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.     

Early seizures after temporal lobectomy predict subsequent seizure recurrence

Patients are understandably anxious if seizures occur immediately after temporal lobectomy. Such "neighborhood" seizures are commonly regarded as irrelevant to seizure outcome and discounted in outcome measurement. We conducted an in-depth examination of early postoperative seizures (<28 days) and outcome. The risk of recurrence at one postoperative year was calculated using Poisson regression, and statistical adjustments were made for preoperative pathology. Of 321 patients, 69 (22%) experienced early postoperative seizures. These early seizures were associated with subsequent seizure recurrence (rate ratio [RR] 5.9; 95% confidence interval [CI], 4.1-8.4). Among patients with early seizures, the only significant factor was the presence of seizure precipitants, which was associated with a lower recurrence risk. However, when compared with patients with no early seizures, those with precipitants to early seizures had a higher risk of recurrence (RR, 3.0; 95% CI, 1.8-5.2). The risk was higher again for patients without precipitants to early seizures (RR, 7.6; 95% CI, 5.0-11.5). Early seizures and other seizure recurrences in the first postoperative year did not differ in their effect on subsequent outcome (X(2) [3] = 3.4, p = 0.33). We conclude that early postoperative seizures are associated with subsequent seizure recurrence. These findings have implications for patient counseling and the measurement of outcome.     

Postoperative seizure outcome in a series of 114 patients with supratentorial arteriovenous malformations.

The incidence of de novo and ongoing postoperative seizures and factors implicated in an increased likelihood of seizures following supratentorial cerebral arteriovenous malformation (AVM) resection remain controversial. We investigated the frequency, severity and variables associated with postoperative seizures in 114 consecutive patients who underwent complete surgical excision of supratentorial AVMs at our institution. The minimal follow up period was 24 months. The incidence of seizures post-AVM surgery was 21% (less than half that found preoperatively). The incidence of postoperative seizures first manifesting >12 months post-AVM resection was 6.3%. A history of preoperative seizures was associated with an increased likelihood of multiple (> or =4) seizures >1 month post-AVM resection (chi2 = 4.38, P = 0.04). Poor functional neurological outcome at 12 months was also a risk factor for the development of > or =1 postoperative seizure using logistic regression analysis (P = 0.04, odds ratio 1.52, 95% CI 1.01-2.28). Cessation of AED therapy in all patients who remain seizure-free at 12 months post-AVM resection is appropriate due to a low risk of new seizure onset or seizure recurrence.     

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.     

Seizures after stroke: a prospective multicenter study

BACKGROUND: Studies of seizures after stroke have largely been retrospective, with small patient numbers and limited statistical analysis. Much of the doctrine about seizures after stroke is not evidenced based. OBJECTIVE: To determine the incidence, outcome, and risk factors for seizures after stroke. DESIGN: International, multicenter, prospective, analytic inception cohort study conducted for 34 months. PATIENTS AND SETTING: There were 2021 consecutive patients with acute stroke admitted to university teaching hospitals with established stroke units. After exclusion of 124 patients with previous epilepsy or without computed tomographic diagnosis, 1897 were available for analysis. Mean follow-up was 9 months. MAIN OUTCOME MEASURES: Occurrence of 1 or more seizures after stroke, stroke disability, and death after stroke. RESULTS: Seizures occurred in 168 (8.9%) of 1897 patients with stroke (28 [10.6%] of 265 with hemorrhagic and 140 [8.6%] of 1632 with ischemic stroke). On Kaplan-Meier survival analysis, patients with hemorrhagic stroke were at significantly greater risk of seizures (P =.002), with an almost 2-fold increase in risk of seizure after stroke (hazard ratio [HR], 1.85; 95% confidence interval [CI], 1.26-2.73; P =.002). On multivariate analysis, risk factors for seizures after ischemic stroke were cortical location of infarction (HR, 2.09; 95% CI, 1. 19-3.68; P<.01) and stroke disability (HR, 2.10; 95% CI, 1.16-3.82; P<.02). The only risk factor for seizures after hemorrhagic stroke was cortical location (HR, 3.16; 95% CI, 1.35-7.40; P<.008). Recurrent seizures (epilepsy) occurred in 47 (2.5%) of 1897 patients. Late onset of the first seizure was an independent risk factor for epilepsy after ischemic stroke (HR, 12.37; 95% CI, 4.74-32.32; P<. 001) but not after hemorrhagic stroke. CONCLUSIONS: Seizures occur more commonly with hemorrhagic stroke than with ischemic stroke. Only a small minority later develop epilepsy. Patients with a disabling cortical infarct or a cortical hemorrhage are more likely to have seizures after stroke; those with late-onset seizures are at greater risk of epilepsy.     

