Cerebral Edema After Temporary and Permanent Middle Cerebral Artery Occlusion in the Rat

Background and Purpose The potential of thrombolytic agents to improve outcome after ischemic stroke could be negated if recanalization of an occluded artery exacerbates cerebral edema. We examined whether infarctions associated with reperfusion have more edema than those without reperfusion and whether the time course for the development of cerebral edema varied with and without reperfusion. Methods Infarct volumes were measured 24 hours after permanent and 1, 2, and 3 hours of temporary right middle cerebral artery (MCA) occlusion in spontaneously hypertensive rats. Hemispheric volume, water, sodium, and potassium were measured 3, 6, 12, 24, 36, and 48 hours after permanent and 3 hours of temporary MCA occlusion and also determined 24 hours after permanent and 2 and 3 hours of temporary MCA occlusion. Results Minimal tissue damage occurred after 1 hour of temporary ischemia. Infarct sizes were similar after permanent and 3 hours of temporary MCA occlusion and significantly greater than after 2 hours of ...