Description

• Carpal tunnel syndrome (CTS) is the most common cause of peripheral nerve compression.
• Increased pressure within the carpal tunnel leads to entrapment and compression of the median nerve.
• The tunnel is composed of the carpal bones dorsally and the transverse carpal ligament palmarly:
  • The tunnel contains flexor tendons and the median nerve.
• Symptoms tend to affect the dominant hand, but >50% of patients experience bilateral symptoms.
• System(s) affected: Musculoskeletal; Nervous

ALERT
Pregnancy: Increased incidence during pregnancy; incidence estimates vary

Epidemiology

• Predominant age: 40–60
• Predominant sex: Female > Male (3:1–10:1)

• 2 peaks: Late 50s in women, and late 70s when the sex ratio is more equal
• Incidence rates of up to 276/100,000 have been reported.

• Incidence of 9.2% in women, and 6% in men.
• Diabetic patients have a prevalence rate of 14% and 30% without and with diabetic neuropathy.
• Increasing prevalence may be due to increased lifespan of population, as well as increasing prevalence of diabetes.

Risk Factors

• Prolonged postures in extremes of wrist flexion or extension, and exposure to vibration are primary reported exposures for development of carpal tunnel syndrome.
• Conditions that alter the fluid balance in the body, including pregnancy, menopause, obesity, renal failure, hypothyroidism, congestive heart failure (CHF), and oral contraceptive use
• Neuropathic factors, such as diabetes, alcoholism, vitamin deficiency, or exposure to toxins, can play a role in eliciting CTS symptoms.
• No universal agreement that CTS is job-related

Genetics
Unknown; however, a familial type has been reported.

General Prevention

There is no known prevention for CTS. It is recommended to take a break once an hour when doing repetitive work involving hands.

Pathophysiology

Combination of mechanical trauma, inflammation, increased pressure, and ischemic injury to the median nerve within the carpal tunnel.

Etiology

• Disorders affecting the musculoskeletal system in the region of the wrist, including the following:
  • Trauma or distal radius fracture
  • Degenerative joint disease
  • Rheumatoid arthritis
  • Ganglion cyst
  • Scleroderma
• Hypothyroidism and diabetes are frequently associated with this condition, which also occurs with increased frequency during pregnancy.
• Other miscellaneous causes include the following:
  • Acromegaly
  • Lupus erythematosus
  • Leukemia
  • Pyogenic infections
  • Sarcoidosis
  • Primary amyloidosis
  • Paget disease
• Hyperparathyroidism, hypocalcemia

Commonly Associated Conditions

• Diabetes
• Obesity
• Pregnancy