Defining early seizure outcomes in pediatric epilepsy: the good, the bad and the in-between

First-Drug Efficacy and Drug-Resistant Epilepsy Rates in Children With New-Onset Epilepsies: A Multicenter Large Cohort Study

Objective: This study aimed to assess the first-drug efficacy rate in newly diagnosed children with epilepsies treated with antiseizure medications. Methods: This retrospective study was conducted on 1003 children (age range: 3-10 years, and the mean duration of follow-up: 22 ± 13 months) with newly diagnosed epilepsy. The following parameters were evaluated: first-drug efficacy rate, first-drug-failure rate, and drug resistance rate in the cohort. Results: The first-drug-failure rate was defined in 335/1003 (33%) of the patients, no seizure control in 315 (31%), and drug withdrawal in 20 (2%). There was no significant difference between the group with focal-onset seizures and the group with generalized onset seizures. The first-drug efficacy rate was 67% in children with focal-onset seizures and 66% in children with generalized-onset seizures. Adjunctive antiseizure medication therapy was initiated in 335 patients-dual therapy with 180 patients (18%) and polytherapy with 155 (15%). Drug-resistant epilepsy was defined as 15% in the follow-up period. Etiology-specific diagnoses of the cohort were structural (n = 165, 17%), genetic (n = 25, 3%), metabolic (n = 15%), immune-infectious (n = 17 (2%), and unknown (n = 781, 77%). With a comparison of the 2 most common etiology subgroups (structural versus unknown), a first-drug efficacy rate of 53% and a higher prevalence of drug-resistant epilepsy at 30% were observed in children with structural etiology. First-drug efficacy was statistically lower in children without well-defined epilepsy syndromes (65%) compared with the rate of those with well-defined epilepsy syndrome (79%). Conclusion: This study revealed a first-drug failure rate (33%) in the presented cohort with a drug-resistance epilepsy rate (15%).

Neuromodulation in Children with Drug-Resistant Epilepsy

The introduction of neuromodulation was a revolutionary advancement in the antiseizure armamentarium for refractory epilepsy. The basic principle of neuromodulation is to deliver an electrical stimulation to the desired neuronal site to modify the neuronal functions not only at the site of delivery but also at distant sites by complex neuronal processes like disrupting the neuronal circuitry and amplifying the functions of marginally functional neurons. The modality is considered open-loop when electrical stimulation is provided at a set time interval or closed-loop when delivered in response to an incipient seizure. Neuromodulation in individuals older than 18 years with epilepsy has proven efficacious and safe. The use of neuromodulation is extended off-label to pediatric patients with epilepsy and the results are promising. Vagus nerve stimulation (VNS), responsive neurostimulation (RNS), and deep brain stimulation (DBS) are Food and Drug Administration-approved therapeutic techniques. The VNS provides retrograde signaling to the central nervous system, whereas DBS and RNS are more target specific in the central nervous system. While DBS is open-loop and approved for stimulation of the anterior nucleus of the thalamus, the RNS is closed-loop and can stimulate any cortical or subcortical structure. We will review different modalities and their clinical efficacy in individuals with epilepsy, with a focus on pediatric patients.

Neonatal seizures as onset of Inborn Errors of Metabolism (IEMs): from diagnosis to treatment. A systematic review

Neonatal seizures (NS) occur in the first 28 days of life; they represent an important emergency that requires a rapid diagnostic work-up to start a prompt therapy. The most common causes of NS include: intraventricular haemorrhage, hypoxic-ischemic encephalopathy, hypoglycemia, electrolyte imbalance, neonatal stroke or central nervous system infection. Nevertheless, an Inborn Error of Metabolism (IEM) should be suspected in case of NS especially if these are resistant to common antiseizure drugs (ASDs) and with metabolic decompensation. Nowadays, Expanded Newborn Screening (ENS) has changed the natural history of some IEMs allowing a rapid diagnosis and a prompt onset of specific therapy; nevertheless, not all IEMs are detected by such screening (e.g. Molybdenum-Cofactor Deficiency, Hypophosphatasia, GLUT1-Deficiency Syndrome) and for this reason neonatologists have to screen for these diseases in the diagnostic work-up of NS. For IEMs, there are not specific semiology of seizures and EEG patterns. Herein, we report a systematic review on those IEMs that lead to NS and epilepsy in the neonatal period, studying only those IEMs not included in the ENS with tandem mass, suggesting clinical, biochemical features, and diagnostic work-up. Remarkably, we have observed a worse neurological outcome in infants undergoing only a treatment with common AED for their seizures, in comparison to those primarily treated with specific anti-convulsant treatment for the underlying metabolic disease (e.g.Ketogenic Diet, B6 vitamin). For this reason, we underline the importance of an early diagnosis in order to promptly intervene with a targeted treatment without waiting for drug resistance to arise.

Safety of responsive neurostimulation in pediatric patients with medically refractory epilepsy

OBJECTIVE

Approximately 75% of pediatric patients who suffer from epilepsy are successfully treated with antiepileptic drugs, while the disease is drug resistant in the remaining patients, who continue to have seizures. Patients with drug-resistant epilepsy (DRE) may have options to undergo invasive treatment such as resection, laser ablation of the epileptogenic focus, or vagus nerve stimulation. To date, treatment with responsive neurostimulation (RNS) has not been sufficiently studied in the pediatric population because the FDA has not approved the RNS device for patients younger than 18 years of age. Here, the authors sought to investigate the safety of RNS in pediatric patients.

METHODS

The authors performed a retrospective single-center study of consecutive patients with DRE who had undergone RNS system implantation from September 2015 to December 2019. Patients were followed up postoperatively to evaluate seizure freedom and complications.

