What term describes ventricular enlargement due to excessive cerebrospinal fluid within the ventricles?

• A. Ventriculomegaly
• B. Hydranencephaly
• C. Arachnoid cyst
• D. Dandy-Walker

Answer: (A)

Ventriculomegaly is the dilation of the brain’s ventricular system caused by an excess of cerebrospinal fluid within the ventricles. In ultrasound, this presents as enlarged lateral ventricles, often defined by an atrial width greater than about 10 mm. This condition specifically reflects CSF accumulating inside the ventricles, which is why it’s the best match for the description.

Other options describe different brain anomalies. Hydranencephaly involves extensive loss of cerebral tissue with large fluid spaces replacing brain matter rather than isolated ventricular enlargement. An arachnoid cyst is a fluid-filled sack within the arachnoid membrane that can cause pressure or shift CSF dynamics, but it’s not CSF accumulating inside the ventricles themselves. Dandy-Walker is a posterior fossa malformation featuring an enlarged fourth ventricle and cerebellar vermis anomalies, not simply ventricles dilated from excess intraventricular CSF.