Abstract: PURPOSE: To assess the long-term seizure outcome and find predictors of outcome for patients who were not initially seizure free 6 months after epilepsy surgery. METHODS: We retrospectively reviewed all adult patients who underwent epilepsy surgery at the Epilepsy Center Bethel, between 1992 and 2003. There were 266 patients included in this analysis. RESULTS: Of the 266 patients who were included in this study, the probability of becoming seizure free was 12% (95%CI 8-16%) after 2years, 19.5% (95%CI 15-24%) after 5years and 34.7% (95%CI 28-41%) after 10years. In patients who had auras only, the probability of being seizure free was 18.2% after 2years, 25.5% after 5years, and 39.1% after 10years. In the multiregression analysis, the EEG carried out 2years after surgery, a psychic aura, the frequency of postoperative focal seizures and hypermotor seizures predicted seizure remission in the long-term outcome. CONCLUSIONS: The frequency and type of postoperative seizures are critical determinants for long-term outcome. Seizure semiology may be the clue to a precise diagnosis and long-term prognosis of epilepsy.
Abstract: BACKGROUND: It is the aim of epilepsy surgery in patients with lesional epilepsy for the surgeon to not only remove the lesion itself, but also the epileptogenic zone. Here, we report our experience with a modified temporal resection technique confined to the apical temporal lobe, i.e., sparing the hippocampal formation in patients with epileptogenic lesions in the anterior part of the temporal lobe. This apical temporal lobe resection (aTLR) includes tailored lesionectomy, amygdalectomy, and resection of the mesial structures only in the apex of the temporal lobe. This paper presents our surgical technical details and the outcome of aTLR. METHODS: Between 2001 and 2008, aTLR was performed in 61 patients. All patients underwent comprehensive presurgical evaluation including video-EEG monitoring, magnetic resonance imaging (MRI), and neuropsychological testing. All patients had a lesion in the apex of the temporal lobe and a normal hippocampus as seen in MRI, as well as intact memory functions in neuropsychological examination. There were 33 males (54.1%) and 28 females (45.9%). The mean age in years at epilepsy onset was 20.2 +/- 13.4, the mean age at epilepsy surgery was 32.1 +/- 11.9, the mean preoperative epilepsy duration was 11.8 +/- 8.8 years and the mean duration of follow-up was 2.1 +/- 1.3 years (range 0.5-6 years). RESULTS: Fifty-four (88.5%) of 61 patients were in Engel Class 1 at 6 months, 38 (80.9%) of 47 at 2 years and nine (81.8%) of 11 at the 5 year follow-up. Histopathological examination showed tumors in 31 patients, FCD in ten patients, amygdala sclerosis in seven patients, cavernomas in six patients, unspecific reactions in eight patients, and gliosis in one patient. Surgical complications occurred in four patients: one had a permanent and three had transient complications which could be successfully treated. Fifty (82%) resections were considered to be complete resections as evaluated by serial postoperative MRI, seven patients (11.5%) had incomplete resection of the preoperative MRI lesion and in four patients (6.6%) it remained unclear. Fifteen patients (29.4%) were withdrawn from antiepileptic drugs for more than 2 years without relapse. Postoperative neuropsychological examination revealed worsening of memory performance in two patients (3.2%) and improved or no changes in the rest of the patients. CONCLUSIONS: Apical temporal resection sparing the mesial temporal structures is an effective procedure with good long-term seizure outcome in patients with refractory epilepsy due to lesions confined to the apex of the temporal lobe.
