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.     

Latency to first seizure after temporal lobectomy predicts long-term outcome

Purpose: Temporal lobectomy is a well‐established treatment for refractory temporal lobe epilepsy, yet many patients experience at least one seizure postoperatively. Little is known about the prognostic significance of the time from surgery to first seizure relapse in predicting long‐term outcome. Methods: In a retrospective analysis of patients who reported at least one complex partial seizure (CPS) or generalized tonic–clonic seizure (GTCS) after anterior temporal lobectomy (n = 268), we used a nominal response logistic model to predict the odds ratio (OR) of a seizure outcome based on length of the latency period from surgery to first postoperative seizure. A modified Engel outcome class scheme was used. We controlled for factors known to influence postoperative outcome, including history of tonic–clonic seizures, intelligence quotient (IQ), preoperative seizure frequency, magnetic resonance imaging (MRI) findings, and history of febrile convulsions. Results: In the univariate analysis, the latency from surgery to the first postoperative disabling seizure was significantly associated with long‐term outcome. Longer latency was associated with higher odds of being seizure‐free or improved (modified Engel’s classes 1, 2, and 3) relative to the unimproved state (class 4) (p < 0.001, 0.001 and 0.004, respectively). Conversely, a shorter latency increased the likelihood of achieving the worst prognosis (class 4) relative to class 1 (p < 0.001). Multivariate analysis yielded similar results. Discussion: Latency to the first postoperative seizure predicts long‐term outcome, with short latencies portending poor prognosis and long latencies portending a good prognosis. This information can be used for patient counseling and may influence decisions regarding reoperation.     

Acute postoperative seizures after epilepsy surgery – a long‐term outcome predictor?

Alfstad KÅ, Lossius MI, Røste GK, Mowinckel P, Scheie D, Borota OC, Larsson PG, Nakken KO. Acute postoperative seizures after epilepsy surgery – a long‐term outcome predictor?
Acta Neurol Scand: 2011: 123: 48–53.
© 2010 The Authors Journal compilation © 2010 Blackwell Munksgaard. Objectives – The prognostic value of acute postoperative seizures (APS) after epilepsy surgery is much debated. This study evaluated APS, defined as seizures in the first week post‐surgery, as a predictor of long‐term seizure outcome, and investigated the utility of other potential outcome predictors. Materials and methods – Medical records of 48 patients with temporal and extra‐temporal epilepsy surgery were studied. Forty patients had lesional surgery. All had at least 2 year postoperative follow‐up. Results – At 2 year follow‐up, 25 patients (53%) were seizure free. Univariate analysis showed that APS (P = 0.048), using ≥six AEDs prior to surgery (P = 0.03), pathological postoperative EEG (P = 0.043) and female gender (P = 0.012) were associated with seizure recurrence. Conclusions – Univariate analysis indicate that APS, a high number of AEDs used prior to surgery, and pathological postoperative EEG are possible predictors of seizure recurrence after epilepsy surgery. Only gender retained significance in the multivariate analysis.     

Predicting seizure frequency after epilepsy surgery

OBJECTIVE: To identify clinical features related to seizure frequency after epilepsy surgery in patients with recurrent seizures. BACKGROUND: No studies have examined the differences between patients who have rare seizures and patients who experience frequent seizures after epilepsy surgery. Since seizure frequency correlates with morbidity and quality of life, it is desirable to know which preoperative clinical features predict postoperative seizure frequency. METHODS: Patients with recurrent seizures were placed in two categories: rare postoperative seizures (< or =2 per year) and frequent postoperative seizures (> or =12 per year) using seizure frequency in the second postoperative year. Variables included preoperative seizure frequency, age of first risk, age at first seizure, epilepsy duration, age at surgery, history of febrile convulsions, tonic-clonic seizures, status epilepticus, or family history, IQ, magnetic resonance imaging (MRI), and positron emission tomography (PET). Variables were analyzed using non-parametric tests to assess relationship to postoperative seizure frequency. RESULTS: Of 475 patients who had epilepsy surgery, 111 had rare or frequent seizures in the second postoperative year. After anterior temporal lobectomy (ATL), age of first risk< or =5 years and presence of mesial temporal sclerosis on MRI were associated with rare seizures (66% of patients), whereas lack of these risk factors was associated with frequent seizures (75% of patients) (p<0.03). For non-ATL operations, preoperative seizure frequency of > or =20 seizures per month was associated with frequent postoperative seizures (p=0.03). No other variables influenced outcome. CONCLUSIONS: Some preoperative clinical features correlate with postoperative seizure frequency in patients with recurrent seizures after epilepsy surgery. This has implications for the surgical decision making process and early postoperative management.     

