Carpal Tunnel Syndrome: INformation

Carpal tunnel syndrome is a condition which is characterised by irritation or entrapement of the median nerve.

This nerve can get entrapped at various sites along its course down the upper limb and each site is specific with regards to the clinical presentation i.e. Pronator Teres Syndrome, Anterior Interosseous nerve entrapement and Carpal Tunnel syndrome

With Carpal Tunnel syndrome, the median nerve is entrapped as it passes through the osteofibrous tunnel created by the transverse carpal ligament and small carpal bones of the wrist. Within this tunnel, the median nerve can become compressed directly from fractures or dislocation. More commonly, the patient has a history of prolonged repetitive wrist and finger use whereby swelling or thickening of the overused tendons is thought to decrease the space for the passage of the nerve into the wrist. Additional factors which may contribute to the development of this condition include diabetes and pregnancy.  Carpal Tunnel syndrome is the most common peripheral nerve entrapement encountered.

The lower part of the median nerve supplies the first and second lumbricales along with the muscles of the thenar eminence namely the Abductor Pollicis Brevis, Opponens Brevis and Flexor Pollicis Brevis. The median nerve also supplies sensation to the thumb and radial side of the index finger, second finger and half of the third finger (see below).

With Carpal Tunnel syndrome, patients report tingling in the median nerve distribution of the hand (see above) which is often worse at night. There is also often a complaint of clumsiness and in severe or prolonged cases, there maybe weakness in the muscles which are supplied by the median nerve in the hand.

Treatment options for Carpal Tunnel Syndrome

Before treatment commences, it is necessary for your healthcare professional to carry out specific neurological and orthopaedic tests to confirm the diagnosis of this condition. In addition, patients may also be referred for specific nerve conduction studies. In the clinic setting, various tests can be utilised include Phalens, Reverse Phalens and Tinels test. A positive finding for these tests are often the reproduction of the tingling in the median nerve distribution. It is also necessary to carry out a full assessment of the neck as if there is some irritation from the lower nerve roots that exit the neck (C6), this may also give rise to or contribute to tingling in the distribution of the median nerve

Once the diagnosis has been established, patients are often advised to modifiy any activities which are contributing to this complaint such as reducing the amount of computer usage or improving their ergonomic set up to reduce the stress on the finger and wrist flexors. A splint may also be advised.

The neck and mid back may also be treated to reduce the possibility of a double crush syndrome whereby if a nerve is mildly irritated in the neck, it will be more susceptible to injury distally lower down the chain such as in the wrist. An important consideration is that Carpal Tunnel syndrome is often relieved by shaking the hand whereas nerve root irritation from the neck is not relieved by this movement.

Conservative treatment involves mobilisation of the bones of the wrist, soft tissue work and exercise prescription. In some cases corticosteroid injections are used to reduce the inflammation within the carpal tunnel. If these conservative measures fail, patients are referred to an orthopaedic consultant to ascertain if they are a good candidate for surgical decompression.