Natural history of treated childhood-onset epilepsy: prospective, long-term population-based study

Long-term outcome of medically treated epilepsy

PURPOSE

To review the long-term outcome of epilepsy in population-based studies.

METHOD

Analysis of population-based studies.

RESULTS

About two of three patients with new-onset epilepsy will, in the long run, enter five-year terminal remission. Chances for remission are best for those with idiopathic or cryptogenic epilepsy. It is unclear whether the seizure outcome has improved over the last several decades. Social outcome, however, may have become better because of the improved level of knowledge on and public attitudes toward people with epilepsy, and possibly fewer prejudices at home, daycare, school, military and labor market.

CONCLUSION

While we still do not have a cure for epilepsy for all patients, relief of the medical and social consequences is available for many and hope is on the horizon for people with epilepsy.

Outcome of seizures in the general population after 25 years: a prospective follow-up, observational cohort study

OBJECTIVES

We investigated long-term (to 25 years) seizure prognosis and survival in people with newly diagnosed epilepsy in the community. We explored whether prognosis is different in those with epilepsy (>2 unprovoked seizures) and those with a single seizure at presentation.

METHODS

This is a prospective observational cohort study of people with newly diagnosed seizures. We investigated seizure outcome and survival in people presenting with a single seizure and in those presenting with >2 seizures (epilepsy).

RESULTS

695 people (median follow-up 23.6 years) had unprovoked epileptic seizures. For seizure analysis we excluded 38 people with missing data leaving 657 (309 male, and 249 aged <18 years). Seizures recurred in 67%. The 354 people with epilepsy were only slightly more likely to have further seizure recurrence than the 302 people with a single seizure at presentation (HR 1.32, 95% CI 1.09 to 1.59). In 327 people with complete follow-up, 268 (82%, 95% CI 77% to 86%) were in terminal remission; (80%, (95% CI 73% to 85%) in those with epilepsy at presentation). Premature mortality was increased in people with epilepsy (standardised mortality ratio 1.67; 95% CI 1.40 to 1.99) and those with a single seizure at presentation (standardised mortality ratio 2.65; 95% CI 2.23 to 3.15). It is also high in those with early remission.

CONCLUSIONS

People with epilepsy and with single seizures at presentation in the community generally have good prognosis for seizure control with prolonged follow-up. The risk of premature mortality is significantly increased in both groups.

Cognitive and behavioral impact of the ketogenic diet in children and adolescents with refractory epilepsy: A randomized controlled trial

PURPOSE

The ketogenic diet (KD) is increasingly used for the treatment of refractory epilepsy in childhood because of the beneficial effect on seizure reduction. The aim of the current study was to objectively assess cognition and aspects of behavior during the first 4months of a randomized controlled study in children and adolescents.

METHODS

Participants from a tertiary epilepsy center were randomized to a KD group (intervention) or a care-as-usual (CAU) group (control). Follow-up assessments on cognition and behavior were performed approximately 4months after initiation of the KD with a combination of parent report questionnaires and individually administered psychological tests for the children.

RESULTS

A total of 50 patients were enrolled in this study, 28 patients from the KD group and 22 patients from the CAU group. The KD group showed lower levels of anxious and mood-disturbed behavior and was rated as more productive. Cognitive test results showed an improvement of activation in the KD group.

CONCLUSIONS

This study showed a positive impact of the KD on behavioral and cognitive functioning in children and adolescents with refractory epilepsy. More specifically, an activated mood and cognitive activation were observed in patients treated with the KD.

Drug-resistant epilepsy in adults: Outcome trajectories after failure of two medications

OBJECTIVE

To examine the seizure trajectories of adults with epilepsy developing drug-resistant epilepsy (DRE) and to identify the predictors of seizure trajectory outcome.

METHODS

Adult patients failing two antiepileptic drugs (AEDs) due to inefficacy and starting their third AED at a tertiary epilepsy center were followed for seizure trajectory outcome during medical management. Seizure trajectories were categorized into one of four patterns: (1) course with constant seizures; (2) fluctuating course; (3) delayed attainment of seizure freedom (seizure freedom delayed for >12 months after start of the study, but patient stayed in seizure freedom); and (4) early attainment of seizure freedom (within 12 months of starting study). Multiple ordinal logistic regression models were used to estimate the association between trajectory categories and clinical factors.

RESULTS

Four hundred three adult patients met the eligibility criteria. Of these, 212 (53%) never achieved a seizure-free period of a year or more. The trajectories of 63 patients (16%) had a complex fluctuating trajectory, 62 (15%) had delayed onset of seizure freedom, and 66 (16%) had an early seizure freedom. Independent predictors associated with more favorable outcome trajectories were epilepsy type and length of follow-up. Specifically, compared to patients with focal epilepsy of temporal lobe, patients with focal epilepsy of occipital lobe (OR 3.80, 95% confidence interval [CI] 1.00-14.51, p = 0.04), generalized genetic (OR 3.23, 95% CI 1.88-5.57, p < 0.0001), unclear epilepsy type (OR 3.82, 95% CI 1.53-9.52, p < 0.005), and both focal and generalized epilepsy(OR 11.73, 95% CI 1.69-81.34, p = 0.01) were significantly more likely to experience a better trajectory pattern.

SIGNIFICANCE

Examination of patterns of seizure trajectory of patients with incident DRE showed that 31% were in continuous seizure freedom at the end of the observation period.

Estimating Epilepsy Incidence and Prevalence in the US Pediatric Population Using Nationwide Health Insurance Claims Data

This study aims to determine prevalence and incidence of epilepsy in the US pediatric population. We analyzed commercial claims and Medicaid insurance claims data between 2008 and 2012. Over 8 million continuously enrolled lives aged 0 to 19 years were included. Our definition of a prevalent case of epilepsy was based on International Classification of Diseases-coded diagnoses of epilepsy or seizures and evidence of prescribed antiepileptic drugs. Incident cases were identified in subjects continuously enrolled for ≥2 years of which the first 2 years had no indication of epilepsy or seizures. The overall prevalence estimate for 2012 was 6.8 per 1,000 children. The overall incidence estimate for 2012 was 104 per 100,000 pediatric population. This study provides estimates of the prevalence and incidence of epilepsy in the US pediatric population, using large claims datasets from multiple US population sectors. The findings appear reasonably representative of the US-insured pediatric population.

Factors predictive of late remission in a cohort of Chinese patients with newly diagnosed epilepsy

PURPOSE

Limited data have focused on predictive factors of late remission in patients with newly diagnosed epilepsy. We are aiming to identify prognostic predictors of late remission in a prospective cohort of Chinese patients.