Predictors for long-term seizure outcome in juvenile myoclonic epilepsy: 25-63 years of follow-up

Purpose: The long‐term seizure outcome of juvenile myoclonic epilepsy (JME) is still controversial; the value of factors that are potentially predictive for seizure outcome remains unclear. The aim of this study was both to investigate the long‐term seizure outcome in patients with JME after a follow‐up of at least 25 years and to identify factors that are predictive for the seizure outcome. Methods: Data from 31 patients (19 women) with JME were studied. All of them had a follow‐up of at least 25 years (mean 39.1 years) and were reevaluated with a review of their medical records and direct telephone or face‐to‐face interview. Key Findings: Of 31 patients 21 (67.7%) became seizure‐free; in six of them (28.6%) antiepileptic drug (AED) treatment was discontinued due to seizure freedom. The occurrence of generalized tonic–clonic seizures (GTCS) preceded by bilateral myoclonic seizures (BMS) (p = 0.03), a long duration of epilepsy with unsuccessful treatment (p = 0.022), and AED polytherapy (p = 0.023) were identified as significant predictors for a poor long‐term seizure outcome, whereas complete remission of GTCS under AED significantly increased the chance for complete seizure freedom (p = 0.012). The occurrence of photoparoxysmal responses significantly increases the risk of seizure recurrence after AED discontinuation (p = 0.05). Significance: This study shows conclusively that JME is a heterogeneous epilepsy syndrome. Life‐long AED treatment is not necessarily required to maintain seizure freedom. Several long‐term outcome predictors that can potentially increase the ability of clinicians and their confidence to recommend different treatment options to patients with JME were identified.     

Late seizures in patients initially seizure free after epilepsy surgery

PURPOSE: Surgery for medically intractable epilepsy is currently the most effective means of achieving seizure control. Although relatively few long-term outcome studies have been performed, evidence is mounting that the possibility of late seizure recurrence exists, even after an early seizure-free period. No published reports document the rate and predictors of late recurrence in a large series of patients undergoing surgery in the magnetic resonance imaging (MRI) era. METHODS: We retrospectively queried the databases of two epilepsy surgery centers. Patients eligible for study had preoperative MRI scans, were seizure free for 1 year after surgery, and had a minimal follow-up period of 3 years. Patients with tumors or vascular lesions were excluded. We performed log-rank comparison of Kaplan-Meier product limit estimates for categoric variables and used a Cox proportional hazards model for continuous variables. Variables that were significant (p<0.05) on a univariate screen were entered into a multivariate forward step-wise Cox regression. RESULTS: The study included 285 patients, 254 with medial temporal lobe (MTLE) and 31 with neocortical epilepsy. The probability of having a single seizure after being seizure free for 1 year was 18.3% at 5 years and 32.7% at 10 years. However, only 13% were not seizure free at the last follow-up. Predictors of late recurrences on both uni- and multivariate analysis were the presence of preoperative generalized tonic-clonic (GTC) seizures in patients with neocortical epilepsy and late age at surgery in patients with MTLE. MRI results and location of surgery were not predictive. CONCLUSIONS: Although the risk of at least one recurrent seizure after initially successful epilepsy surgery is relatively high, the rate of recurrent intractability is low. The finding that late age at surgery and presence of preoperative GTC seizures are predictors of late recurrence indicates the importance of patient selection and early surgery for persistent seizure control.     

