors after epilepsy surgery

Purpose: This study aims to investigate seizure worsening and its predictors after epilepsy surgery. Methods: A retrospective chart review of patients who underwent unilobar epilepsy surgery between 1990 and 2007 and had recurrence of at least one seizure was performed. Seizure worsening was defined as an increase in total average monthly seizure frequency, average monthly generalized tonic–clonic seizures (GTCS), new‐onset GTCS, or new‐onset status epilepticus. The occurrence of sudden unexpected death in epilepsy (SUDEP) was captured. Multivariate logistic regression analysis was used to identify predictors of worsening. Key Findings: A total of 276 patients with postoperative seizure recurrence were identified. Monthly average seizure frequency worsening occurred in 9.8%, GTC worsening in 8.0%, new‐onset GTCs in 1.4%, new‐onset status epilepticus in 2.2%, and death from SUDEP in 1.4%. A higher risk of worsening was seen with extratemporal resections as compared to temporal lobe surgeries (odds ratio [OR] 3.11, 95% confidence interval [CI] 1.21–7.95; p = 0.018), and in patients with low preoperative seizure frequency <30 seizures/month (OR 14.82, 95% CI 2.81–275.41; p = 0.0003). Predictors of increased GTCs included an incomplete resection (OR 3.98, 95% CI 1.39–12.59; p = 0.010) and multiple recorded ictal patterns (OR 5.91, 95% CI 1.20–26.96; p = 0.030). Multiple seizure semiologies correlated with worsening after temporal lobe resections. Significance: The most vulnerable patients for seizure worsening following epilepsy surgery include those with extratemporal resections, incomplete resections, and multiple recorded ictal patterns.     

Failed surgery for temporal lobe epilepsy: predictors of long-term seizure-free course

OBJECTIVES: To identify prognostic factors which predict the outcome 2 years after TLE surgery in those patients who were not seizure-free at the 6-month postoperative examination. METHODS: We included 86 postoperative TLE patients who had undergone presurgical evaluation, including video-EEG and high-resolution MRI, and who had seizures between the second and sixth postoperative months. RESULTS: 32% of patients were seizure-free in the second postoperative year. We found that normal MRI findings and secondarily generalized seizures (SGTCS) preoperatively were associated with a non-seizure-free outcome, while rare postoperative seizures and ipsilateral temporal IED with seizure-free outcome. Newly administered levetiracetam showed a significant positive effect on the postoperative outcome independent of other prognostic factors. Five of seven patients who received levetiracetam became seizure-free (p = 0.006). CONCLUSION: One-third of patients who did not become seizure-free immediately after surgery, eventually achieved long-term seizure freedom. We suggest watching for long-term seizure freedom after failed epilepsy surgery especially in patients who had rare postoperative seizures, focal MRI abnormality, ipsilateral temporal spikes, or no SGTCS preoperatively. Levetiracetam may have a positive effect on postsurgical seizures.     