RESULTS

Of the 27 patients studied, 3 developed infections and were treated with antibiotics. Of these 3 patients, one required partial removal and salvaging of a functioning system, and one required complete removal of the RNS device. No other complications, such as intracranial hemorrhage, stroke, or device malfunction, were seen. The average follow-up period was 22 months. All patients showed improvement in seizure frequency.

CONCLUSIONS

The authors demonstrated the safety and efficacy of RNS in pediatric patients, with infections being the main complication.

ABBREVIATIONS

DBS = deep brain stimulation; DRE = drug-resistant epilepsy; MDC = multidisciplinary conference; MER = microelectrode recording; MSHS = Mount Sinai Health System; RNS = responsive neurostimulation; SEEG = stereo-EEG; VNS = vagus nerve stimulation.

Micronized resveratrol shows promising effects in a seizure model in zebrafish and signalizes an important advance in epilepsy treatment

Resveratrol is a natural non-flavonoid polyphenolic that has been emerging in epilepsy treatment. Despite its pharmacological properties, the poor bioavailability of resveratrol has been an important barrier that hinders its application as an anticonvulsant. The aim of this work was to improve resveratrol's anticonvulsant effects by micronizing this compound through supercritical fluid micronization technology, which promotes an increase of the particles' surface area and allows significantly reduced particle size to be obtained. We obtained commercial and micronized resveratrol and investigated the anticonvulsant effects of resveratrol as commercially found and micronized resveratrol in a pentylenetetrazole-induced seizure model in zebrafish (Danio rerio) larvae. Diazepam was used as the positive control. Also, animals had their locomotor and exploratory activity analyzed 24 h after the seizure occurrence. The occurrence of the tonic-clonic seizure stage was only prevented by diazepam and micronized resveratrol, unlike the non-processed compound. The seizure development was significantly slowed by diazepam and micronized resveratrol, while non-micronized resveratrol was not able to increase the latency of seizure stages. In addition, diazepam and micronized resveratrol prevented the deleterious effects of pentylenetetrazole-induced seizures on animals' locomotor and exploratory behaviour. Obtained data demonstrates that the micronization process potentiates the anticonvulsant effect of resveratrol. Micronized resveratrol achieved a similar effect to the classical drug diazepam, with the benefit that it may be a safe drug candidate to be used during the neurodevelopmental stage.

Validated outcome of treatment changes according to International League Against Epilepsy criteria in adults with drug-resistant focal epilepsy

Objective

Although many studies have attempted to describe treatment outcomes in patients with drug‐resistant epilepsy, results are often limited by the adoption of nonhomogeneous criteria and different definitions of seizure freedom. We sought to evaluate treatment outcomes with a newly administered antiepileptic drug (AED) in a large population of adults with drug‐resistant focal epilepsy according to the International League Against Epilepsy (ILAE) outcome criteria.

Methods

This is a multicenter, observational, prospective study of 1053 patients with focal epilepsy diagnosed as drug‐resistant by the investigators. Patients were assessed at baseline and 6, 12, and 18 months, for up to a maximum of 34 months after introducing another AED into their treatment regimen. Drug resistance status and treatment outcomes were rated according to ILAE criteria by the investigators and by at least two independent members of an external expert panel (EP).

Results

A seizure‐free outcome after a newly administered AED according to ILAE criteria ranged from 11.8% after two failed drugs to 2.6% for more than six failures. Significantly fewer patients were rated by the EP as having a “treatment failure” as compared to the judgment of the investigator (46.7% vs 62.9%, P < 0.001), because many more patients were rated as “undetermined outcome” (45.6% vs 27.7%, P < 0.001); 19.3% of the recruited patients were not considered drug‐resistant by the EP.

Significance

This study validates the use of ILAE treatment outcome criteria in a real‐life setting, providing validated estimates of seizure freedom in patients with drug‐resistant focal epilepsy in relation to the number of previously failed AEDs. Fewer than one in 10 patients achieved seizure freedom on a newly introduced AED over the study period. Pseudo drug resistance could be identified in one of five cases.

Drug-resistant epilepsy in children with partial onset epilepsy treated with carbamazepine

OBJECTIVE

To evaluate the outcome, including drug-resistant epilepsy (DRE) in children with newly diagnosed partial onset epilepsy treated with carbamazepine (CBZ).

METHODS

A retrospective medical records review and telephone questionnaire were undertaken on a total of 100 subjects.

RESULTS

Long-term follow-up was obtained on 79 children with a mean duration of 7.1 years from CBZ initiation. A total of 66 (83.5%) subjects achieved 2-year seizure remission, 48 (72.7%) subjects did so with CBZ monotherapy. Seven (10.6%) had seizure recurrence after 2-year seizure remission. DRE was diagnosed in seven (8.9%) subjects and five subjects had epilepsy surgery. The mean duration from seizure onset to epilepsy surgery was 5.3 (±2.1) years. Contributing factors for the prolonged duration from seizure onset to epilepsy surgery were identified including: relapsing-remitting course of seizure, family reluctance for epilepsy surgery and uncontrolled psychological problems.

CONCLUSIONS

Over 80% of children with newly diagnosed partial onset epilepsy who were initially treated with CBZ achieved 2-year seizure remission, and more than 70% of this group did so with CBZ monotherapy. The majority of these patients maintained seizure remission overtime. However, 8.9% of this population met the criteria for DRE and most of them had epilepsy surgery. The duration from seizure onset to epilepsy surgery is an important potential area for improvement in DRE patient care.

