Long-term Outcomes Of Epilepsy Surgery Research Articles

The need for an individualized approach to what is considered a clinically significant reduction in seizure frequency: A patient's perspective.

The need for an individualized approach to what is considered a clinically significant reduction in seizure frequency: A patient's perspective.

Satisfaction and seizure outcomes of epilepsy surgery in tuberous sclerosis: A Swedish population-based long-term follow-up study

PurposeWe conducted a cross-sectional study to evaluate long-term outcomes of epilepsy surgery in tuberous sclerosis complex (TSC) in a Swedish population. MethodsDemographic and seizure data was retrieved from the Swedish National Epilepsy Surgery Registry and medical records. Patient reported outcome measurements (PROM) were determined by telephonic interviews at long term follow-up. ResultsMedian follow-up was 6 y 8 m (range, 3–15 y 1 m) for tuberectomies (n = 15) and 3 y 6 m (range 2–10 y) for callosotomies (n = 7). Eight of the 15 tuberectomy participants were seizure-free. Four out of seven callosotomies were free from drop attacks. PROMs were provided by caregivers of 18/20 participants (data missing for two callosotomies). In the tuberectomy group, 6/8 patients were seizure-free and 3/7 had continued seizures; surgery was considered satisfactory and beneficial. Overall, satisfaction was high, even among patients who did not achieve remission; 13/15 tuberectomy responders recommended surgery to others with TSC and refractory epilepsy. None of the patients considered the surgery harmful. In the callosotomy group, satisfaction was low and congruent with the seizure outcome. All patients with continued drop attacks were unsatisfied; one considered surgery to be harmful. One participant, who would not recommend surgery to others, still perceived the surgery to be beneficial. ConclusionsThis study confirmed that both tuberectomy and callosotomy are effective treatment options for TSC. Factors other than seizure outcomes seemed to have a major influence on satisfaction and perception of the benefit of surgery.

Utility of magnetoencephalography combined with stereo-electroencephalography in resective epilepsy surgery: A 2-year follow-up.

Precise and accurate implantation of stereo-electroencephalography (SEEG) electrodes is critical for the localization of the seizure onset zone (SOZ), which plays a leading role in the prognosis of resective epilepsy surgery. Magnetoencephalography (MEG) is a noninvasive technique which can delineate the epilepsy focus by visualizing interictal spikes into dipole clusters. MEG may provide supporting information for guiding SEEG electrode implantation and improve the long-term outcomes of epilepsy surgery. In this study, we evaluated the accuracy of MEG in determining the SOZ. We retrospectively analyzed patients with refractory epilepsy who underwent MEG examination and SEEG implantation before resective epilepsy surgery in the Shanghai Ruijin Hospital. The SEEG plan was designed according to the dipole clusters and the resections were operated according to the SEEG recordings. We investigated the relationships of the pattern of MEG dipole clusters and SEEG sampling to the final resective surgery prognosis. We included 42 patients with a postoperative follow-up of at least 2 years (mean 34.1 months). Eighteen (42%) patients who showed concordant localization between MEG and SEEG evaluation had a higher probability of seizure-free outcome (p=0.046, χ2=4.835, odds ratio=5.00, 95% CI=1.12-22.30). Complete sampling of MEG dipole clusters by SEEG electrodes was found in 23 (54%) patients, who had higher probability of seizure-free outcome that those with incomplete sampling (p<0.001, odds ratio=16.67, 95% CI=3.11-89.28). MEG results showing a single, tight cluster or stable orientation were associated to better seizure outcomes after resective surgery. MEG dipole cluster helps SEEG implantation in localizing the SOZ for better long-term epilepsy surgery outcome. The MEG results can play a role as prognostic predictors of epilepsy surgery.

