Primary Occlusion of the Fourth Ventricle: Case Report and Review of the Literature

Idiopathic obstruction of the outlets of the fourth ventricle (FVOO) is a rare cause of hydrocephalus, which can be misdiagnosed as communicating hydrocephalus due to the enlargement of all four ventricles. Different surgical approaches are discussed in the literature. We present a case report of a 25-year-old male admitted with headache, vertigo, and nystagmus. The MRI scan showed a tetraventricular hydrocephalus with a patent aqueduct. After endoscopic third ventriculostomy (ETV), symptoms resolved. We performed a systematic review of the literature, covering 26 years, with the aim to investigate the symptoms, therapy, and outcome of primary FVOO, according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analysis) guidelines. We found 9 case reports and 2 case series and could extract a total of 34 cases. After ETV all symptoms resolved in 10 of 23 cases (43.5%), and in 13 of 23 cases (56.5%) symptoms improved partially. Seven cases (30.4%) required additional surgery. A decrease in ventricular volume occurred in most cases. In the 10 patients who were operated via fenestration, all symptoms resolved in 6 cases. ETV seems to be an effective treatment option for patients with idiopathic FVOO in a majority of cases. In special cases, fenestration of the foramen of Magendie may be suitable.