Multiple anti-epileptic drug use in children with epilepsy in Mulago hospital, Uganda: a cross sectional study

BACKGROUND

Seizures in up to one third of children with epilepsy may not be controlled by the first anti-epileptic drug (AED). In this study, we describe multiple AED usage in children attending a referral clinic in Uganda, the factors associated with multiple AED use and seizure control in affected patients.

METHODS

One hundred thirty nine patients attending Mulago hospital paediatric neurology clinic with epilepsy and who had been on AEDs for ≥6 months were consecutively enrolled from July to December 2013 to reach the calculated sample size. With consent, the history and physical examination were repeated and the neurophysiologic and imaging features obtained from records. Venous blood was also drawn to determine AED drug levels. We determined the proportion of children on multiple AEDs and performed regression analyses to determine factors independently associated with multiple AED use.

RESULTS

Forty five out of 139 (32.4 %) children; 46.7 % female, median age 6 (IQR = 3-9) years were on multiple AEDs. The most common combination was sodium valproate and carbamazepine. We found that 59.7 % of children had sub-therapeutic drug levels including 42.2 % of those on multi-therapy. Sub-optimal seizure control (adjusted odds ratio [OR(a)] 3.93, 95 % CI 1.66-9.31, p = 0.002) and presence of focal neurological deficits (OR(a) 3.86, 95 % CI 1.31-11.48, p = 0.014) were independently associated with multiple AED use but not age of seizure onset, duration of epilepsy symptoms, seizure type or history of status epilepticus.

CONCLUSION

One third of children with epilepsy in Mulago receive multiple AEDs. Multiple AED use is most frequent in symptomatic focal epilepsies but doses are frequently sub-optimal. There is urgent need to improve clinical monitoring in our patients.

Prevalence and correlates of major depressive disorder (MDD) among adolescent patients with epilepsy attending a Nigerian neuropsychiatric hospital

BACKGROUND

A high prevalence of mood disorders exists in patients with epilepsy. In most cases, this is not detected and, consequently, not treated. This study aimed to determine the prevalence and correlates of major depressive disorder (MDD) among adolescents with epilepsy attending a child and adolescent clinic in Nigeria.

METHODS

We recruited 156 participants consecutively for the study. Adherence was assessed using the 8-item Morisky Medication Adherence Questionnaire, while the K-SADS was used to assess the presence of major depressive disorder. Seizure control was evaluated by the frequency of seizures within a year.

RESULTS

Major depressive disorder (DSM-IV criteria) was diagnosed in 28.2% of the participants. The age of participants (p=0.013), seizure control (p=0.03), medication adherence (p=0.045), frequency of seizures in the preceding 4weeks (p<0.001), and duration of illness (p<0.001) were all significantly associated with the presence of MDD. Participants with seizures occurring more than once weekly in the preceding 4weeks were 16 times more likely to have a MDD compared with those with no seizures in the preceding 4weeks (p<0.001, 95% C.I. [4.13, 65.43]), while participants with a duration of illness more than 10years were more than four times likely to have MDD compared with those with an illness duration of 5-10years (p<0.01, 95% C.I. [0.07, 0.70]).

CONCLUSION

The prevalence of MDD among patients with epilepsy was high. Poor seizure control, poor medication adherence, and long duration of illness were associated with the presence of MDD among such patients. Intervention should focus on ensuring good seizure control and optimal adherence in order to mitigate the impact of MDD in patients with epilepsy.

Predictors of spontaneous transient seizure remission in patients of medically refractory epilepsy due to mesial temporal sclerosis (MTS)

PURPOSE

To analyze the predictors of spontaneous transient seizure remission for ≥1 year in patients with drug-resistant epilepsy (DRE) due to mesial temporal sclerosis (MTS).

METHODS

This analysis included 38 patients with DRE (M:F = 20:18, age: 31.7 ± 10.9 years) diagnosed with unilateral MTS (right:left = 16:22). Group I ('remission' group) comprised of patients with seizure remission (M:F = 10:8, age: 32.8 ± 12.3 years, mean seizure free period: 2.2 ± 1.1 years; median: 2.1 years). Group II ('non-remission' group) comprised of age and gender matched 20 patients (M:F = 10:10, age: 30.7 ± 9.7 years) with unilateral MTS who never had seizure remission and subsequently underwent epilepsy surgery. Groups I and II were compared to find the predictors associated with transient seizure remission.

RESULTS

The age at onset of seizures in group I was 13.2 ± 11.8 years and in group II was 12.0 ± 7.6 years. The duration of seizure was: group I - 19.7 ± 12.5 years and group II - 19.3 ± 7.7 years. Past history of seizure remissions (p < 0.001), frequent periods of remissions (p < 0.001), first remission within a year of onset of seizures (p = 0.04) and normal EEG (p = 0.04) were the important clinical predictors associated with seizure remission in this cohort. Fifteen patients in group I (83.3%) experienced remission following either change in AED (p ≤ 0.001) or increase in AED dosages (p < 0.001). There was no difference between the two groups regarding the type of semiology (partial vs. secondarily generalized) (p = 0.50), family history of seizures (p = 1.0), side of the lesion (p = 0.34), history of febrile seizures (p = 1.0) and the number of AEDs used (p = 0.53).

CONCLUSION

The present study unfolds, some of the clinically relevant predictors associated with transient seizure remission in patients with DRE and MTS. Future molecular and network studies are required to understand its mechanism.

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.

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.

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.

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.

A validation of the new definition of drug-resistant epilepsy by the International League Against Epilepsy

OBJECTIVE

To establish applicability, the recently proposed International League Against Epilepsy (ILAE) consensus on drug-resistant epilepsy (DRE) requires testing in clinical and research settings. This study evaluates the reliability and validity of these criteria in a clinical population.

