Carpal Tunnel Syndrome
Carpal tunnel syndrome (CTS): collection of characteristic symptoms and signs that occurs following compression of the median nerve within the carpal tunnel.
Symptoms: numbness, paresthesia, and pain in the median nerve distribution.
Clinical presentation: The patient’s history is more important than the physical examination in making the diagnosis
Numbness and tingling: Among the most common complaints; Complaints should be localized to the palmar aspect of the first to the fourth fingers and the distal palm (ie, the sensory distribution of the median nerve at the wrist). Numbness existing predominantly in the fifth finger or extending to the thenar eminence or dorsum of the hand should suggest other diagnoses.
Clinical examination: important to rule out other neurologic and musculoskeletal diagnoses; often contributes little to the confirmation of the diagnosis of carpal tunnel syndrome (CTS).
Sensory examination: Abnormalities in sensory modalities may be present on the palmar aspect of the first 3 digits and radial one half of the fourth digit.
Motor examination - Wasting and weakness of the median-innervated hand muscles (LOAF muscles) may be detectable.
L - First and second lumbricals
O - Opponens pollicis
A - Abductor pollicis brevis
F - Flexor pollicis brevis
Special tests - No good clinical test exists to support the diagnosis of CTS.
Hoffmann-Tinel sign: Gentle tapping over the median nerve in the carpal tunnel region elicits tingling in the nerve’s distribution. Low sensitivity and specificity.
Phalen sign: Tingling in the median nerve distribution is induced by full flexion (or full extension for reverse Phalen) of the wrists for up to 60 seconds. 80% specificity but lower sensitivity.
The carpal compression test: Applying firm pressure directly over the carpal tunnel, usually with the thumbs, for up to 30 seconds to reproduce symptoms. Sensitivity up to 89% and a specificity of 96%.
Palpatory diagnosis: Examining the soft tissues directly overlying the median nerve at the wrist for mechanical restriction. Sensitivity of over 90% and a specificity of 75% or greater.
The square wrist sign: The ratio of the wrist thickness to the wrist width is greater than 0.7. Sensitivity/specificity of 70%.
Causes: Increasing age; Female sex; Increased body mass index (BMI), especially a recent increase; Square-shaped wrist; Short stature; Dominant hand; Genetics
Medical conditions: Diabetes; Thyroid disorders (usually myxedema); Rheumatoid arthritis and other inflammatory arthritis of the wrist; Recent menopause (including post-oophorectomy); Renal dialysis; Acromegaly; Amyloidosis
Space-occupying lesions within the carpal tunnel (eg, flexor tenosynovitis, ganglions, hemorrhage, aneurysms, anomalous muscles, various tumors, edema)
Other factors: Lack of aerobic exercise; Pregnancy and breastfeeding; Use of wheelchairs and/or walking aids
Activities associated with CTS: Prolonged, severe force through the wrist; Prolonged, extreme posture of the wrist; High amounts of repetitive movements; Exposure to vibration and/or cold
Treatment and management
Medical treatment: NSAIDs, COX2 inhibitors, diuretics
Surgical interventions: Surgical release of the transverse ligament (aka flexor retinaculum or anterior annular ligament) provides high initial success rates (greater than 90%), with low rates of complication; however, it has been suggested that the long-term success rate may be much lower than previously thought (approximately 60% at 5 y).
NOTE 1: In case of pregnancy with CTS; patient is advised to wear Wrist splints until delivery. CTS usually resolves by its own after delivery. If not resolved and long-standing then cut the transverse carpal ligament.
NOTE 2: Guyon’s canal syndrome is an entrapment of the ulnar nerve as it passes through a tunnel in the wrist called Guyon’s canal. This problem is similar to carpal tunnel syndrome but involves a completely different nerve.
Have a look on how the surgery is done.