Intracranial EEG in predicting surgical outcome in frontal lobe epilepsy

Purpose: Surgery in frontal lobe epilepsy (FLE) has a worse prognosis regarding seizure freedom than anterior lobectomy in temporal lobe epilepsy. The current study aimed to assess whether intracranial interictal and ictal EEG findings in addition to clinical and scalp EEG data help to predict outcome in a series of patients who needed invasive recording for FLE surgery. Methods: Patients with FLE who had resective surgery after chronic intracranial EEG recording were included. Outcome predictors were compared in patients with seizure freedom (group 1) and those with recurrent seizures (group 2) at 19–24 months after surgery. Key Findings: Twenty‐five patients (16 female) were included in this study. Mean age of patients at epilepsy surgery was 32.3 ± 15.6 years (range 12–70); mean duration of epilepsy was 16.9 ± 13.4 years (range 1–48). In each outcome group, magnetic resonance imaging revealed frontal lobe lesions in three patients. Fifteen patients (60%) were seizure‐free (Engel class 1), 10 patients (40%) continued to have seizures (two were class II, three were class III, and five were class IV). Lack of seizure freedom was seen more often in patients with epilepsy surgery on the left frontal lobe (group 1, 13%; group 2, 70%; p = 0.009) and on the dominant (27%; 70%; p = 0.049) hemisphere as well as in patients without aura (29%; 80%; p = 0.036), whereas sex, age at surgery, duration of epilepsy, and presence of an MRI lesion in the frontal lobe or extrafrontal structures were not different between groups. Electroencephalographic characteristics associated with lack of seizure freedom included presence of interictal epileptiform discharges in scalp recordings (31%; 90%; p = 0.01). Detailed analysis of intracranial EEG revealed widespread (>2 cm) (13%; 70%; p = 0.01) in contrast to focal seizure onset as well as shorter latency to onset of seizure spread (5.8 ± 6.1 s; 1.5 ± 2.3 s; p = 0.016) and to ictal involvement of brain structures beyond the frontal lobe (23.5 ± 22.4 s; 5.8 ± 5.4 s; p = 0.025) in patients without seizure freedom. The distribution of ictal onset patterns was similar in both groups, and fast rhythmic activity in the beta to gamma range was found in 57% of seizure‐free patients compared to 70% of patients with recurrent seizures. Analysis of the temporal relation between first clinical alterations and EEG seizure onset did not reveal significant differences between both groups of patients. In multivariate analysis, resection in the left hemisphere (odds ratio [OR] 12.197 95% confidence interval [95% CI] 1.33–111.832; p = 0.027) and onset of seizure spread (odds ratio [OR] 0.733, 95% CI 0.549–0.978, p = 0.035) were independent predictors of ongoing seizures. Significance: Widespread epileptogenicity as indicated by rapid onset of spread of ictal activity likely explains lack of seizure freedom following frontal resective surgery. The negative prognostic effect of surgery on the left hemisphere is less clear. Future study is needed to determine if neuronal network properties in this hemisphere point to intrinsic interhemispheric differences or if neurosurgeons are restrained by proximity to eloquent cortex.     

Levetiracetam may favorably affect seizure outcome after temporal lobectomy

Purpose: To study the prognostic implications of antiepileptic drug (AED) use on seizure freedom following temporal lobe resections for intractable epilepsy. Methods: Seizure outcome implications of epilepsy characteristics and AED use were studied in patients who underwent temporal lobectomy patients at the Cleveland Clinic between September 1995 and December 2006. Survival analysis and multivariate regression with Cox proportional hazard modeling were used. Complete seizure freedom was defined as a favorable outcome. Key Findings: Records of 312 patients were analyzed (mean ± standard deviation follow‐up 3.5 ± 1.7 years). The estimated probability of complete seizure freedom was 69% at 12 months (95% confidence interval [CI] 66–72%), and 48% at 36 months (95% CI 45–52%). The mean number of AEDs used per patient at the time of surgery was 1.78 (range 1–4), dropping to 1.02 at last follow‐up (range 0–4). Following multivariate analysis, a lower preoperative seizure frequency and perioperative use of levetiracetam predicted a favorable outcome (risk ratio [RR] 0.62, 95% CI 0.43–0.89, and RR = 0.57, 95% CI 0.39–0.83, respectively), whereas nonspecific pathology (RR 1.71, 95% CI 1.15–2.47) and a higher number of AEDs used at the time of surgery correlated with higher rates of seizure recurrence (whole‐model log‐rank test p‐value < 0.0001). Better outcomes within the levetiracetam group were seen despite a higher proportion of several poor prognostic indicators within this patient group, and started as early as 4 months after surgery, gradually increasing to a 15–20% survival advantage by 5 years. No similar outcome correlations were identified with another AED. Significance: AED use may be a potential new modifiable seizure‐outcome predictor after temporal lobectomy. This possible prognostic indicator is discussed in light of proposed seizure recurrence mechanisms.     

