Hemihydranencephaly:

Hydranencephaly is a severe brain condition characterized by complete or almost complete absence of cerebral cortex with preservation of meninges, basal ganglia, pons, medulla, cerebellum, and falx. It has been ascribed to different causes (infections, irra-diations, fetal anoxia, medications, twin-twin transfusion), all lead-ing to vascular disruption. Hemihydranencephaly is an extremely rare condition in which the vascular anomaly is unilateral. We report on a patient who was suspected to have hydrocephalus in utero; a brain magnetic resonance imaging scan showed left-sided hydranencephaly with preservation of basal ganglia. The patient developed signs of right hemiparesis but notably has only mild lan-guage delay. The available literature on hemihydranencephaly is reviewed. (J Child Neurol 2001;16:218-221). Hemihydranencephaly is a severe and extremely rare brain con