[Unilateral hydrocephalus due to membranous occlusions of the foramen of Monro (author's transl)].

A case of dilatation of the right lateral ventricle due to membranous occlusion of the foramen of Monro is reported. A child aged two and a half years developed raised intracranial pressure together with disturbed consciousness, but other neurological defect, two months after after an attack of bilateral broncopneumonia. The preoperative diagnosis of occlusion of the right foramen of Monro by infiltrating tumour was made angiographically. At operation the obstruction was found to be due to a membrane. The septum lucidum was fenestrated and a ventriculoatrial shunt was inserted. After a year the shunt was removed. Twenty eight cases of unilateral hydrocephalus due to nontumorous occlusion of the foramen of Monro have been reviewed, and the aetiologies have been discussed. Clinical picture and diagnostic procedures are reviewed. The authors discuss surgical treatment, and lay stress on fenestration of the septum lucidum.