Membrane stain in chronic subdural hematoma: a rare angiographic sign. A case report.

Chronic subdural hematoma is diagnosed angiographically by the presence of an avascular zone as a result of medial displacement of the cerebral surface vessels from the inner table. A rare angiographic sign, membrane stain, is reported in a case of chronic subdural hematoma. The stain is presumed to represent the vascular membrane of the chronic subdural hematoma.