Abstract: OBJECTIVES: To present long-term outcome and to identify predictors of seizure freedom after vagus nerve stimulation (VNS). METHODS: All patients who had undergone VNS implantation in the Epilepsy Centre Bethel were retrospectively reviewed. There were 144 patients who had undergone complete presurgical evaluation, including detailed clinical history, magnetic resonance imaging, and long-term video-EEG with ictal and interictal recordings. After implantation, all patients were examined at regular intervals of 4 weeks for 6-9 months. During this period the antiepileptic medication remained constant. All patients included in this study were followed up for a minimum of 2 years. RESULT: Ten patients remained seizure-free for more than 1 year after VNS implantation (6.9%). Seizures improved in 89 patients (61.8%) but no changes were observed in 45 patients (31.3%). The following factors were significant in the univariate analysis: age at implantation, multifocal interictal epileptiform discharges, unilateral interictal epileptiform discharge, cortical dysgenesis, and psychomotor seizure. Stepwise multivariate analysis showed that unilateral interictal epileptiform discharges (IEDs), P=0.014, HR=0.112 (95% CIs, 0.019-0.642), cortical dysgenesis P=0.007, HR=0.065 (95% CIs, 0.009-0.481) and younger age at implantation P=0.026, HR=7.533 (95% CIs 1.28-44.50) were independent predictors of seizure freedom in the long-term follow-up. CONCLUSION: VNS implantation may render patients with some forms of cortical dysgenesis (parietooccipital polymicrogyria, macrogyria) seizure-free. Patients with unilateral IEDs and earlier implantation achieved the most benefit from VNS.
Abstract: PURPOSE: To present long-term outcome and predictors of the health related quality of life (HRQOL) in a large group of patients operated for refractory extratemporal epilepsy. METHODS: A German QOLIE-31 questionnaire and additional questions has been mailed for all adult patients operated for extratemporal epilepsy in the Bethel Epilepsy Centre, between 1992 and 2003, 87 patients were eligible for this study. RESULTS: Seizure freedom, intake of antiepileptic drugs (AEDs), presence of AEDs side effect medical comorbidities and driving a car were significantly correlated to HRQOL in all subscales of QOLIE-31. Gender, age at epilepsy onset, the presence of a partner, psychiatric disease, the presence of auras and tumour pathology have a correlation to QOL in some subscales. Stepwise regression for all patients revealed that seizure freedom and medical comorbidities were highly predictive for most of the subscales of QOLIE-31. Intake of anti-epileptic drugs and AED side effects had a modest effect on QOL. The need for psychiatric treatment predicted poor cognitive function scores. Epilepsy onset at an older age predicted a minimal increase in the overall health scores. An aura at the last follow-up predicted poor medication scores. Regarding the importance of the predictors, seizure freedom and medical comorbidities were the most important predictors of QOL after surgery. AED intake and side effects had an intermediate effect on QOL; however, the gender of the patient and age at epilepsy onset had a minimal effect on QOL. CONCLUSIONS: HRQOL after extratemporal epilepsy surgery has multiple determinants. Medical comorbidities should be considered a negative risk factor for QOL during preoperative and postoperative evaluation process.
Abstract: AIM OF THE STUDY: To find determinants of quality of life (QOL) in long-term follow-up after temporal lobe epilepsy (TLE) surgery in adults. METHODS: The QOLIE-31 questionnaire was sent to 400 of 524 patients who were operated on for refractory TLE between 1991 and 2003 in the Bethel Epilepsy Centre fulfilling the inclusion criteria of this study. Mainly patients with severe cognitive deficits and patients with progressive brain disorders were excluded. There were 222/400 patients who replied to the QOLIE-31 questionnaire and 147/222 of these patients replied to an additional questionnaire. RESULTS: Univariate analyses showed that seizure freedom, presence of auras, intake of antiepileptic drugs (AEDs), severity of AED side effects, and driving a car were significantly correlated with all subscales of QOLIE-31. Furthermore, employment status, psychiatric problems, tumors and hippocampus sclerosis pathology, the presence of a partner, age at reply, age at surgery and medical co-morbidities were significantly correlated with some subscales of the QOLIE-31. Multivariate analyses (stepwise regression analyses) revealed that especially the time since the last seizure and the severity of AED side effects had a strong impact on QOL. However, aura at last follow-up, psychiatric treatment and employment were seen in the multivariate analyses as significant predictors of some QOL subscales as well. Most subscales of QOL showed a steep, non-linear increase within the first years of seizure freedom and remained relatively stable except for cognitive function which showed continuous improvement parallel to seizure freedom. For patients who were seizure free since surgery, side effects of AED and/or psychiatric treatment were the strongest determinants of QOL. CONCLUSION: Duration of seizure freedom and AED side effects have the strongest impact on QOL in the long-term follow-up. Therefore it is important not only to register intake of AEDs but also to assess side effects of AEDs. Persistence of auras also had an impact on different facets of QOL, but was significantly correlated with intake of AEDs. Apart from factors directly related to epilepsy QOL was dependent of psychosocial factors as employment status, psychiatric complications, and driving a car underlining the necessity of postoperative rehabilitation in this group.
