Inherited protein C deficiency and nonhemorrhagic arterial stroke in young adults.

Out of a consecutive series of 50 young people less than 45 years old with nonhemorrhagic arterial stroke, three patients had inherited protein C deficiency. CT revealed hypodense areas consistent with the clinical picture, and angiography showed occlusion of some intracranial arterial vessels. Other possible associated causes of stroke were ruled out. One patient had a transient ischemic attack and a peripheral venous thrombosis prior to the actual stroke, whereas the others were completely asymptomatic, as were relatives with the same deficiency. We suggest determining protein C in ischemic stroke of all young adults, especially when major risk factors are excluded.