CTS is caused by compression of the median nerve as it travels across the wrist with the tendons between the carpal bones and the flexor retinaculum (also know as the transverse carpal ligament):
Compression an injury to the median nerve causes numbness and tingling mostly affecting the thumb, index finger, middle finger, and half of the ring finger.
More severe cases also cause weakness and wasting of the muscle at the base of the thumb that abducts the thumb away from the fingers (abductor pollicis brevis or APB):
In severe cases, the numbness can seem to affect the whole hand, and can even radiate up the forearm and arm:
Symptoms are often worse typing, driving, and frequently wake the affected patient up at night:
CTS can usually be diagnosed on clinical grounds. A helpful physical finding is a tingling in the wrist and fingers caused by a tap over the carpal tunnel (Tinel’s sign):
In some cases, an electrodiagnostic study may be necessary to confirm the diagnosis:
CTS is usually “idiopathic” (we don’t know why it happened), but some cases are caused by diabetes, pregnancy, thyroid disease, joint swelling from rheumatoid arthritis, heavy manual work and work with vibrating tools.
Treatment usually begins with conservative measures, like avoiding exacerbating activities, and wearing a neutral position night splint:
Patients who do not improve with these conservative measures can undergo a surgical procedure to release the compressed median nerve:
Want to find out more?
Click here to take an on-line quiz to see if you have CTS.
Watch this on-line video tutorial explaining the causes and treatment of CTS:
If you think you might have CTS, you should make an appointment to see a neurologist.
Click here to use our physician finder service.