Postoperative seizure control and antiepileptic drug use in pediatric epilepsy surgery patients: the UCLA experience, 1986-1997

PURPOSE: Young children with refractory symptomatic epilepsy are at risk for developing neurologic and cognitive disabilities. Stopping the seizures may prevent these disabilities, but it is unclear whether resective surgery is associated with adequate long-term seizure control. METHODS: This study determined pre- and postsurgery seizure frequency and antiepileptic drug (AED) use (6 months to 10 years) in children with symptomatic seizures from unilateral cortical dysplasia (CD; n = 64) and non-CD etiologies (i.e., ischemia, infection; n = 71), and compared them with older temporal lobe epilepsy (TLE; n = 31) patients with complex partial seizures. RESULTS: Compared with presurgery, postsurgery seizure frequencies were decreased for CD, non-CD, and TLE patients (p < 0.002), and there were no differences between the three groups from 6 to 24 months after surgery (p > 0.12). At 5 years after surgery, seizure frequencies were greater in CD compared with TLE cases (p = 0.009). Compared with presurgery, the number of AEDs declined after surgery in all three groups (p < 0.002), and positively correlated with seizure frequencies (p = 0.0001). CONCLUSIONS: This study indicates that seizure relief and AED use after resective surgery for symptomatic CD and non-CD etiologies was comparable with complex partial TLE cases up to 2 years after surgery. Furthermore, at 5 years after surgery, CD patients had outcomes better than those before surgery, but worse than TLE cases. In young children, these findings support the concept that early removal of symptomatic pathologic substrates is associated with seizure control and reduced AED use, similar to that noted in older TLE cases up to 2 years after surgery. Seizure control may reduce the risk of developing the seizure-related encephalopathy associated with severe symptomatic early-onset childhood epilepsy.     

Seizure recurrence after planned discontinuation of antiepileptic drugs in seizure-free patients after epilepsy surgery: a review of current clinical experience

PURPOSE: Although epilepsy surgery, especially temporal lobe epilepsy surgery, is well established to control seizures in patients remaining on antiepileptic drug (AED) treatment, less information is available about how many seizure-free surgical patients will relapse after discontinuation of AEDs under medical supervision. METHODS: A literature review yielded six retrospective clinical observations. RESULTS: After planned discontinuation of AEDs in patients rendered seizure free after epilepsy surgery, most often various forms of temporal lobe surgery, the mean percentage recurrence rate in adults in four studies was 33.8%[95% confidence interval (CI), 32.4-35.2%], with maximum follow-up ranging from 1 to 5 years. Seizure recurrence increased during the follow-up of 1 to 3 years and occurred within 3 years of AED discontinuation. In one study of children with temporal lobe epilepsy, the recurrence rate was 20%. More than 90% of adult patients with seizure recurrence regained seizure control with reinstitution of previous AED therapy. Seizure recurrence was unaffected by the duration of postoperative AED treatment; as a consequence, delaying discontinuation beyond 1 to 2 years of complete postoperative seizure control seems to have no added benefit. The occurrence of rare seizures or auras after surgery did not eliminate the possibility of eventual successful AED discontinuation. CONCLUSIONS: AED discontinuation is associated with a seizure recurrence in one in three patients rendered seizure free by epilepsy surgery. These results will be useful in counseling patients about discontinuing AED treatment after successful epilepsy surgery.     