When is a postoperative seizure equivalent to “epilepsy recurrence” after epilepsy surgery?

Purpose: Up to one‐half of epilepsy surgery patients will have at least one seizure after surgery. We aim to characterize the prognosis following a first postoperative seizure, and provide criteria allowing early identification of recurrent refractory epilepsy. Methods: Analyzing 915 epilepsy surgery patients operated on between 1990 and 2007, we studied 276 who had ≥1 seizure beyond the immediate postoperative period. The probability of subsequent seizures was calculated using survival analysis. Patients were divided into seizure‐free (no seizures for ≥1 year) and refractory (persistent seizures) and analyzed using multivariate regression analysis. Results: After a first seizure, 50% had a recurrence within 1 month and 77% within a year before the risk slowed down to additional 2–3% increments every two subsequent years. After a second seizure, 50% had a recurrence within 2 weeks, 78% within 2 months, and 83% within 6 months. Having both the first and second seizures within six postoperative months [odds ratio (OR) 4.04; 95% confidence interval (CI) 2.05–8.40; p = 0.0001], an unprovoked initial recurrence (OR 3.92; 95% CI 2.13–7.30; p < 0.0001), and ipsilateral spikes on a 6‐months postoperative electroencephalography (EEG) (OR 2.05; 95% CI 1.10–3.88; p = 0.025) predicted a poorer outcome, with 95% of patients who had all three risk factors becoming refractory. All patients with cryptogenic epilepsy and recurrent seizures developed refractoriness. Discussion: Seizures will recur in most patients who present with their first postoperative event, with one‐third eventually regaining seizure‐freedom. Etiology and early and unprovoked postoperative seizures with epileptiform activity on EEG at six postoperative months may predict recurrent medical refractoriness.     

Seizure outcomes following multilobar epilepsy surgery

Purpose: Outcomes following unilobar surgeries for refractory epilepsy have been well described. However, little is known about long‐term seizure outcomes following multilobar resections. The aim of the current study was to identify long‐term seizure control and predictors of seizure recurrence in this patient population. Methods: Records of patients who underwent multilobar epilepsy surgery at the Cleveland Clinic between 1994 and 2010 were retrospectively reviewed. A postoperative follow‐up of at least 6 months was required. Patients were classified as seizure free if they achieved an Engel class I at last follow‐up. Long‐term chances of seizure freedom were illustrated using a survival analysis, and predictors of recurrence were identified using Cox proportional hazard modeling. Key Findings: Sixty‐three patients with medically intractable epilepsy underwent multilobar surgical resections during the study period (mean follow‐up of 4.6 years). Predominant resection types included extended occipital (temporoparietooccipital, parietooccipital, temporooccipital: 57%), frontotemporal (21%), and temporoparietal (17%). Mean age at surgery was 21.4 years and mean age at seizure onset was 10.1 years. Fifty‐six percent of the patients underwent extraoperative invasive electroencephalography (EEG) evaluations. At 6 postoperative months, 71% (95% confidence interval (CI) 65–77) were seizure‐free (SF), 64% (CI 58–70) were SF at 1 year, 52% (CI 46–59) were SF at 5 years, and 41% (CI 32–50) remained SF at 10 years. Forty‐one patients had at least one breakthrough seizure after surgery (median timing of recurrence 6.1 months), with an Engel class 1 achieved again by last follow‐up in 12 of these 41 cases. Nine patients required a reoperation. Patients who underwent extended occipital/posterior quadrant resections had more favorable outcomes as compared to the other groups. With multivariate analysis, the type of resection (p = 0.03), preoperative auras (p = 0.03), an incomplete resection (0.03), and the presence of postoperative spikes (p = 0.0003) correlated with seizure recurrence. The risk of seizure recurrence for an incomplete resection was 2.3 (CI 1.53–3.36), preoperative aura 2.3 (CI 1.34–3.87), and postoperative spikes on surface EEG 2.5 (CI 1.29–4.71). Significance: A favorable outcome can be achieved in 41% of patients undergoing multilobar resections for epilepsy surgery at 10 years of follow‐up. Close to one‐third of patients who have breakthrough seizures after surgery are able to regain seizure freedom by last follow‐up. Predictors of recurrence include resection type (frontotemporal and parietotemporal resections did worse), presence of preoperative aura, an incomplete surgical resection, and the presence of postoperative interictal discharges on EEG.     

