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Carpal Tunnel Syndrome, Emergency Medicine

Basics

Description

- Chronic: - Occupational/overuse syndromes-high impact, repetitive motion - Pregnancy, birth control pills - Granulomatous disease: Tuberculosis, sarcoidosis - Mass lesions with median nerve compression - Osteophytes - Amyloid - Multiple myeloma - Rheumatoid arthritis - Endocrine disorders: Hypothyroidism, diabetes mellitus, acromegaly - Chronic hemodialysis - Idiopathic

- Pain: - Location: Wrist or hand, sometimes radiating to elbow, forearm, or shoulder - Often worse at night-relieved by "shaking out"ť the hand - Exacerbated by repetitive wrist movement and by activities in which the wrist is flexed (e.g., driving)

- Hand-arm vibration syndrome: - Characterized by Raynaud, numbness and tingling in ulnar and median nerve distributions when exposed to cold or vibration, weakened grip, and upper extremity myalgias - Associated with prolonged exposure to vibration

- Chronic: - Analgesics - Oral corticosteroids - Local corticosteroid injection - Avoidance of repetitive wrist movement - Splint wrist in neutral position (0 °): - Worn at night until follow-up

- Yoga - Referral: - Primary care physician - Occupational medicine for ergometric testing if caused by repetitive motion, and tendon gliding, nerve gliding, or carpal bone mobilization exercises - Hand surgeon for evaluation of surgical intervention

- Analgesics: - There are many choices - NSAIDs have not been shown to improve long-term outcome

- Local corticosteroid injection-transient relief in 2/3 of patients (many different regimens): - Hydrocortisone: 20 mg - Methylprednisolone: 15-40 mg - Triamcinolone: 20 mg - Usually combined with 0.15-0.5 mL 2% lidocaine

  • Carpal tunnel syndrome is caused by compression of the median nerve as it passes through the carpal tunnel.
  • The carpal tunnel is the area bound by the carpal bones and the transverse carpal ligament.
  • The median nerve, flexor digitorum profundus, flexor digitorum superficialis (FDS), and flexor pollicis longus are located in the carpal tunnel.
  • Carpal tunnel syndrome can be classified as acute or chronic.

Etiology

  • Acute:TraumaInfectionSnake biteHemorrhageHigh-pressure injection injury
  • Chronic:Occupational/overuse syndromes-high impact, repetitive motionPregnancy, birth control pillsGranulomatous disease: Tuberculosis, sarcoidosisMass lesions with median nerve compressionOsteophytesAmyloidMultiple myelomaRheumatoid arthritisEndocrine disorders: Hypothyroidism, diabetes mellitus, acromegalyChronic hemodialysisIdiopathic

Idiopathic causes are rare in children; most cases have a correctable cause including:

  • Trauma
  • Mucolipidosis
  • Hamartoma of the median nerve
  • Anomalous FDS
  • Hemophilia with hematoma

Diagnosis

Signs and Symptoms

History

  • Acute or chronic onset
  • Numbness/paresthesia in a median nerve distribution:Thumb, index, middle, and radial aspect of ring finger
  • Pain:Location: Wrist or hand, sometimes radiating to elbow, forearm, or shoulderOften worse at night-relieved by "shaking out"ť the handExacerbated by repetitive wrist movement and by activities in which the wrist is flexed (e.g., driving)

Physical Exam

  • Weakness of the abductor pollicis brevis and opponens muscles:Innervated by the recurrent branch of the median nervePatient may complain of dropping things or having decreased fine motor control.
  • Loss of 2-point discrimination:Late finding, highly specific
  • Atrophy of thenar muscles:Late finding, highly specific

Essential Workup

  • History of characteristic nocturnal pain and paresthesia in the median nerve distribution.
  • Muscle weakness and thenar wasting are later findings.
  • Provocative testing:Overall poor sensitivity and specificityPhalen test:Wrist flexion for 60 sec produces numbness or tingling in the median nerve distribution.Tinel sign:Gentle tapping over the median nerve at wrist produces tingling in the fingers in the median nerve distribution.Carpal compression test:Direct pressure applied over the proximal carpal ligament for 30 sec produces tingling in the fingers in the median nerve distribution.Tourniquet test:BP cuff inflated to just above the patients systolic BP for 2 min produces paresthesia in the median nerve distribution.