Predictors of psychiatric and seizure outcome following temporal lobe epilepsy surgery

Purpose: Neurosurgery is an effective therapy for selected individuals with medically refractory temporal lobe epilepsy (TLE). De novo psychopathology may complicate the postsurgical outcome. Our aims were to identify predictors of de novo psychiatric and seizure outcome following TLE surgery. Methods: Medical records of 280 patients who underwent TLE surgery were reviewed. Preoperative and postoperative psychiatric diagnoses were identified, in addition to information on seizure recurrence and neuropsychological status. Logistic regression analysis was used to identify predictors of having a de novo psychiatric diagnosis and remaining seizure‐free within 4 years following surgery. Key Findings: One hundred five patients (38%) had significant psychiatric problems within 4 years following TLE surgery. Fifty‐one patients (18%) developed de novo psychopathology; half of cases presented within 6 months and 90% of psychopathologies persisted 6 months or longer. A preoperative history of secondary generalized tonic–clonic seizure(s) (SGTCS) was an independent predictor of de novo psychopathology (odds ratio [OR] 2.73, 95% confidence interval [CI] 1.14–6.59, p = 0.02). From patients with available seizure data, 49% (127 of 258) remained seizure‐free for 4 years after surgery. Patients with a history of SGTCS (OR 0.47, 95% CI 0.25–0.90, p = 0.02) and those with a preoperative psychiatric diagnosis (OR 0.53, 95% CI 0.28–0.98, p = 0.04) were significantly less likely to remain seizure‐free. Significance: De novo psychopathology is a significant complication of TLE surgery. Inclusion of neuropsychiatric assessments in the presurgical evaluation may lead to increase in the power of prognostic models used to predict the neurologic outcome of TLE surgery.     

Factors related to successful antiepileptic drug withdrawal after anterior temporal lobectomy for medial temporal lobe epilepsy.

OBJECTIVE: To assess the rate of successful antiepileptic drug (AED) discontinuation, prognostic factors and proper time of AED withdrawal after surgery for medial temporal lobe epilepsy (MTLE). METHODS: We reviewed 171 consecutive patients who underwent resective surgery for MTLE. All patients were followed up for more than two postoperative years. AEDs were slowly tapered with an individualized schedule for each patient. Outcome status was determined from medical records and telephone interviews. RESULTS: 41.2% of patients experienced no seizure recurrence. 34.5% discontinued medication without seizure recurrence for more than 2 years at final assessment. Multivariate analysis revealed that an age greater than 30 years at surgery and postoperative AED reduction before 10 months increased the risk of recurrence [hazard ratio (HR) 2.1, 95% confidence interval (CI) 1.1-3.9 and HR 2.5, CI 1.1-5.8]. CONCLUSIONS: Resective surgery for MTLE brings seizure remission without AED to one-third of patients. Postoperative AED tapering is recommended after at least 10 months. Younger age at surgery is a good predictive factor of remission after MTLE surgery.     

Antiepileptic drug withdrawal in patients with temporal lobe epilepsy undergoing presurgical video-EEG monitoring

PURPOSE: To investigate antiepileptic drug (AED) withdrawal during video-EEG monitoring in adult patients with temporal lobe epilepsy (TLE). METHODS: Between 1995 and 1997, 102 consecutive patients with refractory TLE were admitted to the epilepsy monitoring unit for presurgical evaluation. Patients were monitored with ongoing AEDs being rapidly decreased and discontinued in 4-6 days. The monitoring was continued until sufficient numbers of seizures were recorded. Serum AED levels were checked at admission and after the first complex partial seizure (CPS). RESULTS: In all, 89 patients had 429 CPSs (mean, 4.8 per patient), including 156 (36.4%) secondarily generalized. A mean of 153.8 h (16-451 h) was required for completing the monitoring in each patient. Forty-three (48.3%) patients experienced seizure clusters, and eight (9.0%) had generalized seizures that had never occurred or had been absent for years. However, none evolved to status epilepticus. Carbamazepine was the most commonly used AED in 71.9% of patients, followed by valproate and phenytoin. When the first CPS occurred, mean 77.2 h since the beginning of the monitoring, serum levels of these three AEDs were mostly subtherapeutic rather than minimal. CONCLUSIONS: Acute AED withdrawal effectively provoked seizures in TLE patients undergoing presurgical video-EEG monitoring. However, nearly 50% of patients had seizure clusters or secondarily generalized seizures. Serum AED levels were mostly subtherapeutic when the first CPS occurred.     

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.     

