Hydrocephalus With Vascular Malformations of the Brain

Abstract

Communicating hydrocephalus was noticed in cases of vascular anomalies of the brain. Little attention has been paid to this fact and particularly to its cause in the literature up to now. The authors present 4 cases of arteriovenous aneurysm of brain in each of which hydrocephalus occurred and review the scanty literature concerning this subject. The point of the report is the discussion of the causal relationship between the 2 conditions. The main views concerning the pathogenesis of the hydrocephalus in these cases are: (1) that it is due to obstruction of the subarachnoid spaces by extensive adhesive leptomeningitis, thickening of pia and arachnoid, following subarachnoid hemorrhage from leaking aneurysm. The obstruction of the subarachnoid spaces interferes with cerebrospinal fluid resorption, hence producing accumulation of cerebrospinal fluid and hydrocephalus. Clinical pathological and exptl. data support this view; (2) Hydrocephalus is due to faulty distr. of blood, and therefore of O2, to the brain, because of arteriovenous shunt. Secondary atrophy of brain is likely to occur. Measurement of the amount of 02 in both jugular veins showed remarkably higher values in the jugular vein homolateral to the vascular malformation, suggesting that the blood entering the aneurysm passes more quickly than it should into the venous system. In some cases at least, a combination of the 2 mechanisms (1 and 2) may be responsible for the hydrocephalus. It is felt that further clinical and exptl. proof is needed before final conclusions can be drawn.