Cause | Signs and Symptoms | Risk factors
Caution and Recommendations to Therapist | Notes

The collection of signs and symptoms produced by compression of the median nerve in the wrist.

Cause:

Any condition that reduces the size of the tunnel formed by the transverse carpal ligament and the carpal bones can cause this syndrome. Reduction in size of the tunnel affects the functioning of the flexor tendons and the median nerve as they pass through it. The size of the tunnel can be reduced by bony or ligamentous changes, increase in the volume of contents as in inflammation of the tendons, edema or tumors. Systemic diseases like rheumatoid arthritis, hyperthyroidism, acromegaly and diabetes mellitus can also produce this condition. Other causes are pregnancy, use of contraceptive pills and wrist injury.   Entrapment or injury of the median nerve in the elbow or shoulder (following whiplash injuries), displaced fracture of the distal radius, swelling of the common flexor sheath, dislocation of the carpal bone, vascular deficiency of the median nerve at the carpal tunnel are other causes. 

Signs and Symptoms:
Pain in the wrist and hand, numbness of the thumb, pointer, middle finger and half of the ring finger, atrophy and weakness of the thenar muscles are some of the symptoms seen. Pain and reduced sensations are more at night. There is a tingling  sensation radiating along the palm if the wrist is tapped (Tinel's sign). If the wrist is flexed over a minute or so, the client feels numbness along the distribution of the median nerve (Phalen test). There may be clumsiness of movements that require fine coordination.

Risk factors:
There is a higher risk in occupations requiring repetitive strains of the wrist by flexion, extension, gripping, pinching movements and overwork of the muscles of the arm e.g. massage therapists, secretaries, pianists. Carpal tunnel syndrome is more common in women.

Caution and Recommendations to Therapist:
Since this is one of the occupational hazards, the therapist should take precautions to prevent it's onset by massaging the forearms and hands regularly. Practice stretching and range of motion exercises for the hands, shoulders, and neck. Strengthen the forearm and hand muscles using isometric and isotonic exercises. Special exercise equipment are now available in the market. Maintenance of correct posture in occupations which strain the wrist can prevent carpal tunnel syndrome. On a client with this syndrome avoid local massage over the wrist if there is acute inflammation in the region. In chronic conditions, the local edema can be reduced by lymphatic drainage techniques and elevation of the limb. The limb should be elevated above the level of the heart 5-10 minutes before massage. Deep, moist heat can help soften and allow stretch of collagen fibres that produce adhesions. Movement of the hand under warm water is another form of treatment. Techniques to stretch the flexor retinaculum should also be employed. Use cross-fibre friction to loosen scar tissue and adherent fibres. Passively move the elbow, wrist and finger joints to maintain range of motion.

The neck, shoulders and arms should be thoroughly massaged. Ensure that the tissue is not damaged inadvertently by vigorously massaging regions with reduced sensation. Help the client identify and avoid risk factors. Encourage clients to do remedial exercises such as passive stretching of flexors and extensors of wrist and fingers. Initially, half hour sessions twice a week for three weeks are recommended.

Notes:
In the hand, the median nerve supplies the muscles of the thenar eminence, and the first two lumbricals. Sensations are carried by it from the lateral three and a half fingers and distal part of the palm. Carpal tunnel syndrome is treated by rest, splinting, injection of corticosteroids or surgery to relieve the pressure on the nerve.