Factors associated with seizure freedom in the surgical resection of glioneuronal tumors

Purpose: Gangliogliomas (GGs) and dysembryoplastic neuroepithelial tumors (DNETs) are low‐grade brain tumors of glioneuronal origin that commonly present with seizures. Achieving seizure control in patients with glioneuronal tumors remains underappreciated, as tumor‐related epilepsy significantly affects patients’ quality‐of‐life. Methods: We performed a quantitative and comprehensive systematic literature review of seizure outcomes after surgical resection of GGs and DNETs associated with seizures. We evaluated 910 patients from 39 studies, and stratified outcomes according to several potential prognostic variables. Key Findings: Overall, 80% of patients were seizure‐free after surgery (Engel class I), whereas 20% continued to have seizures (Engel class II–IV). We observed significantly higher rates of seizure‐freedom in patients with ≤1 year duration of epilepsy compared to those with >1 year of seizures [odds ratio (OR) 9.48; 95% confidence interval (CI) 2.26–39.66], and with gross‐total resection over subtotal lesionectomy (OR 5.34; 95% CI 3.61–7.89). In addition, the presence of secondarily generalized seizures preoperatively predicted a lower rate of seizure‐freedom after surgery (OR 0.40; 95% CI 0.24–0.66). Outcomes did not differ significantly between adults and children, patients with temporal lobe versus extratemporal tumors, pathologic diagnosis of GG versus DNET, medically controlled versus refractory seizures, or with the use of electrocorticography (ECoG). Extended resection of temporal lobe tumors, with hippocampectomy and/or corticectomy, conferred additional benefit. Significance: These results suggest that early operative intervention and gross‐total resection are critically important factors in achieving seizure‐freedom, and thus improving quality‐of‐life, in patients with glioneuronal tumors causing epilepsy.     

Mortality in epilepsy in the first 11 to 14 years after diagnosis: multivariate analysis of a long-term, prospective, population-based cohort

The United Kingdom National General Practice Study of Epilepsy is a prospective, population-based study of newly diagnosed epilepsy. A cohort of 792 patients has now been followed for up to 14 years (median follow-up [25th, 75th percentiles] 11.8 years, range 10.6-11.7 years), a total of 11,400 person-years. These data are sufficient for a detailed analysis of mortality in this early phase of epilepsy. Over 70% of patients in this cohort have developed lasting remission from seizures, although the mortality rate in the long term was still twice that of the general population. The standardized mortality ratio (SMR), the number of observed deaths per number of expected deaths, was 2.1 (95% confidence interval [CI] = 1.8, 2.4). Patients with acute symptomatic epilepsy (SMR 3.0; 95% CI = 2.0, 4.3), remote symptomatic epilepsy (SMR 3.7; 95% CI = 2.9, 4.6), and epilepsy due to congenital neurological deficits (SMR 25; 95% CI = 5.1, 73.1) had significantly increased long-term mortality rates, whereas patients with idiopathic epilepsy did not (SMR 1.3; 95% CI = 0.9, 1.9). This increase in mortality rate was noted particularly in the first few years after diagnosis. Multivariate Cox regression and time-dependent co-variate analyses were utilized for the first time in a prospective study of mortality in epilepsy. The former showed that patients with generalized tonic-clonic seizures had an increased risk of mortality. The hazard ratio (HR), or risk of mortality in a particular group with a particular risk factor compared to another group without that particular risk factor, was 6.2 (95% CI = 1.4, 27.7; p = 0.049). Cerebrovascular disease (HR 2.4; 95% CI = 1.7, 3.4; p < 0.0001), central nervous system tumor (HR 12.0; 95% CI = 7.9, 18.2; p < 0.0001), alcohol (HR 2.9; 95% CI = 1.5, 5.7; p = 0.004), and congenital neurological deficits (HR 10.9; 95% CI = 3.2, 36.1; p = 0.003) as causes for epilepsy and older age at index seizure (HR 1.9; 95% CI = 1.7,2.0; p < 0.0001) were also associated with significantly increased mortality rates. These hazard ratios suggest that epilepsy due to congenital neurological deficits may carry almost the same risk of mortality as epilepsy due to central nervous system tumors and that epileptic seizures subsequent to alcohol abuse may carry almost the same risk of mortality as epilepsy due to cerebrovascular disease. The occurrence of one or more seizures before the index seizure (the seizure that led to the diagnosis of epilepsy and enrolment in the study) was associated with a significantly reduced mortality rate (HR 0.57; 95% CI = 0.42, 0.76; p = 0.00001). Time-dependent co-variate analysis was used to examine the influence of ongoing factors, such as seizure recurrence, remission, and antiepileptic drug use, on mortality rates in the cohort. Seizure recurrence (HR 1.30; 95% CI = 0.84, 2.01) and antiepileptic drug treatment (HR 0.97; 95% CI = 0.67, 1.38) did not influence mortality rate. There were only 5 epilepsy-related deaths (1 each of sudden unexpected death in epilepsy, status epilepticus, burns, drowning, and cervical fracture), suggesting that death directly due to epileptic seizures is uncommon in a population-based cohort with epilepsy.     

