Abstracts

Childhood onset epileptic encephalopathies, including infantile spasms (IS), are disorders in which patients with frequent uncontrolled seizures are at risk for significant cognitive and neurologic disabilities. Resective neurosurgery is a treatment option for symptomatic therapy-resistant IS patients if there is a unilateral cortical abnormality[sub]^. [/sub]This study was designed to compare the pre- and post-surgery clinical, seizure, and developmental outcomes in infant-onset epilepsy patients with or without a history of IS. Patients with infant-onset epilepsy were classified into those with medically refractory active IS (active IS; n=39), successfully treated IS but persistent seizures (Rx[rsquo]d IS; n=46), or no history of IS (no H/O IS; n=69). These groups were compared for pre-surgery clinical variables and EEG abnormalities, post-surgery seizure control and anti-epilepsy drug usage, and pre- and post-surgery Vineland Adaptive Behavior Scale (VABS) developmental quotients (DQ). Infant-onset seizures occurred in 55.5% of pediatric epilepsy surgery patients, and 55.6% of children with infant-onset seizures had IS. Active IS were the youngest, Rx[rsquo]d IS intermediate, and no H/O IS cases the oldest at the the time of video-EEG monitoring and surgery. Similarly, active IS had the shortest, Rx[rsquo]d IS intermediate, and no H/O IS patients the longest intervals from seizure onset to video-EEG monitoring and surgery. Compared with the other IS groups, active IS patients had increased interictal contralateral spikes and slowing, bilateral paroxysmal fast activity, and greater morbidity and mortality. Rx[rsquo]d IS patients had numerically better seizure control 0.5 to 2 years post-surgery. Increased post-surgery VABS DQ scores were associated with greater pre-surgery DQs, Rx[rsquo]d IS patient group, seizure control, and shorter seizure durations. Infantile spasms were frequent in pediatric epilepsy surgery patients, and whether IS responded to medical therapy influenced pre-surgery referral, and post-surgery seizure and developmental outcomes. Furthermore, better post-surgery DQ scores were associated with shorter seizure histories, seizure freedom, and better pre-surgery DQ scores. These findings support the concept that infant-onset epilepsy surgery patients with or without IS are at risk for seizure-induced encephalopathy, and should be evaluated and treated promptly. (Supported by NIH grants RO1 NS38992 and PO5 NS02808 to GWM and NS39505 to RFA)