METHODS

In phase I, two independent evaluators reviewed 97 randomly selected medical records of patients with epilepsy at two separate intervals. Both ILEA consensus and standard diagnostic criteria were employed. Kappa, weighted kappa, and intraclass correlation coefficient (ICC) were used to determine interobserver and intraobserver variability. In phase II, ILAE consensus criteria were applied to 250 patients with epilepsy to determine risk factors associated with development of DRE and to calculate point prevalence.

RESULTS

The interobserver agreement of the four definitions was as follows: Berg (0.56), Kwan and Brodie (0.58), Camfield and Camfield (0.69), and ILAE (0.77). The intraobserver agreement of the four definition was as follows: Berg (0.81), Kwan and Brodie (0.82), Camfield and Camfield (0.72), and ILAE (0.82). The prevalence of DRE was the following: with the Berg's definition was 28.4%, Kwan and Brodie 34%, Camfield and Camfield 37%, and with ILAE was 33%.

SIGNIFICANCE

This is first study to establish reliability and validity of ILAE criteria for the diagnosis of DRE. This new definition compares favorably with previously established constructs, which continue to retain clinical significance.

SCN1A variations and response to multiple antiepileptic drugs

In the current study, we have used the haplotype-tagging single-nucleotide polymorphisms (SNPs) to determine associations between genetic variants in SCN1A and treatment response in 519 Caucasian patients with known response status for epilepsy treated with antiepileptic drugs (AEDs) with sodium channel blocking effects. Nine SNPs within SCN1A were genotyped in this cohort. The only association observed was for rs10188577. A greater proportion of drug-resistant patients were heterozygous compared with drug responsive patients (48.3% vs 35.4%, P=0.014). After correction for potential confounding factors, the association for rs10188577 was only marginally significant (P=0.049). In light of our findings, it seems unlikely that rs10188577 could be a major determinant of response to AEDs. However, looking at the influence of rs10188577 on the expressed quantitative trait association patterns within the immediate vicinity of SCN1A, we found significant associations with neighbouring sodium channel genes, SCN7A and SCN9A (P<0.025), which warrants further studies.

Outcomes After Anterior or Complete Corpus Callosotomy in Children

BACKGROUND:

Corpus callosotomy (CC) is a valuable palliative surgical option for children with medically refractory epilepsy due to generalized or multifocal cortical seizure onset.

OBJECTIVE:

To investigate the extent of CC resulting in optimal seizure control in a pediatric patient population and to evaluate the modification of seizure profile after various CC approaches.

METHODS:

The records of 58 children (3–22 years of age at the time of surgery) with medically refractory epilepsy who underwent CC between 1995 and 2011 were retrospectively reviewed.

RESULTS:

Anterior two thirds callosotomy resulted in resolution of absence (P = .03) and astatic (P = .03) seizures, whereas anterior two thirds callosotomy followed by second-stage completion resulted in resolution of generalized tonic-clonic (GTC) (P = .03), astatic (P = .005), and myoclonic (P = .03) seizures in addition to a trend toward resolution of absence seizures (P = .08). Single-stage upfront complete callosotomy resulted in resolution of absence (P = .002), astatic (P &lt; .0001), myoclonic (P = .007), and complex partial (P = .008) seizures in addition to a trend toward resolution of GTC (P = .06). In comparing a composite of subjects who underwent anterior two thirds callosotomy alone or 2-stage complete callosotomy before the second stage to complete the callosotomy with subjects who underwent upfront complete CC, a more favorable outcome was found in those with the upfront complete CC (P = .02).

CONCLUSION:

Single-stage upfront complete callosotomy is effective in relieving a broader spectrum of seizure types than anterior two thirds callosotomy or 2-stage complete callosotomy in children. The advantages of single-stage complete callosotomy must be weighed against the potentially higher risk of neurological and operative complications.

Predicting pharmacoresistance in pediatric epilepsy

Approximately 20% of children with epilepsy will be pharmacoresistant. The impact of intractable epilepsy extends far beyond just the seizures to result in intellectual disability, psychiatric comorbidity, physical injury, sudden unexpected death in epilepsy (SUDEP), and poor quality of life. Various predictors of pharmacoresistance have been identified; however, accurate prediction is still challenging. Population-based epidemiologic studies show that the majority of children who develop pharmacoresistance do so relatively early in the course of their epilepsy. However, approximately one third of children who initially appear pharmacoresistant in the first few years after epilepsy onset will ultimately achieve seizure freedom without surgery. The most significant predictor that early pharmacoresistance will not remit is the presence of a neuroimaging abnormality. Such children should be strongly considered for surgical evaluation.

Quantitative analysis of structural neuroimaging of mesial temporal lobe epilepsy

Mesial temporal lobe epilepsy (MTLE) is the most common of the surgically remediable drug-resistant epilepsies. MRI is the primary diagnostic tool to detect anatomical abnormalities and, when combined with EEG, can more accurately identify an epileptogenic lesion, which is often hippocampal sclerosis in cases of MTLE. As structural imaging technology has advanced the surgical treatment of MTLE and other lesional epilepsies, so too have the analysis techniques that are used to measure different structural attributes of the brain. These techniques, which are reviewed here and have been used chiefly in basic research of epilepsy and in studies of MTLE, have identified different types and the extent of anatomical abnormalities that can extend beyond the affected hippocampus. These results suggest that structural imaging and sophisticated imaging analysis could provide important information to identify networks capable of generating spontaneous seizures and ultimately help guide surgical therapy that improves postsurgical seizure-freedom outcomes.