Long‐term seizure outcome after resective surgery in patients evaluated with intracranial electrodes

Purpose: Despite advances in “noninvasive” localization techniques, many patients with medically intractable epilepsy require the placement of subdural (subdural grid electrode, SDE) and/or depth electrodes for the identification and definition of extent of the epileptic region. This study investigates the trends in longitudinal seizure outcome and its predictors in this group. Methods: We reviewed the medical records, and electroencephalography (EEG) data of 414 consecutive patients who underwent intracranial electrode placement (SDE and/or depth electrodes) at Cleveland Clinic Epilepsy Center between 1998 and 2008. A favorable outcome was defined as complete seizure freedom, discounting any auras or seizures that occurred within the first postoperative week. Survival curves were constructed, and Cox proportional hazard modeling was used to identify outcome predictors. Key Findings: The estimated probability of complete seizure freedom was 61% (95% confidence interval [CI] 58–64%) at one postoperative year, 47% (95% CI 44–50%) at 3 years, 42% (95% CI 39–45%) at 5 years, and 33% (95% CI 28–38%) at 10 years. Half of all seizure recurrences occurred within the first two postoperative months. Subsequently, the rate of seizure freedom declined by 4–5% every 2–3 years. After multivariate analysis, two independent predictors of seizure recurrence were identified: (1) prior resective surgery (p ≤ 0.002), mostly in patients with temporal lobe resections, and (2) sublobar or multilobar resection (p ≤ 0.02), mostly in patients following frontal lobe resections. Significance: Favorable seizure outcomes are possible in the complex epilepsy population requiring invasive EEG studies. We propose that mislocalization of the epileptogenic zone or its incomplete resection account for early postoperative recurrences, whereas epileptogenesis may lead to later relapses.     

影响难治性颞叶癫痫外科疗效的临床特征及相关因素分析

目的探讨影响难治性颞叶癫痫患者术后近、远期疾病控制率的相关临床因素。方法纳入196例难治性颞叶癫痫手术病例进行回顾性分析,观察术后癫痫控制情况及其与影响因素的相关性。结果术后2年内,OC1级142例(72.4%),OC2级10例(5.1%),OC3级25例(12.8%),OC4级14例(7.1%),OC5级5例(2.6%),OC6级0例(0.0%)。效果优良率为77.6%。术后第3年至第6年,平均控制时间为60.287±14.6181个月。颞叶癫痫分型[HR=1.763,95%CI:1.510~2.060],癫痫病程[HR=1.083,95%CI:1.045~1.122]及术后急性期发作频率[HR=1.725,95%CI:1.297~2.296]是影响术后复发的独立危险因素。结论对于难治性颞叶癫痫患者,因根据病程长短,做到尽早手术;术前明确癫痫分型可预测癫痫术后控制率,尤其在颞叶附加症分型上尤为重要;同时减少围术期癫痫的发作频率,对于提升颞叶癫痫术后远期控制率,具有积极的意义。     

Outcome of frontal lobe epilepsy surgery in adults

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.     

