ABSTRACT
Predicting which children are destined to develop medically intractable seizures would be very helpful in developing treatment strategies that would be more aggressive than in children with easily controlled epilepsy. Little is known about the natural history, particularly the time course of development, of refractory epilepsy. To identify clinical, electroencephalographic [EEC] and neuroradiological factors associated with both seizure control and medical intractability in children with epilepsy and to be acquainted with predictors of uncontrolled seizures. A case-control study to identify predictors of medically intractable epilepsy in children. Cases were children who had an average of one seizure or more a month over a 2-year period and who, during that time, had failed trials of at least three different anti-epileptic drugs [AEDs]. Controls were children who had epilepsy, who had been seizure-free for >/= 2 years, and who had never, before becoming seizure-free, met the definition for intractable epilepsy. Features of clinical findings, EEG and Magnetic Resonance Imaging [MR1] were compared in 20 children with well controlled seizures and 40 with intractable epilepsy using contingency 2x2 tables for inference of associations, odds ratios, predictive values, sensitivity and specificity. Logistic regression -was performed for multivariate analysis. Strong associates of clinical factors with intractability included: age at onset; duration of epilepsy; multiple types of seizures; complex partial, simple partial, tonic, atonic and myoclonic seizures; initial seizure frequency; history of status epilepticus; history of febrile seizures; duration of fit at onset; lapse of time before treatment; receiving more than one A ED; a symptomatic etiology of the seizures, and abnormal magnetic resonance imaging [MRl] of the brain. Strong associates were noted between intractability and several EEG factors: abnormal EEG background including diffuse slowing, asymmetry and high frequency spikes. These factors were predictors of refractory epilepsy. With multiple logistic regression, independent predictors of intractability included: early risk factors, complex partial seizures and multi-focal or focal epileptic discharges with secondary generalization. There are a number of clinical, EEG and neuroradiological features that can be identified early in the course of childhood epilepsy that are predictive of outcome. These findings will need to be verified in a prospective study