Diagnosis Tests & Interpretation

Lab

  • Not indicated in most cases
  • Thyroid function studies; rheumatoid factor and immune panel if indicated by history and physical exam

Imaging

  • Wrist radiograph if trauma or degenerative arthritis suspected
  • CT in select cases (not routine):May show encroachment of carpal tunnel
  • MRI displays the soft tissues well but not recommended for routine diagnosis:Findings: Palmar bowing of transcarpal ligament, flattened median nerve, median nerve or synovial swelling, fluid in carpal tunnel, signal abnormality of median nerve
  • Ultrasound can be diagnostic:Sensitivity of 44-95%; specificity of 57-100%Findings: Median nerve swelling at proximal canal, median nerve flattening at distal canal, bowing of transcarpal ligament

Diagnostic Procedures/Surgery

Nerve conduction studies and electromyography are criterion standard tests.

Differential Diagnosis

  • Cervical nerve root compression:Origin of median nerve is at the 6th and 7th cervical roots.Symptoms are aggravated by erect posture and neck movement.
  • Hand-arm vibration syndrome:Characterized by Raynaud, numbness and tingling in ulnar and median nerve distributions when exposed to cold or vibration, weakened grip, and upper extremity myalgiasAssociated with prolonged exposure to vibration
  • Thoracic outlet obstruction
  • Osteoarthritis of the 1st carpometacarpal joint
  • Brachial plexitis
  • Generalized neuropathy
  • Syringomyelia
  • Multiple sclerosis

Treatment

Initial Stabilization/Therapy

None necessary

Ed Treatment/Procedures

  • Acute:Hand surgery consultation for surgical release of transverse carpal ligament using either open or endoscopic technique
  • Chronic:AnalgesicsOral corticosteroidsLocal corticosteroid injectionAvoidance of repetitive wrist movementSplint wrist in neutral position (0 °):Worn at night until follow-upYogaReferral:Primary care physicianOccupational medicine for ergometric testing if caused by repetitive motion, and tendon gliding, nerve gliding, or carpal bone mobilization exercisesHand surgeon for evaluation of surgical intervention

Medication

  • Analgesics:There are many choicesNSAIDs have not been shown to improve long-term outcome
  • Oral corticosteroids-short-term benefit:Prednisone: 20 mg daily — 7 days, 10 mg daily — 7 daysPrednisolone: 20-25 mg daily, tapered over 2-4 wk
  • Local corticosteroid injection-transient relief in 2/3 of patients (many different regimens):Hydrocortisone: 20 mgMethylprednisolone: 15-40 mgTriamcinolone: 20 mgUsually combined with 0.15-0.5 mL 2% lidocaine

Follow-Up

Disposition

Admission Criteria

Acute carpal tunnel syndrome requiring surgical decompression

Discharge Criteria

Chronic carpal tunnel syndrome after adequate pain control

Followup Recommendations

Primary care physician or directly to a specialist in occupational medicine or hand surgery within 1-2 wk

Additional Reading

  • Cranford CS, Ho JY, Kalainov DM, et al. Carpal tunnel syndrome. J Am Acad Orthop Surg. 2007;15(9):L537-L548.
  • Keith MW, Masear V, Chung K, et al. Diagnosis of carpal tunnel syndrome. J Am Acad Orthop Surg. 2009;17(6):389-396.
  • Kothari MJ. Treatment of carpal tunnel syndrome. In: Schefner JM, ed. UpToDate, Waltham, MA, 2013.
  • Seror P. Sonography and electrodiagnosis in carpal tunnel syndrome diagnosis, an analysis of the literature. Eur J Radiol. 2008;67(1):146-152.
  • Tosti R, Ilyas AM. Acute carpal tunnel syndrome. Orth Clin N Am. 2012;43:459-465.

Codes

ICD9

354.0 Carpal tunnel syndrome

ICD10

  • G56.00 Carpal tunnel syndrome, unspecified upper limb
  • G56.01 Carpal tunnel syndrome, right upper limb
  • G56.02 Carpal tunnel syndrome, left upper limb
  • G56.0 Carpal tunnel syndrome

SNOMED

  • 57406009 Carpal tunnel syndrome (disorder)