Long-term outcomes after epilepsy surgery, a retrospective cohort study linking patient-reported outcomes and routine healthcare data

ObjectiveThe objective of the study was to assess the long-term outcomes of epilepsy surgery between 1995 and 2015 in South Wales, UK, linking case note review, postal questionnaire, and routinely collected healthcare data. MethodWe identified patients from a departmental database and collected outcome data from patient case notes, a postal questionnaire, and the QOLIE-31-P and linked with Welsh routinely collected data in the Secure Anonymised Information Linkage (SAIL) databank. ResultsFifty-seven patients were included. Median age at surgery was 34 years (11–70), median: 24 years (2–56) after onset of habitual seizures. Median follow-up was 7 years (2–19). Twenty-eight (49%) patients were free from disabling seizures (Engel Class 1), 9 (16%) experienced rare disabling seizures (Class 2), 13 (23%) had worthwhile improvements (Class 3), and 7 (12%) had no improvement (Class 4). There was a 30% mean reduction in total antiepileptic drug (AED) load at five years postsurgery. Thirty-eight (66.7%) patients experienced tonic–clonic seizures presurgery verses 8 (14%) at last review. Seizure-free patients self-reported a greater overall quality of life (QOL; QOLIE-31-P) when compared with those not achieving seizure freedom. Seizure-free individuals scored a mean of 67.6/100 (100 is best), whereas those with continuing seizures scored 46.0/100 (p < 0.006). There was a significant decrease in the median rate of hospital admissions for any cause after epilepsy surgery (9.8 days per 1000 patient days before surgery compared with 3.9 after p < 0.005). SignificanceEpilepsy surgery was associated with significant improvements in seizures, a reduced AED load, and an improved QOL that closely correlated with seizure outcomes and reduced hospital admission rates following surgery. Despite this, there was a long delay from onset of habitual seizures to surgery. The importance of long-term follow-up is emphasized in terms of evolving medical needs and health and social care outcomes.

The long-term outcomes of epilepsy surgery.

ObjectiveDespite modern anti-epileptic drug treatment, approximately 30% of epilepsies remain medically refractory and for these patients, epilepsy surgery may be a treatment option. There have been numerous studies demonstrating good outcome of epilepsy surgery in the short to median term however, there are a limited number of studies looking at the long-term outcomes. The aim of this study was to ascertain the long-term outcome of resective epilepsy surgery in a large neurosurgery hospital in the U.K.MethodsThis a retrospective analysis of prospectively collected data. We used the 2001 International League Against Epilepsy (ILAE) classification system to classify seizure freedom and Kaplan-Meier survival analysis to estimate the probability of seizure freedom.ResultsWe included 284 patients who underwent epilepsy surgery (178 anterior temporal lobe resections, 37 selective amygdalohippocampectomies, 33 temporal lesionectomies, 36 extratemporal lesionectomies), and had a prospective median follow-up of 5 years (range 1–27). Kaplan-Meier estimates showed that 47% (95% CI 40–58) remained seizure free (apart from simple partial seizures) at 5 years and 38% (95% CI 31–45) at 10 years after surgery. 74% (95% CI 69–80) had a greater than 50% seizure reduction at 5 years and 70% (95% CI 64–77) at 10 years. Patients who had an amygdalohippocampectomy were more likely to have seizure recurrence than patients who had an anterior temporal lobe resection (p = 0.006) and temporal lesionectomy (p = 0.029). There was no significant difference between extra temporal and temporal lesionectomies. Hippocampal sclerosis was associated with a good outcome but declined in relative frequency over the years.ConclusionThe vast majority of patients who were not seizure free experienced at least a substantial and long-lasting reduction in seizure frequency. A positive long-term outcome after epilepsy surgery is possible for many patients and especially those with hippocampal sclerosis or those who had anterior temporal lobe resections.

Long-term outcomes of epilepsy surgery in tuberous sclerosis complex.

