Seizure outcome of intractable partial epilepsy in children

The intractable partial epilepsy outcome information is important in determining not only when epilepsy surgery evaluation should begin but also in deciding who would benefit and what is the likelihood of any benefit from surgery. Medical records of 50 children diagnosed with nontumor-related partial seizures, confirmed by video-electroencephalography (video-EEG), had at least one seizure per week and were followed for at least 2 consecutive years after video-EEGs were reviewed. There were 30 patients who continued with antiepileptic drug treatment after video-EEG. The seizure outcome analysis revealed a significant improvement of seizure control in the first year of follow-up but no difference between the first year and the following 3 years. Only 30% had excellent long-term outcome (seizure free or less than one seizure per 6 months). The presence of focal lesions on neuroimaging was the only risk factor of poor outcome. The other 20 patients underwent epilepsy surgery after video-EEG; 60% attained excellent outcome despite the fact that 90% had focal neuroimaging abnormality. Children whose partial epilepsy remained intractable after 1 year of antiepileptic drug treatment should be evaluated for candidacy of epilepsy surgery, particularly those who have focal lesions on neuroimaging.     

Seizure outcome and hippocampal atrophy in familial mesial temporal lobe epilepsy

OBJECTIVE: To describe the clinical, genetic and MR characteristics of patients with familial mesial temporal lobe epilepsy (MTLE). DESIGN/METHODS: The familial occurrence of MTLE was identified by a systematic search of family history of seizures in patients followed in the authors' epilepsy clinic. All probands and, whenever possible, other affected family members underwent EEG and MR investigations. RESULTS: Twenty-two unrelated families with at least two individuals with MTLE were identified by clinical and EEG findings. Ninety-eight individuals with history of seizures were evaluated. Sixty-eight patients fulfilled the diagnostic criteria for MTLE. MRI was performed in 84 patients, and showed hippocampal atrophy with increased T2 signal in 48 (57%). The distribution of hippocampal atrophy according to the seizure outcome groups was 6 of 13 patients (46%) with seizure remission, 16 of 31 (51%) with good seizure control under medication, and all 16 patients with refractory MTLE. Hippocampal atrophy was found also in patients that did not fulfill the criteria for MTLE: 3 of 10 (30%) patients with febrile seizure alone, 6 of 10 (60%) patients with recurrent generalized tonic-clonic seizures, and 1 of 4 (25%) patients with a single partial seizure. CONCLUSION: Familial MTLE is a clinically heterogeneous syndrome. Hippocampal atrophy was observed in 57% of patients, including those with benign course or seizure remission, indicating that the relationship between hippocampal atrophy and severity of epilepsy might be more complex than previously suspected. In addition, these findings indicate the presence of a strong genetic component determining the development of mesial temporal sclerosis in these families.     

Seizure precipitants in children with intractable epilepsy

PURPOSE: To investigate the seizure precipitants in children with intractable epilepsy, and to determine any distinctive clinical features contributing to seizures in these patients. METHODS: A questionnaire and seizure diary prepared by the parents of the patients. Demographic and seizure data were reviewed. RESULTS: Of 120 patients with intractable epilepsy, 74 (62%) had one (n=43), two (n=23), or three seizure precipitants (n=8). The three most common precipitants were illness or fever (32%), sleep deprivation (13%), and menstruation (10%). Of these precipitants, inducing factors (endogenous origin) were more common than triggering factors (exogenous origin): 73% versus 27%, respectively. Three distinctive clinical features - neurological abnormalities (P=0.01), status epilepticus (P=0.017), and abnormal neuroimaging (P=0.007) - were significantly more common in patients with than in patients without precipitants. CONCLUSIONS: Prompt recognition and management of seizure precipitants has practical implications for treating patients with refractory epilepsy. Such patients can be counseled to avoid specific precipitants.     

Seizure outcome for surgery of extratemporal epilepsy

Over a 10-year period, 64 surgical operations were carried out on 55 patients suffering from refractory extratemporal epilepsy. Patient class outcome 3 years after the final surgical procedure showed that 9 patients (16%) were completely seizure free and 21 patients (38%) had less than a 50% reduction in seizure outcome. Corpus callosal section as a surgical procedure had the highest percentage (57%) of patients with a class 4 outcome. Corpus callosotomy as a final operation resulted in reduction in frequency and severity of ‘drop attacks’ in all patients. Gliosis without atrophy was the most common histopathology. There were no deaths as a result of surgery, although 4 patients died postsurgery; 2 died in status epilepticus. Multiple lobectomy was the most successful surgical procedure, with a Prognostic Index of 2.0, followed by 2.5 for extratemporal tumour resection. Corpus callosotomy and cystectomy had a Prognostic Index of 3.3 and 3.1, respectively.     

