Clinical Analysis of Platelet Shape Change and Coagulation-Fibrinolytic Markers in Patients with Cerebral Infarction in a Spa Resort / 日本温泉気候物理医学会雑誌

ABSTRACT

This study investigated the existence of platelet activation before the onset of cerebral infarction, and analyzed the association between the platelet activation and the degree of atherosclerosis. Furthermore, prediction of the risk of cerebral infarction by assessing platelet activation was attempted. Thirteen patients with cerebral infarction, 7 patients with atherosclerosis and 8 healthy subjects were enrolled in this study. Ultrastructural shape change, peroxidase reaction, and fibrinogen content in the platelets were observed and plasma levels of thrombin antithrombin complex, α₂-plasmin inhibitor plasmin complex, β-thromboglobulin and platelet factor-4 were measured in patients with atherosclerosis and cerebral infarction at the acute, subacute and chronic phases. The ultrastructural shape change, peroxidase reaction, and fibrinogen content did not differ among acute, subacute and chronic phases of cerebral infarction. The frequency of platelet shape changes were also increased in patients with atherosclerosis, compared with healthy subjects. Plasma levels of β-thromboglobulin, platelet factor-4, and thrombin antithrombin complex increased only during the acute phase of cerebral infarction. It is suggested that platelet activation occurs before the onset of cerebral infarction and that platelet shape change is associated with the degree of atherosclerosis, or plaque stability. Platelet activation would be derived not from thrombotic event itself but from endothelial damage or pre-existing atherosclerosis. Platelet shape change, therefore, could predict the risk of cerebral infarction. Taken together with our previous reports demonstrating increased blood viscosity, noctural hypotension, increased human atrial natriuretic peptide, decreased fibrinolytic activity, and platelet shape change were observed after very hot hot-spring bathing, cerebral infarction in spa-resort could be caused partly by very hot hot-spring bathing after traveling on a tight schedule and alcohol drinking by elderly patients with atherosclerosis.