Outcome of frontal lobe epilepsy surgery

Purpose: There is still controversy in deciding which patients with frontal lobe epilepsy (FLE) should undergo resective surgery, even though it is a well‐established therapy. The aim of this study is to define multiple outcome measures and determine whether there are certain subpopulations of preferred surgical candidates that have a more favorable seizure prognosis. Methods: Fifty‐eight patients underwent resective FLE surgery with a mean follow‐up period of 79.3 months (range 12–208 months). Patient demographics, clinical seizure characteristics, seizure‐onset zone within the frontal lobes, and diagnostic tests were tabulated. Engel class, International League Against Epilepsy (ILAE) class, postoperative seizure patterns, time to first recurrent seizure, and seizures and employment during the last year of follow‐up were used as outcome measures. Neuropsychological performance and Beck Depression Inventory (BDI) scores were used to define neuropsychological outcome and examined as predictors of seizure outcome. Key Findings: Thirty‐three (57%) patients with resective surgery had an Engel class I outcome and 29 (50%) had an ILAE class I outcome. Mean time to first seizure after surgery was 33.3 months (range 0–208). Only 14 patients (24%) were completely seizure‐free without auras (Engel IA) throughout the entire follow‐up period. The most common pattern of seizure recurrence was mixed, with prolonged periods of seizure freedom intermixed with recurrences. In addition, 32% of patients made gains in employment and 52% were able to reduce use of antiepileptic drugs (AEDs), although only 9% discontinued AEDs. No significant association was found between class I or class IA outcome and the presence of a focal magnetic resonance imaging (MRI) abnormality, any specific localization of seizure focus within the frontal lobe, or neuropsychological change. Significance: Findings indicate that that long‐term outcome is generally favorable in FLE resective surgery, and support the need for considering multiple outcome measures to more fully characterize clinically relevant postsurgical changes. Outcome can be favorable even in MRI‐negative patients.     

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.     

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.     

Periictal heart rate variability analysis suggests long‐term postictal autonomic disturbance in epilepsy

Background: One of the possible pathomechanisms of sudden death in epilepsy (SUDEP) is a postictal dysregulation of autonomic nervous system. We performed a heart rate variability (HRV) analysis of the periictal state to analyze whether a cardiac autonomic disturbance exists after an epileptic seizure. Methods: We included 31 periictal video–EEG–ECG recordings of 31 patients with epilepsy who had consecutively undergone pre‐surgical evaluation. Nine generalized tonic‐clonic (GTCS), 15 complex partial, and seven simple motor seizures were included. HRV was evaluated by analyzing 5‐min‐long ECG epochs, sampling from baseline, direct preictal, early‐postictal (<15 min after the seizure), and late‐postictal (5–6 h after the seizure) periods. Results: The heart rate was elevated immediately after the seizures, but 5–6 h postictally returned to the baseline level. Time‐domain components of HRV decreased after the seizure and this decrease lasted for 5–6 h. Low‐frequency power decreased in the early‐postictal phase and high‐frequency power of HRV dropped in the late‐postictal phase. GTCS had an impact on short‐term but not on long‐term postictal HRV decrease. Conclusions: We found decreased HRV immediately after the seizures, which lasted at least 5–6 h postictally, indicating a long‐term postictal disturbance of the autonomous nervous system. GTCS were accompanied by a more decreased HRV than other seizures. Our results may have relevance in explaining pathomechanism of SUDEP.     

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.     

Long-term seizure outcome and risk factors for recurrence after extratemporal epilepsy surgery

