[Hydrocephalus due to a large aneurysm in the basilar artery (author's transl)].

In the light of the literature the authors discuss the case of a 66 year-old hypertensive patient presenting headaches, disorders of gait and deglutition, dysphonia and urinary incontinence. A CAT scan showed dilatation of the entire ventricular system. Anatomo- pathological investigation showed a voluminous bisaccular aneurysmal malformation in the basilar artery. By deforming the pons and the medulla oblongata, the aneurysm had compressed the fourth ventricle and cerebral aqueduct, thus causing hydrocephalus. (Acta neurol. belg., 1980, 80, 80-85).