Abstract: OBJECTIVE: The aim of this study was to evaluate the short- and long-term seizure outcome and to find predictors of outcome after epilepsy surgery in lesional posterior cortical epilepsies (PCEs). METHODS: The operative outcome in 80 consecutive adult patients with lesional PCEs who underwent resective surgery for intractable partial epilepsy between 1991 and 2006 was retrospectively studied. RESULTS: The probability of remaining in Engel Class I was 66.3% (95% CI 60 to 72) at 6 months, 52.5% (95% CI 47 to 57) at 2 years, 52.9% (CI 45 to 59) at 5 years and 47.1% (CI 42 to 52) at 10 years. Factors predicting poor outcome were the presence of a somatosensory aura, extraregional spikes, incomplete resection, interictal epileptiform discharge (IED) in EEG 6 months and 2 years postsurgery, history of generalised tonic-clonic seizure (GT-CS) and the presence of focal cortical dysplasia in the resected specimen. Factors predicting good outcome were childhood onset of epilepsy, short epilepsy duration, ipsilateral spikes, visual aura, presence of well-circumscribed lesion in preoperative MRI and a pathologically defined tumour. In the multivariate analysis, predictors were different in the long and short term as follows: incomplete resection as proven by postoperative MRI (hazard ratio (HR) 2.059 (CI 1.19 to 3.67)) predicts seizure relapse in short-term follow-up. The presence of IED in the EEG performed 6 months after surgery (HR 2.3 (CI 1.128 to 4.734)) predicts seizure relapse in the long-term fellow-up. However, the absence of a history of GT-CS independently predicts seizure remission in short- and long-term follow-up. CONCLUSIONS: Surgery in PCEs proved to be effective in short- and long-term follow-up. Lesional posterior cortical epilepsy may be a progressive process in a substantial number of cases.
Abstract: OBJECT: The aim of this study was to evaluate the long-term efficacy of temporal lobe epilepsy (TLE) surgery and potential risk factors for seizure recurrence after surgery. METHODS: This retrospective study included 434 consecutive adult patients who underwent TLE surgery at Bethel Epilepsy Centre between 1991 and 2002. RESULTS: Hippocampal sclerosis was found in 62% of patients, gliosis in 17.3%, tumors in 20%, and focal cortical dysplasia (FCD) in 6.9%. Based on a Kaplan-Meier analysis, the probability of Engel Class I outcome for the patients overall was 76.2% (95% CI 71-81%) at 6 months, 72.3% (95% CI 68-76%) at 2 years, 71.1% (95% CI 67-75%) at 5 years, 70.8% (95% CI 65-75%) at 10 years, and 69.4% (95% CI 64-74%) at 16 years postoperatively. The likelihood of remaining seizure free after 2 years of freedom from seizures was 90% (95% CI 82-98%) for 16 years. Seizure relapse occurred in all subgroups. Patients with FCD had the highest risk of recurrence (hazard ratio 2.15, 95% CI 0.849-5.545). Predictors of remission were the presence of hippocampal atrophy on preoperative MR imaging and a family history of epilepsy. Predictors of relapse were the presence of bilateral interictal sharp waves and versive seizures. Six-month follow-up electroencephalography predicted relapse in patients with FCD. Short epilepsy duration was predictive of seizure remission in patients with tumors and gliosis; 28.1% of patients were able to discontinue antiepileptic medications without an increased risk of seizure recurrence (hazard ratio 1.05, 95% CI 0.933-1.20). CONCLUSIONS: These findings highlight the role of etiology in prediction of long-term outcome after TLE surgery.