Multiple subpial transections in pediatric epilepsy: indications and outcomes

Objective Multiple subpial transection (MST) is a surgical technique mainly used when epileptiform activity arises from eloquent or functional brain cortex. In the medical literature, there are relatively few studies reporting the efficacy and safety of this procedure in adults and in children. We review the scientific rationale, the indications, and the results of this procedure.Methods Neuroanatomic studies show that the basic functional cortical unit is arranged vertically, and epileptic activity spreads horizontally. Minimal cortical unit is essential for maintenance of cortical activity. Vertical incisions in the cortex interrupt transverse synaptic connections, preventing seizure propagation while preserving the vertical column subserving neuronal function. In the past, it has been difficult to assess the efficacy of MSTs per se, as they have usually been performed together with cortical resection or lesionectomy. After MSTs, studies show that 33–46% of treated children are in Engel class I or II. The permanent complication rate is low with no permanent language or motor disabilities.Conclusions MST is a safe procedure with unclear specific efficacy. It has been used mainly in conjunction with cortical resection or lesionectomy, when the eloquent cortex is involved in the seizure activity. Further prospective studies are needed to define the role of MST in epilepsy surgery.     

Seizure prediction in patients with focal hippocampal epilepsy

Objective

We evaluated the performance of our previously developed seizure prediction approach on thirty eight seizures from ten patients with focal hippocampal epilepsy.

Seizure remission in adults with long-standing intractable epilepsy: an extended follow-up

Recent studies have provided much needed data on the probability of seizure remission among adults with chronic intractable epilepsy treated medically. Here we provide an extended follow-up to our earlier study in order to provide a more comprehensive picture of long-term prognosis in this patient population during medical treatment. The prevalence cohort was followed for two outcomes-complete seizure remission for ≥ 12 months and subsequent seizure relapse among those attaining a seizure remission. The study outcomes were estimated using Kaplan-Meier analysis. We found that the probability of attaining a ≥ 12 months of complete seizure freedom to be approximately 3-4% per year through 8 years of follow-up. By year 5 since the start of seizure remission, the cumulative probability of seizure relapse was 81%, although only half of the patients with seizure relapse went on to experience their previous seizure frequency.     

Multiple subpial transection for intractable partial epilepsy: an international meta-analysis

PURPOSE: Because the number and variety of patients at any single facility is not sufficient for clinical or statistical analysis, data from six major epilepsy centers that performed multiple subpial transections (MSTs) for medically intractable epilepsy were collected. METHODS: A meta-analysis was performed to elucidate the indications and outcome, and to assess the results of the procedure. Overall, 211 patients were represented with data regarding preoperative evaluation, procedures, seizure types and frequencies before and after surgery, postoperative deficits, and demographic information. Fifty-three patients underwent MST without resection. RESULTS: In patients with MST plus resection, excellent outcome (>95% reduction in seizure frequency) was obtained in 87% of patients for generalized seizures, 68% for complex partial seizures, and 68% for simple partial seizures. For the patients who underwent MST without resection, the rate of excellent outcome was only slightly lower, at 71% for generalized, 62% for complex partial, and 63% for simple partial seizures. EEG localization, age at epilepsy onset, duration of epilepsy, and location of MST were not significant predictors of outcome for any kinds of seizures after MST, with or without resection. New neurologic deficits were found in 47 patients overall, comparable in MST with resection (23%) or without (19%). CONCLUSIONS: These preliminary results suggest that MST has efficacy by itself, with minimal neurologic compromise, in cases in which resective surgery cannot be used to treat uncontrolled epilepsy. MST should be investigated as a stand-alone procedure to allow further development of criteria and predictive factors for outcome.     

