Mesencephalic developmental venous anomaly causing obstructive hydrocephalus: illustrative case

BACKGROUND: Developmental venous anomalies (DVAs) are congenital anatomical variants of the normal deep parenchymal veins. DVAs are occasionally found incidentally on brain imaging, and most cases are asymptomatic. However, they rarely cause central nervous disorders. Herein, a case of mesencephalic DVA that caused aqueduct stenosis and hydrocephalus and discuss its diagnosis and treatment is reported. OBSERVATIONS: The patient was a 48-year-old female who presented with depression. Computed tomography and magnetic resonance imaging (MRI) of the head revealed obstructive hydrocephalus. Contrast-enhanced MRI revealed an abnormally distended linear region with enhancement on the top of the cerebral aqueduct, which was confirmed as a DVA by digital subtraction angiography. An endoscopic third ventriculostomy (ETV) was performed to improve the patient’s symptoms. Intraoperative endoscopic imaging showed obstruction of the cerebral aqueduct by the DVA. LESSONS: This report describes a rare case of obstructive hydrocephalus caused by DVA. It highlights the usefulness of contrast-enhanced MRI for diagnosing cerebral aqueduct obstructions due to DVAs and the effectiveness of ETV as a treatment option.