Abstracts

Rationale: Decisions about treatment after a first recognized seizure are usually based on the expectation of recurrence. Prior studies have found that children with very early onset seizures, symptomatic seizures, abnormal neurological examinations, and/or intellectual disability are at higher risk for developing recurrent seizures. Children without these risk factors may still develop persistent seizures but there are few data to help predict recurrence. The purpose of this study was to determine risk factors for persistent seizures in a generally healthy group of child with first recognized seizures.Methods: The 282 children, ages 6-14 years, were part of a study of first recognized seizures. None of the children had mental retardation. Seizure history was obtained at baseline, 18 and 36 months. Seizures were considered persistent if they occurred between every available assessment. Variables assessed were age of seizure onset, IQ, psychotropic drug use, prior unrecognized seizures (n=102), seizure type and epilepsy syndrome, antiepileptic drug (AED) use, and results of neurological examination, EEG, and MRI. Results: Persistent seizures occurred in 42/282 (15%) children. There was no association between persistent seizures and age at seizure onset, neurological examination, presence of epileptiform activity or slowing on EEG, IQ, seizure type, epilepsy syndrome, or psychotropic drug use. Children with prior unrecognized seizures were significantly more likely to have persistent seizures (p=0.002). Persistent seizures occurred in 23.5% of the children with prior unrecognized seizures and 10.0% of those with true first seizures. Children with a normal MRI were less likely to have persistent seizures (p=0.049). At baseline, AED use was not associated with subsequent persistent seizures, though at follow up, AED use was associated with recurrent seizures. Conclusions: Prospective studies of adults (Hauser et al., 1998) and children (Shinnar et al., 2000) after first seizure have shown that having a second seizure substantially increases the likelihood of multiple recurrent seizures. Out study extends this find by showing that the presence of a prior unrecognized seizure at baseline assessment significantly increases the risk for persistent seizures. The presence at baseline of prior unrecognized seizures suggests the need for initiation of AEDs. Funding supported by: NIH/NINDS #22416 References: 1. Hauser AW, Rich SS, Lee JR, et al. Risk of recurrent seizures after two unprovoked seizures. N Eng J Med 1998; 338:429-434. 2. Shinnar S, Berg AT, O’Dell C, et al. Predictors of multiple seizures in a cohort of children prospectively followed from the time of their first unprovoked seizure. Ann Neurol 2000; 48: 140-147.