THE ROLE OF THE COAGULATION CASCADE IN BRAIN EDEMA FORMATION AFTER INTRACEREBRAL HEMORRHAGE

The coagulation cascade has a potential role in brain edema formation due to intracerebral hemorrhage. In this study blood and other solutio ns were injected stereotactically into the right basal ganglia in rats . Twenty-four hours following injection, brain water and ion contents were measured to determine the amount of brain edema. Intracerebral bl ood resulted in an increase in brain water content. The amount of brai n edema surrounding the intracerebral hematoma was reduced by a thromb in inhibitor N fonylglycyl)-4-amidino-DL-phenylalaninepiperidide, (alp ha-NAPAP) infused into the hematoma after the clot had been allowed to solidify. The inhibitor did not alter the actual size of the clot mas s. An artificial clot composed of fibrinogen, thrombin, and styrene mi crospheres also produced brain edema. A fibrin clot led to edema forma tion even in the absence of mass effect provided by the microspheres. The single component responsible for production of brain edema in all these models was thrombin. The edema was formed in response to a fibri nogen-independent pathway. These results indicate that the coagulation cascade is involved in brain edema that develops adjacent to an intra cerebral hematoma.