Limitations in the Medical Treatment of Cryptogenic or Symptomatic Localization-Related Epilepsies of Childhood Onset

Summary: We retrospectively examined 169 patients who had cryptogenic or symptomatic localization-related epilepsies (LRE) and were followed-up for more than 5 years. The probability of seizure control was 0.13 during the first year of treatment, 0.25 during the first 5 years, and 0.09 during the second and third 5 years. No patients who continued to have intractable seizures for 15 years became free of seizures. The onset of LRE at the age of 3 years or less, seizure cluster, mesial temporal sclerosis (MTS), and temporal lobe epilepsy (TLE) were significantly associated with a poor seizure control. If an antiepileptic drug (AED) failed to control seizures, probability of seizure control by the next drug was low, in particular in patients in whom more than 4 AEDs have already been tried, and seizure control could not be expected after a trial of 6 AEDs. A tentative indication of epilepsy surgery for LRE of childhood onset may be 5 years of poor seizure control and/or failure of four AEDs.     

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.     

Risk factors for suicide in epilepsy: a case control study

PURPOSE: Suicide is considered to be one of the most important causes of death contributing to the increased mortality of persons with epilepsy. We investigated the association between the risk of suicide in persons with epilepsy and clinical factors that might increase or have been suggested to increase the risk of suicide. METHODS: A case-control study was nested within a cohort of 6,880 patients registered in the Stockholm County In-Patient Register with a diagnosis of epilepsy. The study population was followed up through the National Cause of Death Register. Twenty-six cases of suicide, 23 cases of suspected but not proven suicide, and 171 controls, living epilepsy patients, were selected from the cohort. Clinical data were collected through medical record review. RESULTS: There was a ninefold increase in risk of suicide with mental illness and a 10-fold increase in relative risk (RR) with the use of antipsychotic drugs. The estimated RR of suicide was 16.0 [95% confidence interval (CI), 4.4-58.3] for onset of epilepsy at younger than 18 years, compared with onset after 29 years. The risk of suicide seemed to increase with high seizure frequency and antiepileptic drug (AED) polytherapy, although the estimates were imprecise and the associations not statistically significant. Insufficient data on seizure frequency and changes in AED dosage due to incomplete case records were associated with high RRs. We found no association between risk of suicide and any particular AED, with type of epilepsy, or localization or lateralization of epileptogenic focus on EEG [RR = 0.3 (95% CI, 0.1-1.7)]. CONCLUSIONS: The profile of the epilepsy patient who commits suicide that emerges from our study is a patient with early onset (particularly onset during adolescence) but not necessarily severe epilepsy, psychiatric illness, and perhaps inadequate neurologic follow-up. Previous reports of an association with temporal lobe epilepsy could not be confirmed.     

Automatic ictal onset source localization in presurgical epilepsy evaluation

Objective

To test the diagnostic accuracy of a new automatic algorithm for ictal onset source localization (IOSL) during routine presurgical epilepsy evaluation following STARD (Standards for Reporting of Diagnostic Accuracy) criteria.

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.     

Seizure outcome after temporal lobectomy for temporal lobe epilepsy: a Kaplan-Meier survival analysis

OBJECTIVE: To determine seizure outcome and its predictors in patients with medically refractory temporal lobe epilepsy (TLE) after temporal lobectomy (TL). BACKGROUND: TL is the most common surgical procedure performed in adolescents and adults for the treatment of medically refractory TLE. Seizure outcome has been reported extensively during the first few postoperative years, but little is known beyond that time. METHODS: The authors analyzed seizure outcome in 79 patients who underwent TL for epilepsy at the Duke University Medical Center from 1962 through 1984. Patients with less than 2 years of follow-up and degenerative disorders were excluded. Predictors of seizure outcome were analyzed using Kaplan-Meier survival analyses. RESULTS: The mean follow-up was 14 years (range, 2.1 to 33.6 years). Using Engel's classification, 65% of patients were class I, 15% were class II, 11% were class III, and 9% were class IV. At least one postoperative seizure occurred in 55% of subjects. The majority of recurrences (86%) took place within 2 years of surgery. Later recurrences tended not to lead to medical intractability. Higher monthly preoperative seizure frequency was associated with poor seizure outcome. A seizure-free state at 2 years was found to be a better predictor of long-term outcome than the 6-, 12-, and 18-month landmarks. CONCLUSIONS: TL provides sustained, long-term benefit in patients with medically refractory TLE. Seizure-free status at 2 years from the time of surgery is predictive of long-term remission.     

