Carpal Tunnel Syndrome
The carpal tunnel is a passage formed by the wrist (or carpal) bones, ligaments connecting the bones and the transverse carpal ligament, which makes the ‘roof’ of the tunnel. The median nerve is one of the main nerves of the upper limb, supplying feeling to the thumb and all of the fingers apart from the little finger and part of the ring finger. The median nerve also supplies most of the muscles in the hand. This nerve runs from the neck, down the arm and into the hand via the carpal tunnel, along with flexor tendons of the forearm muscles. Carpal tunnel syndrome occurs when there is pressure or compression of the median nerve as it passes through the carpal tunnel, and can result in pain, numbness, tingling or weakness.
Causes of Injury
The carpal tunnel is generally narrow and fairly rigid, therefore any increase in pressure in the area may compress the median nerve. Overuse of the forearm flexor muscles, often due to repetitive tasks which place stress on the tendons, can cause swelling and irritation. The swelling of the tendons can cause further narrowing of the carpal tunnel and compression of the median nerve (carpal tunnel syndrome). Rarely, carpal tunnel syndrome develops suddenly due to a traumatic injury, such as falling onto the hand. There are a number of factors that can increase a person’s risk of developing carpal tunnel syndrome. These include:
- Activities such as typing on a keyboard, sewing or knitting
- Occupations involving repetitive use of vibrating hand tools or tools such as a screwdriver.
- Participation in sports involving gripping or frequent wrist movement such as gymnastics, golf, cycling or racquet sports.
- Pregnant women
- Diseases such as diabetes, arthritis, thyroid problems or gout
- A tumour, infection or cyst in the region
- Burning pain, numbness or tingling in the thumb and next 2 or 3 fingers of one or both hands
- Pain worst at night or in the morning
- Loss of strength or wasting away of the muscles around the thumb and hand
- Reduced coordination in one or both hands
- Difficulty with tasks such as gripping or carrying
- Tapping over the median nerve at the wrist may cause pain to shoot from the wrist to the hand (tinel’s sign)
Most individuals respond well to non-surgical treatment, including:
- Sufficient rest from aggravating activities and modification of specific activities to avoid repeat episodes.
- Bracing or splinting the wrist.
- Pain relief and anti-inflammatory medication as recommended by a doctor or pharmacist
- Physiotherapy- massage, ultrasound, ice therapy, joint mobilisations and stretches
- Range of movement exercises, stretching and strengthening
In cases where conservative management does not result in improved symptoms, a corticosteroid injection may be recommended. Carpal tunnel release surgery may also be considered to release pressure on the median nerve if symptoms persist for longer than 6 months.
Many individuals make a full recovery with conservative treatment, however it may take up to 6 months to regain full strength. Full recovery from surgery is usually achieved, however this does depend on the duration of a person’s symptoms and the degree of muscle wasting and loss of sensation.