METHODS

Patients with newly diagnosed epilepsy were included from 2009 to September 2012 at a tertiary hospital, with follow-up of at least two years. Early remission was defined by seizure free either immediately or within six months of treatment initiation, late remission was defined by seizure free achieved after more than six months. All analyses were performed with SPSS 13.0 software.

RESULTS

A total of 223 patients were included, and followed for an average of 43 months. 115 patients (51.6%) achieved early remission and 39 patients (17.5%) achieved late remission. Multivariable logistic regression analysis demonstrated more than 3 seizures prior to treatment (OR=3.12, 95% CI 1.39-7.04, p=0.006) and multiple seizure types (OR=2.49, 95% CI 1.02-6.11, p=0.046) may predict late remission. However, nonadherence was not significantly associated with late remission.

CONCLUSION

Patients with a high frequency of seizures prior to treatment or multiple seizure types may achieve late remission. Particular consideration should be given to these patients.

Response to placebo in clinical epilepsy trials--Old ideas and new insights

Randomized placebo-controlled trials are a mainstay of modern clinical epilepsy research; the success or failure of innovative therapies depends on proving superiority to a placebo. Consequently, understanding what drives response to placebo (including the "placebo effect") may facilitate evaluation of new therapies. In this review, part one will explore observations about placebos specific to epilepsy, including the relatively higher placebo response in children, apparent increase in placebo response over the past several decades, geographic variation in placebo effect, relationship to baseline epilepsy characteristics, influence of nocebo on clinical trials, the possible increase in (SUDEP) in placebo arms of trials, and patterns that placebo responses appear to follow in individual patients. Part two will discuss the principal causes of placebo responses, including regression to the mean, anticipation, classical conditioning, the Hawthorne effect, expectations from symbols, and the natural history of disease. Included in part two will be a brief overview of recent advances using simulations from large datasets that have afforded new insights into causes of epilepsy-related placebo responses. In part three, new developments in study design will be explored, including sequential parallel comparison, two-way enriched design, time to pre-randomization, delayed start, and cohort reduction techniques.

A population-based study of active and drug-resistant epilepsies in Northern Italy

Drug-resistant epilepsy (DRE) is defined by the International League Against Epilepsy as a failure of adequate trials of two tolerated, appropriately chosen, and used antiepileptic drugs to achieve sustained seizure freedom. Our aim was to calculate the following: (1) the prevalence of active epilepsy and DRE in a well-defined population of Northern Italy and (2) the proportion of incident cases developing DRE. The study population (146,506; year 2008) resided in the province of Lecco, Northern Italy. The medical records of 123 general practitioners were reviewed to identify patients with epilepsy, diagnosed by a neurologist during the period 2000-2008. The point prevalence of active epilepsy and DRE was calculated on December 31, 2008. A total of 747 prevalent patients with epilepsy, 684 patients with active epilepsy, and 342 incident cases were identified. The frequency of DRE was 15.6% (107/684) of all active epilepsies and 10.5% (36/342) of incident cases. The point prevalence was 0.73 per 1000. The standardized prevalence of DRE was 0.7 per 1000 (Italian population) and 0.8 per 1000 (world population). Our data indicate that 1/6 patients with active epilepsy in the general population has DRE, and 1/10 patients with newly diagnosed epilepsy will develop DRE within nine years from the diagnosis.

Prognostic factors of drug-resistant epilepsy in childhood: An Italian study

BACKGROUND

Epilepsy is drug resistant in 30-40% of cases. We studied, retrospectively, the prognostic factors of drug resistance (DR) during a 15 year period, in an Italian sample of patients with childhood epilepsy.

METHODS

A total of 117 patients were divided into two groups: one with DR, and the other without DR. The two groups were compared at the following time points: epilepsy onset (T0), and at 2, 5, 8 and 10 years after seizure onset (T2, T5, T8 and T10, respectively) using Fisher's exact test and randomization test. Multiple logistic regression analysis was then used to identify the most reliable predictive model of DR.

RESULTS

Positive neurological examination at onset, symptomatic/probable symptomatic etiology, lack of response to the first drug, seizure clustering during follow up, intelligence quotient ≤ 70, altered neuropsychological examination at onset, and presence of cerebral lesions were predominant in cases of DR. The most reliable combinations of predictors of DR included partial or no response to the first drug, presence of seizure clustering during follow up, altered neurological examination at onset, and long latency between epilepsy onset and first drug at T2; partial or absent response to the first drug and positive magnetic resonance imaging (MRI) at T5; positive MRI and absence of generalized seizures at T8; and positive MRI at T10. DR also sometimes appeared after discontinuation of an effective therapy.

CONCLUSIONS

Predictive factors of DR can be recognized in a large number of patients with epilepsy at disease onset, although the current possibility of predicting epilepsy outcome remains limited. In the long term, evidence of cerebral lesions appears to become the most significant prognostic factor.

Clinical Applications of Simultaneous PET/MR Imaging Using (R)-[11C]-Verapamil with Cyclosporin A: Preliminary Results on a Surrogate Marker of Drug-Resistant Epilepsy

BACKGROUND AND PURPOSE

The development of resistance to antiepileptic drugs is explained well by the transporter hypothesis, which suggests that drug resistance is caused by inadequate penetration of drugs into the brain barrier as a result of increased levels of efflux transporter such as p-glycoprotein. To evaluate the brain expression of p-glycoprotein in patients with drug-resistant epilepsy, including neocortical epilepsy, we developed a noninvsive quantitative analysis including asymmetry indices based on (R)-[(11)C]-verapamil PET/MR imaging with cyclosporin A, a p-glycoprotein inhibitor.

MATERIALS AND METHODS

Six patients with drug-resistant epilepsy, 5 patients with drug-sensitive epilepsy, and 8 healthy controls underwent dynamic (R)-[(11)C]-verapamil PET/MR imaging with an intravenous infusion of cyclosporin A. Asymmetry indices [(Right Region - Left Region)/(Right Region + Left Region) × 200%] of the standard uptake values in each of the paired lobes were calculated.

RESULTS

All patients with drug-resistant epilepsy had significantly different asymmetry from the healthy controls, whereas all patients with drug-sensitive epilepsy had asymmetry similar to that in healthy controls. In the temporal lobe, the asymmetry indices of patients with left temporal lobe drug-resistant epilepsy were more positive than those of healthy controls (healthy controls: 4.0413 ± 1.7452; patients: 7.2184 ± 1.8237; P = .048), and those of patients with right temporal drug-resistant epilepsy were more negative (patients: -1.6496 ± 3.4136; P = .044). In addition, specific regions that had significant asymmetry were different between the lateral and medial temporal lobe epilepsy groups. In the frontal lobe, the asymmetry index of patients with right frontal lobe drug-resistant epilepsy was more negative than that in healthy controls.

