Carpal Tunnel Syndrome
Numbness, tingling, and pain in the hand caused by a pinched nerve in the wrist.
Emergency Management: Acute carpal tunnel syndrome following a distal radius fracture or wrist crush injury represents compartment syndrome of the carpal tunnel and requires emergent surgical release.
A compressive neuropathy caused by entrapment of the median nerve as it travels through the carpal tunnel of the wrist. It is the most common entrapment neuropathy.
Detailed Overview
The carpal tunnel is a rigid passageway bounded by the carpal bones and the transverse carpal ligament. It contains nine flexor tendons and the median nerve. Any condition that increases the volume of the contents or decreases the size of the tunnel compresses the median nerve, leading to ischemia of the nerve. This results in pain, paresthesia, and eventually weakness in the hand.
Epidemiology & Demographics
Affects roughly 3-6% of the general population. Three times more common in women than men. Peak incidence is between 40 and 60 years of age.
Etiological Mechanism
Usually idiopathic, related to repetitive wrist flexion/extension or sustained grip. Often associated with systemic conditions that cause fluid retention or synovial hypertrophy.
Primary Causes
["Repetitive strain or biomechanical overuse", "Pregnancy (due to fluid retention)", "Rheumatoid arthritis (synovial proliferation)"]
Increased pressure in the carpal tunnel (>30 mmHg) exceeds the venous pressure of the intraneural microcirculation, leading to venous congestion and nerve ischemia. Prolonged ischemia causes demyelination, disrupting nerve conduction (causing numbness/tingling). If compression persists, axonal loss occurs, leading to irreversible muscle atrophy and permanent sensory loss.
Diagnostic Criteria & Guidelines
Clinical diagnosis based on history and typical exam findings. Confirmed objectively with Electrodiagnostic testing (EMG/NCS).
Conservative management for mild to moderate cases: Volar wrist splinting in a neutral position, worn primarily at night. Avoidance of aggravating activities. Short course of oral NSAIDs (Ibuprofen 400 mg PRN).
Second-Line & Adjunctive Therapy
Corticosteroid injection (e.g., Methylprednisolone 40 mg mixed with 1% Lidocaine) directly into the carpal tunnel provides significant transient relief (months) and can be diagnostic.
Surgical & Procedural Management
Carpal Tunnel Release (CTR). Surgical division of the transverse carpal ligament to decompress the nerve. Indicated for severe disease (thenar atrophy), failure of conservative treatment for >6 months, or severe EMG abnormalities.
Patient Counseling & Advice
Explain that night splinting works by preventing the wrists from curling up during sleep, which decreases pressure in the tunnel. Inform patients with severe disease/atrophy that surgery will stop progression and relieve pain, but sensory return may be incomplete.
Follow-Up & Monitoring Schedule
Re-evaluate after 4-6 weeks of splinting. If symptoms progress or thenar weakness develops, refer to hand surgery.
Preventive Strategies
Maintaining neutral wrist posture during typing or manual labor. Avoidance of prolonged exposure to vibrating tools.
Excellent with appropriate treatment. CTR surgery has a success rate of >90% for symptom relief. Mild CTS in pregnancy often resolves spontaneously after delivery.