The topography of microthrombi in ischemic brain infarct.

Following cerebral ischemia a tendency to increased coagulation can be detected. Vascular occlusion may develop either as a result of local thrombus formation or from emboli caused by circulating platelet aggregates. We studied the localization of microthrombi and their effects on tissue in double-hemisphere sections. Fresh brain infarcts showed a large number of microthrombi limited to the ischemic region. In more advanced infarcts they were found mainly at the border of the necrosis and diffusely distributed over both hemispheres. Older, subsiding infarcts showed only isolated microthrombi limited to the area of the necrosis. This indicates that great importance must be attached to microthrombi in infarct progression.