Early predictors of outcome in newly diagnosed epilepsy

Longitudinal studies of newly diagnosed epilepsy in children and adults have identified prognostic factors that allow early identification of patients whose seizures are likely to remain uncontrolled with antiepileptic medication. Results from outcome studies may be subject to bias, depending on the setting (community versus clinic), design (retrospective versus prospective) and characteristics of the patient cohort studied (age, types of epilepsy, specific comorbidities). Nevertheless, factors such as early response to medication, underlying aetiology, and number of seizures prior to initiation of treatment have consistently been found to be predictive of seizure outcomes. Other variables such as age, electroencephalographic findings and the presence or absence of psychiatric co-morbidities have been correlated with outcomes in some analyses. This review has examined studies of seizure outcomes in adults and children with newly diagnosed epilepsy identifying the risk factors that are associated with subsequent refractory epilepsy.

What predicts enduring intractability in children who appear medically intractable in the first 2 years after diagnosis?

PURPOSE

In a population-based retrospective cohort of children with newly diagnosed epilepsy, to determine (1) what proportion meet criteria for early medical intractability, and (2) predictors of enduring intractability.

METHODS

Children with newly diagnosed epilepsy between 1980 and 2009 while resident in Olmsted County, MN, and followed >36 months, were stratified into groups based on both early medical intractability ("apparent" medical intractability in the first 2 years) and enduring intractability (persisting intractability at final follow-up or having undergone surgery for intractable epilepsy), and variables predicting these outcomes were evaluated.

KEY FINDINGS

Three hundred eighty-one children were included, representing 81% of our cohort with newly diagnosed epilepsy. Seventy five (19.7%) had early medical intractability, and predictors of this outcome on multivariable analysis were neuroimaging abnormality (risk ratio, 2.70; p = 0.0004), abnormal neurologic examination at diagnosis (risk ratio, 1.87; p = 0.015), and mode of onset (association was significant for focal vs. generalized onset [risk ratio, 0.25; p < 0.0001] but not unknown vs. generalized onset [p = 0.065]). After a median follow-up of 11.7 years, 49% remained intractable, 8% had rare seizures (≤ every 6 months), and the remainder were seizure-free. The only factor predicting enduring intractability on multivariable analysis was neuroimaging abnormality (risk ratio, 7.0; p = 0.0006).

SIGNIFICANCE

Although a significant minority of children with early medical intractability ultimately achieved seizure control without surgery, those with an abnormal imaging study did poorly. For this subgroup, early surgical intervention is strongly advised to limit comorbidities of ongoing, intractable seizures. Conversely, a cautious approach is suggested for those with normal imaging, as most will remit with time.

Characterization of the supplementary motor area syndrome and seizure outcome after medial frontal lobe resections in pediatric epilepsy surgery

BACKGROUND

In adults, resection of the medial frontal lobe has been shown to result in supplementary motor area (SMA) syndrome, a disorder characterized by transient motor impairment. Studies examining the development of SMA syndrome in children, however, are wanting.

OBJECTIVE

To characterize the development of SMA syndrome and to analyze seizure outcomes after surgery in the medial frontal lobe for medically intractable epilepsy.

METHODS

Thirty-nine patients with medically intractable epilepsy who underwent surgery in the medial frontal lobe were reviewed retrospectively. The progression of neurological impairment and seizure outcome after surgery was recorded, and the extent of cortex resected was analyzed.

RESULTS

After resection in the region of the SMA, 23 patients (59%) developed postoperative neurological impairment; 17 (74%) were identified as SMA syndrome. No neurological impairment was found after surgery in 16 patients (41%). Six patients (15%) experienced permanent neurological impairment. The majority of patients (82%) who developed SMA syndrome had resolution of their symptoms by 1 month postoperatively. Preoperative magnetic resonance imaging finding of lesional cases was associated with a significantly decreased likelihood of developing SMA syndrome (P = .02). Seizure outcome was favorable after surgery in most patients.

CONCLUSION

Surgery for medically intractable epilepsy in the region of the medial frontal cortex is effective and associated with reversible neurological impairment in children. All patients had resolution of their SMA syndrome by 6 months postoperatively.

Refractory epilepsy: one size does not fit all

A unifying definition of refractory epilepsy has been hotly debated but, to date, has not been agreed upon. Evidence from clinical trials indicates that some patients actually are not refractory, as many will partially respond to add-on treatment or will worsen when antiepileptic drugs (AEDs) are removed. There are several important issues relating to the assessment of AED response that routinely have not been addressed in the determination of treatment responsiveness, such as incorporating baseline seizure severity, including partial response rather than solely an all-or-none response, and the consideration of variability in response over time.

When to start drug treatment for childhood epilepsy: the clinical-epidemiological evidence

INTRODUCTION

Many data on the course and prognosis after provoked and unprovoked single and multiple seizures in childhood have been collected in the past decennia by prospective, large-scale, long-term observational cohort studies. These data may serve to guide treatment decisions and help to design controlled trials investigating treatment strategies in childhood epilepsy.

METHODS

The results of the Dutch study of epilepsy in childhood will be compared with those of other studies. We will also discuss the potential consequences of these results for the "why" and "when" of the decision to start treatment.

