Characterization of local hyperfibrinolysis in chronic subdural hematomas by SDS-PAGE and immunoblot.

Fibrinogen, fibrin monomer, and D dimer were analyzed in 41 cases of chronic subdural hematoma (SDH) to characterize local rebleeding, coagulation, and fibrinolysis using sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and immunoblotting. Chronic SDH's were divided into five groups according to their appearance on computerized tomography: high-density, isodensity, low-density, mixed-density, and layering types. The concentration of fibrinogen, which indicates rebleeding, was higher in the mixed-density (15.7 +/- 3.4 mg/dl (mean +/- standard error of the mean)) and layering (15.7 +/- 2.6 mg/dl) types of hematoma, and lower in the low-density hematomas (1.4 +/- 0.6 mg/dl) compared with the isodense hematomas (6.9 +/- 1.1 mg/dl). Fibrin monomer, which indicates coagulative activity, had a distribution similar to that of fibrinogen: 87 +/- 22, 18 +/- 8, 175 +/- 40, and 177 +/- 23 micrograms/ml in isodense, low and mixed-density, and layering types of hematomas, respectively. The D dimer, which indicates fibrinolytic activity, was higher in the layering hematoma type (2032 +/- 384 micrograms/ml), and lower in low-density hematomas (301 +/- 164 micrograms/ml) compared to isodense (1310 +/- 256 micrograms/ml) and mixed-density (1039 +/- 207 micrograms/ml) types of hematomas. These observations suggest the following characterization of each type of chronic SDH. The layering type is active, with a high tendency to rebleed and for hyperfibrinolytic activity. The mixed-density type has a high tendency to rebleed with lower hyperfibrinolytic activity than the layering type. The low-density hematoma is stable with a low tendency to rebleed and to fibrinolytic activity.