Carpal Tunnel Syndrome
What is carpal tunnel syndrome?
Components are Reproduced with permission from Dr Stuart Myers at www.myhand.com.au
Carpal Tunnel sydrome is a painful condition of the arm, wrist and hand due to compression of the median nerve as it passes through a tunnel at the wrist.
The floor of the tunnel is formed by the small bones in the wrist. The bones are in the shape of an arch. The roof is formed by some thick fibrous tissue called the Flexor Retinaculum. Through the carpal tunnel pass tendons to the hand and the median nerve.
what causes c.t.s.?
It is common to have no obvious cause. There are many risk factors
- Age (30-60) In men the incidence increases with age
- Female > male 3 : 1
- Genetic - (often runs in families) – ? small tunnel
- Post menopausal (? Hormonal)
- Fluid retention
- Obesity – Best predictor of developing CTS
- Family history of Diabetes (1/4)
- High Cholesterol
- Smoking – (reduce blood flow to nerve)
- Alcohol – Lifetime intake
- Hormones – Eg under-active Thyroid
- Arthritis - Eg Base of thumb or Scapho-trapezial
- Inflammatory eg Rheumatoid
- Wrist fractures - Recent or Old
- Neck Problems ( Double crush)
- Kidney disease
- Activities - Prolonged posture
- Renovating , Pruning garden etc
- Work? – Highly repetitive +
- Highly forceful +
- Cold environment eg Butchers
- +/- Vibration stress
What are the symptoms?
The symptoms are very variable.
Tingling in the fingers (as above) is a classic syptom. Pain in the forearm.
The pain and tingling are usually worse at night
Carpal Tunnel can result in a weak or clumsy hand.
It may be relieved by shaking the hands or hanging them over the side of the bed.
The diagnosis is usually straight forward and is made after eliciting a typical history (as above) and an examination.
Nerve conduction tests are often performed.
An injection of Cortisone into the tunnel can be helpful to check if compression is at the wrist or another site.
In Diabetes and some similar conditions it is sometimes unclear whether the nerve dysfunction is due to pressure on the nerve, chemical damage to the nerve or lack of blood flow to the nerve. Again a Cortisone injection may be of assistance. A positive response to other treatment modalities eg a Wrist brace may help confirm the diagnosis.
What are the risks?
It is usually not a serious problem. If the symptoms are present for a long time or the numbness becomes constant (i.e. present night & day) then it may cause permanent nerve damage. This may cause permanent weakness and numbness in the hand.
What is the treatment?
- Identify treatable causes for the condition
- Activity Modification
- Night Splints (OAPL wrist brace holds wrist straight & opens up the tunnel.
Can be obtained from the physiotherapist or from a chemist)
- Weight loss & Fitness training
- Stop smoking
- Cortisone injections
- Fluid tablets (occasional)
- Operation - Involves cutting the membrane (Flexor retinaculum) to create more space in the tunnel for the nerve
It is indicated in those patients in whom non-operative treatment has failed to eliminate their symptoms & when the symptoms are severe or if there is permanent numbness or muscle wasting in the hand.
The operation can be performed under local or general anaesthetic & requires admission to hospital for 1/2 day.
Pros & cons of surgery
Carpal tunnel release is usually very effective in relieving the symptoms of carpal tunnel syndrome in 95% of cases.
Recovery periods are extremely variable.
- If the symptoms are only present at night then many people notice resolution of their symptoms immediately after the operation
- If the numbness is constant then the sensation may never fully recover or may recover over a period of 9 -12 months
Wasting of the muscles at the base of the thumb may never fully recover.
The major problem with the surgery is persistent weakness or aching pain in the base of the hand that may take about 3 months to settle down. (Pillar pain)
About 10% of people notice some permanent weakness or pain in the hand following the operation.
While this is not a major issue for the majority of people if you were a heavy manual worker this could potentially be career ending.
- Nerve, tendon or artery damage
- Regional pain syndrome ( 0.5 – 1.0%)
- Colour change , sweating
Recurrent Carpal Tunnel syndrome is possible but very uncommon.
If you are at all concerned or have any questions feel free to discuss them with me prior to the surgery.