[Aqueductal stenosis and hydrocephalus in a psychotic adolescent].

Examination of a 14-year-old male who was admitted to an inpatient unit with an acute paranoid syndrome yielded serious organic findings: macroencephaly, head tilted to one side, strabismus, neurological deficits, hydroencephaly and an expressive speech disorder. The personal and family history revealed a disturbance of motor development since infancy and psychiatric illness in the immediate family. The medication and the surgical procedure selected--endoscopic third ventriculostomy--are described and the difficult differential diagnosis is discussed.