Biochemistry of carpal tunnel syndrome.

Although carpal tunnel syndrome (CTS) occurs due to intrinsic or extrinsic causes, the idiopathic group outnumbers the rest by far. Compression of the median nerve may be due to mechanical or ischemic causation. The cause of idiopathic CTS is thought to be intermittent compression of the median nerve in predisposed people, especially working females, producing ischemia of the nerve. Reperfusion injury may occur during periods of recovery. Intermittent perfusion of the cellular tissue following ischemia releases free oxygen radicals. With continued oxidative stress, the normal antioxidant system is overwhelmed and cellular injury ensues, affecting both nerve and synovial cells. This is confirmed by changes seen locally in nerve and synovial tissue both serologically and histologically. These changes are reverted or checked by the use of antioxidants in vitro. Simulated compression of the nerve in laboratory animals also confirms these findings, further corroborating the pathophysiology and suggesting means of preventing idiopathic CTS.