Purpose: We aimed to assess long‐term seizure outcome and risk factors for seizure recurrence in a cohort of patients who have undergone extratemporal resection for management of refractory seizures. Methods: Eighty‐one patients underwent extratemporal resection at Austin Health, Melbourne, Australia (1991–2004). Seizure recurrence was any postoperative disabling seizure (complex partial seizure [CPS] ± secondary generalization). Multivariate Cox proportional hazards regression models examined potential preoperative and perioperative risk factors and the risk associated with early postoperative seizures (≤28 days postsurgery). The change between preoperative and postoperative seizure frequency was also measured. Key Findings: Median follow‐up was 10.3 years (range 1–17.7). The probabilities of freedom from disabling seizures (on or off antiepileptic medication) were 40.7% (95% confidence interval [CI] 30–51) at 1 month, 23.5% (95% CI 15–33) at 1 year, and 14.7% (95% CI 8–23) at 5 years postoperative. Reduction of disabling seizures to at least 20% of preoperative frequency was attained by 57% of patients at 5 postoperative years. Of the preoperative/perioperative factors, focal cortical dysplasia (FCD) type 1 (hazard ratio [HR] 1.90, 95% CI 1.08–3.34, p = 0.025) and incomplete resection (HR 1.71, 95% CI 1.06–2.76, p = 0.028) were independent recurrence risks. After surgery, an early postoperative seizure was the only factor associated with higher risk (HR 4.28 [2.42–7.57], p = 0.00). Significance: Distinction between subtypes of focal cortical dysplasia, which can be made using magnetic resonance imaging (MRI) criteria, may be useful for preoperative prognostication. Early seizures after surgery are not benign and may be markers of factors that contribute to seizure recurrence. Most patients achieve substantial reduction in seizure frequency. Further study of the significance of this reduction in terms of surgical “success” or otherwise is required.     

A longitudinal study of surgical outcome and its determinants following posterior cortex epilepsy surgery

Purpose:   To investigate the longitudinal seizure outcome and identify potential prognostic indicators following posterior cortex epilepsy (PCE) surgery.
Methods:   We reviewed patients who underwent a parietal, occipital, or parietooccipital resections between 1994 and 2006, using survival analysis and multivariate regression with Cox proportional hazard modeling. A favorable outcome was defined as Engel Class I at last follow-up.
Results:   Fifty-seven patients were identified with a mean follow-up of 3.3 years (range 1–12 years). The estimated chance of seizure freedom (SF) was 73.1% at 6 postoperative months, 68.5% at 1 year, 65.8% at between 2 and 5 years, and 54.8% at 6 years and beyond. Most recurrences (75%) occurred within the first 6 postoperative months. Parietal resections had a worse outcome than occipital or parietooccipital resections (52% SF vs. 89% and 93%, respectively, at 5 years). Independent predictors of recurrence included an epilepsy etiology other than tumor or dysplasia [risk ratio (RR) 2.29], limiting resection to a lesionectomy (RR 2.10), having ipsilateral temporal spiking on preoperative scalp electroencephalography (EEG) (RR 2.06), or any ipsilateral spiking on postoperative EEG (RR 2.70) (Log likelihood-ratio test p < 0.0001). Only 40–50% of patients with a poor outcome predictor were SF at 5 postoperative years as opposed to about 80% otherwise. In surgical failures, recurrent seizure frequency was related directly to baseline seizure frequency and to the presence of ipsilateral spiking on postoperative EEG.
Discussion:   These data highlight favorable long-term outcomes following PCE surgery. Limited surgical resection and diffuse baseline epileptogenicity may be important predictors of seizure recurrence.     

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.     

Impact of epilepsy surgery on seizure control and quality of life: a 26-year follow-up study

Purpose: The short‐term efficacy and safety of epilepsy surgery relative to medical therapy has been established, but it remains underutilized. There is a lack of data regarding the long‐term seizure‐control rates and quality of life outcomes after epilepsy surgery. This study represents the longest follow‐up study to date, with a mean follow‐up duration of 26 years. Methods: We studied the seizure and health‐related quality of life outcomes of patients who underwent epilepsy surgery by Dr. Sidney Goldring from 1967 to 1990. Retrospective clinical chart reviews gathered perioperative data and surveys obtained follow‐up data. Seizure outcome was evaluated using the Engel classification system. Key Findings: Of 361 patients, 117 (32.4%) completed follow‐up interviews. Fifty‐six patients (48%) were Engel class I. Mean overall Quality of Life in Epilepsy (QOLIE‐31) questionnaire score for the cohort was 68.2 ± 16. Eighty percent of patients reported their overall quality of life now as being better than before surgery. Seizure freedom was associated with better quality of life. We did not observe a statistically significant association between postoperative complications and long‐term outcome. Patients who underwent temporal lobe resection achieved better seizure outcomes than those who underwent other types of procedures. Astatic seizures and bilateral surgery were associated with a worse Engel class outcome. Significance: Our study demonstrates that the beneficial effects of epilepsy surgery are sustained over decades, and that these beneficial effects are correlated with an improved quality of life. The confirmation of its durability makes us optimistic that the outcomes from modern epilepsy surgery will be even better and that our present enthusiasm for this treatment modality is not misplaced.     

