Carpal tunnel syndrome (CTS) is a compression neuropathy of the median nerve. Although compression of the median nerve can occur at multiple levels, CTS refers to compression at the wrist by the transverse carpal ligament.
The degree of symptoms depends on the chronicity and degree of compression. Symptoms can progress from purely sensory to include motor loss with associated atrophy. Sensation loss occurs at the tips of the first three fingers and may travel to the forearm and wrist. Weakness of grip may occur in more advanced cases. Patients typically state that symptoms are worst at night or after participating in a repetitive activity.
History and physical exam are highly suggestive of the diagnosis of CTS. Sensation should be tested in the median nerve distribution, as should the strength of thumb opposition. Provocative tests include Tinel's sign and Phalen's sign (Fig. 7.2). Tinel's sign involves tapping over the transverse carpal ligament with the wrist held
in extension. Phalen's sign involves holding both wrists in extreme volar flexion for 30-60 seconds. Electromyography (EMG) and nerve conduction velocity (NCV) studies can be performed to confirm clinical suspicion. NCV testing is positive in approximately 70% of cases. It should be noted that a negative NCV does not exclude the possibility of median nerve compression. If symptoms are intermittent and mild, NCV/EMG may be normal. In these cases, a median nerve block can be used to confirm the diagnosis.
Mild to moderate CTS can be managed medically, whereas advanced CTS requires surgical release. Medical management includes minimizing provocative factors. This might require reducing gripping, grasping, or repetitive wrist motion. A Velcro wrist splint with a metal stay to reduce symptoms is also recommended. At the least, the splint should be used at night. When indicated, a steroid injection can be highly useful. Corticosteroid injection is advanced just through the transverse carpal tunnel ligament to bathe the nerve and relieve inflammation. Many patients have good relief after one injection.
Those suffering from CTS can participate in sport as tolerated. Splints as described in the treatment section may assist avoiding aggravating factors.
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