Carpal and Cubital Tunnel Syndromes
Both Carpal and Cubital Tunnel Syndromes are common disorders resulting from tight constriction or trapping of the 2 major nerves to the front of the hand. These are the Median and Ulnar nerves, imparting sensation respectively to the thumb and little (pinky) finger sides. Most of the back of the hand is supplied by a different nerve (the Radial Nerve), compression of which is much less common.
Patients with Carpal Tunnel Syndrome typically wake up at night with pins and needles affecting the thumb, index, middle and perhaps the thumb-side of the ring finger. They often shake the wrist in an effort to relieve the discomfort, and may experience similar daytime symptoms when holding the hand up for any length of time, such as driving, doing their hair or using a telephone. Pain may radiate up the arm, and they may start dropping objects. If neglected, the affected fingers go numb and the thumb muscles can start to wither.
Early diagnosis is therefore important, and your GP may have to refer you to a Hand Specialist (Orthopaedic Surgeon, Plastic Surgeon or Hand Therapist) for this. The commonest site of entrapment is the transverse ligament at the wrist (Fig 1), but occasionally the Median Nerve can get trapped at other sites (Fig 2). If examination alone does not provide a clear diagnosis, electrical tests may be needed (Nerve Conduction Study or Electromyography).
Early stages can be kept at bay by Physiotherapy and a Futuro splint. Steroid carefully injected near the nerve can also give temporary relief. When none of these are helping, it is time to consider Surgery (and at least 2 weeks off manual work or driving). This is commonly performed awake under local anaesthesia as a day-surgery, where the ligament compressing the nerve is released using a short incision in the palm. Depending on the extent of existing damage, the nerve can take time to recover.
Patients with Cubital Tunnel Syndrome (Cubit= elbow) experience similar pins and needles affecting the little finger (and perhaps the facing side of the ring finger). This area gets its sensation from the Ulnar Nerve, and the common site of compression is near the ‘funny bone’ at the inside elbow (the nerve here is in a tunnel directly on bone, and gets stimulated when tapped- Fig 3). The wrist and adjoining heel of the hand (Guyon’s Canal) is a much rarer site of compression. This ‘funny bone nerve’ also supplies the fine muscles of the hand responsible for delicate precision tasks; hence again it is important to make the diagnosis and accurately define the site/sites of compression early. If neglected, the hand loses all dexterity and goes into a claw posture.
Initially soft splints designed to rest the nerve can help. If this fails, or if the muscles of the hand are starting to get affected, the trapped nerve should be released without delay. Surgery for Cubital Tunnel syndrome is considerably more involved than Carpal Tunnel release, as there can be many potential sites of compression around the elbow tunnel, all of which need to be seen and carefully released (Fig 4). Very occasionally the nerve may have to be repositioned completely out of its tunnel and onto the front of the elbow, or need even further complex surgery. All these issues, time off work and driving, recovery length, physiotherapy and aftercare will be discussed in detail at the consultation.
Obviously prevention of muscle damage is paramount as established wasting of muscle is irreversible. However, if for any reason this has happened, it may be possible to switch over unaffected and relatively expendable healthy muscle. These Tendon Transfer operations are quite sophisticated and crucially need a very dedicated Physiotherapist to succeed. Mr Agarwal has a special interest in the areas of peripheral nerve and tendon transfer surgery, and will ensure the best possible outcomes for you.