Abstracts

Rationale: There is a broad consensus that antiepileptic drugs (AEDs) may be withdrawn after two years of seizure freedom for most children with epilepsy. If seizures recur off AEDs and are again completely controlled with AEDs, there is little known about discontinuing a second time. We surveyed American and Canadian pediatric epileptologists to understand their current practice. Methods: In 2014, a survey was sent via email to 193 pediatric epileptologists who were identified through membership lists of the American Epilepsy Society, Child Neurology Society, Canadian Pediatric Epilepsy Network or the American Board of Psychiatry and Neurology Certification. Respondents with ≥25 years in practice were defined as "experts," 10-24 years as "more experienced (ME)," and <10 years as "less experienced (LE)." Wilcoxon matched-pairs signed-ranks test were used to evaluate differences between first and second attempts to discontinue AEDs. Results: There were 94 (49%) completed surveys (27 experts, 36 ME, 31 LE). The mean years of practice was 17.1 (expert 31±4, ME 16±5, LE 6±2). Overall, 62% recommended AED discontinuation for the first time after 2-3 years seizure-free and 61% recommended discontinuation for the second time after 2-3 years. Fifty-six percent of experts and 56% of ME clinicians required a longer seizure-free period prior to a second discontinuation (expert, p = 0.001; ME, p =0.001) compared to 26% of LE clinicians (p = ns). Overall, 53% suggested 2-6 months for the first AED taper duration and 69% for the second. All three groups wean AEDs more slowly during the second attempt (p = 0.002). The presence of the following factors negatively influenced their decisions to discontinue AEDs the second time more so than the first time: age <2 years at onset, polytherapy, abnormal neurological exam but not intellectual disability, "therapeutic" blood levels and selected epilepsy syndromes. The following factors positively influenced their decisions to discontinue AEDs the second time but less so than the first time: normal EEG, low blood levels, unknown cause, normal EEG and selected epilepsy syndromes (all positive and negative factors listed were statistically significant). Six "real life" cases presented mixtures of factors for the decision to discontinue AEDs for a second time. Respondents were asked if they would or would not discontinue. For 2 cases (Doose syndrome and unknown cause with normal EEG) there was reasonable agreement to discontinue (87% and 96%); however, for 4 cases (cortical dysplasia, congenital hemiparesis, unknown cause + EEG spikes, and JME) there was only 40-60% agreement. Conclusions: Many pediatric epileptologists require a longer seizure-free period the second time they attempt to discontinue AEDs compared to the first attempt and wean down AEDs somewhat more slowly. Although a variety of factors influence decision making there is a high level of disagreement to discontinue AEDs a second time in "real life" cases.