CONCLUSIONS

We confirmed that statistical parametric mapping analysis by using asymmetry indices of (R)-[(11)C]-verapamil PET/MR imaging with cyclosporin A could be used as a surrogate marker for drug-resistant epilepsy, and this approach might be helpful for localizing or lateralizing the epileptic zone.

Elemental changes in the hippocampal formation following two different formulas of ketogenic diet: an X-ray fluorescence microscopy study

The main purpose of the following study was the determination of elemental changes occurring within hippocampal formation as a result of high-fat and carbohydrate-restricted ketogenic diet (KD). To realize it, X-ray fluorescence microscopy was applied for topographic and quantitative analysis of P, S, K, Ca, Fe, Cu, Zn and Se in hippocampal formations taken from rats fed with two different KDs and naive controls. The detailed comparisons were done for sectors 1 and 3 of the Ammon's, the dentate gyrus and hilus of dentate gyrus. The results of elemental analysis showed that the KDs induced statistically significant changes in the accumulation of P, K, Ca, Zn and Se in particular areas of hippocampal formation and these alterations strongly depended on the composition of the diets. Much greater influence on the hippocampal areal densities of examined elements was found for the KD which was characterized by a lower content of carbohydrates, higher content of fats and increased proportion of unsaturated fatty acids. The levels of P, K and Zn decreased whilst those of Ca and Se increased as a result of the treatment with the KDs.

Patterns of seizure control in patients with mesial temporal lobe epilepsy with and without hippocampus sclerosis

OBJECTIVE

Patients with mesial temporal lobe epilepsy (MTLE) may present unstable pattern of seizures. We aimed to evaluate the occurrence of relapse-remitting seizures in MTLE with (MTLE-HS) and without (MTLE-NL) hippocampal sclerosis.

METHOD

We evaluated 172 patients with MTLE-HS (122) or MTLE-NL (50). Relapse-remitting pattern was defined as periods longer than two years of seizure-freedom intercalated with seizure recurrence. "Infrequent seizures" was considered as up to three seizures per year and "frequent seizures" as any period of seizures higher than that.

RESULTS

Thirty-seven (30%) MTLE-HS and 18 (36%) MTLE-NL patients had relapse-remitting pattern (X2, p = 0.470). This was more common in those with infrequent seizures (X2, p < 0.001). Twelve MTLE-HS and one MTLE-NL patients had prolonged seizure remission between the first and second decade of life (X2, p = 0.06).

CONCLUSION

Similar proportion of MTLE-HS or MTLE-NL patients present relapse-remitting seizures and this occurs more often in those with infrequent seizures.

Intraoperative computed tomography for intracranial electrode implantation surgery in medically refractory epilepsy

OBJECT

Accurate placement of intracranial depth and subdural electrodes is important in evaluating patients with medically refractory epilepsy for possible resection. Confirming electrode locations on postoperative CT scans does not allow for immediate replacement of malpositioned electrodes, and thus revision surgery is required in select cases. Intraoperative CT (iCT) using the Medtronic O-arm device has been performed to detect electrode locations in deep brain stimulation surgery, but its application in epilepsy surgery has not been explored. In the present study, the authors describe their institutional experience in using the O-arm to facilitate accurate placement of intracranial electrodes for epilepsy monitoring.

METHODS

In this retrospective study, the authors evaluated consecutive patients who had undergone subdural and/or depth electrode implantation for epilepsy monitoring between November 2010 and September 2012. The O-arm device is used to obtain iCT images, which are then merged with the preoperative planning MRI studies and reviewed by the surgical team to confirm final positioning. Minor modifications in patient positioning and operative field preparation are necessary to safely incorporate the O-arm device into routine intracranial electrode implantation surgery. The device does not obstruct surgeon access for bur hole or craniotomy surgery. Depth and subdural electrode locations are easily identified on iCT, which merge with MRI studies without difficulty, allowing the epilepsy surgical team to intraoperatively confirm lead locations.

RESULTS

Depth and subdural electrodes were implanted in 10 consecutive patients by using routine surgical techniques together with preoperative stereotactic planning and intraoperative neuronavigation. No wound infections or other surgical complications occurred. In one patient, the hippocampal depth electrode was believed to be in a suboptimal position and was repositioned before final wound closure. Additionally, 4 strip electrodes were replaced due to suboptimal positioning. Postoperative CT scans did not differ from iCT studies in the first 3 patients in the series and thus were not obtained in the final 7 patients. Overall, operative time was extended by approximately 10–15 minutes for O-arm positioning, less than 1 minute for image acquisition, and approximately 10 minutes for image transfer, fusion, and intraoperative analysis (total time 21–26 minutes).

CONCLUSIONS

The O-arm device can be easily incorporated into routine intracranial electrode implantation surgery in standard-sized operating rooms. The technique provides accurate 3D visualization of depth and subdural electrode contacts, and the intraoperative images can be easily merged with preoperative MRI studies to confirm lead positions before final wound closure. Intraoperative CT obviates the need for routine postoperative CT and has the potential to improve the accuracy of intracranial electroencephalography recordings and may reduce the necessity for revision surgery.

Effect of reduction of antiepileptic drugs in patients with drug-refractory epilepsy

PURPOSE

The present study was conducted with the aim of evaluating the effects of reducing the number of antiepileptic drugs (AEDs) administered to patients with drug-refractory epilepsy (DRE) during their admission and document any change in seizure frequency in subsequent follow up.

METHODS

A total of 962 patients with DRE who were admitted to the neurology wards waiting for connection to video EEG were recruited for this prospective study. After their admission to the neurology ward, modifications in the number and dosage of AEDs were done with a target of a maximum of three AEDs in every patient. Drug tapering was done using a standardized protocol. The primary outcome was the change in seizure frequency in the follow-up period of 6 months. Secondary outcome measures were the adverse event profile (AEP) and the quality of life (QOL).

RESULTS

Of the 1134 patients screened, 962 patients gave consent to participate in the study. The mean number of AEDs received by each patient was 4.24. After the tapering following a standardized protocol each patient received a mean of 2.65 AEDs per patient. In 82.70% patients with DRE, there was either a reduction or no change in seizure frequency in the subsequent 6 months follow up. There was a significant reduction in the AEP score after the reduction in the number of AEDs (P = 0. 001).

