Carpal Tunnel Syndrome is an entrapment of the median nerve at the wrist where it passes through the carpal tunnel. This causes paraesthesia (abnormal sensations) pain, numbness, tingling and burning along the median nerve’s distribution (thumb, index finger, middle finger and half of the ring finger).
This syndrome is of mostly unknown origin yet appears to possibly be caused by genetic and environmental factors such as an under-active thyroid, rheumatoid arthritis, diabetes, obesity, pregnancy, and heavy physical work or working with vibrating equipment. Another debated hypothesis is that of a “double crush syndrome” whereby nerve irritation closer to, or at the spine is contributing to a hypersensitivity of the median nerve. In this event the nerve may react excessively to the slightest increase in pressure within the carpal tunnel. Understanding and considering this possibility may be vital in avoiding ineffective management and unnecessary surgeries in tackling the presentation of these symptoms.
The most common symptom of carpal tunnel syndrome is numbness along the distribution and especially at night. Keeping the wrist straight by using a splint may ease the increased numbness at night. Long-term pressure on the nerve may lead to nerve damage or nerve death resulting in weakness and wasting of the muscles in the hand supplied by this nerve.
Diagnosis of the syndrome can be done clinically using Tinel’s sign, Phalen’s maneuver and abnormal sensory testing (by e.g. a Physiotherapist) or by electro-diagnostic testing (by a neurophysiologist). Steroid injections may be beneficial in reducing the swelling and irritation of all the structures within the tunnel.
Physiotherapy for this condition may include splinting, ultrasound and other anti-inflammatory modalities, nerve mobilization exercises and joint mobilizations. As a last resort (after 2-7 weeks of failed conservative treatments or if there is signs of nerve damage), the transverse carpal ligament may be surgically removed to allow for more space within the carpal tunnel.