Nonlissencephalic cortical dysplasias: correlation of imaging findings with clinical deficits.

PURPOSE: To establish correlations between MR patterns and clinical outcome in patients with nonlissencephalic cortical dysplasias. PATIENTS AND METHODS: MR and clinical data from 36 patients with cerebral cortical gyral anomalies (other than classical type I or type II lissencephaly) were retrospectively reviewed. RESULT: The five patients with diffuse cortical dysplasia, including two with congenital infections, had microcephaly and severe development delay from a very early age. Infantile spasms occurred in three of the five. Focal areas of cortical dysplasia were most common in the frontal lobes, but were seen in all areas of the brain. The most common MR appearances were 1) a thickened, irregularly bumpy cortex with shallow, wide sulci, and 2) a deep infolding of thickened cortex. The twelve patients with bilateral focal dysplasia had a high incidence of bilateral motor dysfunction (67%), delayed speech (67%), and generalized developmental delay (92%). When the dysplasia was unilateral, contralateral spastic hemiplegia or monoplegia was present in 14 of 19 patients (74%), but dysphasia was uncommon, even in patients with dysplasia in the frontal lobe of the dominant hemisphere. CONCLUSION: Surgical resection of focal areas of cortical dysplasia in patients with medically refractory seizures is becoming more common, and the neuroradiologist will play an increasingly important role in the initial diagnosis and delineation of these anomalies.