Abstract: OBJECT: 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. METHODS: 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. RESULTS: 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). CONCLUSIONS: 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.
Abstract: OBJECTIVE: Our aim was to determine the surgical outcome in adult patients with intractable extratemporal epilepsy and follow it over time. METHODS: 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. RESULTS: 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). CONCLUSION: 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.
Abstract: Our aim is to investigate seizure outcome and prognostic factors after pure frontal lobe epilepsy (FLE) surgery. We retrospectively studied the operative outcome in 97 consecutive adult patients who underwent resective surgery for intractable partial epilepsy between 1991 and 2005. Based on Kaplan-Meier, the probability of an Engel Class I outcome was found to be 54.6% (95% CI 44-64) at 6 months, 49.5% (95% CI 39.3-59.6) at 2 years, 47% (CI 34-59) at 5 years and 41.9% (CI 23.5-60.3) at 10 years. If the patient was seizure free at 2-year follow-up, the probability of remaining seizure free up to 10 years was 86% (95% CI 76-98). For 13.6% of the patients a running down of seizures could be shown. Factors predictive of poor long-term outcome were incomplete resection, using of subdural grids, IED in follow-up EEG, tonic seizures and an unspecific aura or a postoperative aura. Factors predictive of good long-term outcome were the presence of a well-circumscribed lesion in preoperative MRI, ipsilateral IED in preoperative EEG, surgery before age of 30 and short epilepsy duration prior to surgery. In the multivariate analysis, preoperative well-circumscribed lesion in MRI predicts seizure remission whereas persistent postoperative auras predict seizure relapse. FLE surgery should depend on restrictive patient selection to assure favorable outcome.
Abstract:
Purpose: To evaluate the relationship between preoperative epilepsy duration and postoperative outcome after epilepsy surgery.
Method: We retrospectively reviewed all adult patients who underwent epilepsy surgery (1991 to 2005) in the Bethel Epilepsy Centre. There were 890 patients, 479 (53.7%) males and 411 (46.3%) females, 661 (74.3%) underwent temporal and 229 (25.7%) extratemporal epilepsy surgery. Mean age at epilepsy onset was 12.79 ±10.66 (range 0-68 years), mean age at time of surgery was 32.79 ± 11.38 (range 16-71 years), mean duration of epilepsy was 29.1 ±11.8 (range 0-64 years), and mean duration of follow-up was 3.01 ± 2.6 years.
Results: Engel Class I was reached by 84.6% (17) of the patients who were operated within one year of epilepsy onset, 78.3% (29) of patients operated within 2 years of epilepsy onset, 71% (44) of patients operated within 5 years, 47.2% (59) within (6 to 10) years, 63.9% (160) within (10 to 20) years and 62.2% (248) more than 20 years. Correlation between duration of epilepsy and Engel Class I was significant at level 0.05 (r = 0, 096; p = 0.009). Extratemporal and temporal epilepsy differed regarding preoperative epilepsy duration. Extratemporal epilepsy had a significantly better outcome if operated within 3 years of onset (p = 0.002), and temporal epilepsy if operated within 5 years after onset (p = 0.018).
Conclusion: A strong relationship was found between preoperative epilepsy duration and Engel Class I outcome. Extratemporal epilepsy showed an earlier and stronger relation to Engel class 1 outcome compared to temporal lobe epilepsy.