Seizure outcomes following multilobar epilepsy surgery

Purpose: Outcomes following unilobar surgeries for refractory epilepsy have been well described. However, little is known about long‐term seizure outcomes following multilobar resections. The aim of the current study was to identify long‐term seizure control and predictors of seizure recurrence in this patient population. Methods: Records of patients who underwent multilobar epilepsy surgery at the Cleveland Clinic between 1994 and 2010 were retrospectively reviewed. A postoperative follow‐up of at least 6 months was required. Patients were classified as seizure free if they achieved an Engel class I at last follow‐up. Long‐term chances of seizure freedom were illustrated using a survival analysis, and predictors of recurrence were identified using Cox proportional hazard modeling. Key Findings: Sixty‐three patients with medically intractable epilepsy underwent multilobar surgical resections during the study period (mean follow‐up of 4.6 years). Predominant resection types included extended occipital (temporoparietooccipital, parietooccipital, temporooccipital: 57%), frontotemporal (21%), and temporoparietal (17%). Mean age at surgery was 21.4 years and mean age at seizure onset was 10.1 years. Fifty‐six percent of the patients underwent extraoperative invasive electroencephalography (EEG) evaluations. At 6 postoperative months, 71% (95% confidence interval (CI) 65–77) were seizure‐free (SF), 64% (CI 58–70) were SF at 1 year, 52% (CI 46–59) were SF at 5 years, and 41% (CI 32–50) remained SF at 10 years. Forty‐one patients had at least one breakthrough seizure after surgery (median timing of recurrence 6.1 months), with an Engel class 1 achieved again by last follow‐up in 12 of these 41 cases. Nine patients required a reoperation. Patients who underwent extended occipital/posterior quadrant resections had more favorable outcomes as compared to the other groups. With multivariate analysis, the type of resection (p = 0.03), preoperative auras (p = 0.03), an incomplete resection (0.03), and the presence of postoperative spikes (p = 0.0003) correlated with seizure recurrence. The risk of seizure recurrence for an incomplete resection was 2.3 (CI 1.53–3.36), preoperative aura 2.3 (CI 1.34–3.87), and postoperative spikes on surface EEG 2.5 (CI 1.29–4.71). Significance: A favorable outcome can be achieved in 41% of patients undergoing multilobar resections for epilepsy surgery at 10 years of follow‐up. Close to one‐third of patients who have breakthrough seizures after surgery are able to regain seizure freedom by last follow‐up. Predictors of recurrence include resection type (frontotemporal and parietotemporal resections did worse), presence of preoperative aura, an incomplete surgical resection, and the presence of postoperative interictal discharges on EEG.     

Not surgical technique,but etiology,contralateral MRI,prior surgery,and side of surgery determine seizure outcome after pediatric hemispherotomy

Objective

We aimed to assess determinants of seizure outcome following pediatric hemispherotomy in a contemporary cohort.

Methods

We retrospectively analyzed the seizure outcomes of 457 children who underwent hemispheric surgery in five European epilepsy centers between 2000 and 2016. We identified variables related to seizure outcome through multivariable regression modeling with missing data imputation and optimal group matching, and we further investigated the role of surgical technique by Bayes factor (BF) analysis.

Results

One hundred seventy seven children (39%) underwent vertical and 280 children (61%) underwent lateral hemispherotomy. Three hundred forty-four children (75%) achieved seizure freedom at a mean follow-up of 5.1 years (range 1 to 17.1). We identified acquired etiology other than stroke (odds ratio [OR] 4.4, 95% confidence interval (CI) 1.1–18.0), hemimegalencephaly (OR 2.8, 95% CI 1.1–7.3), contralateral magnetic resonance imaging (MRI) findings (OR 5.5, 95% CI 2.7–11.1), prior resective surgery (OR 5.0, 95% CI 1.8–14.0), and left hemispherotomy (OR 2.3, 95% CI 1.3–3.9) as significant determinants of seizure recurrence. We found no evidence of an impact of the hemispherotomy technique on seizure outcome (the BF for a model including the hemispherotomy technique over the null model was 1.1), with comparable overall major complication rates for different approaches.

Significance

Knowledge about the independent determinants of seizure outcome following pediatric hemispherotomy will improve the counseling of patients and families. In contrast to previous reports, we found no statistically relevant difference in seizure-freedom rates between the vertical and horizontal hemispherotomy techniques when accounting for different clinical features between groups.     