Postsurgical outcome of children and adolescents with medically refractory frontal lobe epilepsies

OBJECTS: In the adult population surgical treatment is generally less favorable for refractory frontal lobe epilepsy (FLE) than for temporal lobe epilepsy (TLE). Predictive factors and outcome of FLE surgery had not previously been described for the pediatric and adolescent population. Therefore, 32 children and adolescents who underwent FLE surgery were analyzed in this study. METHODS: Medical records were reviewed for demographic data, presurgical evaluation procedures, surgical procedures, pathological findings and follow-up. RESULTS: Mean age at operation was 10.8 years, with seizure onset at 4.6 years. Excellent outcomes were observed in 21 of the 32 patients following evaluation a mean of 34.5 months after surgery. Nineteen of 22 patients became seizure free after tailored resections, versus 2 out of 10 after lobectomy. Transient neurological and surgical complications occurred in 4 patients. Focal neoplastic lesions detectable by MRI were associated with a favorable outcome. CONCLUSIONS: As seen in adult FLE series, the detection of a resectable ictal neoplastic lesion on preoperative MRI is associated with an excellent outcome comparable to that of TLE surgery.     

Foramen ovale electrodes in the preoperative evaluation of temporal lobe epilepsy in children

Purpose:  Foramen ovale electrodes (FOEs) can localize the epileptogenic zone in adults with mesial temporal lobe epilepsy (TLE). Our aim was to investigate the feasibility and safety of using FOEs to investigate refractory TLE in children.
Methods:  Thirty-eight children with seizure semiology and video-EEG (electroencephalography) consistent with medically refractory TLE, and/or the presence of a lesion in the temporal lobe, had FOEs inserted. Complications occurring during the monitoring and up to 3 months after surgery and the long-term seizure outcome were registered.
Results:  Forty electrodes were placed in 38 patients. The mean age of the patients was 9.8 years (range 2.3–15.4 years). FOEs confirmed a unilateral mesial temporal lobe seizure onset in 14 patients, onset in both FOEs and lateral electrodes in two patients, and onset in the anterior temporal electrodes in only one patient. Six patients had seizures recorded but were not considered surgical candidates; four patients had no seizures recorded, and 11 patients were further investigated with depth electrodes. One patient (2.6%) developed a hematoma in the cheek, and in two patients the electrodes were extracranial but could still be used for recording. Twenty-eight children had a temporal resection; 25 were Engel class I at follow-up.
Discussion:  FOEs are safe to use in children and provide valuable information on the mesial temporal lobe structures in the preoperative investigation of pediatric TLE. Patient selection for FOE investigation is, however, essential for a conclusive result.     

Kaplan-Meier analysis on seizure outcome after epilepsy surgery: do gender and race influence it?

