What is Carpal Tunnel Syndrome?
It is a common condition caused by an increased pressure within a tunnel in the wrist which squeezes the median nerve that runs through the tunnel.
The roof of the carpal tunnel is made of a thick tough band of ligament while the floor and walls of the tunnel are made up of carpal bones of the wrist, hence the name, carpal tunnel.
Pressure on median nerve causes numbness, tingling (‘pin and needle’) sensation, and pain in the hand, fingers and thumbs. The pain may also travels upwards towards your forearm, arm, shoulder and neck.
Who is affected?
It can affect people of all ages but more commonly affect female between 40 to 60 years old. It may also occur in pregnant ladies.
What are the symptoms?
The common symptoms are pain, numbness and/or tingling of the hand. Some patients may be able to localise these symptoms to the thumb, index, middle and ring fingers. The symptoms are usually present at night (and may wake the patients) and early morning. Daytime symptoms may occur during activities like driving, holding the phone, reading a newspaper or typing. Patients may find relieve from these symptoms by moving or shaking their hands. Patients may notice a weaker grip and a tendency to drop things. In severe cases, the numbness is felt constantly and the muscles at the base of the thumb shrink causing weaker pinch.
What are the causes of CTS?
In most cases, there is no obvious cause. Pressure in the carpal tunnel can build up several ways: swelling of the lining of the flexor tendons that traverses the tunnel (called tenosynovitis); fracture, dislocation or arthritis of the wrist which narrow the tunnel. Fluid retention during pregnancy can cause swelling within the tunnel and compress the nerve. Thyroid conditions, rheumatoid arthritis, diabetes, gout and chronic renal failure can be associated with carpal tunnel syndrome. Certain occupation requiring strenuous repetitive wrist motion and a use of vibrating tools may predispose to carpal tunnel syndrome. In some cases, there may be a combination of causes.
Diagnosis is mostly made by your doctor through a thorough history and physical examination.
Occasionally imaging such as an X-ray will be required to check for arthritis or fracture, an MRI for soft tissue swelling in the tunnel such as tumour, tenosynovitis and gouty tophi. Electrodiagnostic studies (Nerve conduction study and electromyogram) may be carried out to confirm the diagnosis of carpal tunnel syndrome in some cases. Blood tests may be required if there is a suspected medical conditions that is associated with CTS.
Early and intermittent symptoms of numbness and night pain of carpal tunnel can be treated with non-operative treatment. The patient is advised on avoiding strenuous repetitive wrist motion or using a vibrating tool. Wearing night wrist splint which keeps the wrist in neutral position ensure an optimum carpal tunnel size during sleep time and may help with the night pain and numbness. Drugs such as anti-inflammatory drugs to relief pain, vitamin supplements such as B6 and B12 to improve and restore nerve function may help. Steroid injection into carpal tunnel may also help relieve symptoms but risk of recurrence is high.
Surgery for carpal tunnel syndrome is indicated when the non-operative treatment has failed. When the patient experiences deterioration of symptoms from intermittent to more frequent episodes or constant numbness or pain, surgery becomes necessary. The surgical aim is to relieve the pressure of median nerve by cutting the transverse carpal ligament which forms the roof of the tunnel. Blood supply to the nerve then improves. The surgery can be performed through a mini-open technique or arthroscopically (key-hole surgery).
This operation is safe with excellence results. Complications are minimal. Scar tenderness and pillar pain may occur. Wound infection is uncommon. Injury to the motor branch to the thumb muscle is rare with the use of loupe magnification during surgery. Recurrent of symptoms can happen if transverse carpal ligament is incompletely cut or fibrosis develops around the nerve after surgery.