Approximately 50% of patients with tuberous sclerosis complex (TSC) present intractable epilepsy, and surgery is an option for those patients. Hereby, we analyze long-term seizure control and neuropsychological outcomes of epilepsy surgery in patients with TSC. Clinical data were retrospectively collected from 66 patients with TSC and epilepsy followed up over 5years, 51 of whom underwent epilepsy surgery between 2001 and 2011. Reductions in the number of seizures were analyzed at 1-year (1FU), 5-year (5FU), and 10-year (10FU) follow-ups visits after the operation. Influential factors on postoperative seizure free and intelligence quotient (IQ) and quality-of-life (QOL) outcomes were evaluated at 5FU. Resective procedures included 26 tuber resections, 15 lobectomies, and 10 tuber resections and lobectomies. Corpus callosotomies were performed as the adjunctive approach in 11 cases with low IQ. The percentages of seizure-free cases were 74.5% at 1FU, 58.8% at 5FU, and 47.8% at 10FU, and the predictive factor for long-term postoperative seizure freedom was the history of preoperative seizures and preoperative full-scale IQ. Significant improvements were found in performance IQ, full-scale IQ, and QOL in patients from the surgery group, particularly those who were seizure free after the operation. Our study showed that epilepsy surgery in TSC with epilepsy rendered improvements in seizure control, full-scale IQ, and QOL. Satisfactory long-term seizure control was often achieved with an early operation and without mental retardation, and improvements in QOL and IQ were frequently observed in postoperative patients who remained seizure free.

Cognition in epilepsy: current clinical issues of interest.

This review provides an update and summary of recent neuropsychological findings in epilepsy focusing on three major clinical topics among the many developments in the field. We will critically outline the current state with regard to cognition in new-onset epilepsies, social cognition in epilepsy, and the long-term outcome of epilepsy surgery and the cognitive outcomes of superselective surgical procedures. Current studies indicate that neuropsychological impairments are prevalent already at the onset of epilepsy and even before, social cognition (i.e., emotion recognition and theory of mind) is impaired in different epilepsy populations, the long-term outcome of epilepsy surgery is mostly characterized by a stable or even improved cognitive status, and superselective epilepsy surgeries are associated with a promising neuropsychological outcome. The high prevalence of cognitive deficits around epilepsy onset challenges the assumption that epilepsy is the major cause of cognitive problems and calls for early neuropsychological diagnostics. Social cognition seems to be a relevant domain that is not yet routinely considered in epilepsy. The cognitive long-term outcome of epilepsy surgery is mostly positive. Stereotactic thermocoagulation and gamma knife surgery appear to be cognitively safe procedures.

Long-term outcomes of epilepsy surgery in 85 pediatric patients followed up for over 10 years: a retrospective survey.

OBJECTIVE The aim of this study was to investigate the treatment outcomes and social engagement of patients who had undergone pediatric epilepsy surgery more than 10 years earlier. METHODS Between 1983 and 2005, 110 patients younger than 16 years underwent epilepsy surgery at the National Epilepsy Center, Shizuoka Institute of Epilepsy and Neurological Disorders. The authors sent a questionnaire to 103 patients who had undergone follow-up for more than 10 years after surgery; 85 patients (82.5%) responded. The survey contained 4 categories: seizure outcome, use of antiepileptic drugs, social participation, and general satisfaction with the surgical treatment (resection of the epileptic focus, including 4 hemispherectomies). The mean patient age at the time of surgery was 9.8 ± 4.2 (SD) years, and the mean duration of postoperative follow-up was 15.4 ± 5.0 years. Of the 85 patients, 79 (92.9%) presented with a lesional pathology, such as medial temporal sclerosis, developmental/neoplastic lesions, focal cortical dysplasia, and gliosis in a single lobe. RESULTS For 65 of the 85 responders (76.5%), the outcome was recorded as Engel Class I (including 15 [93.8%] of 16 patients with medial temporal sclerosis, 20 [80.0%] of 25 with developmental/neoplastic lesions, and 27 [73.0%] of 37 with focal cortical dysplasia). Of these, 29 (44.6%) were not taking antiepileptic drugs at the time of our survey, 29 (44.6%) held full-time jobs, and 33 of 59 patients (55.9%) eligible to drive had a driver's license. Among 73 patients who reported their degree of satisfaction, 58 (79.5%) were very satisfied with the treatment outcome. CONCLUSIONS The seizure outcome in patients who underwent resective surgery in childhood and underwent followup for more than 10 years was good. Of 85 respondents, 65 (76.5%) were classified in Engel Class I. The degree of social engagement was relatively high, and the satisfaction level with the treatment outcome was also high. From the perspective of seizure control and social adaptation, resective surgery yielded longitudinal benefits in children with intractable epilepsy, especially those with a lesional pathology in a single lobe.

