Enhanced acetylcholinesterase in chronic subdural hematomas.

Hematomas and specimens were studied from 13 surgically-operated chronic subdural hematoma cases. Evacuated hematomas contained elevated potassium ions and slightly increased levels of Acetylcholinesterase (AChE), and the dural specimens including hematoma capsules stained positive for AChE using histochemical methods, especially in the inner membrane of the dura where the Masson Trichrome staining revealed damaged and irregular collagen fibers. This article suggests that the initial dural damage caused by trauma results in minor bleeding, which in turn causes a raised potassium ion concentration in the hemolytic fluid, which may also cause depolarization and elevated AChE in the dura.