Carpal Tunnel Syndrome
Hand Numbness and Pain
This 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. Pressure on median nerve causes numbness, tingling (‘pin and needle’) sensation, and pain in the hand, fingers and thumbs.
The roof of this 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. It allows the passage of all the tendons that bend the fingers and thumb as well as the median nerve. All these structures are in close contact which one another and any increase in the volume or additional swelling will result in an increased pressure within the tunnel.
Who gets carpal tunnel syndrome?
It can affect people of all ages but more commonly affect female between 40 to 60 years old. It is common in pregnant ladies. Patients with diabetes, chronic renal failure, rheumatoid arthritis and gout may have higher risk of getting this condition.
Both hands can be affected at the same time.
What are the causes of carpal tunnel syndrome?
In most cases, there is no obvious cause.
Generally, an increased pressure in the carpal tunnel can occur because of 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 also 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. Familial or genetic factors may play a role as some patients have small narrow tunnel. In some cases, there may be a combination of causes.
What are the symptoms?
Patients will have numbness, tingling (‘pin and needles’) sensation or burning pain over the hand. Some patients may be able to localise the numbness to the thumb, index, middle and half of the ring fingers. This pain may also radiates to the forearm, arm and shoulder. These symptoms commonly occur at night or early morning but as it worsens they become more persistent and severe throughout the day. Patients find it difficult to drive, hold the handphone or type for a long period of time. In early cases, the symptoms may be relieved by shaking the hand rapidly. In prolonged cases, the muscles of the thumb can be wasted and weak.
Early and intermittent symptoms of numbness and night pain can be treated with non-operative treatment. Avoid strenuous repetitive wrist motion Wearing night wrist splint keeps the wrist in neutral position to ensure an optimum carpal tunnel space and may help with the night symptoms. Drugs such as anti-inflammatory drugs to relief pain, vitamin supplements such as B6 and B12 to improve and restore nerve function may also help.
Steroid injection into the carpal tunnel may be successful in relieving symptoms but risk of recurrence is high.
Surgery is indicated when the above treatment has failed. When the symptoms worsen 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. 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. Recurrence is uncommon and can happen if transverse carpal ligament is incompletely cut or fibrosis develops around the nerve after surgery.
Dr Low Tze Hau
Consultant Hand and Microreconstructive Surgeon Orthopaedic Surgery
Hand and Microsurgery
Dr Ng Eng Seng
Consultant Hand and Microsurgeon
Hand and Microsurgery