With the typical complaints tingling, pain and decreasing muscle strength, several tests are performed, which can distinguish the carpal tunnel syndrome from other nerve damage. A positive Hoffmann-Tinel sign is said to occur when tapping the flexor region below the wrist results in electrifying pain. Phalen’s sign is positive when greater flexion in the wrist over 60 seconds results in tingling and pain in the first three fingers. Radiographs reveal bony changes in the carpus, possibly narrowing the carpal tunnel.
Measure nerve conduction velocity
In addition, nerve conduction velocity can be measured; in carpal tunnel syndrome, measurements of the peripherally located median nerve are typically altered compared with the opposite side and other nerves.
However, other conditions can also cause pain, tingling, and decreased muscle strength or loss of sensation: If there are degenerative bony changes in the cervical spine that constrict the nerve roots, especially the C6/C7 nerve root, then similar symptoms can occur. However, this often involves the other arm nerves and symptoms are not limited to the thumb, index and middle fingers and palm.
In ulnar nerve syndrome (sulcus ulnaris syndrome), it is not the median nerve that is damaged, but the ulnar nerve. It runs along the inside of the elbow near the bone and hurts when you “bump your funny bone.” If you often sit at a table with your elbow propped up or write a lot with your forearm resting on the table, you may irritate the nerve. In this case, unlike the median, the little finger area is increasingly affected.
What can be done about carpal tunnel syndrome?
Unfortunately, there are no known measures that actively counteract or prevent the development of carpal tunnel syndrome. In the early stages, when symptoms have only been present for a short time, conservative treatment can be attempted. A splint is used to immobilize the wrist at night; the narrowing of the carpal tunnel is then not further constricted by unconscious hand flexion during sleep. Cortisone injections into the carpal tunnel are also possible – however, this can result in nerve injury.
In cases of prolonged discomfort, the narrowing of the carpal tunnel is surgically repaired. During the operation, which is now offered under local anesthesia by many office-based hand surgeons, the retinaculum flexorum is split, thus widening the space for tendons and nerves. The surgery is offered as an open and endoscopic variant. The risk of nerve injury is slightly higher with the endoscopic variant, but the scar is much smaller.
After the operation, movement exercises are started quickly, heavy work with the hand is allowed after six weeks at the earliest. The nerve recovers slowly, within a month the nerve fibers regenerate by about 10 millimeters. The discomfort recedes over the course of months – even after six months, there may still be an improvement.
