Familial coagulation-inhibiting and fibrinolytic protein deficiencies in juvenile transient ischaemic attacks.

The aim of this study was to investigate the role of natural cascade inhibitors in Juvenile Transient Ischemic Attacks. Fifty patients with anterior or posterior brain attacks were studied. One hundred healthy subjects matched for sex and age were randomly assigned to a control group. All had a physical examination and radiologic work-up. Computerized tomography showed no ischaemia either with or without contrast medium. Digital angiography of epiaortic and intracerebral vessels was unremarkable patients non controls ever had war-farin therapy. Antithrombin III, protein C and plasminogen were determined by functional methods. Protein S was assayed by a functional clotting method based on prolonged PT. The activated protein C resistance test was performed and a poor response to activated protein C was verified in patients. Our findings show protein S, protein C and antithrombin III type I deficiency with a functional activity < 70% compared to controls. Eight of fifty patients (16%) had low protein S levels, 5 (10%) had low protein C, 2 (4%) had low antithrombin III and 1 (2%) plasminogen deficiency. A significant (p < 0.01) difference in activated protein C ratio was seen for controls and patients. These results suggest that screening for natural anticoagulants in young people suffering from transient ischemic attacks could be beneficial and should be encouraged.