OBJECTIVE: To evaluate seizure outcome following epilepsy surgery for patients with temporal lobe epilepsy and evaluate is gender and race/ethnicity influence it. METHODS: Data were obtained from the discharge database of the University of Alabama at Birmingham, Epilepsy Center, between 1985 and 2001. The sample consisted of all patients with a primary diagnosis of medically intractable temporal lobe epilepsy (TLE) who underwent anterior temporal lobectomy. Seizure recurrence was tabulated at 7 days, 2 months, 6 months, 1, 2, 3, 4, 5, and 6 years following surgery. Logistic regression analysis was used to model the presence of seizure recurrence after anterior temporal lobectomy for all patients. Kaplan-Meier analysis was done to obtain estimates and 95% CIs of seizure freedom from baseline. Baseline variables--age at surgery, age at seizure onset, sex, side of resection, immediate postoperative seizures, and pathology results--were assessed as potential predictors of each outcome by comparing the survival curves within each variable with a log rank test. RESULTS: Three hundred sixty-eight patients underwent surgical treatment for TLE, mean age of 30.2 years. Thirty-five patients were African American, 43% were men. Immediate postoperative seizures were seen in 23 patients, while seizure recurrence occurred in 27.3% patients within a year after surgery, and in 33.6% within 6 years. Logistic regression results showed no differences between African Americans and whites, between males and females. The occurrence of immediate postoperative seizures was a strong predictor of late seizure recurrence only at 1 year after surgery. CONCLUSIONS: The occurrence of seizures in the immediate postoperative period is a strong predictor of later seizure recurrence. Sex and race/ethnicity do not appear to be predictors of long-term outcome following surgery for temporal lobe epilepsy.     

Long term outcome of temporal lobe epilepsy surgery: analyses of 140 consecutive patients

OBJECTIVE: To analyse the long term results of temporal lobe epilepsy surgery in a national epilepsy surgery centre for adults, and to evaluate preoperative factors predicting a good postoperative outcome on long term follow up. METHODS: Longitudinal follow up of 140 consecutive adult patients operated on for drug resistant temporal lobe epilepsy. RESULTS: 46% of patients with unilateral temporal lobe epilepsy became seizure-free, 10% had only postoperative auras, and 15% had rare seizures on follow up for (mean (SD)) 5.4 (2.6) years, range 0.25 to 10.5 years. The best outcome was after introduction of a standardised magnetic resonance (MR) imaging protocol (1993-99): in unilateral temporal lobe epilepsy, 52% of patients became seizure-free, 7% had only postoperative auras, and 17% had rare seizures (median follow up 3.8 years, range 0.25 to 6.5 years); in palliative cases (incomplete removal of focus), a reduction in seizures of at least 80% was achieved in 71% of cases (median follow up 3.1 years, range 1.1 to 6.8 years). Most seizure relapses (86%) occurred within one year of the operation, and outcome at one year did not differ from the long term outcome. Unilateral hippocampal atrophy with or without temporal cortical atrophy on qualitative MR imaging (p < 0.001, odds ratio (OR) 5.2, 95% confidence interval (CI) 2.0 to 13.7), other unitemporal structural lesions on qualitative MR imaging (p < or = 0.001, OR 6.9, 95% CI 2.2 to 21.5), onset of epilepsy before the age of five years (p < 0.05, OR 2.9, 95% CI 1.2 to 7.2), and focal seizures with ictal impairment of consciousness and focal ictal EEG as a predominant seizure type (p < 0.05, OR 3.4, 95% CI 1.2 to 9.1) predicted Engel I-II outcome. Hippocampal volume reduction of at least 1 SD from the mean of controls on the side of the seizure onset (p < 0.05, OR 3.1, 95% CI 1.1 to 9.2) also predicted Engel I-II outcome. CONCLUSIONS: Outcome at one year postoperatively is highly predictive of long term outcome after temporal lobe epilepsy surgery. Unitemporal MR imaging abnormalities, early onset of epilepsy, and seizure type predominance are factors associated with good postoperative outcome.     

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.     