CONCLUSION

Our study proves that optimization of reduction of the number of AED's in patients with DRE leads to reduction or no change in seizure frequency with a significant decrease in adverse effects.

Seizure suppression through manipulating splicing of a voltage-gated sodium channel

Voltage-gated persistent sodium current (INaP) is a tractable target for antiepileptic drugs. Using a strategy focused on INaP reduction, Lin et al. identify 95 regulators of voltage-gated sodium channel splicing for which RNAi knockdown reduces seizure duration in Drosophila. Manipulation of splicing regulators could improve control of epilepsy.

Seizure can result from increased voltage-gated persistent sodium current expression. Although many clinically-approved antiepileptic drugs target voltage-gated persistent sodium current, none exclusively repress this current without also adversely affecting the transient voltage-gated sodium current. Achieving a more selective block has significant potential for the treatment of epilepsy. Recent studies show that voltage-gated persistent sodium current amplitude is regulated by alternative splicing offering the possibility of a novel route for seizure control. In this study we identify 291 splicing regulators that, on knockdown, alter splicing of the Drosophila voltage-gated sodium channel to favour inclusion of exon K, rather than the mutually exclusive exon L. This change is associated with both a significant reduction in voltage-gated persistent sodium current, without change to transient voltage-gated sodium current, and to rescue of seizure in this model insect. RNA interference mediated knock-down, in two different seizure mutants, shows that 95 of these regulators are sufficient to significantly reduce seizure duration. Moreover, most suppress seizure activity in both mutants, indicative that they are part of well conserved pathways and likely, therefore, to be optimal candidates to take forward to mammalian studies. We provide proof-of-principle for such studies by showing that inhibition of a selection of regulators, using small molecule inhibitors, is similarly effective to reduce seizure. Splicing of the Drosophila sodium channel shows many similarities to its mammalian counterparts, including altering the amplitude of voltage-gated persistent sodium current. Our study provides the impetus to investigate whether manipulation of splicing of mammalian voltage-gated sodium channels may be exploitable to provide effective seizure control.

Placebo and nocebo responses in drug trials of epilepsy

Placebo response can be defined as any therapeutic change on placebo, while the nocebo response is any ill effect during placebo exposure. Several meta-analytic approaches have investigated the extent of placebo response in randomized, placebo-controlled, clinical trials of focal epilepsies. Placebo response rates (proportion of patients with ≥50% improvement of seizures versus baseline) ranging from 9.9% up to 15.2% have been reported. Interestingly, a sham response of 15.8% has been noted in trials of transcranial magnetic stimulation. Recently, nocebo response rates of 60.3% and 3.9% were noted, which were defined as the proportion of patients with adverse events (AEs) and those withdrawing because of intolerable AEs, respectively. Factors which were found to influence placebo response were as follows: the year of publication (with more recent studies showing higher rates of placebo response), some clinical characteristics of recruited patients (lower placebo response rates with a history of 7 or more prior lifetime AEDs, a high baseline seizure frequency, prior epilepsy surgery, and higher age at diagnosis), trial design and statistical analysis, and whether studies have been conducted in children or adults. Furthermore, placebo and nocebo rates were correlated with respective seizure outcome and adverse events of the experimental AED. Several mechanisms of placebo and nocebo responses are discussed. Specifically, the role of positive or negative expectations of patients and of investigators may influence the placebo and the nocebo response. Finally, recommendations are given on how to address placebo and nocebo responses in clinical practice.

Personalized medicine approaches in epilepsy

Epilepsy affects 50 million persons worldwide, a third of whom continue to experience debilitating seizures despite optimum anti-epileptic drug (AED) treatment. Twelve-month remission from seizures is less likely in female patients, individuals aged 11-36 years and those with neurological insults and shorter time between first seizure and starting treatment. It has been found that the presence of multiple seizures prior to diagnosis is a risk factor for pharmacoresistance and is correlated with epilepsy type as well as intrinsic severity. The key role of neuroinflammation in the pathophysiology of resistant epilepsy is becoming clear. Our work in this area suggests that high-mobility group box 1 isoforms may be candidate biomarkers for treatment stratification and novel drug targets in epilepsy. Furthermore, transporter polymorphisms contributing to the intrinsic severity of epilepsy are providing robust neurobiological evidence on an emerging theory of drug resistance, which may also provide new insights into disease stratification. Some of the rare genetic epilepsies enable treatment stratification through testing for the causal mutation, for example SCN1A mutations in patients with Dravet's syndrome. Up to 50% of patients develop adverse reactions to AEDs which in turn affects tolerability and compliance. Immune-mediated hypersensitivity reactions to AED therapy, such as toxic epidermal necrolysis, are the most serious adverse reactions and have been associated with polymorphisms in the human leucocyte antigen (HLA) complex. Pharmacogenetic screening for HLA-B*15:02 in Asian populations can prevent carbamazepine-induced Stevens-Johnson syndrome. We have identified HLA-A*31:01 as a potential risk marker for all phenotypes of carbamazepine-induced hypersensitivity with applicability in European and other populations. In this review, we explore the currently available key stratification approaches to address the therapeutic challenges in epilepsy.

Functional magnetic resonance imaging networks induced by intracranial stimulation may help defining the epileptogenic zone

Patients with medically intractable epilepsy often undergo invasive evaluation and surgery, with a 50% success rate. The low success rate is likely due to poor identification of the epileptogenic zone (EZ), the brain area causing seizures. This work introduces a new method using functional magnetic resonance imaging (fMRI) with simultaneous direct electrical stimulation of the brain that could help localize the EZ, performed in five patients with medically intractable epilepsy undergoing invasive evaluation with intracranial depth electrodes. Stimulation occurred in a location near the hypothesized EZ and a location away. Electrical recordings in response to stimulation were recorded and compared to fMRI. Multiple stimulation parameters were varied, like current and frequency. The brain areas showing fMRI response were compared with the areas resected and the success of surgery. Robust fMRI maps of activation networks were easily produced, which also showed a significant but weak positive correlation between quantitative measures of blood-oxygen-level-dependent (BOLD) activity and measures of electrical activity in response to direct electrical stimulation (mean correlation coefficient of 0.38 for all acquisitions that produced a strong BOLD response). For four patients with outcome data at 6 months, successful surgical outcome is consistent with the resection of brain areas containing high local fMRI activity. In conclusion, this method demonstrates the feasibility of simultaneous direct electrical stimulation and fMRI in humans, which allows the study of brain connectivity with high resolution and full spatial coverage. This innovative technique could be used to better define the localization and extension of the EZ in intractable epilepsies, as well as for other functional neurosurgical procedures.

