What is Carpal Tunnel Syndrome?

Carpal tunnel syndrome is a condition that causes numbness, pain and tingling in the hand and arm.

What is involved?

Median Nerve at the wrist


The Carpal Tunnel, at the wrist

Common symptoms

  • Worse in the dominant hand
  • Dropping objects
  • Numbness tingling, hand/wrist —-> Thumb, Index and/or Middle finger
  • May radiate up the arm, occasionally to the shoulder
  • Symptoms primarily at night. Patient wakes up and shake their hands to obtain relief
  • Frequently bilateral, although may only be symptomatic on one side


Usually slow, insidious over months/years

Risk factors

  • Women more than Men, Diabetes or family history, Pregnancy, weight gain, trauma, HIV infection
  • Working with hands a lot, secretaries, homemakers, operating machinery, computer joysticks, factory workers in assembly jobs, manual laborers


  • Look for hand Abductor Pollicis Brevis (APB) flattening
  • Test the APB strength (push thumb upwards against resistance)
  • Positive Tinel sign (tingling upon tapping nerve) at the wrist usually with appropriate radiation to finger(s) with symptoms


Very good at localizing Median entrapment to the Carpal Tunnel (disease is frequently bilateral, so test other side even if asymptomatic)

Ulnar testing helpful for comparing Median and Ulnar distal latencies, and checking for underlying peripheral neuropathy.


  • Prolonged Median Sensory/Motor distal latencies
  • If Median and Ulnar Conductions are abnormal, test the lower extremity to rule out Peripheral Neuropathy
  • Check for active/Chronic denervation in the APB on Needle Examination

Suggested Treatment

  • Mild ——> Wrist splints, wear mostly at night
  • Moderate ——> Wrist splints/Steroid Injection (contraindicated in Diabetics)
  • Severe or active denervation in APB ——> Surgery
  • Recommendations

    • Stop/address cause of problem
    • Treat Diabetes if present, address weight gain problems
    • Wrist splints (both sides) mostly at night for mild to moderate carpal tunnel (see above)
    • Steroid Injections, Surgery for moderate to severe cases (see above)
    • Surgery may be indicated if mild to moderate but symptoms intolerable or interfere with job

    What else could it be?

    • Repetitive stress injury with joint, tendon, myofascial symptoms (not carpal tunnel) in musicians, computer/machinery operators
    • Cervical root lesion
    • Thoracic outlet syndrome (very rare)

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