Efficacy of temporal lobe surgery for epilepsy in patients with negative MRI for mesial temporal lobe sclerosis

Epilepsy surgery is a successful treatment for refractory temporal lobe epilepsy (TLE). Reports suggest fewer seizure-free outcomes for patients with TLE and who have a negative brain MRI (nMRI) for mesial temporal sclerosis. Data were collected prospectively from patients with nMRI who underwent temporal lobe surgery for TLE characterized by unilateral ictal temporal lobe seizure onset based on a scalp video electroencephalogram or invasive subdural electrode recordings. A total of 86 patients were followed for at least 24 months after surgery. Outcome was evaluated using the Engel classification. Seizure control was obtained by 55% (47/86) of patients (Class [CL]-I), 27% (23/86) showed significant improvement (CL-II) and 19% (16/86) were deemed surgical failures. Shorter duration of epilepsy, later onset of seizures, and ictal theta rhythm (5-7 Hz) were the most significant predictors of postoperative seizure control. Although hypometabolism on positron emission tomography scan and significant memory disparity (>2.5/8) were not significant prognosticators independently, cumulatively they were predictors for favorable outcome.     

ApoE epsilon4 allele and disease duration affect verbal learning in mild temporal lobe epilepsy

PURPOSE: To clarify the possible role of other factors including the ApoE epsilon4 allele for memory decline in temporal lobe epilepsy (TLE). METHODS: We conducted a neuropsychological and molecular study in 138 consecutive patients (78 female patients; mean age, 50.2 years, SD +/- 17.9; range, 14 to 87 years) with mild nonlesional TLE, who rarely or never had seizures at long-term follow-up. The mean age at seizure onset was 33.0 years (SD, +/-21.7), and the mean duration of epilepsy was 17.1 years (SD, +/-15.7). RESULTS: Thirty-four (25%) of 138 patients had test scores indicating verbal learning deficit (VLD). The presence of an ApoE epsilon4 allele was associated with an increased risk of VLD (OR, 4.18; 95% CI, 1.66-10.55). The effect of the ApoE genotype was independent of both the age at epilepsy onset and disease duration as well as of a low educational level, which were separately associated with VLD (p values = 0.045, 0.001, and 0.001, respectively). A significant linear trend (p = 0.005) was seen in the relation between disease duration and cognitive impairment, with the highest risk being in patients with an epilepsy duration > or =25.5 years (OR, 7.06; 95% CI, 1.67-29.85), especially if they carried the epsilon4 allele (OR, 32.29; 95% CI, 5.23-195.72). CONCLUSIONS: These results provide evidence for an alteration in cognitive performance as a function of the presence of the ApoE epsilon4 allele and point to the critical role of disease duration itself for cognitive impairment in TLE.     

Long-term seizure outcome and antiepileptic drug treatment in surgically treated temporal lobe epilepsy patients: a controlled study

PURPOSE: To evaluate the long-term impact of surgical treatment on seizure outcome and antiepileptic drug (AED) use in patients with pharmacoresistant temporal lobe epilepsy (TLE). METHODS: Comparison of seizure outcome and AED us in operated-on TLE patients (n=148) and nonsurgically treated TLE patients (n=94) at a baseline visit and a follow-up visit after a mean period of 4.8 years. RESULTS: At follow-up, 44.6% of the surgical patients and 4.3% of the nonsurgical patients had been continuously seizure- free since the baseline visit (including the immediate postoperative period). A further 17.6% of the operated-on and 3.2% of the not operated-on patients had been seizure-free for at least the previous year; 37.8% of the surgical and 92.5% of the nonsurgical patients had had seizures during the previous 12 months (p < 0.001). Of the surgical patients, 8.8% versus none of the nonsurgical patients were AED free at follow-up; 55.4% versus 20.2% were receiving monotherapy, and 35.8% versus 79.8% were receiving polytherapy (p < 0.001). Mean number of AEDs and mean change in number of AEDs were significantly more favorable in operated-on than in non-operated-on patients. Further subgroup analysis revealed that not only the continuously seizure-free surgical patients, but also the operated-on patients with ongoing seizures took fewer AEDs than their respective non-operated-on counterparts. CONCLUSIONS: This controlled study for the first time provides comprehensive information on long-term seizure outcome and AED use in surgical TLE patients. It shows a more favorable seizure outcome and AED use in the surgically treated patients. The latter holds true even for the not seizure-free patient subgroup.