Hydrocephalus Caused by Primary Fourth Ventricle Outlet Obstruction: Our Experience and Literature Review.

OBJECTIVE: Primary fourth ventricle outlet obstruction (PFVOO) is a rare cause of hydrocephalus with an unclear etiopathogenesis, and thus, consensus regarding the recommended treatment protocol is lacking. This study aims to summarize current knowledge of this condition in the light of our own treatment experience. METHODS: Retrospective analysis was carried out of all patients treated for noncommunicating tetraventricular hydrocephalus between 2006 and 2019, from which a subgroup of patients with PFVOO was created. A literature review of PFVOO cases was also carried out. RESULTS: A total of 62 patients with PFVOO were discovered, of whom 8 were treated at our institution, representing 3.8% of our patients with noncommunicating hydrocephalus. Patients most commonly presented with headaches, gait disturbance, or symptoms of intracranial hypertension. The mean follow-up duration was 75.4 months among our patients and 29.9 months in the literature. Most patients (54.8%) were treated by endoscopic third ventriculostomy (ETV), with the remainder undergoing suboccipital craniotomy alone (17.7%) or in combination with shunt surgery (9.7%), or endoscopic magendieplasty (12.9%). Treatment failure was noted in 28.6% of ETVs and 9% of craniotomies. No failures were recorded after endoscopic magendieplasty. The risk of treatment failure was found to be significantly higher with ETV compared with other treatment modalities (P < 0.0005). CONCLUSIONS: Despite the fact that PFVOO can be defined as an obstructive hydrocephalus, there seems to be a higher risk of ETV failure in such cases. The alternative treatment modalities presented are still recommended. Confirmation of these findings requires a larger multicenter study.

Non-communicating hydrocephalus with a primary empty sella presenting with growth hormone deficiency and delayed puberty successfully treated by endoscopic third ventriculocisternostomy.

The authors present the unusual case of a 15-year-old boy with a primary empty sella caused by non-communicating hydrocephalus due to fourth ventricle outflow obstruction whose secondary symptoms of growth hormone deficiency and delayed puberty were successfully treated by endoscopic third ventriculocisternostomy (ETV). Hypopituitarism occurs only rarely in cases of hydrocephalus; rarer still are cases where hypopituitarism is the sole symptom of hydrocephalus. A primary empty sella may indicate elevated intracranial pressure; if the cause is non-communicating hydrocephalus, ETV is indicated as the preferred treatment modality.