Unilateral truncal seizures: frontal origin.

The locus of origin of seizures involving the muscles of the trunk is unresolved. The brainstem has been postulated by some investigators, whereas others have implicated the parietal cortex. We report a patient with epilepsia partialis continua involving the rectus abdominus of one side in whom each contraction correlated with an epileptiform complex in the contralateral central-vertex scalp region. This appears to be the first instance in which ictal EEG has localized truncal seizures to an area that probably corresponds to the precentral cortex.