Median nerve compression at the wrist; nocturnal hand paresthesias and thenar weakness; managed with splinting, steroid injection, or surgical release.
Also known as: CTS, carpal tunnel, median nerve entrapment
Overview
Compressive neuropathy of the median nerve at the level of the carpal tunnel beneath the transverse carpal ligament. Most common upper-extremity entrapment neuropathy.
Epidemiology
Affects ~3-5% of adults; women > men 3:1. Peak incidence 45-60. Bilateral involvement common (often worse in the dominant hand).
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Question 1MusculoskeletalMedium
A 30-year-old woman at 32 weeks gestation reports bilateral wrist pain and paresthesias of the thumb, index, and middle fingers that awaken her from sleep and improve with hand shaking. Examination shows reproduction of symptoms with wrist percussion over the volar wrist and with sustained wrist flexion bilaterally. Which of the following is the most appropriate initial management?
AThumb spica splint
BNighttime neutral wrist splints
CLocal corticosteroid injection
DNerve gliding exercises and NSAIDs
Reveal answer & full explanation
Correct answer: B — Nighttime neutral wrist splints
AThumb spica splint
BNighttime neutral wrist splints✓
CLocal corticosteroid injection
DNerve gliding exercises and NSAIDs
Why Nighttime neutral wrist splints is correct
Carpal tunnel syndrome in pregnancy is common due to fluid retention compressing the median nerve.
Median nerve distribution: thumb, index, middle, and radial half of ring finger.
First-line treatment in pregnancy is neutral wrist splints at night.
Corticosteroid injections are generally avoided in pregnancy.
Symptoms typically resolve postpartum.
Why the others are wrong
Thumb spica splint — immobilizes the thumb CMC/MCP joints for de Quervain tenosynovitis or first-CMC arthritis, not the median nerve; it does not relieve carpal tunnel compression.
Local corticosteroid injection — reserved for symptoms that persist despite splinting and generally deferred in pregnancy, when the compression is expected to resolve after delivery.
Nerve gliding exercises and NSAIDs — systemic NSAIDs are avoided in the third trimester because of premature ductus arteriosus closure and oligohydramnios, so this pairing is not appropriate initial therapy at 32 weeks.
Additional high-yield points
Electromyography/nerve conduction studies (EMG/NCS) are used if the diagnosis is uncertain or surgery is being considered.
Question 2MusculoskeletalMedium
A 42-year-old male has bilateral hand numbness and tingling affecting the thumb, index, middle, and radial ring fingers that worsens at night and with prolonged driving. Tinel sign and Phalen test are positive bilaterally. Nerve conduction studies confirm bilateral median nerve compression at the wrist. He has no thyroid disease or diabetes. Which of the following is the most appropriate first-line treatment?
AWrist splinting
BOral prednisone taper
CCarpal tunnel release
DTherapeutic ultrasound
Reveal answer & full explanation
Correct answer: A — Wrist splinting
AWrist splinting✓
BOral prednisone taper
CCarpal tunnel release
DTherapeutic ultrasound
Why Wrist splinting is correct
Carpal tunnel syndrome (CTS) is median nerve compression at the carpal tunnel
First-line treatment includes a wrist splint in the neutral position, especially at night, which reduces nerve compression
Other first-line options include corticosteroid injection (short-term relief for 3-6 months) and activity modification
Why the others are wrong
Oral prednisone taper — corticosteroid injection (not oral) may be used, but splinting comes first in conservative management (right-concept-wrong-route)
Carpal tunnel release — reserved for severe CTS with constant numbness, thenar atrophy, failed conservative therapy after 6 months, or severe denervation on nerve conduction studies (NCS) (premature escalation)
Therapeutic ultrasound — not an established first-line treatment for CTS (confused-with adjunctive modality)
Additional high-yield points
Classic symptoms: nocturnal paresthesias in the median nerve distribution (thumb, index, middle, radial ring fingers), wrist/palm pain, and thenar weakness in severe disease
Tinel sign positive ~60%; Phalen test positive ~80% — useful but not diagnostic
Nerve conduction studies (NCS): gold standard for diagnosis and severity
Endoscopic vs open carpal tunnel release: equivalent long-term outcomes; endoscopic has faster recovery
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Amyloidosis (consider in atypical or bilateral disease, especially with carpal tunnel as harbinger of cardiac amyloid)
Acromegaly
Hemodialysis (beta-2 microglobulin amyloid)
Repetitive hand or wrist activities (modest association)
Vibrating tool use
Wrist fracture (Colles)
Pathophysiology
Increased pressure within the carpal tunnel — from synovial swelling, tendon thickening, fluid retention, or space-occupying lesion — compresses the median nerve, producing initial sensory symptoms in the median distribution (thumb, index, middle, lateral half of ring finger). Persistent compression causes axonal damage with thenar atrophy and weakness.
