Epilepsy surgery outcomes in temporal lobe epilepsy with a normal MRI

Purpose:   To determine the long-term efficacy of anterior temporal lobectomy for medically refractory temporal lobe epilepsy in patients with nonlesional magnetic resonance imaging (MRI).
Methods:   We identified a retrospective cohort of 44 patients with a nonlesional modern "seizure protocol" MRI who underwent anterior temporal lobectomy for treatment of medically refractory partial epilepsy. Postoperative seizure freedom was determined by Kaplan-Meyer survival analysis. Noninvasive preoperative diagnostic factors potentially associated with excellent surgical outcome were examined by univariate analysis in the 40 patients with follow-up of >1 year.
Results:   Engel class I outcomes (free of disabling seizures) were observed in 60% (24 of 40) patients. Preoperative factors associated with Engel class I outcome were: (1) absence of contralateral or extratemporal interictal epileptiform discharges, (2) subtraction ictal single photon emission computed tomography (SPECT) Coregistered to MRI (SISCOM) abnormality localized to the resection site, and (3) subtle nonspecific MRI findings in the mesial temporal lobe concordant to the resection.
Discussion:   In carefully selected patients with temporal lobe epilepsy and a nonlesional MRI, anterior temporal lobectomy can often render patients free of disabling seizures. This favorable rate of surgical success is likely due to the detection of concordant abnormalities that indicate unilateral temporal lobe epilepsy in patients with nonlesional MRI.     

Predicting seizure frequency after epilepsy surgery

OBJECTIVE: To identify clinical features related to seizure frequency after epilepsy surgery in patients with recurrent seizures. BACKGROUND: No studies have examined the differences between patients who have rare seizures and patients who experience frequent seizures after epilepsy surgery. Since seizure frequency correlates with morbidity and quality of life, it is desirable to know which preoperative clinical features predict postoperative seizure frequency. METHODS: Patients with recurrent seizures were placed in two categories: rare postoperative seizures (< or =2 per year) and frequent postoperative seizures (> or =12 per year) using seizure frequency in the second postoperative year. Variables included preoperative seizure frequency, age of first risk, age at first seizure, epilepsy duration, age at surgery, history of febrile convulsions, tonic-clonic seizures, status epilepticus, or family history, IQ, magnetic resonance imaging (MRI), and positron emission tomography (PET). Variables were analyzed using non-parametric tests to assess relationship to postoperative seizure frequency. RESULTS: Of 475 patients who had epilepsy surgery, 111 had rare or frequent seizures in the second postoperative year. After anterior temporal lobectomy (ATL), age of first risk< or =5 years and presence of mesial temporal sclerosis on MRI were associated with rare seizures (66% of patients), whereas lack of these risk factors was associated with frequent seizures (75% of patients) (p<0.03). For non-ATL operations, preoperative seizure frequency of > or =20 seizures per month was associated with frequent postoperative seizures (p=0.03). No other variables influenced outcome. CONCLUSIONS: Some preoperative clinical features correlate with postoperative seizure frequency in patients with recurrent seizures after epilepsy surgery. This has implications for the surgical decision making process and early postoperative management.     

Seizure outcome after anterior temporal lobectomy and its predictors in patients with apparent temporal lobe epilepsy and normal MRI

PURPOSE: Very little reliable information is available regarding the role of anterior temporal lobectomy (ATL), optimal presurgical evaluation strategy, post-ATL seizure outcome, and the factors that predict the outcome in patients with medically refractory temporal lobe epilepsy (TLE) and normal high-resolution magnetic resonance imaging (MRI). To be cost-effective, epilepsy surgery centers in developing countries will have to select candidates for epilepsy surgery by using the locally available technology and expertise. METHODS: We reviewed the electroclinical and pathological characteristics and seizure outcome of 17 patients who underwent ATL for medically refractory TLE after being selected for ATL based on a noninvasive selection protocol without the aid of positron emission tomography (PET) or single-photon emission computed tomography (SPECT), despite a normal preoperative high-resolution MRI. RESULTS: Seven (41%) patients achieved an excellent seizure outcome; five of them were totally seizure free. An additional five (29%) patients had >75% reduction in seizure frequency. The following pre-ATL factors predicted an excellent outcome: antecedent history of febrile seizures, strictly unilateral anterior temporal interictal epileptiform discharges (IEDs), and concordant type 1 ictal EEG pattern. All the five patients with pathologically verified hippocampal formation neuronal loss were seizure free. The presence of posterior temporal, bilateral temporal, and generalized IEDs portended unfavorable post-ATL seizure outcome. CONCLUSIONS: A subgroup of patients destined to have an excellent post-ATL outcome can be selected from MRI-negative TLE patients by using history and scalp-recorded interictal and ictal EEG data. The attributes of these patients are antecedent history of febrile seizures, strictly unilateral anterior IEDs, and concordant type 1 ictal EEG pattern.     

