Many of us have heard about ‘Trapped nerve’ or Carpal Tunnel syndrome in the hand which causes numbness and ‘tingly’ fingers. This common condition affects around 3% of those aged over 60 years in the UK and can be quite disabling, affecting day to day life and indeed can cause symptoms enough to disturb the sleep.
To help us understand the causes, investigations, treatment options of this common condition, Mr Srinivasan, Specialist Hand Surgeon answers some key questions:
What is Carpal Tunnel Syndrome and what are the typical symptoms?
Carpal Tunnel Syndrome is entrapment of the nerve called the ‘Median’ nerve as it passes through a tunnel called Carpal Tunnel in the hand as shown in the diagram. Abnormally high pressure on the nerve causes the numbness and tingling of the thumb, index and middle fingers.
Patients often complain of pain, clumsiness and weakness of hand in addition to the typical numb and tingly fingers. They tend to lose dexterity or fine skills (finesse) in the hand and complain of dropping objects like chinaware, etc.
The symptoms are often worse in the night, resulting in disturbed sleep and patients sometimes complain they have to shake the hands vigorously or hang the hand at the edge of the bed to relieve the numbness. In long standing cases the grip is weakened and the function of the hand can be significantly affected.
What causes Carpal Tunnel Syndrome?
The majority of patients with carpal tunnel syndrome are above 55 years of age and women are more predisposed to be affected. Although in most cases no specific cause can be identified, the following conditions can be associated with carpal tunnel syndrome:
- Rheumatoid Arthritis
- Thyroid disorders
- Kidney disorders
- Following wrist fractures
- Repetitive work conditions
- Reynaud’s phenomenon
Is the condition work related?
The condition is NOT caused by any specific work or employment but can be aggravated by vibratory tools and ‘bad’ workstations e.g. computer. etc. So it is vital to get the workstation checked by the occupational health department. Further information regarding workstation improvement can be accessed at Health and Safety Executive, www.hse.gov.uk or World Health Organization at www.who.int.
How can the diagnosis be confirmed?
Initial diagnosis of the condition is by clinical examination. Sometimes there is wasting of the muscles below the thumb. The clinical examination will reveal positive Tinsels sign and Phalanx’s test, all reproducing the typical tingling or pins and needles sensation in the fingers. The clinical diagnosis is confirmed by special nerve conduction studies which will establish the severity of the entrapment of the nerve.
What are Nerve Conduction Studies? Are they painful?
Nerve conduction studies are the specific test for carpal tunnel syndrome. The severity of the entrapment of the nerve and condition of the nerve can be assessed by the test. The investigation is a simple out-patient test performed using a state of the art mobile device called the ‘Neurometrix’ system (Used by Mr Srinivasan at the Spire Parkway Hospital, Solihull).
Testing involves attaching sensors to the thumb and little fingers and recording the signals generated. The patient experiences little or no discomfort in the fingers during the test and no pain at all.
This test takes around 30 minutes and the results are available instantly. This means that further treatment can be organised within the next few days to weeks. The test will provide definitive information to help choose the appropriate treatment option.
What are the treatment options?
When the symptoms are mild and the test confirms early carpal tunnel syndrome, splinting is advised. The splint provides rest to the nerve and is essentially worn during the night time (it is often called a night splint). In some cases local steroid injections can provide short term relief.
What is the role of surgery and what does the surgery involve?
Surgery is indicated when the condition has been present for more than a few months and if there is wasting of the thumb muscles, signifying moderate to severe carpal tunnel syndrome. The severity is further confirmed by nerve conduction studies.
Carpal Tunnel decompression surgery is a day case procedure and is performed under local anaesthesia. The transverse carpal ligament of the carpal tunnel is divided, releasing the nerve from pressure. A simple bandage is applied and the sutures are removed after two weeks.
What precautions are followed after the surgery?
The hand should be kept elevated and active movement and use of the hand is encouraged from the next day. Driving should be avoided for about ten days and the wound should be kept dry until the sutures are removed. Heavy household work or manual work should be deferred for four to six weeks.
What is the success rate of the surgery for carpal tunnel syndrome?
Carpal tunnel decompression surgery has high success rates approaching 90% in terms of pain relief and complete relief from tingling and numbness of the fingers .The complications from the operation are rare (occuring in less than 3% of cases) and include infection, scar tenderness and sensitivity and nerve damage (1%).
JAMA. 2002 Sep 11;288(10):1245-51.
Splinting vs. surgery in the treatment of carpal tunnel syndrome: a randomized controlled trial.
Gerritsen AA, de Vet HC, Scholten RJ, Bertelsmann FW, de Krom MC, Bouter LM.
Institute for Research in Extramural Medicine, Vrije Universiteit Medical Center, Van der Boechorststraat 7, 1081 BT Amsterdam, The Netherlands. email@example.com