Ischemic stroke due to deficiency of coagulation inhibitors. Report of 10 young adults.

BACKGROUND AND PURPOSE Deficiencies in coagulant inhibitors protein C, protein S, and antithrombin III increase the risk of venous thrombosis. We describe 10 young adults with cerebral arterial thrombosis due to deficiencies in these factors. METHODS Sixty patients younger than 45 years were hospitalized because of acute ischemic stroke diagnosed through computed tomography or magnetic resonance imaging. Cerebral angiography was performed in 54 cases. Hematologic and coagulation profiles, autoantibody screen, syphilis serology, and lupus anticoagulant were analyzed in all patients. Among the total cases, Holter monitoring was performed in 13 patients, echocardiography in 20, and cerebrospinal fluid studies for cysticercosis and tuberculosis in two. The quantitative analysis of protein C, protein S (by Laurell rocket immunoelectrophoresis), and antithrombin III (by radial immunodiffusion) was performed on admission and 3 months after stroke in all patients and in relatives of six patients. RESULTS In 10 cases (17%) the stroke was attributed to deficiency of coagulation inhibitors: three men had protein C deficiency, two women had protein S deficiency, and five had antithrombin III deficiency (three men and two women). The cerebral infarction involved the carotid territory in these 10 patients. None had previous thromboembolic disease. Eight patients showed a complete recovery. An acquired disorder was presumed in one protein S-deficient and in two antithrombin III-deficient patients; the remainder were considered heterozygous. CONCLUSIONS The cerebral vasculature may be primarily involved in the deficiency of these natural anticoagulants. Young adults seem to be the most often affected. A knowledge of these new clotting defects will enable the clinician to improve the prevention and treatment of this devastating neurological disease.