DIAGNOSTICS AND LONG-TERM OUTCOMES AFTER SURGICAL TREATMENT OF EPILEPSY IN CHILDREN WITH STRUCTURAL BRAIN CHANGES

Objective. To identify predictive factors of favourable outcomes in children with drug resistant epilepsy (DRE) associated with structural brain changes, who received surgical treatment. Methods. We performed a retrospective analysis of surgical treatment in 239 children with drug resistant epilepsy treated at the Pediatric Neurosurgery Department of the A. L. Polenov Russian Neurosurgical Institute from 2004 to 2014. The age of the patients varied between 2 and 18 years. The follow-up time ranged from 1 year to 10 years (on average 4.3 years). Results. According to magnetic resonance imaging (MRI), 223 (93.3%) patients had different structural brain changes. Among the patients, 47 (21.1%) had cerebral cicatrix, gliosis, cysts and atrophic changes, 33 (14.8%) had malformations of the cortical development, 43 (19.3%) had benign brain tumors, 47 (21.1%) had vascular malformations, 21 (9.4%) had arachnoid cysts, 12 (5.4%) had hippocampal sclerosis, 11 (4.9%) had phacomatosis, 5 (2.2%) had Rasmussen’s encephalitis, and 4 (1.8%) had hypothalamic hamartoma. Positron emission tomography revealed the areas of gray matter hypometabolism in the brain, which correspond to the areas of a metabolic deficiency around the epileptic focus. Favorable long-term outcomes of epilepsy surgery (class I according to Engel scale) were registered in 67.6% of the cases. The most favorable results (class I according to Engel scale) were achieved after lesionectomy (81.9%), temporal resections (78.4%), and hemispherectomy (72.7%). Conclusions. The most important predictive factors of favorable outcomes after epilepsy surgery are as follows: detection of epileptogenic morphological changes of the brain, completeness of resection of an epileptic and epileptogenic areas, and absense of seizures in the early postoperative period.

Long-term outcome of epilepsy surgery: A retrospective study in a population of 379 cases

We evaluated the long-term outcome of epilepsy surgery in drug-resistant epilepsy patients, and investigated preoperative factors associated with postoperative long-term surgical outcome. We performed a retrospective study of 379 patients who received epilepsy surgeries from 2000 to 2010. Patients had completed a minimum of 2-year and up to 12-year follow-up. Preoperative evaluations, surgical outcomes and clinical data of patients were collected and analyzed. We found that the epilepsy surgery was effective in drug-resistant patients and the long-term outcome of epilepsy surgery was satisfactory. The bipolar electro-coagulation could improve the surgical outcome when the epileptogenic focus was on the functional cortex. Results of the 2-year follow-up showed that preoperative seizure characteristics including the history of febrile seizure, seizure frequency, and location, quantity and range of seizure foci were significantly associated with the surgical outcome. The surgery procedure including the surgery type and the extent of resection also affected outcome. Abnormal head or hippocampus MRI, inconsistent results of preoperative investigations, seizure types, and pathology type might also be predictors of long-term surgical outcome.

