Unilateral periventricular nodular heterotopia associated with diffuse areas of cerebral functional abnormalities

A 17-year-old boy with polymorphic simple and complex partial seizures is d escribed. Magnetic resonance imaging revealed a unilateral periventricular nodular heterotopia near the occipital ventricular right horn. Interictal a nd ictal electroencephalographic recordings showed bilateral specific epile ptiform anomalies in the occipital region and asynchronous slow waves in fr ontal areas. Single photon emission computed tomography documented a reduct ion in regional cerebral blood flow in an area of the left occipital cortex and a symmetric increase in tracer uptake in the frontal lobes. The neurop sychologic assessment revealed a dysfunction of the frontal associative are as. Data collected led the authors to suspect a more diffuse cortical dysfu nction than the nodular heterotopia revealed on magnetic resonance imaging.