Seizure remission and relapse in adults with intractable epilepsy: a cohort study

Purpose: To investigate the cumulative probabilities of ≥12 month seizure remission and seizure relapse following remission, and to test the associations of clinical characteristics with these two study end points in a prevalence cohort of intractable adult epilepsy patients during medical management.
Methods: A retrospective cohort study of intractable epilepsy patients seen in 2001 at a single center was conducted. Kaplan–Meier analysis was used to estimate the cumulative probabilities of seizure remission and subsequent seizure relapse. Cox proportional hazards models were used to estimate the association (1) between clinical factors and ≥12 month seizure remission and (2) between clinical factors and seizure relapse following remission.
Results: One hundred eighty-seven subjects met the eligibility criteria for intractable epilepsy. The estimate of probability of remission was about 4% per year. Seizure remission was temporary for some individuals, as 5 out of 20 subjects with remission ultimately relapsed. No clinical factors predicted the likelihood of achieving ≥12 month seizure remission or subsequent seizure relapse.
Discussion: Some people with intractable epilepsy achieve ≥12 month seizure remission during medical treatment. Remission, however, is only temporary for some individuals. We were unable to identify clear predictors for remission.     

Predicting outcome following reoperation for medically intractable epilepsy.

The purpose of this study was to determine predictors of probable outcome following reoperation for medically intractable partial epilepsy. We reviewed outcome at least 1 year after reoperation in 21 patients with intractable seizures, for whom an earlier operation had failed. We examined age of onset of epilepsy, duration of seizures, gender, details of the history and clinical examination, pre-operative magnetic resonance (MRI) findings, electroencephalographic (EEG) studies obtained before and after the failed surgery, presence or absence of lateralizing neuro-psychological deficits, sites of operation and pathology of resected tissue to identify the factors associated with outcome. We found two factors that were significantly related to outcome: (1) no individual with a history of central nervous system (CNS) infection which predated the onset of epilepsy had a seizure-free outcome after reoperation (P = 0.04). (2) Reoperations that extended previous resections, based on new ictal EEG recordings that were concordant with both EEG ictal onsets and MRI findings obtained before the first, failed surgery resulted in a seizure-free outcome or >95% reduction in seizures for 100% (7/7) of such patients. This compares to 29% (4/14) of the remaining individuals without such concordance who had a similar outcome (P = 0.009). Site of operation (temporal or extratemporal) did not, in and of itself, predict outcome. A portion of patients who fail surgery for intractable partial seizures will achieve significant improvement following reoperation. Furthermore, we may be able to identify those individuals most likely to have an excellent result from a second operation.     

Seizure outcome after extratemporal epilepsy surgery in childhood

Aim The aim of the study was to describe seizure outcome following surgery for focal extratemporal epilepsy and identify factors associated with prolonged postsurgical freedom from seizures. Method In this retrospective cohort study, children with drug‐resistant focal extratemporal epilepsy were treated surgically and followed up in a single tertiary care centre between 1997 and 2008. Results Eighty children were identified for inclusion in the study (42 males, 38 females; median age 9y 1mo, range 3mo–18y 7mo). The aetiology was identified as focal cortical dysplasia (n=37), low‐grade tumour (n=22), tuberous sclerosis (n=9), or non‐specific (n=12). Children were followed for a median of 3 years 1 month (range 8mo–10y 7mo) after surgery. Overall, at last follow‐up, 50% of the children had been completely seizure free since surgery (Engel class Ia); of these 40 individuals, 15 had discontinued all antiepileptic drugs. Several presurgical factors were associated with a favourable outcome. However, after controlling for confounding factors, aetiology appeared to be the only determinant of long‐term seizure outcome as non‐specific lesion pathology was associated with seizure recurrence (hazard ratio 10.43; 95% confidence interval 3.26–33.39). Interpretation In 50% of cases, children with surgically treated drug‐resistant extratemporal epilepsies have an excellent long‐term outcome. The aetiology of the epileptogenic lesion appears to be the only significant determinant of surgical outcome in this population of children. It is difficult to correctly identify non‐specific pathology on presurgical magnetic resonance imaging.     

Seizure outcome in patients with juvenile absence epilepsy

The purpose of this study was to identify seizure outcome and factors potentially predictive for seizure outcome in patients with juvenile absence epilepsy (JAE). In this case–control study all patients with JAE were recruited at the outpatient epilepsy clinic at Shiraz University of Medical Sciences from 2008 till 2012. All patients had to be under the care of the epileptologist for at least 18 months. We divided the patients into two groups: patients who were seizure free in the last 12 months of their follow-up period and those who had any seizures. During the study period, 2750 patients with epilepsy were registered at our epilepsy clinic; 641 patients (23.3 %) had idiopathic generalized epilepsy (IGE). Among patients with IGE, 81 patients (12.6 %) were diagnosed as having JAE and of these, 33 patients (20 women and 13 men) were eligible to enter into the study. Ten patients (30.3 %) were seizure free in the last 12 months of their follow-up and 23 (69.6 %) patients reported at least one seizure of any type. We could not identify any factor to be associated with seizure outcome in these patients. All studies in the literature suffer from small number of patients; so does our study. Besides, they used different methodologies. A large multicenter study is required to explore the variables that predict seizure outcome in patients with juvenile absence epilepsy. This is particularly needed to provide an appropriate counselling for patients and their families and also to formulate better individualized treatment plans for the patients.     

