Carpal tunnel syndrome article series: An introduction

When the median nerve, a major nerve in our arm and wrist, is compressed, it can cause discomfort and disrupt everyday routines due to the symptoms it causes. More seriously, it can lead to permanent nerve damage if it goes untreated.

Renowned consultant orthopaedic surgeon Miss Samantha Tross speaks to Top Doctors for a three-part series about this common and sometimes debilitating, yet treatable, condition. She goes into expert detail about just what carpal tunnel syndrome is and its symptoms in the following article.

What is carpal tunnel syndrome?

Carpal tunnel syndrome is a condition in which the median nerve in the wrist is compressed within the carpal tunnel. The carpal tunnel is formed by the carpal bones below and the flexor sheath above. Passing through the tunnel are the flexor tendons, i.e., the tendons that cause your fingers to bend as well as the median nerve. The median nerve supplies your thumb, index, middle and radial half (the thumb half) of the ring finger. Hence compression of the nerve causes symptoms in one, some or all of these digits.

What are the symptoms of carpal tunnel syndrome?

The symptoms are:

• Pain

• Burning

• Tingling, numbness and then ultimately, weakness

The above symptoms can be experienced in the fingers or wrist. The pain can also radiate into the forearm and occasionally into the arm. At an advanced stage, there may be weakness of the fingers and so you may find it difficult to do tasks such as closing buttons, opening jars, etcetera.

What causes carpal tunnel syndrome?

Anything that reduces the space around the nerve in the carpal tunnel, may lead to carpal tunnel syndrome. For example, if there's encroachment of the carpal bones leading to reduction of space from below, such as arthritis or malalignment of the bones due to a fracture or a previous injury, like a joint dislocation, all can lead to carpal tunnel syndrome.

Another possible cause is inflammation of the flexor tendons that pass through the tunnel with the medial nerve. Inflammation leads to swelling of the tendons and/or their sheath and is associated with conditions such as rheumatoid arthritis or any inflammatory condition.

If there's increased fluid in the tunnel, which can happen during conditions such as pregnancy where you get fluid retention, this leads to pressure on nerve and hence possible carpal tunnel syndrome.

If you have any kind of chronic disease, you can have a deposition of substance called amyloid within the carpal tunnel, which can lead to the syndrome. If you have extra fat in there, (we have fat all around the body and fat can also exist in the tunnel), this can lead to carpal tunnel syndrome.

Activities that involve persistent wrist flexion like typing without adequate wrist supports, lead to a reduction in the carpal tunnel space and can also lead to carpal tunnel syndrome.

To find out more about carpal tunnel syndrome, you can read Miss Tross’ articles about treatment and diagnosis in part two and surgery in part three.

Considering getting treatment for carpal tunnel syndrome or other orthopaedic conditions? Visit Miss Tross’ Top Doctors profile to make an appointment, here.