Longitudinal brain volumes in children with intractable partial seizures.

Cross sectional studies in children with epilepsy have reported variable changes in brain volume. The study hypothesis was that seizures result in injury to the developing brain, which is manifested as a reduction in brain volume. The aim was to evaluate the gray and white matter volumes longitudinally in children with partial epilepsy. All patients had two magnetic resonance scans, 1-7 years apart. The total, cerebral, and hemispheric gray and white matter volumes of 20 children with intractable partial epilepsy were measured. The correlation between change in volume and age at epilepsy onset and duration of epilepsy were assessed. There were no significant differences in total, cerebral, or hemispheric gray and white matter volumes with time. Up to six patients exhibited greater than 10% volume loss in total, cerebral, or hemispheric gray or white matter. There were no significant correlations between change in volume and age or duration of epilepsy. The findings suggest that volume loss does not occur in the shorter-term monitoring of children with partial seizures. It is possible that volume loss could become evident with long-term monitoring of children with epilepsy. Alternatively, brain volume may be an insensitive measure of alteration in brain structure secondary to epilepsy, and that other imaging techniques, such as diffusion tensor imaging, may be more sensitive for detecting microstructural changes induced by recurrent seizures.