Hydranencephaly: sleep and movement characteristics.

Sleep and body movements were studied in 2 hydranencephalic neonates using visual analysis and polygraphic recording. They manifested periodic alternation of active and quiet sleep with peculiar movements of bilateral synchronized patterns. Generalized phasic movements were significantly increased and localized tonic movements were reduced. In view of the complete absence of cerebral hemisphere in this disorder, the movement of bilaterally synchronized pattern or increase of generalized phasic movement are considered to be generated from the basal ganglia and/or brain stem without cerebral hemisphere, whereas, localized tonic movements have more cortical correlation in its organization. The observation of body movements may be useful in detecting hydranencephaly in early infancy.