Primary Fourth Ventricle Outlet Obstruction in Childhood: New Clinical Insights and Long-Term Outcome

PFVOO should be included in the differential diagnosis of unexplained tetraventricular hydrocephalus in children when conventional imaging is inconclusive. Advanced MRI sequences such as 3D-CISS are valuable for identifying subtle outlet obstructions. This case, extending the pediatric follow-up to two years, reinforces ETV as a safe and durable first-line treatment option in selected patients with PFVOO.