Causation and Prevalence

Causation

· Location: Hand

· Affect digits: Thumb ,index, middle, half of fourth

· Character: Numbness, pain, weakness, tingling.

· Cause: Compression of the Median Nerve.

Pathophysiology

· Occurs usually after bedtime.

· CTS is caused by compression on median nerve, due to edema or hypertrophy on the flexor synovium.

· Position of extreme flexion and extension are known to increase carpal tunnel stress and apply pressure to nerve.

Prevalence

· 3.8% of Malaysia general population is affected.

· Mostly middle age women

· Family susceptibility shows significant relationships. CTS family history known to be 9,84 [ 95% CI, 1.13, 85.83, P value 0.039) times the odds compared to those without (USM, 2008)

Sufficient Causation

• Inflammation of the flexor tendon sheath caused by activities involving repetitive wrist flexion (eg, assembly packing, computer keyboard work, playing a musical instrument, craftwork)
• Edema from trauma of any type (eg, fractures), which can compress the median nerve
• Compression of the median nerve from pregnancy or oral contraceptive-related edema
• Strong association between being overweight or obese and the presence of CTS
• Acromegaly
• Rheumatoid arthritis
• Gout or pseudogout
• Tuberculosis
• Renal failure and hemodialysis
• Hypothyroidism
• Amyloidosis
• Has been associated with diabetes mellitus