RESULTS

Recurrence after a solitary unprovoked seizure in childhood is about 50%. Those with a recurrence have a similar outcome of their epilepsy compared to children presenting with multiple seizures, regardless whether they were treated after the first seizure or not. This argues in favour of postponing anti-epileptic drug (AED) treatment until at least a second seizure has occurred. After an unprovoked status epilepticus (SE), later outcome is not worse than after presentation with a short seizure. Therefore, long-term AED treatment after a single unprovoked SE may not be necessary either. The same holds true for children presenting with a short (less than one week) burst of unprovoked seizures. One quarter of them do not have recurrences and the final prognosis of children with recurrences does again not differ from the prognosis of the entire cohort. Findings in new-onset epilepsy further indicate that AED treatment can be safely omitted or at least postponed in about 15%, especially those with only a small number of seizures before presentation, those with benign partial epilepsy and those with sporadic generalised tonic-clonic seizures. On the reverse side, three considerations might lead to the decision to start early and aggressive treatment: the dangers of the seizures, the chance of intractability and the possibility of intellectual decline caused by recurrent seizures or epileptic activity. In idiopathic generalised absence epilepsy, the risks of accidents and learning problems indeed prompt early AED treatment. A self-propagating mechanism of seizures promoting the occurrence of more seizures, in the end causing intractable epilepsy (Gowers), occurs only rarely. Real intractability is seen in only 5-15% of the children with new-onset epilepsy. The chance of intractability is increased by variables like symptomatic aetiology, localisation-related epilepsy, and an early unfavourable course. Landau-Kleffner or continuous spikes and waves during sleep (CSWS) syndrome cause cognitive decline and syndromes like West, Lennox-Gastaut or Dravet's induce both psychomotor regression and intractability. In such cases, early aggressive treatment is indicated, including early consideration of the ketogenic diet, immunotherapy, vagus nerve stimulation and, if possible, referral for epilepsy surgery.

CONCLUSIONS

Omitting or postponing treatment after a solitary seizure, an unprovoked SE, a single burst of seizures or multiple infrequent seizures usually does not worsen the prognosis. A poor prognosis and the consequent indication for early and aggressive treatment are dependent mainly upon the presence of variables like symptomatic aetiology, certain epilepsy types and syndromes, and the early evolution of the epilepsy in that particular child. Intellectual decline caused by seizures or epilepsy is rare and may be confined to certain specific and readily recognizable syndromes.

Multidrug resistance in epilepsy and polymorphisms in the voltage-gated sodium channel genes SCN1A, SCN2A, and SCN3A: correlation among phenotype, genotype, and mRNA expression

OBJECTIVES

Many antiepileptic drugs (AEDs) prevent seizures by blocking voltage-gated brain sodium channels. However, treatment is ineffective in 30% of epilepsy patients, which might, at least in part, result from polymorphisms of the sodium channel genes. We investigated the association of AED responsiveness with genetic polymorphisms and correlated any association with mRNA expression of the neuronal sodium channels.

METHODS

We performed genotyping of tagging and candidate single nucleotide polymorphisms (SNPs) of SCN1A, 2A, and 3A in 471 Chinese epilepsy patients (272 drug responsive and 199 drug resistant). A total of 27 SNPs were selected based on the HapMap database. Genotype distributions in drug-responsive and drug-resistant patients were compared. SCN2A mRNA was quantified by real-time PCR in 24 brain and 57 blood samples. Its level was compared between patients with different genotypes of an SCN2A SNP found to be associated with drug responsiveness.

RESULTS

SCN2A IVS7-32A>G (rs2304016) A alleles were associated with drug resistance (odds ratio = 2.1, 95% confidence interval: 1.2-3.7, P=0.007). Haplotypes containing the IVS7-32A>G allele A were also associated with drug resistance. IVS7-32A>G is located within the putative splicing branch site for splicing exons 7 and 9. PCR of reverse-transcribed RNA from blood or brain of patients with different IVS7-32A>G genotypes using primers in exons 7 and 9 showed no skipping of exon 8, and real-time PCR showed no difference in SCN2A mRNA levels among genotypes.

CONCLUSION

Results of this study suggest an association between SCN2A IVS7-32A>G and AED responsiveness, without evidence of an effect on splicing or mRNA expression.

First-drug treatment failures in children newly diagnosed with epilepsy

In adults newly diagnosed with epilepsy, treatment with the first prescribed antiepileptic drug fails for approximately one half. In two studies that addressed this question in children, the failure rates were 20% and 40%. The present study used a detailed chart review of children newly diagnosed with epilepsy over a 4-year span in a major childhood epilepsy referral clinic to assess (1) the percentage of children for whom first-line antiepileptic drug treatment failed and (2) the reasons for the treatment failure. Charts were reviewed for 95 children who were diagnosed with epilepsy, started on their first antiepileptic drug, and then monitored for approximately 5 years. Of these 95 children, 48 were classified as having idiopathic epilepsy (50.5 %), 30 as having cryptogenic epilepsy (31.6%), and 17 as having symptomatic epilepsy (17.9%). The two main antiepileptic drugs used were valproic acid (43.2% of patients) and carbamazepine (38.9% of patients). Treatment with the first antiepileptic drug failed in 30/95 children (31.6%). Treatment failure was due to adverse effects in 12/30 children (40.0%), due to lack of efficacy in 11/30 (37.9%), and due to both adverse effects and lack of efficacy in 7/30 (24.1%). Also examined was the effect on treatment failure of patient age at diagnosis, antiepileptic drug choice, maximum drug dose, etiology of epilepsy, and particular epilepsy syndromes on treatment failures; there was no statistically significant effect of any of these variables on first-line treatment outcome. In this population, approximately one third of children newly diagnosed with epilepsy experienced treatment failure with the first antiepileptic drug used. Lack of efficacy and unacceptable adverse effects contributed equally to these treatment failures.

Growing up with epilepsy: a two-year investigation of cognitive development in children with new onset epilepsy

PURPOSE

To characterize patterns and determinants of normal and abnormal cognitive development in children with new onset epilepsy compared to healthy controls.