Old versus New: Why Do We Need New Antiepileptic Drugs?

Achieving complete seizure remission without adverse events is the goal of epilepsy treatment. Recently, many new antiepileptic drugs (AEDs) have been developed. Even though the efficacy of new AEDs is not stronger than that of old AEDs, there are advantages in using new AEDs. They have unique or different mechanisms of action that enable the creation of possible synergistic combinations. They usually exhibit fewer or no pharmacokinetic drug interactions. Furthermore, the response to AEDs varies individually. A similar efficacy does not imply a similar response from all patients. Many new AEDs have fewer adverse events, including induction of congenital malformations. Other concerns about the long-term effects of established AEDs, such as bone health and development of atherosclerosis, may be alleviated by the use of new AEDs. New AEDs are needed to achieve better care of patients with epilepsy.

The course of childhood-onset epilepsy over the first two decades: a prospective, longitudinal study

OBJECTIVES

Determine frequency of remissions, relapses, and pharmacoresistance over two decades. Develop a composite measure of seizure control over that time.

METHODS

Community-based cohort of children with newly diagnosed epilepsy prospectively followed for up to 21 years with frequent calls and periodic medical record review. Multiple periods of 1-, 2-, 3-, and 5-year remission with subsequent relapses were recorded. Other outcomes included pharmacoresistance (failure of two adequately used drugs), early remission and early pharmacoresistance by 2 years, and complete remission at last contact (CR-LC, 5 years both seizure- and drug-free at last contact). A composite summary of seizure course was created with eight categories ranging from early sustained remission and CR-LC (best) to never achieving a 1-year remission (worst).

RESULTS

Five hundred sixteen of 613 participants were followed ≥10 years. An initial 1- 2-, 3-, and 5-year remission occurred, respectively, in 95%, 92%, 89%, and 81%. Relapses followed in 52%, 41%, 29%, and 15%, respectively. Repeated remission after relapse was common. Up to seven 1-year, five 2-year and 3-year, and two 5-year remissions were recorded per participant. Pharmacoresistance at any time, early pharmacoresistance (<2 years), early remission, and CR-LC occurred in 118 (22.9%), 70 (13.6%), 283 (54.8%), and 311 (60.3%). Composite outcomes were early sustained remission with CR-LC (N=172, 33%); later but then sustained remission with CR-LC (N=51, 10%); one (N=61, 12%) or more (N=27, 5%) remission-relapse episodes but then CR-LC; various non-CR-LC outcomes (N=179, 35%); and never achieved 1-year remission (N=26, 5%). These patterns varied across groups defined by epilepsy type and presence of brain insults or neurodisability (p<0.0001).

SIGNIFICANCE

The seizure prognosis of pediatric epilepsies is highly variable. Most patients follow complex courses not easily summarized by remission status at the end of a period of follow-up. These complexities may facilitate efforts to understand the impact epilepsy has on young people entering adulthood.

Epidemiologic aspects: lost in transition

Population-based studies focusing on the long-term prognosis of childhood-onset epilepsy show that despite seizure remission in 70-80% of cases, cognitive, behavioral and psychosocial complications are common and will require management and monitoring in adulthood. This type of study design also demonstrates that death is rare in children who are intellectually and neurologically normal and followed for many years, which is the same for the general population. Only those children with neurologic problems sufficiently severe to interfere with activities of daily living have an increased risk of death in childhood. Investigation of potentially remediable complications is paramount, and the use of antiepileptic medications with potential adverse cognitive and behavioral effects should be identified and eliminated or reduced. In addition, education of the family should be improved. As well, identification and control of social and psychiatric complications is necessary and implies a comprehensive management of the patient before and after the transition from childhood into adulthood.

Post-status epilepticus treatment with the cannabinoid agonist WIN 55,212-2 prevents chronic epileptic hippocampal damage in rats

Repeated seizures are often associated with development of refractory chronic epilepsy, the most common form of which is temporal lobe epilepsy. G-protein-coupled cannabinoid receptors (CB1 and CB2 receptors) regulate neuronal excitability and have been shown to mediate acute anticonvulsant effects of cannabinoids in animal models. However, the potential of cannabinoids to prevent chronic neuronal damage and development of epilepsy remains unexplored. We hypothesized that treatment with a CB receptor agonist after an episode of status epilepticus--but before development of spontaneous recurrent seizures--might prevent the development of functional changes that lead to chronic epilepsy. Using the rat pilocarpine model, a therapeutic approach was simulated by administering the CB agonist, WIN 55,212-2 after an episode of status epilepticus. Epileptic behavior was monitored during development of spontaneous recurrent seizures for up to 6 months. Histology, neurochemistry, redox status and NMDA receptor subunit expression were assessed at 6 months after pilocarpine-induced seizures. Sub-acute treatment with WIN 55,212-2 (for 15 days starting 24h after PILO injection) dramatically attenuated the severity, duration and frequency of spontaneous recurrent seizures. Further, in contrast to vehicle-treated animals, hippocampi from WIN 55,212-2-treated animals showed: normal thiol redox state, normal NR2A and NR2B subunit expression, preservation of GABAergic neurons and prevention of abnormal proliferation of GABAergic progenitors. This study shows for the first time that, after a known inciting event, treatment with a compound targeting CB receptors has the potential to prevent the epileptogenic events that result in chronic epileptic damage.

