Carpal Tunnel Syndrome Davis Cook

Definition A painful condition of the hand and fingers caused by compression of a major nerve where it passes over the carpal bones through a passage at the front of the wrist, alongside the flexor tendons of the hand.

Demographics and Involved Anatomy CTS is a common condition that occurs in 2.7% of the general population. It is more common in women than men, and the average age of people with CTS is 40–50 years. It is caused by compression of the median nerve within the wrist. CTS is characterised by pain, numbness and weakness in the parts of the hand supplied by the median nerve. People with CTS may complain of “pins and needles” in the thumb, index and middle fingers, and half of the ring finger, as well as pain in the wrist. The carpal tunnel is a narrow, rigid passageway of ligament and bones below the wrist at the heel of the hand which houses the median nerve and tendons. The carpal tunnel is normally quite snug, and there is just enough room in it for the tendons and nerves that have to pass through it. If anything takes up extra room in the canal (such as inflammatory swelling or injury), the nerve in the canal becomes compressed or “pinched”. This leads to CTS symptoms.

Mechanism of Injury Predisposing factors are repetitive manual activities, exposure to vibrations and cold temperatures. CTS is usually caused by excessive manual work. Repetitive extension and flexion movements of the wrist combined with flexion of the fingers and supination of the forearm have been mentioned to be the cause. During this motion the pressure in the carpal tunnel increases. Acute CTS is caused by trauma (displacements or fractures), infection, hemorrhage, high-pressure injection, acute thrombosis of the artery and burns.

Levels of Severity Normal (grade 0); very mild (grade 1), CTS apparent only with most sensitive tests; mild (grade 2), sensory nerve conduction velocity slow on finger/wrist measurement, normal terminal motor latency; moderate (grade 3), sensory potential preserved with motor slowing, distal motor latency to abductor pollicis brevis (APB) < 6.5 ms; severe (grade 4), sensory potentials absent but motor response preserved, distal motor latency to APB < 6.5 ms; very severe (grade 5), terminal latency to APB > 6.5 ms; extremely severe (grade 6), sensory and motor potentials unrecordable (surface motor potential from APB < 0.2 mV amplitude).

Prognosis Carpal tunnel syndrome responds well to treatment, but less than half of individuals report their hands feeling completely normal after surgery. Some residual numbness or weakness is common. Most people may need to modify work activity for several weeks after surgery. Stretching exercises, taking frequent rest breaks, wearing splints to keep wrists straight, and using correct posture and wrist position can help prevent or worsen symptoms.

HOPS History- numbness and/or tingling in the median nerve area Observation- muscle atrophy, decreased RROM in thumb movement Palpation- wrist joints, carpal bones Special Tests- Phalen’s test, Tinel’s test, carpal tunnel test

Special Tests Phalen’s test- The patient places their flexed elbows on a table, allowing their wrists to fall into maximum flexion. The patient is asked to push the dorsal surface of their hands together and hold this position for 30-60 seconds. This position will increase the pressure in the carpal tunnel, in effect compressing the median nerve between the transverse carpal ligament and the anterior border of the distal end of the radius. A positive is indicated by reproduced symptoms of that experienced with carpal tunnel syndrome. Tinel’s test- performed by lightly tapping over the nerve to elicit a sensation of tingling or "pins and needles" in the distribution of the nerve. A positive is indicated by pressure in the nerve.

Neurological Tests The examination may include an electrodiagnostic study called an electromyogram, or EMG. The EMG permits the definitive diagnosis of CTS and also allows the physician to objectively measure whether it is mild, moderate or severe.

Works Cited https://www.myvmc.com/diseases/carpal-tunnel-syndrome/ https://www.physio-pedia.com/Carpal_Tunnel_Syndrome https://www.ncbi.nlm.nih.gov/pubmed/10918269 https://www.ninds.nih.gov/disorders/all-disorders/carpal-tunnel-syndrome- information-page https://www.physio-pedia.com/Phalen%E2%80%99s_Test https://www.neurologycenter.com/neurological-conditions/carpal-tunnel-syndrome