Dacrystic seizures: Demographic,semiologic, and etiologic insights from a multicenter study in long‐term video‐EEG monitoring units

Purpose: To provide an estimate of the frequency of dacrystic seizures in video‐electroencephalography (EEG) long‐term monitoring units of tertiary referral epilepsy centers and to describe the clinical presentation of dacrystic seizures in relationship to the underlying etiology. Methods: We screened clinical records and video‐EEG reports for the diagnosis of dacrystic seizures of all patients admitted for video‐EEG long‐term monitoring at five epilepsy referral centers in the United States and Germany. Patients with a potential diagnosis of dacrystic seizures were identified, and their clinical charts and video‐EEG recordings were reviewed. We included only patients with: (1) stereotyped lacrimation, sobbing, grimacing, yelling, or sad facial expression; (2) long‐term video‐EEG recordings (at least 12 h); and (3) at least one brain magnetic resonance imaging (MRI) study. Key Findings: Nine patients (four female) with dacrystic seizures were identified. Dacrystic seizures were identified in 0.06–0.53% of the patients admitted for long‐term video‐EEG monitoring depending on the specific center. Considering our study population as a whole, the frequency was 0.13%. The presence of dacrystic seizures without other accompanying clinical features was found in only one patient. Gelastic seizures accompanied dacrystic seizures in five cases, and a hypothalamic hamartoma was found in all of these five patients. The underlying etiology in the four patients with dacrystic seizures without gelastic seizures was left mesial temporal sclerosis (three patients) and a frontal glioblastoma (one patient). All patients had a difficult‐to‐control epilepsy as demonstrated by the following: (1) at least three different antiepileptic drugs were tried in each patient, (2) epilepsy was well controlled with antiepileptic drugs in only two patients, (3) six patients were considered for epilepsy surgery and three of them underwent a surgical/radiosurgical or radioablative procedure. Regarding outcome, antiepileptic drugs alone achieved seizure freedom in two patients and did not change seizure frequency in another patient. Radiosurgery led to moderately good seizure control in one patient and did not improve seizure control in another patient. Three patients were or are being considered for epilepsy surgery on last follow‐up. One patient remains seizure free 3 years after epilepsy surgery. Significance: Dacrystic seizures are a rare but clinically relevant finding during video‐EEG monitoring. Our data show that when the patient has dacrystic and gelastic seizures, the cause is a hypothalamic hamartoma. In contrast, when dacrystic seizures are not accompanied by gelastic seizures the underlying lesion is most commonly located in the temporal cortex.     

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.     

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.     

Temporal pattern of oxcarbazepine and phenytoin withdrawal seizures during epilepsy monitoring

PURPOSE: To compare the temporal pattern of seizures after acute withdrawal of oxcarbazepine (OXC) and phenytoin (PHT) in the epilepsy monitoring unit (EMU). METHODS: We identified all epilepsy patients admitted to our EMU on OXC or PHT monotherapy, over a period of 5 years. The OXC taper usually occurred over 2 days while PHT was abruptly discontinued on admission day. For each patient, we recorded the number and type of seizures for each EMU day. We used Poisson regression models to estimate daily seizure frequency separately for complex partial seizures (CPSs) and generalized tonic-clonic seizures (GTCSs). RESULTS: Forty patients were admitted on OXC and 32 on PHT monotherapy. The temporal distribution of seizures varied between the two groups. The first GTCS was more likely to occur in the first 2 days of monitoring for the OXC group (p<0.046). There was a higher frequency of GTCS on day 2 of admission in the OXC group (p=0.011). The groups did not differ in the pattern of CPS. CONCLUSIONS: OXC is disproportionately associated with increased GTCS in the first 2 days after acute withdrawal. The early peak of GTCS favors a rebound phenomenon in addition to loss of therapeutic effect.