Epilepsy surgery in tuberous sclerosis: a systematic review

PURPOSE: Tuberous sclerosis complex (TSC) is often associated with intractable epilepsy. Although epilepsy surgery has gained interest in recent years uncertainties exist about which patients are good surgical candidates. A systematic review of the available literature has been undertaken to assess the overall outcome of epilepsy surgery and identify risk factors of seizure recurrence. METHODS: We searched MEDLINE, Embase, and bibliographies of reviews and book chapters to identify articles published in English since 1960. Twenty-five articles, describing postoperative seizure outcome and type of surgery in 177 TSC patients, were included in this study. Seizure outcome was analyzed both as seizure freedom and good outcome, including patients with >90% seizure reduction. RESULTS: Seizure freedom was achieved in 101 patients (57%). Seizure frequency was improved by > 90% in 32 patients (18%). Moderate or severe intellectual disability (IQ < 70) (RR 1.8; 95% CI 1.2-2.8) and the presence of tonic seizures (RR 1.7; 95 % CI 1.2-2.4) were related to seizure recurrence. CONCLUSIONS: A relation between multiple seizures types with early onset, multiple cortical tubers and multifocal epileptogenicity, and poor outcome is not supported by this systematic analysis. Although there is considerable variation among studies reviewed here, the literature suggests that resective surgery may offer benefit in a selected population of TSC patients with drug-resistant epilepsy.     

Moderators of the effect of preoperative emotional adjustment on postoperative depression after surgery for temporal lobe epilepsy

PURPOSE: Other outcome measures besides seizure control must be considered when assessing the benefit of epilepsy surgery. We investigated the effect of preoperative psychosocial adjustment on postoperative depression in epilepsy patients followed up prospectively for 2 years after temporal lobectomy. METHODS: The Washington Psychosocial Seizure Inventory (WPSI) evaluated psychosocial functioning; the Centre for Epidemiological Studies Depression Scale (CES-D) measured depression. Both were completed at baseline and follow-up. RESULTS: Follow-up occurred in 39 temporal lobectomy patients at 2 years after surgery. Greatest improvement in depression scores was limited to patients with good seizure outcomes (seizure free, or marked reduction in seizure frequency), and seizure outcome was a significant predictor of postoperative depression. Despite this, preoperative scores on the emotional adjustment scale of the WPSI were most highly correlated with depression 2 years after surgery. To clarify this relation, moderated hierarchic regression suggested that good preoperative emotional adjustment (WPSI) was generally associated with less depression after surgery. Moreover, poorer preoperative adjustment combined with older age, generalized seizures, the finding of preoperative neurologic deficits, a family history of psychiatric illness, and/or a family history of seizures was related to higher depression scores 2 years after surgery. CONCLUSIONS: Depression after temporal lobectomy is dependent on a complex interaction of variables and can have a significant effect on indices of postoperative adjustment. The WPSI emotional adjustment scale may help to predict which patients are likely to be chronically depressed after surgery.     

Race/ethnicity: a predictor of temporal lobe epilepsy surgery outcome?