METHODS

Longitudinal (2-year) cognitive growth was examined in 100 children, age 8-18 years, including healthy controls (n = 48) and children with new onset epilepsy (n = 52). Cognitive maturation was examined as a function of the presence/absence of two neurobehavioral comorbitiies (attention deficit hyperactivity disorder and/or academic problems) identified at the time of epilepsy diagnosis. Groups were compared across a comprehensive neuropsychological battery assessing intelligence, academic achievement, language, memory, executive function, and psychomotor speed.

RESULTS

Children with new onset epilepsy without neurobehavioral comorbidities were comparable to healthy controls at baseline, rate of cognitive development, and follow-up assessment across all neuropsychological domains. In contrast, the presence of neurobehavioral comorbidities was associated with significantly worse baseline and prospective cognitive trajectories across all cognitive domains, especially executive functions.

CONCLUSION

The presence of neurobehavioral comorbidities at the time of epilepsy onset is a major marker of abnormal cognitive development both prior to and after the onset of epilepsy.

Pharmacologically intractable epilepsy in children: diagnosis and preoperative evaluation

It is important to correctly diagnose medically intractable epilepsy in children and to identify those children whose medically refractory, localization-related seizures may be surgically remediable as soon as possible to optimize the surgical outcome. In this paper the authors review the definition of medically intractable seizures and discuss the various causes and risk factors for this disorder in children. They also outline the presurgical diagnostic evaluation process for pharmacologically intractable epilepsy in children who may be candidates for surgical treatment of localization-related seizures. The treatment of children with medically intractable epilepsy is both challenging and rewarding. Surgery has the potential of altering the natural history of epilepsy by improving or eliminating seizures in carefully selected patients.

Assessing severity of epilepsy in children: preliminary evidence of validity and reliability of a single-item scale

The development and initial validity and reliability testing of a single-item, 7-point global rating scale designed for neurologists to assess the overall severity of epilepsy in children, the Global Assessment of Severity of Epilepsy (GASE) Scale, is described. The GASE Scale was quick and easy to use. Median epilepsy severity in the development sample was 3 (moderately severe), with a range from 1 ("not severe at all") in 36 patients (26.9%) to 7 ("extremely severe") in 7 patients (5.2%). Preliminary evidence of construct validity was found in support for our a priori predictions of associations between GASE scores and neurologists' ratings of seven individual clinical aspects of epilepsy and in a cumulative R(2) for the GASE score of 81% using ratings of the clinical aspects of epilepsy. Weighted kappa was 0.85 (95% CI: 0.79, 0.90) for inter-rater reliability and 0.90 (95% CI: 0.82, 0.98) and 0.95 (95% CI: 0.91, 0.98) for test-retest reliability for each of two raters. These promising initial results support continuation of the multistage process of testing the validity and reliability of the GASE Scale within various clinical contexts.

Risk factors predicting refractoriness in epileptic children with partial seizures

The aim of this retrospective study was to determine the risk factors associated with intractability to therapy in childhood epilepsy. Fifty children with intractable epilepsy as evidenced by at least 1 epileptic fit per month were included in the study group, whereas the control group consisted of children who did not experience any recurrent seizure for at least 1 year at the time of the study. A chi( 2) test was used to evaluate the relationship between the test variables for the 2 groups, and the estimated relative risk (odds ratio) for each variable was calculated. The risk factors were subsequently determined by logistic multiple regression analysis. Univariate analysis showed that mental retardation, neurological abnormality, neuroradiological abnormality, perinatal anoxia, neonatal convulsion, presence of status epilepticus, and symptomatic etiology were significant risk factors for the development of refractory epilepsy (P < .05). For multivariate logistic regression analysis, age at seizure onset, status epilepticus, mixed type of seizures, and history of frequent seizures (more than once a month) were all found to be significant and independent risk factors for refractory epilepsy, and the number of drugs used in the study group was significantly higher than that in the control group (P < .05). In line with these findings, it was concluded that children who present with epilepsy and have these risk factors should be referred to a center where epileptic surgery is carried out without delay.

How long does it take for epilepsy to become intractable? A prospective investigation

OBJECTIVE

To determine prospectively when in the course of epilepsy intractability becomes apparent.

METHODS

Data are from a prospective cohort of 613 children followed for a median of 9.7 years. Epilepsy syndromes were grouped: focal, idiopathic, catastrophic, and other. Intractability was defined in two ways: (1) 2 drugs failed, 1 seizure/month, on average, for 18 months (stringent), and (2) failure of 2 drugs. Delayed intractability was defined as 3 or more years after epilepsy diagnosis.

RESULTS

Eighty-three children (13.8%) met the stringent and 142 (23.2%) met the two-drug definition. Intractability depended on syndrome (p < 0.0001): 26 (31.3%) children meeting stringent and 39 (27.5%) meeting the 2-drug definition had delayed intractability. Intractability was delayed more often in focal than catastrophic epilepsy (stringent: 46.2 vs 14.3%, p = 0.003; two-drug: 40.3 vs 2.2%, p <or= 0.0001). Early remission periods preceded delayed intractability in 65.4 to 74.3% of cases. After becoming intractable, 20.5% subsequently entered remission and 13.3% were seizure free at last contact.

INTERPRETATION

Intractable epilepsy may be delayed, especially in focal epilepsy. It often is preceded by a quiescent period, followed by further remissions. These findings help explain why surgically treatable epilepsies may take 20 years or longer before referral to surgery.

Understanding the delay before epilepsy surgery: who develops intractable focal epilepsy and when?