Long-term outcomes of epilepsy surgery in Sweden

Objective:To investigate prospective, population-based long-term outcomes concerning seizures and antiepileptic drug (AED) treatment after resective epilepsy surgery in Sweden.Methods:Ten- and 5-year follow-ups were performed in 2005 to 2007 for 278/327 patients after resective epilepsy surgery from 1995 to 1997 and 2000 to 2002, respectively. All patients had been prospectively followed in the Swedish National Epilepsy Surgery Register. Ninety-three patients, who were presurgically evaluated but not operated, served as controls.Results:In the long term (mean 7.6 years), 62% of operated adults and 50% of operated children were seizure-free, compared to 14% of nonoperated adults (p < 0.001) and 38% of nonoperated children (not significant). Forty-one percent of operated adults and 44% of operated children had sustained seizure freedom since surgery, compared to none of the controls (p < 0.0005). Multivariate analysis identified ≥30 seizures/month at baseline and long epilepsy duration as negative predictors and positive MRI to be a positive predictor of long-term seizure-free outcome. Ten years after surgery, 86% of seizure-free children and 43% of seizure-free adults had stopped AEDs in the surgery groups compared to none of the controls (p < 0.0005).Conclusions:This population-based, prospective study shows good long-term seizure outcomes after resective epilepsy surgery. The majority of the patients who are seizure-free after 5 and 10 years have sustained seizure freedom since surgery. Many patients who gain seizure freedom can successfully discontinue AEDs, more often children than adults.Classification of evidence:This study provides Class III evidence that more patients are seizure-free and have stopped AED treatment in the long term after resective epilepsy surgery than nonoperated epilepsy patients.

Long-Term Outcomes of Epilepsy Surgery in School-Aged Children With Partial Epilepsy

The pediatric epileptic spectrum and seizure control in surgical patients have been defined in developed countries. However, corresponding data on school-aged children from developing countries are insufficient. We summarized epileptic surgical data from four centers in China, to compare surgical outcomes of school-aged children with intractable partial epilepsy from China and those from developed countries, and introduce surgical candidate criteria. Data from 206 children (aged 6-14 years) undergoing surgical resection for epilepsy between September 2001 and January 2007 were selected. Postoperative freedom from seizures was achieved in 173 cases (84.0%) at 1 year, 149 (72.3%) at 3 years, and 139 (67.5%) at 5 years. Patients with focal magnetic resonance imaging abnormalities and a short history of seizure were most likely to become seizure-free postoperatively. Those with preoperative low intelligence quotients who became seizure-free postoperatively achieved improvements in full memory quotients, intelligence quotients, and overall quality of life at 2 years. Significant differences were evident in mean changes of full intelligence quotient, full memory quotient, and overall quality of life between patients with preoperative low intelligence quotients who received corpus callosotomies and those with a normal preoperative intelligence quotient, and between seizure-free children and those with continual seizures.

The long-term outcome of adult epilepsy surgery, patterns of seizure remission, and relapse: a cohort study

Surgery is increasingly used as treatment for refractory focal epilepsy; however, few rigorous reports of long-term outcome exist. We did this study to identify long-term outcome of epilepsy surgery in adults by establishing patterns of seizure remission and relapse after surgery. We report long-term outcome of surgery for epilepsy in 615 adults (497 anterior temporal resections, 40 temporal lesionectomies, 40 extratemporal lesionectomies, 20 extratemporal resections, 11 hemispherectomies, and seven palliative procedures [corpus callosotomy, subpial transection]), with prospective annual follow-up for a median of 8 years (range 1-19). We used Kaplan-Meier survival analysis to estimate time to first seizure, and investigated patterns of seizure outcome. We used survival methods to estimate that 52% (95% CI 48-56) of patients remained seizure free (apart from simple partial seizures [SPS]) at 5 years after surgery, and 47% (42-51) at 10 years. Patients who had extratemporal resections were more likely to have seizure recurrence than were those who had anterior temporal resections (hazard ratio [HR] 2·0, 1·1-3·6; p=0·02); whereas for those having lesionectomies, no difference from anterior lobe resection was recorded. Those with SPS in the first 2 years after temporal lobe surgery had a greater chance of subsequent seizures with impaired awareness than did those with no SPS (2·4, 1·5-3·9). Relapse was less likely the longer a person was seizure free and, conversely, remission was less likely the longer seizures continued. In 18 (19%) of 93 people, late remission was associated with introduction of a previously untried antiepileptic drug. 104 of 365 (28%) seizure-free individuals had discontinued drugs at latest follow-up. Neurosurgical treatment is appealing for selected people with refractory focal epilepsy. Our data provide realistic expectations and indicate the scope for further improvements in presurgical assessment and surgical treatment of people with chronic epilepsy. UK Department of Health National Institute for Health Research (NIHR) Biomedical Research Centres funding scheme, Epilepsy Society, Dr Marvin Weil Epilepsy Research Fund.

