Blood clotting factors in cerebrospinal fluid.

The activity of blood clotting factors has been investigated in cerebrospinal fluid. No cephalin-like activity was found in cerebrospinal fluid but prothrombin activity averaged about 0.5% of normal plasma activity. The activity of factor VII was negligible in almost all cases. The activity of antihaemophilic factors showed great variation but in the majority of cases it did not exceed 1% of normal plasma activity. High activity for factor V was found in almost all samples of cerebrospinal fluid.