Prolonged survival to adulthood of an individual with hydranencephaly.

Hydranencephaly is a rare condition in which the brain's cerebral hemispheres are absent. The outlook for children with hydranencephaly is generally poor, and many children with this disorder die during infancy. Although rare, patients with prolonged survival have been reported. A 22-year-old female patient was admitted to our hospital in a bedridden state for management of bedsores. The initial brain computed tomography showed complete replacement of the cerebral hemispheres with fluid and no cortical plate or hemispheric white matter. The bilateral brain stem, some of the left cerebellum, and the inferior frontal lobe were spared. Although certain behaviors were observed, such as eye opening in response to sound and painful stimuli, examination identified neither a definite awareness of the environment nor a meaningful action. To our knowledge, this is the longest survival of a patient with hydranencephaly in the world.