Long-term epilepsy surgery outcomes in patients with MRI-negative temporal lobe epilepsy

Purpose: The outcome of surgery in patients with temporal lobe epilepsy (TLE) and normal high‐resolution magnetic resonance imaging (MRI) has been significantly worse than in patients with unilateral hippocampal damage upon MRI. The purpose of this study was to determine the long‐term outcomes of consecutive true MRI‐negative TLE patients who all underwent standardized preoperative evaluation with intracranial electroencephalography (EEG) electrodes. Methods: In this study we present all adult MRI‐negative TLE surgery candidates evaluated between January 1990 and December 2006 at Kuopio Epilepsy Center in Kuopio University Hospital, which provides a national center for epilepsy surgery in Finland. During this period altogether 146 TLE surgery candidates were evaluated with intracranial electrodes, of whom 64 patients with normal high‐resolution MRI were included in this study. Results: Among the 38 patients who finally underwent surgery, at the latest follow‐up (mean 5.8 years), 15 (40%) were free of disabling seizures (Engel class I) and 6 (16%) were seizure‐free (Engel class IA). Twenty‐one (55%) of 38 patients had poor outcomes (Engel class III–IV). Outcomes did not change compared to 12‐month follow‐up. Histopathologic examination failed to reveal any focal pathology in 68% of our MR‐negative cases. Only patients with noncongruent positron emission tomography (PET) results had worse outcomes (p = 0.044). Discussion: Our results suggest that epilepsy surgery outcomes in MRI‐negative TLE patients are comparable with extratemporal epilepsy surgery in general. Seizure outcomes in the long‐term also remain stable. Modern imaging techniques could further improve the postsurgical seizure‐free rate. However, these patients usually require chronic intracranial EEG evaluation to define epileptogenic areas.     

Psychological outcome profiles in childhood‐onset temporal lobe epilepsy

Purpose: To examine the effect of childhood‐onset temporal lobe epilepsy (TLE) on long‐term psychological function and to identify outcome profiles related to the natural course and treatment of TLE. Methods: Psychological function was studied in a prospective, community‐based cohort of childhood‐onset TLE, approximately 13 years following seizure onset. Fifty‐three patients were assessed using a semi‐structured psychosocial interview, supplemented by self‐report questionnaires measuring quality‐of‐life, depression, self‐esteem, and anxiety. Results: Common patterns were observed, giving rise to four distinct patient groups and psychological outcomes: (1) patients who experienced spontaneous remission of their seizures fared best; their psychological profile was characterized by heightened worry about the possibility of seizure recurrence; (2) patients who progressed to surgery and were seizure free reported adjustment difficulties associated with learning to become “well”; (3) patients who progressed to surgery and were not seizure free had the poorest psychological outcomes, with depression featuring prominently; and (4) patients with ongoing intractable epilepsy reported psychological and social features consistent with the effects of their chronic illness. Discussion: Patients with childhood‐onset TLE face distinctive long‐term psychological challenges. The specific nature of these challenges can be understood in terms of the natural evolution and treatment of their epilepsy.     

Factors associated with seizure freedom in the surgical resection of glioneuronal tumors

Purpose: Gangliogliomas (GGs) and dysembryoplastic neuroepithelial tumors (DNETs) are low‐grade brain tumors of glioneuronal origin that commonly present with seizures. Achieving seizure control in patients with glioneuronal tumors remains underappreciated, as tumor‐related epilepsy significantly affects patients’ quality‐of‐life. Methods: We performed a quantitative and comprehensive systematic literature review of seizure outcomes after surgical resection of GGs and DNETs associated with seizures. We evaluated 910 patients from 39 studies, and stratified outcomes according to several potential prognostic variables. Key Findings: Overall, 80% of patients were seizure‐free after surgery (Engel class I), whereas 20% continued to have seizures (Engel class II–IV). We observed significantly higher rates of seizure‐freedom in patients with ≤1 year duration of epilepsy compared to those with >1 year of seizures [odds ratio (OR) 9.48; 95% confidence interval (CI) 2.26–39.66], and with gross‐total resection over subtotal lesionectomy (OR 5.34; 95% CI 3.61–7.89). In addition, the presence of secondarily generalized seizures preoperatively predicted a lower rate of seizure‐freedom after surgery (OR 0.40; 95% CI 0.24–0.66). Outcomes did not differ significantly between adults and children, patients with temporal lobe versus extratemporal tumors, pathologic diagnosis of GG versus DNET, medically controlled versus refractory seizures, or with the use of electrocorticography (ECoG). Extended resection of temporal lobe tumors, with hippocampectomy and/or corticectomy, conferred additional benefit. Significance: These results suggest that early operative intervention and gross‐total resection are critically important factors in achieving seizure‐freedom, and thus improving quality‐of‐life, in patients with glioneuronal tumors causing epilepsy.     