Long-term seizure and psychosocial outcomes of epilepsy surgery

Most results reported in studies focusing on long-term outcomes of epilepsy surgery resemble those reported in studies with shorter follow-up, indicating that many of the surgical results are enduring. In general, about 60% of patients with temporal epilepsy and 25% to 40% of those with extratemporal epilepsy achieve long-term seizure freedom after epilepsy surgery. Over a long term, about 20% of patients discontinue antiepileptic drugs, whereas 41% continue monotherapy and 31% use polytherapy. Evidence concerning the impact of epilepsy surgery on mortality is inconclusive, but some data support a reduction in the risk of death if patients become seizure-free. The information regarding long-term cognitive outcomes is limited but is similar to that derived from short-term studies. Decline in verbal memory occurs frequently after resections of the left temporal lobe; better memory outcomes are reported in seizure-free patients, and memory decline has been documented in patients with intractable epilepsy who do not undergo surgery. However, important confounders such as the effects of antiepileptic drugs, practice effects, and regression to the mean have not been adequately accounted for in these studies. All uncontrolled long-term studies report improved psychosocial outcomes with epilepsy surgery, including employment, education, driving status, satisfaction, and quality of life, but the results of the few existing controlled studies are less persuasive.

Longterm outcome of epilepsy surgery among 399 patients with nonlesional seizure foci including mesial temporal lobe sclerosis

Longterm outcome of epilepsy surgery among 399 patients with nonlesional seizure foci including mesial temporal lobe sclerosis

Long‐term Prognosis and Psychosocial Outcomes after Surgery for MTLE

To assess the seizure-freedom rates and self-perceived psychosocial changes associated with the long-term outcome of epilepsy surgery in patients with refractory medial temporal lobe epilepsy associated with hippocampal sclerosis. A standard questionnaire was given to 183 patients who underwent surgery between 1988 and 2004, and 110 were completed. The mean duration of follow-up after surgery was 7 years, with a maximum of 17 years. The probability that patients were seizure-free after surgery was dependent on the definition of the seizure freedom. For the patients who were seizure-free since surgery (Engel's class Ia), the probability was 97.6% at 1 year after surgery, 85.2% at 2 years after surgery, 59.5% at 5 years after surgery, and 42.6% at 10 years after surgery. For the patients who still experienced rare disabling seizures after surgery but were seizure-free at least 1 year before the time of assessment, the probability was of 97.6% at 1 year after surgery, 95% at 2 years after surgery, 82.8% at 5 years after surgery, and 71.1% at 10 years after surgery. The psychosocial long-term outcome, as measured by indices of driving, employment, familial and social relationships, and marital status, was similar to the psychosocial short-term outcome. It did not depend on seizure freedom or on follow-up time interval and was not influenced statistically by seizure frequency in cases of persisting seizures. Most but not all patients noticed a substantial overall improvement in their psychosocial condition; 48% drove (increased by 7%), 47% improved (14% worsened) in their employment status, and 68% improved (5% worsened) in their familial and social relationships. Overall, 91% of patients were satisfied with the surgery, and 92% did not regret their decision. The results of this study suggest that temporal lobe surgery has real long-term benefits. Two specific conclusions emerge: (a) the long-term rates of freedom from seizure depend on how seizure freedom is defined, and (b) the psychosocial long-term outcome does not change dramatically over years and does not depend on seizure freedom.

