Factors related to acute hydrocephalus after subarachnoid hemorrhage.

PURPOSE: To evaluate the influence of the amount and distribution of blood on acute ventricular enlargement in subarachnoid hemorrhage (SAH).
MATERIAL AND METHODS: In a retrospective study, non-contrast computed tomography (CT) images of 180 patients with aneurysmal SAH were analysed by two neuroradiologists. The amount and distribution of the hemorrhage were scored, and prospective hydrocephalus was identified on the basis of acute CT images by calculating the cella media index, by measuring the width of the third ventricle, and by visual impression. Statistical analysis was done using the logistic regression model, analysis of variance, and chi-square test.
RESULTS: The incidence of acute hydrocephalus was higher among the patients with blood distributed in the anterior, lateral, and basal regions (70.8%) than among the patients who did not have blood distributed in all three areas (P=0.010). The proportion of acute hydrocephalus differed depending on the type of hemorrhage (P<0.001). Intraventricular hemorrhage was the most consistent predictive factor in the logistic regression model, while the other predictive factors included the total blood amount score and the volume of intracerebral hemorrhage.
CONCLUSIONS: A positive correlation was found between acute hydrocephalus and the amount of subarachnoid and, more importantly, intraventricular blood. This is consistent with the literature and confirms the current pathophysiologic concepts that the acute hydrocephalus following SAH is an obstructive form of hydrocephalus.