Carpal Tunnel Syndrome Flashcards
What is carpal tunnel syndrome (CTS)?
A peripheral neuropathy caused by compression of the median nerve under the transverse carpal ligament.
What is the most common entrapment neuropathy?
Carpal tunnel syndrome (90% of all cases).
What structures form the carpal tunnel?
Carpal bones (floor) and transverse carpal ligament (roof).
What is the pathophysiology of CTS?
Increased pressure within the carpal tunnel compresses the median nerve, causing ischemia, inflammation, and axonal degeneration.
What are occupational risk factors for CTS?
Repetitive wrist flexion/extension, use of vibrating tools, manual labor.
What systemic conditions increase the risk of CTS?
Diabetes mellitus, hypothyroidism, rheumatoid arthritis, pregnancy, obesity, chronic kidney disease (dialysis-related amyloidosis).
What is a common mechanism of post-traumatic CTS?
Fractures (e.g., distal radius), lunate dislocation.
What are the primary symptoms of CTS?
Pain, tingling, and numbness in the thumb, index, middle, and radial half of the ring finger, often worsening at night.
What motor symptoms can occur in severe CTS?
Weakness of thumb opposition and grip strength due to thenar muscle involvement.
What physical exam findings suggest CTS?
Thenar muscle atrophy, positive Tinel’s sign, Phalen’s test, and carpal compression test.
What is a positive Phalen’s test?
Pain or paresthesia in the median nerve distribution after holding wrist flexion for 60 seconds.
What is a positive Tinel’s sign?
Tingling in the median nerve distribution when tapping over the carpal tunnel.
When is electrodiagnostic testing (nerve conduction studies) indicated for CTS?
When the diagnosis is unclear or before surgical intervention.
What imaging is used to evaluate CTS?
Ultrasound (nerve swelling), MRI (if considering other pathologies).
What is the first-line treatment for mild-to-moderate CTS?
Wrist splinting (especially at night), activity modification, and corticosteroid injections.
What is the role of corticosteroid injections in CTS?
Provide temporary symptom relief but do not alter disease progression.
When is surgical treatment indicated for CTS?
Severe symptoms (thenar atrophy, motor dysfunction) or failure of conservative treatment after 6+ weeks.
What surgical procedure is performed for CTS?
Release of the transverse carpal ligament (open or endoscopic).
What is the prognosis after CTS surgery?
Most patients improve within 2 weeks, but severe cases may not fully recover function.
What conditions should be considered in the differential diagnosis of CTS?
Cervical radiculopathy (C6-C7), pronator teres syndrome, ulnar neuropathy, diabetic neuropathy.
