What is carpal tunnel syndrome?
Carpal tunnel syndrome (CTS) refers to a collection of symptoms and signs due to increased pressure within the carpal tunnel leading to compression of the median nerve.
Prevalence
The prevalence is between 1-5% of the community. CTS is commoner in women than men (3:1) and is commonest in people between the ages of 45-65.
What causes it?
In most cases, no obvious underlying cause is identified (i.e. idiopathic). However certain conditions may predispose a person to developing CTS:
- Family history
- Pregnancy
- Hypothyroidism
- Diabetes mellitus
- Rheumatoid arthritis
- Obesity
- Excessive, prolonged vibration
- Trauma involving the wrist
Symptoms & Signs
- Pins & needles, tingling sensation affecting the thumb, index, middle and half of ring fingers
- The symptoms are often nocturnal with night waking
- It may also lead to numbness and pain in the hand and sometimes forearm
- In severe cases, the thumb may be weak, the hand becomes clumsy and the muscles could be wasted
Investigations
The diagnosis of CTS remains clinical (i.e.based on history and examination findings). Nerve conduction studies may be requested to confirm the diagnosis (particularly in equivocal cases) and to grade the severity. Xray of the wrist is necessary only in the situation of trauma. MRI of the neck is sometimes required if the symptoms are felt to be arising from the neck instead.
Treatment
Nonoperative
- Steroid (cortisone) injection and a nocturnal (night) neutral wrist splint. This is useful in pregnancy or in those with mild CTS (intermittent tingling but no numbness or muscle wasting) of duration less than a year. Relief may last up to 12-18 months.
Operative
- Carpal tunnel release (decompression) which involves division of the transverse carpal ligament is the definitive treatment of CTS.
- This can be performed using wide awake technique or local anaesthesia only, which is very well tolerated by most patients.
What should I expect when undergoing a carpal tunnel release?
- It is performed as a day-case procedure, under local anaesthesia (so no fasting is required).
- At the end of the procedure, a bulky dressing is applied over the wrist and palm but the fingers and thumb are left free.
- The dressing is reduced within 3 days and sutures are removed at 2 weeks.
- Tingling (night time in particular) often resolves first but the altered sensation/numbness, if present preoperatively, may take a while to resolve and the recovery of normal sensation may not be complete in some patients.
- If there was preoperative muscle wasting (severe CTS), the recovery of muscle is less predictable.
What are the risks?
CTR is successful in the vast majority of patients. There are however recognised risks of wound infection, nerve injury, pain syndrome, incomplete recovery and recurrence. These are fortunately rare. Some may experience scar tenderness but this tends to improve with time and therapy.