Seizure outcome after epilepsy surgery in children and adolescents

Few epilepsy surgery outcome data are available from series of pediatric patients. We studied seizure outcome in 136 pediatric patients who had surgery for intractable epilepsy at The Cleveland Clinic between January 1990 and June 1996, with a postoperative follow-up of 1 to 7.5 years (mean, 3.6 years). Sixty-two children (3 months to 12 years old at time of surgery) were compared with 74 adolescents (13–20 years old). Extratemporal or multilobar resections and hemispherectomies were similarly frequent among children (50%) and adolescents (44%), but these procedures strongly predominated in infancy (90% of patients 0–2 years of age). The remaining patients had temporal resection. Cortical dysplasia and low-grade tumor were the most common causes and hippocampal sclerosis was rare. Seizure-free outcome was achieved for 69% of adolescents, 68% of children, and 60% of the infant subgroup, overall; for 23 (74%) of 31 children and 33 (80%) of 41 adolescents after temporal resection; for 11 (58%) of 19 children and 15 (52%) of 29 adolescents after extratemporal or multilobar resection; and for 8 (67%) of 12 children and 3 (75%) of 4 adolescents after functional hemispherectomy. Seizure-free outcome was more frequent after temporal resection (56 of 72, 78%) than after extratemporal or multilobar resection (26 of 48, 54%; 41 of 48 with a focal lesion on magnetic resonance imaging), and among patients with tumor (36 of 44, 82%) versus cortical dysplasia (16 of 31, 52%). The frequency of seizure-free outcome after epilepsy surgery was similar for infants, children, and adolescents, and comparable with results from adult series. Most patients in each age, surgery type, and causal group were free from seizures after surgery. These results suggest that children should be considered for surgical evaluation at whatever age they manifest with severe, intractable, disabling localization-related epilepsy.     

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.     

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.     

Potentially misleading extratemporal lobe lesions in patients with temporal lobe epilepsy

From a series of 217 consecutive temporal resections for intractable epilepsy between 1993 and 2000, we identified all patients with large non-neoplastic extratemporal lesions. Only patients with known postsurgical outcomes with follow up for more than two years were included. Fifteen patients were identified. All patients had a history of medically refractory epilepsy with clinical and ictal evidence of mesial temporal seizure onset. Eleven patients had extratemporal lesions ipsilateral to the seizure focus, whereas four patients had the lesions contralateral to the seizure focus. Nine of the 15 patients had evidence of hippocampal atrophy on magnetic resonance imaging (MRI). Following temporal resection, nine of these patients (60%) became seizure free (Engel class 1A), two patients were free of disabling seizures only (Engel class 1B), and two patients had a few early seizures but then became seizure free for at least two years (Engel class 1C). Two patients had significant improvement (Engel class 2). Thus, the finding of large extratemporal lesions on MRI was potentially misleading. When clinical semiology and ictal EEG recordings provide evidence of temporal onset seizures, anterior temporal resection should be considered in patients with extratemporal lesions.     

Natural history of recurrent seizures after resective surgery for epilepsy.

Seizures persist or recur in 20-60% of patients after resective surgery for intractable partial epilepsy. Further information about the natural course of these seizures is lacking in the literature. During one decade of epilepsy surgery at a single institution, we identified 72 patients with recurrent postoperative seizures after resective procedures for epilepsy. Prospectively compiled seizure diaries, hospital records, and outpatient office records were reviewed and supplemented by telephone communications to assess subsequent seizure frequency. Follow-up data was available ranging from 6 months to 7 years 5 months (mean 3 years 5 months). The likelihood of persistent seizures and recurrent intractability was examined with life-tables. Seizures recurred within the first postoperative year in 86% of patients and were similar to preoperative events in 74% of patients. After the first seizure recurrence, there was 80% likelihood of persistent seizures in the next 6 years and 40% likelihood of intractability (more than one seizure a month despite optimal medical therapy). The interval until recurrence within the first postoperative year did not affect the likelihood of subsequent seizures or intractability. Late seizure recurrence (after the first year) was not associated with any instances of subsequent intractability. Recurrent seizures after extratemporal resections were more likely to become persistent and intractable than seizures recurring after temporal resections. This information provides rational prognostication and assists in counseling patients with recurrent seizures after resective surgery for intractable epilepsy.     

