Carpal Tunnel Syndrome


The carpal tunnel is created by the wrist bones on the bottom and a ligament over the top. The median nerve runs through the tunnel along with the flexor tendons to the wrist. Pressure within the tunnel can compromise the nerve and lead to carpal tunnel syndrome.


The hallmark of carpal tunnel syndrome is numbness in the thumb, index and middle finger. Additional symptoms can include:

  • Numbness that is worse at night
  • Weakness in the thumb muscles of the hand (in severe cases).


Generally speaking, any condition that exerts pressure on the median nerve at the wrist can cause carpal tunnel syndrome

  • Repetitive strain and prolonged flexion/extension of the wrist, notably from activities such as driving, reading, uninterrupted typing, and holding a telephone, as all these can cause tendon inflammation
  • Rheumatoid arthritis
  • Hypothyroidism
  • Diabetes
  • Wrist fracture and associated swelling
  • Pregnancy/oral contraceptive use leading to swelling in the limbs
  • Underlying nerve dysfunctions

Screening and Diagnosis

Proper history and physical examination is key for diagnosis of Carpal tunnel syndrome.

The condition is diagnosed by a nerve conduction study (NCV/EMG), an electrical study that measures the length of time that it takes for a signal to cross the carpal tunnel. A delay is indicative of carpal tunnel syndrome.


– Initial treatment usually consists of NSAIDs and wrist splints (especially for use at night).

– If the symptoms persist, cortisone injections can be used to decrease the inflammation around the nerve, thus helping with the symptoms. Very good results can be obtained if used in combination with wrist splints.

– If conservative measures fail, or there is evidence of nerve damage (such as weak thumb muscles or profound numbness that does not respond to conservative treatment), then the carpal tunnel can be released by surgically incising the ligament to give the nerve root more room. This procedure is a commonly performed surgery and is considered very reliable.

Related Research Articles

Title: Treatment outcome in carpal tunnel syndrome: Does distribution of sensory symptoms matter? 
Authors: Franka Claesa, Kristel M. Kasiusb, Jan Meulsteec, J. André Grotenhuisd, Wim I.M. Verhagenc
Journal: Journal of Neurological Sciences