PREDICTORS OF INTRACTABLE EPILEPSY IN CHILDHOOD - A CASE-CONTROL STUDY

Little is known about what factors predict intractable epilepsy at the time of initial diagnosis. We performed a case-control study to ident ify early predictors of medically intractable epilepsy in children. Ca ses were children who had an average of one seizure or more a month ov er a 2-year period and who, during that time, had failed trials of at least three different antiepileptic drugs (AEDs). Controls were childr en who had epilepsy, who had been seizure-free for greater than or equ al to 2 years, and who had never, before becoming seizure-free, met th e definition for intractable epilepsy. Strong univariate associations were noted between intractability and several factors: infantile spasm s (IS) remote symptomatic epilepsy, a history of status epilepticus (S E) before the diagnosis of epilepsy, neonatal seizures, and microcepha ly. Cases were significantly younger than controls at onset (1.8 vs. 5 .8 years); this was not due solely to cases with onset during the firs t year of life but was an association apparent throughout the age rang e studied, With multiple logistic regression, independent predictors o f intractability were IS, odds ratio(OR) = 10.32, p = 0.03; age at ons et with a decreasing risk with increasing age, OR = 0.77 per year, p < 0.0001; remote symptomatic epilepsy, OR = 2.24, p = 0.04; and SE, OR = 3.30, p = 0.04. These findings complement those of recent cohort stu dies of remission of epilepsy and provide useful leads for future pros pective studies of intractable epilepsy.