Most common cause of fetal ventriculomegaly is ?: (A) Arnold Chiari malformation–I, (B) Arnold Chiari malformation–II, (C) Aqueductal stenosis, (D) Dandy Walker malformation
Answer is C. Hydrocephalus is characterized by an increased CSF volume with progressive ventricular dilatation (ventriculomegaly).
Obstructive or noncommunicating hydrocephalus/ventriculomegaly develops most commonly in children because of an abnormality of the aqueduct or a lesion in the 4th ventricle.
Obstruction of the aqueduct is the single most common cause of fetal and neonatal hydrocephalus/ ventriculomegaly.
Non obstructive or communicating hydrocephalus most commonly follows a subarachnoid hemorrhage, which is usually a result of intraventricular hemorrhage in a premature infant.