Corresponding to this weakness is a loss of muscle mass or fullness at the base of the thumb. Motor weakness and resulting muscle atrophy are seen in chronic cases in which the nerve has been persistently and severely compressed for several months. Physiologic confirmation of the diagnosis is obtained by demonstrating a delay in the conduction of electrical impulses down the nerve as it crosses the wrist at the point of compression. Splinting, especially at night, relieves symptoms. Fixation of the wrist, by resting wrist splints at 15 degrees of extension, maximizes the space within the carpal tunnel and reduces the compression by the transverse carpal ligament on the nerve.
Splints protect during lifting and working.
Treatment of underlying causes is important. Correcting a thyroid hormone deficiency reduces swelling in the tunnel and relieves symptoms. Treatment of rheumatoid arthritis with systemic anti-rheumatic drugs reduces swelling and inflammation, thus reducing crowding of the nerve by the hypertrophied synovial tissue. People with occupational related injuries often respond to simple interventions. Altering keyboard height by using a key pad will markedly improve symptoms of keyboard users.