Physiopathogenesis of chronic subdural hematomas: a new look to an old problem.

The genesis and development of a CSDH are presently explained in terms of a) neoformation of a subdural membrane; b) abnormal vascular permeability; c) defective local hemostasis (hyperfibrinolysis) and chronic rebleeding. Many etiological factors are involved, mechanical, hematogenic and vasogenic in nature. Both clinical and experimental evidence supports the hypothesis that hormonal factors, in addition to the above mentioned ones, could play a role in the pathogenesis of CSDHs.