Intractable temporal lobe epilepsy that is surgically treated in adulthood is a disorder whose onset frequently occurs during childhood and early adolescence. The average duration of epilepsy prior to surgery is on the order of 20 years. The long delay between onset and surgery has at least two components: time from onset to intractability and time from evidence of intractability to surgery. The first interval is prolonged >10 years especially if the onset is during childhood. This suggests a complex natural history that we have not fully appreciated as well as a potential window of opportunity for early secondary intervention. The second interval is also prolonged, especially if onset was during childhood. Reasons for this are not fully clear but may include a reluctance to consider surgery and perhaps difficulty deciding whether seizures are sufficiently intractable to warrant surgery especially after what may have been a relatively benign initial course. Factors involved in the second delay need to be better understood so that surgical interventions can be appropriately targeted early rather than late, thereby reducing serious social, psychological, and educational consequences associated with uncontrolled seizures.

Drug treatment of epilepsy: when does it fail and how to optimize its use?

Although modern community-based studies have shown that a majority of people with newly diagnosed epilepsy will enter long-term remission, seizures remain refractory to treatment in a substantial proportion of this population--perhaps as much as 40%. A consensus is being reached that, for operational purposes, pharmacoresistance can be suspected when two appropriately chosen, well-tolerated, first-line antiepileptic drugs (AEDs) or one monotherapy and one combination regimen have failed due to lack of efficacy. Poor prognostic factors include lack of response to the first AED, specific syndromes, symptomatic etiology, family history of epilepsy, psychiatric comorbidity, and high frequency of seizures. These observations suggest that prognosis can often be determined early in the course of the disorder. We propose a management paradigm that aims to maximize the chance of successful AED therapy, including the early use of "rational polytherapy" for patients not responding to monotherapy, and to identify efficiently patients suitable for "curative" resective surgery, in particular those with mesial temporal lobe epilepsy. An orderly approach to each epilepsy syndrome will optimize the chance of perfect seizure control and help more patients achieve a fulfilling life.

Spontaneous long-term remission of intractable partial epilepsy in childhood

Drug-resistant partial epilepsy in children often has a major impact on cognitive development, and early surgical intervention has been advocated to prevent adverse neurobehavioral effects of seizures in such patients. We report a 5-year-old boy who had cryptogenic partial epilepsy of right parietal origin as documented by ictal electroencephalogram (EEG) and glucose metabolism positron emission tomographic (PET) scan. His atonic seizures could not be controlled by multiple antiepilepsy drugs; therefore, cortical resection was scheduled. However, his seizures remitted spontaneously after 1 year of failed medical treatment. The epileptiform abnormality disappeared on the follow-up EEGs, and a glucose PET scan also normalized. This boy has fully retained his cognitive and motor functions and has remained seizure free in the past 4z\x years off medications.

Update on the epidemiology and prognosis of pediatric epilepsy

Epilepsy is among the most common serious neurologic disorders in childhood. Epidemiologic studies over the past few decades have greatly increased current knowledge of the incidence and prognosis of seizures. Newer epidemiologic studies have used population- or community-based cohorts, and careful attention has been given to etiology and specific epilepsy syndromes, the two most important factors affecting prognosis. Risk of epilepsy is highest in patients with an associated serious neurologic abnormality, such as mental retardation or cerebral palsy. More than two thirds of patients with childhood-onset epilepsy ultimately achieve remission. Of those attaining remission on medications, approximately 70% remain seizure free when medications are discontinued. Mortality is increased in patients with epilepsy, but the increased mortality risk in childhood-onset epilepsy is primarily seen in patients with neurologic abnormalities or intractable epilepsy. Although long-term seizure outcomes are generally favorable, childhood-onset epilepsy is associated with adverse long-term psychosocial outcomes, even in patients attaining remission. This review summarizes recent data on the epidemiology and prognosis of pediatric epilepsy.

Two-year remission and subsequent relapse in children with newly diagnosed epilepsy

PURPOSE

Although remission is the ultimate measure of seizure control in epilepsy, and epilepsy syndrome should largely determine this outcome, little is known about the relative importance of syndrome versus other factors traditionally examined as predictors of remission or of relapse after remission. The purpose of this study was to examine remission and relapse with respect to the epilepsy syndrome and other factors traditionally considered with respect to seizure outcome.

METHODS

A prospectively identified cohort of 613 children with newly diagnosed epilepsy was assembled and is actively being followed to determine seizure outcomes. Epilepsy syndrome and etiology were classified at diagnosis and again 2 years later. Remission was defined as 2 years completely seizure-free, and relapse as the recurrence of seizures after remission. Multivariable analysis was performed with the Cox proportional hazards model.

RESULTS

Five hundred ninety-four of the original 613 children were followed > or = 2 years (median follow-up, 5 years). Remission occurred in 442 (74%), of whom 107 (24%) relapsed. On multivariable analysis, idiopathic generalized syndromes and age at onset between 5 and 9 years were associated with a substantially increased remission rate, whereas remote symptomatic etiology, family history of epilepsy, seizure frequency, and slowing on the initial EEG were associated with a decreased likelihood of attaining remission. Young onset age (<1 year) and seizure type were not important after adjustment for these predictors. Relapses occurred more often in association with focal slowing on the initial EEG and with juvenile myoclonic epilepsy. Benign rolandic epilepsy and age at onset <1 year were associated with markedly lower risks of relapse. About one fourth of relapses were apparently spontaneous while the child was taking medication with good compliance, and more than half occurred in children who were tapering or had fully stopped medication.

CONCLUSIONS

A large proportion of children with epilepsy remit. Symptomatic etiology, family history, EEG slowing, and initial seizure frequency negatively influence, and age 5-9 years and idiopathic generalized epilepsy positively influence the probability of entering remission. Factors that most influence relapse tend to be different from those that influence remission.