Computed tomographic appearance of lissencephaly syndromes.

Lissencephaly is a rare malformation of the human brain manifest by a smooth cerebral surface. It is usually associated with other brain anomalies. The computed tomographic appearance in nine patients with lissencephaly, representing several separate types and syndromes, is reported. Common manifestations include a smooth cerebral surface and absent opercula that may lend a figure-eight appearance to the brain and smooth subsurface lines that represent abnormal cortical layers or an abnormal white-gray interface.