胶质瘤相关性癫痫术后疗效及影响因素分析

目的探讨胶质瘤相关性癫痫患者术后恢复情况,以及痫性再次发作的危险因素。方法收集89例胶质瘤相关性癫痫患者的一般资料。所有患者行肿瘤及致痫灶切除术,记录患者术后1周,术后1个月,术后3个月,术后6个月的Engle分级评分,其差别行组内重复测量资料的方差分析,应用Kaplan—Meier法制作痫性再发风险曲线,并对癫痫再次发作相关因素行Cox回归模型分析。结果术后癫痫再发率为26.97%(24/89),术后1周Engle分级评分为2.966±0.081,术后1月为2.202±0.080,术后3月为1.730±0.093,术后6月为1.313±0.042,差异存在统计学意义(F_(时间)=96.076,P0.01);Cox回归模型显示,肿瘤累及部位(RR=2.908,CI:1.083~7.806),术后水肿形成(RR=4.769,CI:1.737~13.096)以及肿瘤复发(RR=8.309,CI:3.379~20.432)是癫痫再次发作的重要危险因素(均P0.05)。结论术后患者的癫痫发作减少甚至消除,长期疗效优于短期疗效,对癫痫再次发作相关因素应尽早处理,有利于提高患者预后的生存质量。     

Predictors of seizure outcomes in patients with diffuse low-grade glioma-related epilepsy after complete glioma removal

Aims

We aimed to identify predictors of postoperative seizures in patients with diffuse low-grade glioma (DLGG)-related epilepsy after complete tumor resection in this study.

Methods

We retrospectively collected data from individuals with DLGG-related epilepsy whose tumors were completely resected at Xiangya Hospital, Central South University between January 2014 and January 2020. The predictors of seizure outcomes were assessed by employing univariate analysis and a multivariate logistic regression model in a backward binary logistic regression model.

Results

Among the 118 cases that met the inclusion criteria, 83.05% were seizure-free following an average follow-up of 4.27 ± 1.65 years, all of whom were classified as International League Against Epilepsy class I outcome. Univariate and multivariate analyses indicated that seizure duration of >6 years (odds ratio [OR], 6.62; 95% confidence interval [CI], 1.76–24.98; p = 0.005) and first clinical symptoms other than seizures (OR, 4.51; 95% CI, 1.43–14.23; p = 1.010) were both independent predictors of unfavorable seizure outcomes.

Conclusion

Our results imply that satisfactory seizure outcomes can be achieved in most patients with DLGG-related epilepsy after complete tumor resection. Patients with seizure duration of >6 years or first clinical symptoms other than seizures were more likely to experience postoperative seizure recurrence.     

Predictors of seizures during pregnancy in women with epilepsy

We aimed to characterize the seizure pattern during pregnancy in a large cohort of women with epilepsy (WWE) and identify possible predictors of seizure relapse during pregnancy. We recorded the antiepileptic drug (AED) use and seizure frequency for WWE during the prepregnancy month and pregnancy. The seizure profile was correlated with the clinical details and seizure type as abstracted from the clinical records maintained in the registry. Of the 1,297 pregnancies in WWE with complete seizure data, 47.8% were seizure-free during pregnancy. Seizure relapse was highest during the three peripartum days. Women with partial seizures-had higher risk of relapse (odds ratio [OR] 1.6, 95% confidence interval [CI] 1.2-2.0) than those with generalized seizures. They had two peaks of seizure relapse (second to third month and sixth month). Those with generalized seizures had one peak at first trimester. Those who were on polytherapy had increased risk of seizures (OR 2.98, 95% CI 2.3-3.9) when compared to those on monotherapy. Those who had seizures in the prepregnancy month had higher risk (OR 15, 95% CI 9-25.1) of seizures during pregnancy when compared to those who were seizure-free during that period. On multiple logistic regression, prepregnancy seizure was the most important predictor of seizures during pregnancy.