Clinical presentation
Symptoms
Numbness and tingling in the thumb, index, middle, and radial half of the ring finger
Nocturnal symptoms that wake the patient and are relieved by shaking the hand (flick sign)
Symptoms worsened by activities requiring sustained wrist flexion (driving, holding a phone or book)
Hand clumsiness, dropping objects
Pain may radiate proximally to the forearm or shoulder
Signs / physical exam
Diminished sensation in median nerve distribution (sparing the thenar eminence palm — supplied by the palmar cutaneous branch that runs SUPERFICIAL to the carpal tunnel)
Thenar atrophy and weakness of thumb abduction and opposition (advanced disease)
Positive Tinel sign (percussion over median nerve at wrist reproduces symptoms)
Positive Phalen sign (1 minute of wrist flexion reproduces symptoms)
Positive carpal compression test (Durkan) — sensitive and specific
Differential diagnosis
Cervical radiculopathy (C6-C7) — Neck pain, dermatomal pattern, positive Spurling test; weakness in larger muscle distribution
Pronator teres syndrome (proximal median nerve) — Forearm pain, weakness in pronation; sensory loss extends to thenar eminence palm (palmar cutaneous branch — spared in CTS)
Anterior interosseous nerve syndrome — Pure motor; weakness of FPL, FDP to index, pronator quadratus ('OK sign')
Brachial plexus lesion (thoracic outlet) — More diffuse arm symptoms, often ulnar predominant
Peripheral neuropathy (diabetes, alcohol) — Symmetric stocking-glove distribution
Cervical syringomyelia — Cape-like dissociated sensory loss
Diagnostic workup
Labs
Screen for contributing conditions if atypical: A1c, TSH, CBC, CMP
Consider workup for amyloidosis (especially bilateral CTS in elderly men or those with cardiac/renal involvement): SPEP/UPEP, free light chains, transthyretin
Imaging
Generally NOT needed
Ultrasound of median nerve at the wrist — increased cross-sectional area
Local corticosteroid injection — substantial short-term benefit; many patients have lasting relief but surgery often eventually required for definitive resolution
Carpal tunnel release (open or endoscopic) — first-line for severe disease (thenar atrophy, persistent weakness, denervation on EMG) and second-line for refractory mild-to-moderate disease
Definitive treatment; most patients have rapid symptom relief, though established axonal damage may not fully reverse
Complications
Permanent median nerve damage with thenar atrophy and persistent weakness
The palmar cutaneous branch of the median nerve runs SUPERFICIAL to the carpal tunnel — sensory loss extending into the thenar palm suggests a proximal lesion (pronator teres syndrome or radiculopathy), not CTS.
Nocturnal symptoms and the 'flick sign' are highly suggestive of CTS.
Severe CTS with thenar atrophy is a surgical referral, not a splinting decision.
Bilateral CTS in elderly men should raise concern for amyloidosis — sometimes precedes cardiac amyloid by years.
Pregnancy-related CTS typically resolves within months of delivery — conservative management preferred.
References
AAOS 2016 — AAOS Clinical Practice Guideline on the Management of Carpal Tunnel Syndrome (2016, 2024 update)
AAN 2002 — Practice Parameter for Electrodiagnostic Studies in CTS (Jablecki et al., Neurology 2002)
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