Complete remission of childhood-onset epilepsy: stability and prediction over two decades

The ultimate seizure outcome of childhood epilepsy is complete resolution of all seizures without further treatment. How often this happens and how well it can be predicted early in the course of epilepsy could be valuable in helping families understand the nature of childhood epilepsy and what to expect over time. In the Connecticut study of epilepsy, a prospective cohort of 613 children with newly-diagnosed epilepsy (onset age 0-15 years), complete remission, ≥5 years both seizure-free and medication-free, was examined as a proxy of complete seizure resolution. Predictors at initial diagnosis were tested. Information about seizure outcomes within 2 years and from 2-5 years after diagnosis was sequentially added in a proportional hazards model. The predictive value of the models was determined with logistic regression. Five hundred and sixteen subjects were followed ≥10 years. Three hundred and twenty-eight (63%) achieved complete remission; 23 relapsed. The relapse rate was 8.2 per 1000 person-years and decreased over time: 10.7, 6.7, and 0 during first 5 years, the next 5 years, and then >10 years after complete remission (P=0.06 for trend). Six participants regained complete remission; 311 (60%) were in complete remission at last contact. Baseline factors predicting against complete remission at last contact included onset age≥10 years (hazard ratio=0.55, P=0.0009) and early school or developmental problems (hazard ratio=0.74, P=0.01). Factors predicting for complete remission were uncomplicated epilepsy presentation (hazard ratio=2.23, P<0.0001), focal self-limited epilepsy syndrome (hazard ratio=2.13, P<0.0001), and uncharacterized epilepsy (hazard ratio=1.61, P=0.04). Remission (hazard ratio=1.95, P<0.0001) and pharmaco-resistance (hazard ratio=0.33, P<0.0001) by 2 years respectfully predicted in favour and against complete remission. From 2 to 5 years after diagnosis, relapse (hazard ratio=0.21, P<0.0001) and late pharmaco-resistance (hazard ratio=0.21, P=0.008) decreased and late remission (hazard ratio=2.40, P<0.0001) increased chances of entering complete remission. The overall accuracy of the models increased from 72% (baseline information only), to 77% and 85% with addition of 2-year and 5-year outcomes. Relapses after complete remission are rare making this an acceptable proxy for complete seizure resolution. Complete remission after nearly 20 years is reasonably well predicted within 5 years of initial diagnosis.

Rational management of epilepsy

Management of epilepsies in children has improved considerably over the last decade, all over the world due to the advances seen in the understanding of the patho-physiology of epileptogenesis, availability of both structural and functional imaging studies along with better quality EEG/video-EEG recordings and the availability of a plethora of newer anti-epileptic drugs which are tailormade to act on specific pathways. In spite of this, there is still a long way to go before one is able to be absolutely rational about which drug to use for which type of epilepsy. There have been a lot of advances in the area of epilepsy surgery and is certainly gaining ground for specific cases. Better understanding of the genetic basis of epilepsies will hopefully lead to a more rational treatment plan in the future. Also, a lot of work needs to be done to dispel various misunderstandings and myths about epilepsy which still exists in our country.

Long-term impact of the ketogenic diet on growth and resting energy expenditure in children with intractable epilepsy

AIM

The long-term effects of the ketogenic diet, a high fat diet for treating intractable epilepsy, on resting energy expenditure (REE) are unknown. The aim of this study was to evaluate the impact of 15 months of ketogenic diet treatment on growth and REE in children with intractable epilepsy.

METHOD

Growth, body composition, and REE were assessed at baseline, 3 months and 15 months in 24 children (14 males, 10 females; mean age 5 y 6 mo [SD 26 mo], range 7 mo-6 y 5 mo), 10 with cerebral palsy [CP]). Fifteen were identified as ketogenic diet responders at 3 months and continued on the ketogenic diet until 15 months. These were compared to 75 healthy children (43 males, 32 females; mean age 6 y 3 mo [SD 21 mo] age range 2-9 y). REE was expressed as percentage predicted, growth as height (HAz) and weight (WAz) z-scores, and body composition as fat and fat free mass (FFM).

RESULTS

HAz declined -0.2 and -0.6 from baseline to 3 months and 15 months respectively (p = 0.001), while WAz was unchanged. In ketogenic diet responders, FFM, age and CP diagnosis predicted REE (overall R(2) = 0.76, p<0.001) and REE did not change. REE adjusted for FFM was lower (p<0.01) in children with CP at baseline (mean [standard error], -143[51] kcals/d) and 15 months (-198[53] kcals/d) compared to the healthy children.

INTERPRETATION

After 15 months of the ketogenic diet, linear growth status declined while weight status and REE were unchanged. REE remained reduced in children with CP.

Clinical conditions of long-term cure in childhood-onset epilepsy: a 45-year follow-up study

Clinical conditions of long-term cure in childhood-onset epilepsy, defined as sustained remission off antiepileptic drug (AED) treatment, are not well known. To address that clinically important question, we determined clinical factors predictive of long-term seizure cure in a population-based cohort of 133 patients followed up since their first seizure before the age of 16 years. At the end of the 45-year follow-up (mean=39.8, median=44, range=11-47), 81 (61%) of the 133 patients had entered at least 5-year remission off AEDs, meeting our definition of cure. The 81 patients were seizure-free off AEDs for a mean of 34.4 (median=38, range=6-46) years and 59 (73%) of the 81 patients following the first standard medication until the end of follow-up (mean=36.5, median=39, range=14-46 years). Four independent factors were found to be associated with cure compared with having seizures while on AEDs: seizure frequency less than weekly during the first 12 months of AED treatment (p=0.002), pretreatment seizure frequency less than weekly (p=0.002), higher IQ (>70; p=0.021), and idiopathic or cryptogenic vs. symptomatic etiology (p=0.042). Patients with seizure frequency of less than once a week during early treatment and idiopathic etiology had a ninefold chance to of being cured since the onset of the first adequate antiepileptic therapy until the end of follow-up compared with patients who a symptomatic etiology had at least weekly seizures while on AEDs (RR=8.7, 95% CI=2.0-37.0; p<0.001). In conclusion, IQ, etiology, and seizure frequencies both in the first year of AED treatment and prior to medication appear to be clinical predictors of cure in childhood-onset epilepsy.

Depression and anxiety in people with epilepsy

Many recent epidemiological studies have found the prevalence of depression and anxiety to be higher in people with epilepsy (PWE) than in people without epilepsy. Furthermore, people with depression or anxiety have been more likely to suffer from epilepsy than those without depression or anxiety. Almost one-third of PWE suffer from depression and anxiety, which is similar to the prevalence of drug-refractory epilepsy. Various brain areas, including the frontal, temporal, and limbic regions, are associated with the biological pathogenesis of depression in PWE. It has been suggested that structural abnormalities, monoamine pathways, cerebral glucose metabolism, the hypothalamic-pituitary-adrenal axis, and interleukin-1b are associated with the pathogenesis of depression in PWE. The amygdala and the hippocampus are important anatomical structures related to anxiety, and γ-aminobutyric acid and serotonin are associated with its pathogenesis. Depression and anxiety may lead to suicidal ideation or attempts and feelings of stigmatization. These experiences are also likely to increase the adverse effects associated with antiepileptic drugs and have been related to poor responses to pharmacological and surgical treatments. Ultimately, the quality of life is likely to be worse in PWE with depression and anxiety than in PWE without these disorders, which makes the early detection and appropriate management of depression and anxiety in PWE indispensable. Simple screening instruments may be helpful for in this regard, particularly in busy epilepsy clinics. Although both medical and psychobehavioral therapies may ameliorate these conditions, randomized controlled trials are needed to confirm that.

