Extratemporal Epilepsy Surgery Research Articles

OUTCOME OF EXTRATEMPORAL EPILEPSY SURGERY EXPERIENCE OF A SINGLE CENTER

Our aim was to determine the surgical outcome in adult patients with intractable extratemporal epilepsy and follow it over time. We retrospectively studied the operative outcome in 218 consecutive adult patients with extratemporal lesions who underwent resective surgical treatment for intractable partial epilepsy in the Bethel Epilepsy Center, Bielefeld, Germany, between 1991 and 2005. Patients were divided into three groups according to the 5-year period in which the surgical procedure took place. Group I (1991-1995) consisted of 64 patients. The postoperative Engel Class I outcome was 50% at 6 months, 44.4% at 2 years, and 45.2% at 5 years. Group II (1996-2000) included 91 patients. Engel Class I outcome was 57.1% at 6 months, 53.8% at 2 years, and 53.5% at 5 years. In Group III (2001-2005), there were 63 patients. Engel Class I outcome was 65.1% at 6 months, 61.3% at 2 years, and 60.6% at 5 years. Short duration of epilepsy, surgery before 30 years of age, pathological findings of neoplasm, and well-circumscribed lesions on the preoperative magnetic resonance imaging scan were good prognostic factors. Poor prognostic factors were one or more of the following: psychic aura, generalized tonic-clonic seizure, versive seizure, history of previous surgery, and focal cortical dysplasia. On multivariate analysis, only the presence of well-circumscribed lesions on preoperative magnetic resonance imaging predicted a positive outcome (P = 0.001). Our results indicate that extratemporal epilepsy surgery at the Bethel Epilepsy Center has become more effective in the treatment of extratemporal epilepsy patients over the years, ensuring continuous improvement in outcome. This improvement can be attributed mainly to more restrictive patient selection.

Long-term outcome of extratemporal epilepsy surgery among 154 adult patients

The goal of this study was to evaluate the long-term outcome of patients who underwent extratemporal epilepsy surgery and to assess preoperative prognostic factors associated with seizure outcome. This retrospective study included 154 consecutive adult patients who underwent epilepsy surgery at Bethel Epilepsy Centre, Bielefeld, Germany between 1991 and 2001. Seizure outcome was categorized based on the modified Engel classification. Survival statistics were calculated using Kaplan-Meier curves, life tables, and Cox regression models to evaluate the risk factors associated with outcomes. Sixty-one patients (39.6%) underwent frontal resections, 68 (44.1%) had posterior cortex resections, 15 (9.7%) multilobar resections, 6 (3.9%) parietal resections, and 4 (2.6%) occipital resections. The probability of an Engel Class I outcome for the overall patient group was 55.8% (95% confidence interval [CI] 52-58% at 0.5 years), 54.5% (95% CI 50-58%) at 1 year, and 51.1% (95% CI 48-54%) at 14 years. If a patient was in Class I at 2 years postoperatively, the probability of remaining in Class I for 14 years postoperatively was 88% (95% CI 78-98%). Factors predictive of poor long-term outcome after surgery were previous surgery (p = 0.04), tonic-clonic seizures (p = 0.02), and the presence of an auditory aura (p = 0.03). Factors predictive of good long-term outcome were surgery within 5 years after onset (p = 0.015) and preoperative invasive monitoring (p = 0.002). Extratemporal epilepsy surgery is effective according to findings on long-term follow-up. The outcome at the first 2-year follow-up visit is a reliable predictor of long-term Engel Class I postoperative outcome.

Quality of life after extratemporal epilepsy surgery: A prospective clinical study

Purpose The purpose of this prospective clinical study was to assess quality of life (QOL) and impact of seizure status on QOL in patients with extratemporal epilepsy after surgery. Patients and methods Twenty-three consecutive patients who had been operated due to extratemporal epilepsy were included in this study. Quality of Life Inventory in Epilepsy-10 (QOLIE-10) questionnaire was completed by all patients before 6 months and 2 years after surgery. Results obtained from short- and long-term follow-up were compared to baseline. Furthermore, patients who were seizure-free since surgery and those who had seizure were also compared in terms of outcome in QOL after surgery. Results All patients showed significantly improved QOL in both short- and long-term follow-ups compared to preoperative status regardless of seizure status ( p < 0.001). Seizure-free patients showed better QOL than those of patients who continued to have seizure during postoperative period. Furthermore, improved QOL was correlated with seizure status and shorter duration of epilepsy ( p = 0.001). Conclusion Our findings showed that improved QOL is related to postoperative seizure status. However, future clinical studies including larger population of patients with extratemporal epilepsy are required to elucidate the role of other factors.

Presurgical seizure frequency and tumoral etiology predict the outcome after extratemporal epilepsy surgery

To examine the predictive value of demographic data for the seizure outcome after extratemporal epilepsy surgery. Eightyone patients who underwent resective extratemporal epilepsy surgery were retrospectively studied concerning (a) age at surgery, (b) onset of epilepsy, (c) duration of epilepsy, (d) number of seizures at the time of presurgical evaluation, (d) number of presurgically tested antiepileptic substances and (f) number of seizure types. The data were correlated to the postoperative seizure outcome after two years. 33 patients (40.7%) were seizure free two years after surgery. Univariate and multivariate analysis revealed that both tumor etiology and low presurgical seizure frequency were independently associated with seizure freedom after epilepsy surgery. The recurrence rate in patients with one or more seizures per day was more than two-fold if compared with patients with fewer seizures. The remaining demographic factors did not show a significant association with seizure outcome in our 81 patients. Fewer than daily seizures prior to surgery and a tumoral etiology independently increase the likelihood of remaining seizure free two years after extratemporal epilepsy surgery.

