Thrombin activity in CSF after SAH is correlated with the degree of SAH the persistence of subarachnoid clot and the development of vasospasm.

We previously reported that the coagulation system in cerebrospinal fluid (CSF) is strongly activated in the early stage of a subarachnoid haemorrhage (SAH). We evaluated the relationship among thrombin activity, degree of SAH, amount of clearance of SAH, and vasospasm. The CSF levels of fibrinopeptide A (FPA) were measured by radio-immunoassay in 36 SAH patients, who were diagnosed by computerized tomography (CT) within 12 hours and on whom surgery was performed within 48 hours. Clearance of SAH (%) was evaluated as the size of the clot in the basal cistern visualized between the initial and postoperative CT. The mean level of FPA in the patients of Group 3 (Fisher's CT classification) (182.2 ng/ml) was significantly higher than those in the patients of Group 2 (36.2 ng/ml). There was a significant difference in the mean level of FPA between patients with (47.6 ng/ml) and without infarction (408.3 ng/ml). In 18 of the 27 patients of Group 3 for whom the clearance of the SAH was determined, the patients showing a lower clearance rate (< 50%) of SAH demonstrated a significantly higher rate of infarction and a significantly higher level of FPA (466.6 ng/ml) than did the patients with a higher clearance rate (> 50%) of SAH (79.2 ng/ml). These results suggest that, the thrombin activity in CSF is correlated with the degree of SAH, the persistence of subarachnoid clot and the development of vasospasm.