Treatment strategy for the patient with hippocampal sclerosis who failed to the first antiepileptic drug

Despite many epilepsy patients respond to antiepileptic drugs (AED) successfully, more than 30% of patients continue to have seizures on multiple AEDs. The refractory epilepsy increases the risk of cognitive deterioration, psychosocial dysfunction, and sudden unexpected death of epilepsy patients (SUDEP). It is important to identify refractory epilepsy early and make the goal of epilepsy treatment as the prevention of decline in social, vocational, and cognitive performances and minimizing the risk of accident or SUDEP. The syndrome of medial temporal lobe epilepsy with hippocampal sclerosis (MTLE with HS) is often resistant to AEDs, and surgically remediable. Initially well-controlled seizures often become intractable to AEDs. There are progressive behavioral changes including increasing memory deficit. Surgical outcome is also worse with longer duration of epilepsy or increasing age at surgery, which suggests that MTLE is a progressive disorder. Some emphasized the ultimate intractability of MTLE in which intractability of MTLE could be evident only after some years following initial diagnosis. However, when patients considered to have intractable epilepsy were followed up for a long period of time, many of them experienced seizure-free state. Some studies clearly demonstrated the wax and wane courses of treatment response in epilepsy. Late remission could be achieved up to in a half of patients. Thus intractable state is not a static condition but a fluctuating one and initial refractoriness does not necessarily mean the final intractability. Even though the chance of seizure remission with AEDs is not high for MTLE, some of them do well respond to drugs. It is even possible to withdraw AEDs for a few patients. Though epilepsy surgery is very effective method to treat MTLE, considering the fluctuation courses of intractability and the possibility of delayed remission, at least two adequate AEDs could be applied to the patients before surgery. However, medical intractability becomes evident by definition, it is not reasonable to delay epilepsy surgery.

Predictors of quality of life and their interrelations in Korean people with epilepsy: a MEPSY study

PURPOSE

People with epilepsy (PWE) are more likely to have impaired quality of life (QOL) than the general population. We studied predictors of QOL and their interrelations in Korean PWE.

METHODS

Subjects who consecutively visited outpatient clinics in four tertiary hospitals and one secondary care hospital were enrolled. These subjects completed the Korean version of the Neurological Disorders Depression Inventory for Epilepsy (K-NDDI-E), the Generalized Anxiety Disorder-7 (GAD-7), the Quality of Life in Epilepsy-10 (QOLIE-10), and the Korean version of Liverpool Adverse Event Profile (K-LAEP). We evaluated the predictors of QOL by multiple regression analyses and verified the interrelations between the variables using a structural equation model.

RESULTS

A total of 702 PWE were eligible for the study. The strongest predictor of the overall QOLIE-10 score was the K-LAEP score (β=-0.375, p<0.001), followed by the K-NDDI-E score (β=-0.316, p<0.001), seizure control (β=-0.152, p<0.001), household income (β=-0.375, p<0.001), and GAD-7 score (β=-0.119, p=0.005). These variables explained 68.7% of the variance in the overall QOLIE-31 score. Depression and seizure control had a bidirectional relationship and exerted direct effects on QOL. These factors also exerted indirect effects on QOL by provoking adverse effects of AEDs. Anxiety did not have a direct effect on QOL; it had only indirect effect through the adverse effects of AEDs.

CONCLUSION

Depression, anxiety, seizure control, and adverse effects of AEDs have complex interrelations that determine the QOL of PWE.

Prevalence of epilepsy--an unknown quantity

The incidence, prevalence, and mortality of epilepsy vary across countries with different economies. Differences can be explained by methodological problems, premature mortality, seizure remission, socioeconomic factors, and stigma. Diagnostic misclassification-one possible explanation-may result from inclusion of patients with acute symptomatic or isolated unprovoked seizures. Other sources of bias include age and ethnic origin of the target population, definitions of epilepsy, retrospective versus prospective ascertainment, sources of cases, and experienced and perceived stigma. Premature mortality is an issue in low-income countries (LICs), where treatment gap, brain infections, and traumatic brain injuries are more common than in high-income countries (HICs). Death rates may reflect untreated continued seizures or inclusion of acute symptomatic seizures. Lack of compliance with antiepileptic drugs has been associated with increased risk for death, increased hospital admissions, motor vehicle accidents, and fractures in poor communities. Epilepsy is a self-remitting clinical condition in up to 50% of cases. Studies in untreated individuals from LICs have shown that the proportion of remissions overlaps that of countries where patients receive treatment. When the identification of patients is based on spontaneous reports (e.g., door-to-door surveys), patients in remission may be less likely to disclose the disease for fear of stigmatization with no concurrent benefits. This might lead to underascertainment of cases when assessing the lifetime prevalence of epilepsy. In LICs, the proportion of people living in poverty is greater than in HICs. Poverty is associated with risk factors for epilepsy, risk for developing epilepsy, and increased mortality. The high incidence and prevalence of epilepsy found in LICs is also observed in low income individuals from HICs. Epileptogenic conditions are associated with an increased mortality. This may partly explain the difference between incidence and lifetime prevalence of epilepsy in LICs. Poverty within LICs and HICs could be a preventable cause of mortality in epilepsy.

Acute administration of the small-molecule p75(NTR) ligand does not prevent hippocampal neuron loss or development of spontaneous seizures after pilocarpine-induced status epilepticus

Neurotrophins, such as brain-derived neurotrophic factor (BDNF), are initially expressed in a precursor form (e.g., pro-BDNF) and cleaved to form mature BDNF (mBDNF). After pilocarpine-induced status epilepticus (SE), increases in neurotrophins regulate a wide variety of cell-signaling pathways, including prosurvival and cell-death machinery in a receptor-specific manner. Pro-BDNF preferentially binds to the p75 neurotrophin receptor (p75(NTR) ), whereas mBDNF is the major ligand of the tropomyosin-related kinase receptor. To elucidate a potential role for p75(NTR) in acute stages of epileptogenesis, rats were injected prior to and at onset of SE with LM11A-31, a small-molecule ligand that binds to p75(NTR) to promote survival signaling and inhibit neuronal cell death. Modulation of early p75(NTR) signaling and its effects on electrographic SE, SE-induced neurodegeneration, and subsequent spontaneous seizures were examined after LM11A-31 administration. Despite an established neuroprotective effect of LM11A-31 in several animal models of neurodegenerative disorders (e.g., Alzheimer's disease, traumatic brain injury, and spinal cord injury), high-dose LM11A-31 administration prior to and at onset of SE did not reduce the intensity of electrographic SE, prevent SE-induced neuronal cell injury, or inhibit the progression of epileptogenesis. Further studies are required to understand the role of p75(NTR) activation during epileptogenesis and in seizure-induced cell injury in the hippocampus, among other potential cellular pathologies contributing to the onset of spontaneous seizures. Additional studies utilizing more prolonged treatment with LM11A-31 are required to reach a definite conclusion on its potential neuroprotective role in epilepsy.