Long-term outcome of epilepsy surgery among 399 patients with nonlesional seizure foci including mesial temporal lobe sclerosis

The authors reviewed the long-term outcome of focal resection in a large group of patients who had intractable partial nonlesional epilepsy, including mesial temporal lobe sclerosis (MTS), and who were treated consecutively at a single institution. The goal of this study was to evaluate the long-term efficacy of epilepsy surgery and the preoperative factors associated with seizure outcome. This retrospective analysis included 399 consecutive patients who underwent epilepsy surgery at Mayo Clinic in Rochester, Minnesota, between 1988 and 1996. The mean age of the patients at surgery was 32 +/- 12 years (range 3-69 years), and the mean age at seizure onset was 12 +/- 11 years (range 0-55 years). There were 214 female (54%) and 185 male (46%) patients. The mean duration of epilepsy was 20 +/- 12 years (range 1-56 years). The preceding values are given as the mean +/- standard deviation. Of the 399 patients, 237 (59%) had a history of complex partial seizures, 119 (30%) had generalized seizures, 26 (6%) had simple partial seizures, and 17 (4%) had experienced a combination of these. Preoperative evaluation included a routine and video-electroencephalography recordings, magnetic resonance imaging of the head according to the seizure protocol, neuropsychological testing, and a sodium amobarbital study. Patients with an undefined epileptogenic focus and discordant preoperative studies underwent an intracranial study. The mean duration of follow up was 6.2 +/- 4.5 years (range 0.6-15.7 years). Seizure outcome was categorized based on the modified Engel classification. Time-to-event analysis was performed using Kaplan-Meier curves and Cox regression models to evaluate the risk factors associated with outcomes. Among these patients, 372 (93%) underwent temporal and 27 (7%) had extratemporal resection of their epileptogenic focus. Histopathological examination of the resected specimens revealed MTS in 113 patients (28%), gliosis in 237 (59%), and normal findings in 49 (12%). Based on the Kaplan-Meier analysis, the probability of an Engel Class I outcome (seizure free, auras, or seizures related only to medication withdrawal) for the overall patient group was 81% (95% confidence interval [CI] 77-85%) at 6 months, 78% (CI 74-82%) at 1 year, 76% (CI 72-80%) at 2 years, 74% (CI 69-78%) at 5 years, and 72% (CI 67-77%) at 10 years postoperatively. The rate of Class I outcomes remained 72% for 73 patients with more than 10 years of follow up. If a patient was in Class I at 1 year postoperatively, the probability of seizure remission at 10 years postoperatively was 92% (95% CI 89-96%); almost all seizures occurred during the 1st year after surgery. Factors predictive of poor outcome from surgery were normal pathological findings in resected tissue (p = 0.038), male sex (p = 0.035), previous surgery (p < 0.001), and an extratemporal origin of seizures (p < 0.001). The response to epilepsy surgery during the 1st follow-up year is a reliable indicator of the long-term Engel Class I postoperative outcome. This finding may have important implications for patient counseling and postoperative discontinuation of anticonvulsant medications.

Long-term outcome of epilepsy surgery in patients with tuberous sclerosis.

Seizures associated with tuberous sclerosis (TS) can be difficult to control with medical therapy. The authors followed 22 patients with TS who underwent epilepsy surgery for 1 to 14 years to assess the value of epilepsy surgery and predictors of long-term postoperative outcome. Unifocal onset seizures and mild to no developmental delay at the time of surgery are predictive of excellent long-term outcome.