Cerebral ischemia in young patients: it is associated with mitral valve prolapse and abnormal platelet activity in vivo?

The etiology of cerebrovascular disease (CDV) in young patients is difficult to establish if the common causes of a focal neurological deficit are excluded by appropriate investigations. Since in some observations prolapse of the mitral-valve (MVP), alterations of platelet function, or both have been linked with cerebral ischemic events, we studied the in vivo platelet release reaction and the incidence of MVP in 47 patients (12 males, 35 females) under 45 years of age with TIA or stroke of unknown cause and in an age- and sex-matched control group. The mean plasma beta-thromboglobulin (beta-TG) level of the patients (mean = 54.9 +/- 31.4 ng/ml) was significantly higher than that of the controls (mean = 20.6 /- 6.9 ng/ml, p less than 0.001). MVP was demonstrated in 13 of 47 patients in contrast to 4 of the controls (p less than 0.01). However, the beta-T levels of patients with MVP (n = 13, 52.9 +/- 25.5 ng/ml) did not differ from those of patients without MVP (n = 34, 55.7 +/- 33.7 ng/ml) significantly (p less than 0.4). Our results confirm that the incidence of MVP is higher in young patients with cerebral ischemia of unknown cause than in asymptomatic controls. The significantly elevated plasma beta-TG concentrations in the patient's group indicate an increased platelet activity in vivo. Since there was no significant difference between beta-TG levels of patients with and without MVP, the mitral-valve abnormality can not be the cause for the altered platelet activity.