Presurgical evaluation and surgical treatment of medically refractory epilepsy.

Thanks to today's modern imaging examination techniques and especially to the common use of intracranial electrodes for localizing seizure foci, more and more patients with partial epilepsy can be treated microsurgically. The results of such neurosurgical therapies are very good, particularly in mesial temporal lobe epilepsy. In recent years, good results (60-70% seizure freedom) have also been achieved in extratemporal epilepsy surgery, so that such procedures can now be recommended for carefully selected patients. In this review, presurgical evaluations and the different surgical approaches are presented.

The Early Identification of Candidates for Epilepsy Surgery

The effectiveness of resective surgery for the treatment of carefully selected patients with medically intractable, localization-related epilepsy is clear. Seizure-free rates following temporal lobectomy are consistently 65% to 70% in adults and 68% to 78% in children. Extratemporal resections less commonly lead to a seizure-free outcome, although one recent childhood series reported a seizure-free rate of 62% following extratemporal epilepsy surgery. With both temporal and extratemporal resections, additional patients have a reduction in seizures following surgery but are not completely seizure free. The identification of favorable surgical candidates has been the subject of extensive research, and many investigators have examined predictors of outcome following epilepsy surgery. However, the early identification of the potential epilepsy surgery candidate and the optimal timing of surgery have only occasionally been addressed in the literature. This issue is methodologically challenging to study since studies require large numbers of patients with new-onset partial epilepsy who are followed over time. The purpose of this article is to review the current ability for early prediction of medical intractability in patients with surgically remediable epilepsy. Emphasis will be placed on the early prediction of intractable temporal lobe epilepsy in children and adolescents, since temporal lobectomy remains the prototype epilepsy surgery, and early surgery may improve psychosocial outcome in younger patients.

Subtraction peri-ictal SPECT is predictive of extratemporal epilepsy surgery outcome.

To determine whether localization of extratemporal epilepsy with subtraction ictal SPECT coregistered with MRI (SISCOM) is predictive of outcome after resective epilepsy surgery, whether SISCOM images provide prognostically important information compared with standard tests, and whether blood flow change on SISCOM images is useful in determining site and extent of excision required. The value of SISCOM in predicting surgical outcome for extratemporal epilepsy is unknown, especially if MRI findings are nonlocalizing. SISCOM images in 36 consecutive patients were classified by blinded reviewers as "localizing and concordant with site of surgery," "localizing but nonconcordant with site of surgery," or "nonlocalizing." SISCOM images were coregistered with postoperative MRI, and reviewers visually determined whether cerebral cortex underlying the SISCOM focus had been completely resected, partially resected, or not resected. Twenty-four patients (66.7%) had localizing SISCOM, including 13 (76.5%) of those without a focal MRI lesion. Eleven of 19 patients (57.9%) with localizing SISCOM concordant with the surgical site, compared with 3 of 17 (17.6%) with nonlocalizing or nonconcordant SISCOM, had an excellent outcome (p < 0.05). With logistic regression analysis, SISCOM findings were predictive of postsurgical outcome, independently of MRI or scalp ictal EEG findings (p < 0.05). The extent of resection of the cortical region of the SISCOM focus was significantly associated with the rate of excellent outcome (100% with complete resection, 60% with partial resection, and 20% with nonresection, p < 0.05). SISCOM images may be useful in guiding the location and extent of resection in extratemporal epilepsy surgery.

Pre- and postoperative socioeconomic development of 151 patients with focal epilepsies.

We evaluated retrospectively the socioeconomic development of epilepsy patients after temporal or extratemporal epilepsy surgery and analyzed the relationship to clinical and neuropsychological data. 151 patients (from ages 11-65 years; mean postoperative followup: 3 years) replied to a structured questionnaire, which referred to objective data of the patient's educational and vocational development. Neuropsychological data were obtained from pre- and postoperative (1-year follow-up) examinations. The preoperative development data indicated that patients exposed to epilepsy at any developmental stage had a higher prevalence of educational/vocational difficulties as compared with patients with a later onset of epilepsy. Postoperatively, the integration of the formerly unemployed improved and the unemployment rate decreased from 33 to 16%. Out of those patients who had been schooled or who were employed, 79%-91% made progress in development, or were at least able to keep their status. Only 2 of 14 patients, who had been retired early because of their epilepsy, returned to employment. In general, a deterioration of the socioeconomic status was significantly related to insufficient seizure control. A reemployment of patients who were formerly unemployed depended mainly on age and neuropsychological outcome. Our results suggest that early and successful surgical intervention improves or at least maintains the socioeconomic situation, especially the employment status.

Surgery for Extratemporal Partial Epilepsy

The results of surgery for extratemporal partial epilepsy that began in childhood are reported from the Department of Surgery, Stanford University Medical School; Department of Neurology, University of Rochester; University of Colorado Health Sciences Center; and the Children’s Hospital, Boston MA.

Results of Surgery for Extratemporal Partial Epilepsy That Began in Childhood

Thirty-five consecutive patients who underwent surgery for intractable extratemporal seizures originating in childhood are described. Candidates for surgery were selected on the basis of clinical criteria, neurodiagnostic imaging, and an electroencephalographic investigation that included the use of sphenoidal electrodes and long-term monitoring. Invasive preoperative monitoring was not used. Our results, with respect to the control of seizures and behavioral improvement, are comparable with series in which data from invasive recordings were used in the selection process. Sixty-three percent of the 35 patients (76.5% of those operated on after the introduction of long-term electroencephalographic monitoring) became either seizure free or experienced a reduction in their frequency of seizures by at least 75%. The favorable outcome in this group of patients strengthens the argument for early operation in children with intractable epilepsy, even when the seizure focus is outside the temporal lobe.