[2 cases of unilateral hydrocephalus developing in the fetal period].

Dilatation of the lateral ventricle may occur as a result of unilateral hydrocephalus with obstruction of the foramen of Monro. Two cases with congenital dilatation of unilateral ventricle are presented, in which no obstruction of the foramen of Monro was demonstrated. The patients had infantile spasm, asymmetry of the skull and face, and contralateral hemiparesis. Angiography showed embryonal type of the middle cerebral artery. These findings suggest probable presence of active unilateral hydrocephalus in the fetal period.