Aetiology

Any pathological process that compromises space for the median nerve may cause carpal tunnel syndrome.

• there appears to be an anatomical predisposition with females affected three times more often than males.
• 60% of patients are aged between 40 and 60 years.

CTS is mostly an idiopathic syndrome. Certain risk factors have been described associated with this syndrome:

• environmental risk factors – hand in extremes of wrist flexion or extension for prolonged period of time, repetitive use of the flexor muscles, and exposure to vibration
• medical risk factors
  • extrinsic risk factors – there is an increase in the volume within the tunnel e.g. - pregnancy, menopause, obesity, renal failure, hypothyroidism, the use of oral contraceptives and congestive heart failure
  • intrinsic risk factor - increased occupied volume inside the tunnel e,g, - tumours and tumour-like lesions
  • extrinsic factors that alter the contour of the tunnel – e.g. - after fractures of the distal radius, directly or via posttraumatic arthritis
  • neuropathic factors – e.g. - diabetes, alcoholism, vitamin toxicity or deficiency, and exposure to toxins (1)

The causes of CTS can also be classified into:

• endocrine causes
• infiltrative causes
• others

Pregnancy and rheumatoid arthritis are the most likely causes of carpal tunnel syndrome in young patients

Reference:

• (1) I Ibrahim et al. Carpal Tunnel Syndrome: A Review of the Recent Literature. Open Orthop J. 2012; 6: 69–76