PURPOSE: The success of epilepsy surgery in temporal lobe epilepsy reaches a 64% rate of seizure freedom, based on a randomized control trial. Observational studies from epilepsy centers worldwide indicate seizure freedom rates up to 93% when the etiology is unilateral hippocampal sclerosis. Several risk factors are attributed to the recurrence of seizures following the surgical procedure. Nonetheless, whether race influences the outcome of temporal lobe surgery is unknown. The purpose of this study was to evaluate if race plays a role in outcome following surgery. METHODS: Data were obtained from the discharge database of the University of Alabama at Birmingham video/EEG monitoring unit, between 1998 and 2003, as well as the clinical charts. Seizure recurrence was evaluated 1 year following surgery. The sample consisted of all patients with a primary diagnosis of mesial temporal sclerosis (MTS) who underwent anterior temporal lobectomy. Multiple logistic regression analysis was used to model the presence of seizure recurrence after anterior temporal lobectomy for MTS. Two sets of logistic regression models were estimated to generate odds ratios (ORs) for seizure recurrence after an anterior temporal lobectomy for African-Americans or other possible ethnic/racial group present relative to non-Hispanic Caucasians. The first model incorporated only ethnicity as the independent variable and generated unadjusted ORs for seizure recurrence following the surgical procedure. The second set included the independent variables: duration of epilepsy, history of febrile seizures, lateralization of epileptogenic focus, handedness, and age. RESULTS: Seventy patients underwent surgical treatment and all of them had pathologic confirmation of MTS. Follow-up information for six was not available. Analysis of the remaining 64 patients revealed that African-Americans were more likely than non-Hispanic Caucasians to have seizure recurrence after surgery (OR=2.1, 95% CI=0.6-8.0). After potential confounders (duration of epilepsy, history of febrile seizures, lateralization of epileptogenic focus, handedness, and age) were controlled, this finding did not change (OR=1.7, 95% CI=0.3-10.7). CONCLUSION: Our data suggest that race may be an important factor related to seizure outcome following temporal lobectomy.     

Preoperative psychological adjustment and surgical outcome are determinants of psychosocial status after anterior temporal lobectomy.

This investigation evaluated the role of preoperative psychological adjustment, degree of postoperative seizure reduction, and other relevant variables (age, education, IQ, age at onset of epilepsy, laterality of resection) in determining emotional/psychosocial outcome following anterior temporal lobectomy. Ninety seven patients with complex partial seizures of temporal lobe origin were administered the Minnesota Multiphasic Personality Inventory (MMPI), Washington Psychosocial Seizure Inventory (WPSI), and the General Health Questionnaire (GHQ) both before and six to eight months after anterior temporal lobectomy. The data were subjected to a nonparametric rank sum technique (O'Brien's procedure) which combined the test scores to form a single outcome index (TOTAL PSYCHOSOCIAL OUTCOME) that was analysed by multiple regression procedures. Results indicated that the most powerful predictors of patients' overall postoperative psychosocial outcome were: 1) The adequacy of their preoperative psychosocial adjustment, and 2) A totally seizure-free outcome. Additional analyses were carried out separately on the MMPI, WPSI, and GHQ to determine whether findings varied as a function of the specific outcome measure. These results were related to the larger literature concerned with the psychological outcome of anterior temporal lobectomy.     

Prognostic Significance of Ictal and Interictal Epileptiform Activity in Temporal Lobe Epilepsy

Summary: Long-term electrocorticograms (ECoG), recorded by chronically implanted subdural electrodes during preoperative evaluation of 59 patients with temporal lobe epilepsy (TLE) were analyzed retrospectively to assess the prognostic relevance of distribution of interictal epileptiform potentials (IEP) and seizure origin (SO) and to investigate factors affecting their lateralization. Subsequent to preoperative evaluation, a standardized two thirds anterotemporal lobectomy including subtotal hippocampectomy had been performed in all patients. The following results were obtained: (a) Only patients with 100% lateralization of SO and IEP had excellent seizure outcome (= 89% seizure-free); (b) patients with bitemporal SO were unlikely to benefit from surgical treatment (=12.5% seizure-free); (c) 40–56% patients with unilateral temporal SO and bitemporal IEP, became seizure-free irrespective of the degree of lateralization of IEP; and (d) multidimensional analysis of variance showed that lateralization of SO, presence of a magnetic resonance imaging (MRI)-detectable lesion, presence of hippocampal sclerosis, presence of febrile seizures and seizures at age ≥6 years are the five most important variables indicating abolition of seizures. Combined analysis of ECoG-recorded SO and IEP allows prediction of postoperative seizure control within close boundaries.     

Factors predictive of the outcome of frontal lobe epilepsy surgery

PURPOSE: To identify factors that predict the outcome in seizure control after frontal lobe epilepsy surgery (FLES). FLES is the second most frequent type of epilepsy surgery, but the results are generally not as good as those after anterior temporal lobectomy. METHODS: Our cohort consisted of 68 consecutive patients whose first epilepsy surgery involving the frontal lobe occurred between 1987 and 1994. Clinical history and results of imaging and electroencephalographic studies were reviewed in detail. Excellent outcome was defined as being seizure free or having only nondisabling seizures at last follow up. RESULTS: Forty of the 68 patients (58.8%) had an excellent outcome; none of the patients with a history of childhood febrile seizures had an excellent outcome, whereas outcome was excellent in 63% of those without that history (p 相似文献