Abstract
For the purpose of evaluating the role of platelet function in the pathogenesis of the cerebral vasospams (VS), time sequential changes of platelet function in blood sampled at three different sites were comparatively examined in 13 patietns with ruptured cerebral aneurysm admitted within 48 hours of the onset. Blood was sampled from the internal jugular vein (JV) and the peripheral vein (PV) every 3 days from the day of admission for about 2 weeks, to examine platelet aggregability, β-thromboglobulin (βTG), and thromboxane B2 (TXB2). In some cases blood was also sampled from the superior sagittal sinus (SSS) during surgery for similar examinations.
The results were as follows : 1) Differences of mesured values in three examinations were less between JV and SSS blood samples than between PV and SSS blood samples. When the time sequential changes of platelet functions were compared between JV and PV blood samples in patients presented 2 or more consecutively high values, JV blood samples showed much higher values than PV blood samples during the period with promoted platelet function. Therefore, the blood sampled from the closer site to the brain may reflects the closer intracranial condition. 2) Platelet function in blood samples from JV tended to have been enhanced during Day 0-1, but it recovered to the normal range during Day 2-4. After the Day 5, its course showed various patterns depending on the clinical course, and was particularly influenced by the symptomatic VS. In patients without symptomatic VS, time sequential changes were relatively minor with normal or a little high values. Patients with symptomatic VS showed high platelet aggregability alredy in the early stage of VS. The values of β-TG increased several days after the onset of VS, and reached to 90 ng/ml or more in patients with poor prognosis. Sequential changes of the TXB2 values were not always consistent. These results may suggest that the VS activates platelets and promotes its aggregation, and that increasing tendency of thrombus formation may affect the patient's prognosis in the advanced stage.