Progressive hippocampal atrophy in chronic intractable temporal lobe epilepsy

We report on a 28-year-old man with long-standing intractable complex partial and secondary generalized seizures, whose magnetic resonance imaging scans 4 years apart documented progressive decrease in the left hippocampal volume. Left anterior temporal lobectomy with amygdalohippocampectomy rendered the patient seizure free at 12 months' follow-up. The findings demonstrate that patients with uncontrolled temporal lobe seizures may develop progressive atrophy of the hippocampus, in the absence of status epilepticus.     

Predictors of seizure outcome after temporal lobectomy for intractable epilepsy

OBJECTIVES: To assess predictors of outcome of temporal lobectomy for intractable epilepsy. MATERIAL AND METHODS: In 63 adult patients operated with anterior temporal lobectomy during 198892, we used logistic regression analysis to assess predictors of being seizure-free (Engel's class I) 2 years after surgery. As potential predictors, we included the following variables: gender, age at operation, age at onset of seizures, epilepsy duration, etiology, generalized vs not generalized seizures, seizure frequency, intelligence quotient, ictal electroencephalography, magnetic resonance imaging (MRI), single-photon emission computed tomography (SPECT), side of resection, and extent of the resection. RESULTS: About 44% of the surgery patients were seizure-free (Engel's class I) 2 years after surgery. In multivariate analysis (n = 55), MRI pathology defined as atrophy in the temporal lobe, angioma, tumor or mesial temporal sclerosis (odds ratio, OR 7.4, 95%CI: 1.7-32.9) and extent of the hippocampal resection (increase of 1 cm) (OR 2.2, 95%CI: 1.1-4.6) predicted being seizure-free. CONCLUSION: Focal pathology in preoperative MRI and the extent of the hippocampal resection were the only significant predictors of being seizure-free after 2 years.     

Bilateral hippocampal stimulation for intractable temporal lobe epilepsy: Impact on seizures and memory

The effect of continuous electrical stimulation of the hippocampus bilaterally on seizures and memory was assessed in two subjects with seizures from both mesial temporal lobes who were not candidates for resective epilepsy surgery. A double blind, randomized, controlled, cross‐over trial design was utilized. Two electrodes with four contacts each were implanted along the axis of the hippocampus bilaterally. Simultaneous stimulation of all electrodes contacts was either on or off during each 3‐month interval. Seizure frequency decreased by 33% in the two patients during stimulation and remained lower by 25% for the 3 months after stimulation was turned off before returning to baseline (p < 0.01). No consistent change in objective or subjective measures of memory occurred. No other adverse effects occurred. Seizure frequency is reduced both during and for a period after bilateral hippocampal stimulation, but the overall impact in this study is not as robust as has been previously reported.     

Seizure control and educational outcome in childhood-onset epilepsy.

Patients with epilepsy are more prone to have learning disabilities. This study investigated the therapeutic and educational outcome of 102 epileptic children. Analyzed data included age at onset, etiology, presence of underlying brain lesions, seizure type, and electroencephalographic (EEG) patterns. Cryptogenic seizures, remote symptomatic seizures, and underlying brain lesions were found in 29, 26, and 14 patients, respectively, whereas 47 patients had idiopathic seizures. Eighty-three patients achieved seizure control (46 remained seizure free), and 19 patients remained poorly controlled. Sixty-five patients were in regular schools, and 37 required special education (17 with mental retardation). Predictors for poor seizure control were remote symptomatic seizures, underlying brain lesions, and (when grouped together) hypsarrhythmia and mixed EEG patterns (P < .001). Predictors for special education needs were young age at onset, remote symptomatic seizures, underlying brain lesions, hypsarrhythmia and mixed EEG patterns, and poor seizure control (P < .001). We conclude that in childhood epilepsy, the need for special education is substantial and more common than treatment failure.     

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.     

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.