Parsonage-Turner syndrome

Background

• Syndrome characterized by sudden onset, severe shoulder pain followed by weakness and sensory loss as pain resolves over the course of days to weeks
• Also known by many other names including acute brachial neuritis, acute brachial plexitis, idiopathic brachial plexopathy, neuralgic amyotrophy
• More common in males in the 4th decade of life
• Can affect any part of the brachial plexus
  • Most commonly affected nerves: long thoracic nerve, suprascapular nerve, axillary nerve, musculocutaneous nerve, radial nerve
• Up to 1/3 may have bilateral involvement²
• Upper trunk most frequently affected³
• May have preceding viral syndrome
• Two forms
  • Idiopathic
  • Hereditary

Clinical Features

• Severe shoulder girdle pain
• Weakness, paresthesias, and sensory losses that depend on which nerves are involved
• Muscle atrophy may develop after several weeks of neuropathy
• Loss of reflexes
• Scapular winging

Differential Diagnosis

• Brachial plexopathy
  • Idiopathic
  • Post-infectious
    • Viral
      • Epstein-Barr, CMV, influenza, parvovirus, coxsackie, HIV, Polio
    • Bacterial
      • Lyme, Leptospirosis, TB, Salmonella
  • Post-immunization
  • Compressive
    • Neoplasm
      • Pancoast tumor
  • Post-traumatic
    • Penetrating or blunt neck/shoulder trauma
    • Traction injury
    • Birth trauma
      • Erb's palsy
      • Klumpke's paralysis
  • Connective tissue disorders
  • Autoimmune disorders
    • Lupus
    • Polyarteritis nodosa
    • Temporal arteritis
  • Iatrogenic
    • Post-surgical
    • Medication induced
    • Radiation
  • Hereditary Neuralgic Amyotrophy

• Rotator Cuff Injury
• Adhesive capsulitis
• Calcific tendinitis
• Thoracic outlet syndrome
• ALS
• Poliomyelitis

Upper extremity peripheral nerve syndromes

Median Nerve Syndromes

• Carpal tunnel syndrome
• Pronator teres syndrome
• Anterior interosseous neuropathy

Ulnar Nerve Syndromes

• Ulnar neuropathy at the elbow and wrist

Radial Nerve Syndromes

• Radial neuropathy at the spiral groove (ie. "Saturday night palsy")
• Posterior interosseous neuropathy

Proximal Neuropathies

• Suprascapular neuropathy
• Long thoracic neuropathy
• Axillary neuropathy
• Spinal accessory neuropathy
• Musculocutaneous neuropathy

Other

• Brachial plexopathy
• Cervical radiculopathy

Evaluation

• Plain films if there is history of trauma
• Consider MRI in the ED to rule out acute cervical spine pathology
• Outpatient brachial plexus MRI/MRN
• Outpatient EMG - should be performed at least 3 weeks after symptom onset to show findings⁴

Management

• Early conservative management
  • NSAIDs, sling, physical therapy
  • Antiviral medications if etiology is viral in nature
  • Oral steroids recommended by some in early disease for pain^3,4
• Operative management considered for space occupying lesions or if no recovery is seen in 6-9 months
  • Nerve decompression, neurolysis, neurorrhaphy, nerve transplant/grafting, muscle/tendon transplant/grafting

Disposition

• Depends on etiology - acute traumatic injuries may need urgent or emergent surgery
• Most idiopathic cases can be discharged with neurology/orthopedics follow up
• Full recovery can take up to 2-3 years

References

1. Feinberg et al. Parsonage-Turner Syndrome. HSSJ. 2010;6:199-205.
2. Misamore et al. Parsonage-Turner Syndrome (Acute Brachial Neuritis). Journal of Bone and Joint Surgery. 1996;78(9)1405-1408.
3. Moghekar et al. Brachial Plexopathies: Etiology, Frequency, and Electrodiagnostic 4. Localization. Journal of Clinical Neuromuscular Disease. 2007;9(1):243-247.
4. Ortiz Torres M et al. Brachial Plexitis (Parsonage Turner Syndrome, Brachial Neuropathy, Brachial Radiculitis) [Updated 2020 Apr 23]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2020 Jan-. Available from:https://www.ncbi.nlm.nih.gov/books/NBK448114/