Understanding Carpal Tunnel Syndrome

What is a carpal tunnel?

The carpal tunnel is a rigid narrow passage formed by the carpal bones of the wrist and the transverse carpal ligament. The transverse carpal ligament goes across the underside of the wrist. When the thumb or fingers are flexed, the flexor tendons which connect the muscles in the forearm to the fingers, slide through the carpal tunnel. The median nerve lies in the tunnel along with the tendons.

What is Carpal Tunnel Syndrome (CTS)?

CTS is the numbness, weakness and pain caused by compression of the median nerve against the transverse carpal ligament. It is the most common disorder of the hands. It is often caused by swilling in the flexor tendons which puts pressure on the median nerve.

What are the Symptoms?

Numbness and tingling of the hand ( paresthesias ): especially in the thumb and first few fingers. Some say it feels like pins and needles.

Night pain: Relieved by shaking or exercising.

Daytime pain: aggravated by certain repetitive hand movements.

Thumb muscle weakness: Grasping and pinching are difficult, or weak. The hand may feel clumsy or stiff. The thumb muscle may become smaller and weaker in severe cases.

What Causes CTS?

CTS can be caused by anything that contributes to increased pressure on the median nerve. Often several of the following factors are present.

Tunnel size: Small size can be inherited.

Repetitive movements: Certain movements can expose the nerve to friction, pressure, and stretching. Flexion movement means to bend the hand downward and it compresses the median nerve between tendons and the transverse carpel ligament. Extension movement means to bend the hand upward and it stretches the median nerve across the tendons and bones of the wrist.

Systemic disorders: amyloidodisamloidodis, diabetes, rheumatoid arthritis, and hypothyroidism can be factors affecting CTS.

Edema: Increased fluid levels in the carpel tunnel can be due to injury, inflamed tissue, pregnancy, obesity, or congestive heart failure.

How is CTS Treated?

Rest the hand.

Wear a wrist splint to prevent excessive wrist movement.

Avoid movements and activities that cause pain or an increase of symptoms.

Modify hand and wrist activity and your work environment.

Take anti-inflammatory medication and diuretics or steroid injections.

Treat underlying systemic diseases.

Keep your hands warm.

In severe cases surgery may be necessary to reduce the pressure on the median nerve. It is a minor surgical procedure, requiring only a local anesthetic. Your doctor may want a nerve conduct study done in order to determine the severity of the CTS.