Anti-epileptogenic clinical trial designs in epilepsy: issues and options

Although trials with anti-seizure drugs have not shown anti-epileptogenic or disease-modifying activity in humans, new compounds are on the horizon that may require novel trial designs. We briefly discuss the unique challenges and the available options to identify innovative clinical trial designs that differentiate novel anti-epileptogenic and disease-modifying compounds, preferably early in phase II, from current anti-seizure drugs. The most important challenges of clinical testing of agents for epilepsy prevention include having sufficient preclinical evidence for a suitable agent to proceed with a human trial of an anti-epileptogenic drug, and to demonstrate the feasibility of doing such a trial. Major challenges in trial design to assess agents for disease modification include the choice of suitable study parameters, the identification of a high-risk study population, the type of control, the time and duration of treatment, and a feasible follow-up period.

Dispersion durations of P-wave and QT interval in children treated with a ketogenic diet

BACKGROUND

Limited data are available on the effects of a ketogenic diet on dispersion duration of P-wave and QT-interval measures in children. We searched for the changes in these measures with serial electrocardiograms in patients treated with a ketogenic diet.

METHODS

Twenty-five drug-resistant patients with epilepsy treated with a ketogenic diet were enrolled in this study. Electrocardiography was performed in all patients before the beginning and at the sixth month after implementation of the ketogenic diet. Heart rate, maximum and minimum P-wave duration, P-wave dispersion, and maximum and minimum corrected QT interval and QT dispersion were manually measured from the 12-lead surface electrocardiogram.

RESULTS

Minimum and maximum corrected QT and QT dispersion measurements showed nonsignificant increase at month 6 compared with baseline values. Other previously mentioned electrocardiogram parameters also showed no significant changes.

CONCLUSIONS

A ketogenic diet of 6 months' duration has no significant effect on electrocardiogram parameters in children. Further studies with larger samples and longer duration of follow-up are needed to clarify the effects of ketogenic diet on P-wave dispersion and corrected QT and QT dispersion.

Association of MDR1 gene C3435T polymorphism with childhood intractable epilepsy: a meta-analysis

Drug-resistant epilepsy is also referred to as intractable, medically refractory, or pharmacoresistant epilepsy. Approximately, one-third of patients with epilepsy have recurrent seizures despite therapy. Multidrug resistance 1 (MDR1) gene may play a role in drug-resistance in epilepsy. To assess the association between MDR1 C3435T polymorphism and the response to anticonvulsants in childhood intractable epilepsy, we conducted a systematic review and meta-analysis. Studies were obtained from the electronic database of PubMed, Medline, Embase and CNKI up to September 2013. All the case-control association researches evaluating the role of MDR1 C3435T polymorphism in childhood epilepsy to antiepileptic drugs were identified. The odds ratios (ORs) with 95% confidence intervals (CIs) were calculated for comparisons of the alleles and genotypes with co-dominant (C/C vs. T/T, C/T vs. T/T), dominant (C/C + C/T vs. T/T), and recessive (C/C vs. C/T + T/T) models in overall and in ethnicity subgroups to measure the strength of genetic association. A total of 8 related studies, including 634 drug-resistant patients, 615 drug-responsive patients and 1,052 healthy controls were pooled in this meta-analysis. The allelic association of MDR1 C3435T with risk of drug-resistance was not significant (OR 1.03, 95% CI 0.87-1.22, P = 0.73; OR 1.00, 95% CI 0.86-1.16, P = 0.98) in overall and in the subgroup analysis by ethnicity (Asian: OR 0.95, 95% CI 0.77-1.18, P = 0.67; Caucasian: OR 1.18, 95% CI 0.89-1.57, P = 0.25). Neither association was found in other genetic models. Our results did not show a significant association between MDR1 C3435T polymorphism and response to anticonvulsant drugs, suggesting that this polymorphism may not be a risk factor to childhood intractable epilepsy.

Surgical treatment of epilepsy

PURPOSE OF REVIEW

This article outlines indications for neurosurgical treatment of epilepsy, describes the presurgical workup, summarizes surgical approaches, and details expected risks and benefits.

RECENT FINDINGS

There is class I evidence for the efficacy of temporal lobectomy in treating intractable seizures, and accumulating documentation that successful surgical treatment reverses much of the disability, morbidity, and excess mortality of chronic epilepsy.

SUMMARY

Chronic, uncontrolled focal epilepsy causes progressive disability and increased mortality, but these can be reversed with seizure control. Vigorous efforts to stop seizures are warranted. If two well-chosen and tolerated medication trials do not achieve seizure control, an early workup for epilepsy surgery should be arranged. If this workup definitively identifies the brain region from which the seizures arise, and this region can be removed with a low risk of disabling neurologic deficits, neurosurgery will have a much better chance of stopping seizures than further medication trials.

Neuropsychological performance in children with temporal lobe epilepsy having normal MRI findings

BACKGROUND AND AIMS

Most information on the neuropsychological performance of pediatric patients with temporal lobe epilepsy (TLE) is derived from selected surgical series. Non-lesional pediatric TLE patients were studied here at the population level in order to investigate the extent to which neuropsychological deficits predisposing to learning difficulties exist in this more common group.

METHODS

Language, memory and executive functions were measured in children aged 8-15 years with non-lesional TLE and of normal intelligence (n = 21), and their performance was compared with that of healthy age and gender-matched children (n = 21). The effects of clinical epilepsy variables on performance were examined.

RESULTS

Although neuropsychological performance did not differ between the TLE patients and the healthy controls, female gender, early onset, longer duration and abnormal interictal EEG had a negative effect on neuropsychological performance.

CONCLUSIONS

Children with early-onset epilepsy should be assessed carefully for neuropsychological impairment using sufficiently broad batteries of tests in order to detect even slight deficits. Our sample size was small and these findings should be interpreted as preliminary results and need to be confirmed in larger studies.