C-reactive protein and seizures in focal epilepsy: a video-electroencephalographic study

Purpose: C‐reactive protein (CRP) has been studied extensively in many noninflammatory neurologic conditions, but there has been little study of CRP in the context of seizures or epilepsy. The purpose of this study was to examine CRP concentrations in patients with refractory focal epilepsy who were undergoing video‐electroencephalography (EEG) monitoring compared with healthy controls, and CRP change during 24 h after a seizure. Methods: CRP levels were measured in serum at the onset of video‐EEG recording (CRP‐0h) and at 3, 6, 12, and 24 h after index seizure (the first verified localized‐onset seizure) in 31 patients during inpatient video‐EEG monitoring by using high sensitivity measurement of CRP concentration. The patients were categorized into two groups: temporal lobe epilepsy (TLE; n = 15) and extratemporal lobe epilepsy (XLE; n = 16). Eighty healthy volunteers served as controls. Key Findings: CRP‐0h concentration was significantly higher in patients with refractory focal epilepsy than in controls (3.5 vs. 0.7 mg/ml, p < 0.001). All five patients with elevated CRP‐0h (>mean + 2 standard deviations in controls) had TLE (vs. none in XLE; p = 0.018). Index seizure type was associated with CRP increase from baseline to maximum level after index seizure (p = 0.005). The most important predictor of increase in CRP level was secondarily generalized tonic–clonic seizure (SGTCS; p = 0.030). Significance: The higher baseline levels in patients with epilepsy compared with healthy controls demonstrates that CRP concentrations are also affected in refractory epilepsy. Our data suggest that SGTCS stimulates CRP production. These results emphasize the association between inflammation and refractory epilepsy.     

Predicting and preventing psychopathology following temporal lobe epilepsy surgery

Less than 3% of temporal lobe epilepsy (TLE) surgical outcome studies have investigated the psychiatric sequelae and morbidity associated with surgery. This is disproportionate to the extent of the problem. Variable prevalence rates have been reported for post-surgical depression, anxiety, and interictal psychosis. Until recently, very few studies distinguished de novo postoperative presentations from pre-existing conditions, making it difficult to accurately assess the impact of TLE surgery on psychiatric morbidity. Predictors of de novo postoperative presentations have proved elusive. This current review summarizes the findings from a systematic literature review of the psychiatric morbidity associated with TLE surgery including newly published follow-up data from our own series of 280 surgical patients. A framework for future research, possible pathophysiological mechanisms, and translational models are also discussed.This article is part of a Special Issue entitled “The Future of Translational Epilepsy Research”.     

Seizure clusters in drug‐resistant focal epilepsy

We investigated clinical factors associated with seizure clustering in patients with drug‐resistant focal epilepsy and any association between seizure clustering and outcome after surgery. We performed a retrospective study including patients with a diagnosis of drug‐resistant focal epilepsy who underwent epilepsy surgery. Patients were prospectively registered in a database from 1986 until 2015. Seizure cluster was defined as two or more seizures occurring within 2 days. Potential risk factors for seizure clustering were assessed. To investigate any potential association between seizure clusters and seizure outcome after surgery, time to event analysis was used to produce a Kaplan‐Meier estimate of seizure recurrence. We studied 764 patients. Seizure clusters were reported in 23.6% of patients with temporal lobe epilepsy (TLE) and 16.9% of extratemporal patients (p = 0.2). We could not identify any significant clinical factors associated with seizure clustering. Among patients with TLE, those who had history of seizure clusters fared better after surgery (p < 0.01). We found that seizure clusters relate to prognosis after temporal lobe surgery in drug‐resistant TLE. These data may provide added value for surgical prognostication when combined with other data types. A better understanding of the neurobiology underlying seizure clusters is needed.     

