Experimental subarachnoid hemorrhage in the rat: influences of nimodipine.

BACKGROUND: Traumatic subarachnoid hemorrhage is a common finding following traumatic brain injury. Clinical studies revealed a positive influence of Nimodipine. However, till now no experimental studies have been performed. The aim of the present study was to determine the influence of early Nimodipine administration on outcome and histological findings in the rat:

METHODS: Diffuse brain injury was produced in Sprague-Dawley rats using a brass weight falling from a predetermined height. Traumatic subarachnoidal hemorrhage was produced by administration of heparin before the injury. A total number of 52 animals were divided in 4 groups.

FINDINGS: Mortality increased following administration of heparin. Mortality was not reduced following administration of Nimodipine. The histological investigation revealed less cell loss in animals with administration of Nimodipine as well as increased GFAP immunoexpression.

CONCLUSIONS: Administration of Heparin results in a marked traumatic subrachnoidal hemorrhage following diffuse traumatic brain injury. Administration of Nimodipine does not reduce overall mortality. However, histological investigations indicate a positive effect of Nimodipine on cell loss.