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.     

Psychogenic nonepileptic seizures in patients with surgically treated temporal lobe epilepsy: Presurgical and de novo postsurgical occurrence

Whether occurring before or after an epilepsy surgery, psychogenic nonepileptic seizures (PNES) impact treatment options and quality of life of patients with epilepsy. We investigated the frequency of pre- and postsurgical PNES, and the postsurgical Engel and psychiatric outcomes in patients with drug-resistant temporal lobe epilepsy (TLE). We reviewed 278 patients with mean age at surgery of 37.1 ± 12.4 years. Postsurgical follow-up information was available in 220 patients, with average follow-up of 4 years.Nine patients (9/278 or 3.2%) had presurgical documented PNES. Eight patients (8/220 or 3.6%) developed de novo PNES after surgery. Pre- and postsurgery psychiatric comorbidities were similar to the patients without PNES. After surgery, in the group with presurgical PNES, five patients were seizure-free, and three presented persistent PNES. In the group with de novo postsurgery PNES, 62.5% had Engel II–IV, and 37.5% had Engel I. All presented PNES at last follow-up.Presurgical video-EEG monitoring is crucial in the diagnosis of coexisting PNES. Patients presenting presurgical PNES and drug-resistant TLE should not be denied surgery based on this comorbidity, as they can have good postsurgical epilepsy and psychiatric outcomes. Psychogenic nonepileptic seizures may appear after TLE surgery in a low but noteworthy proportion of patients regardless of the Engel outcome.     

Behaviour problems in children and adolescents with seizure disorder: associations and risk factors.

PROBLEM: Fifty million people worldwide have epilepsy of whom 33 million are children. Children and adolescents with epilepsy are known to have high rates of behaviour problems and psychiatric co-morbidity. No studies on this topic have been conducted in developing countries, although 90% of such children live in the developing world. METHODS: The current study, set in Vellore in India, assessed the prevalence of psychopathology and its associations in children and adolescents with seizure disorder. One hundred and thirty two children were rated for psychopathology on the Child Behaviours Check List, and those who qualified as psychiatric cases were compared with those who did not. RESULTS: Seizure disorder was associated with significant psychopathology in 53.8% children. Belonging to a higher income group and living in an urban area (OR: 7.61, 95% CI: 2.78-20.8, p=0.0001), having longer than 3 years of illness (OR: 2.39, 95% CI: 2.18-5.67, p=0.03) and being treated by more than one anti-epileptic drug (OR: 3.08, 95% CI: 1.09-8.72, p=0.03) independently predicted psychopathology. CONCLUSIONS: Psychopathology reflected a complex interaction of seizures, socio-demographic factors and treatment related variables, in accord with studies in industrialised countries. Clinicians should be sensitive to identifying psychopathology since this may lead to effective interventions for this group of children.     

Psychiatric comorbidity in patients with pharmacoresistant focal epilepsy and psychiatric outcome after epilepsy surgery

There are only a few studies in which both preoperative psychiatric comorbidity in pharmacoresistant focal epilepsy and its outcome after epilepsy surgery have been investigated. In this study, 144 patients evaluated for epilepsy surgery received psychiatric examination, 84 proceeding to intervention were reassessed postoperatively. Preoperatively, 60% met criteria for ICD-10- or epilepsy-specific psychiatric diagnosis. Twenty-seven percent, predominantly female, suffered from dysphoric disorder (DD) associated with temporal epileptogenic foci. Prevalence of DD correlated with complex partial seizure frequency and presence of ictal fear suggesting limbic-cortical dysregulation. Psychotic syndromes were linked to a history of febrile convulsions and left-sided temporomesial epileptogenic foci. High seizure frequency and early epilepsy onset predisposed to the development of personality disorders. Postoperative assessment revealed 18% of patients with "de novo" interictal affective disorders after surgery. Symptoms in 48% of patients with preoperative affective syndromes and 60% of patients with DD remitted after surgery. Seizure freedom and improved psychosocial status predicted remission of preoperative psychopathology.