Synopsis
Recognise neuralgic amyotrophy from its pain-then-weakness sequence, localise patchy plexus and individual-nerve injury, exclude cervical, structural and malignant mimics, and protect movement during slow axonal recovery.
- Brachial neuritis, also called neuralgic amyotrophy or Parsonage-Turner syndrome, typically begins with abrupt severe shoulder or upper-arm pain followed days later by patchy weakness and wasting.
- Pain is often relentless, worse at night and not consistently reproduced by neck movement; as pain settles, weakness becomes more apparent and may be mistakenly attributed to guarding.
- The upper trunk, long thoracic, suprascapular and anterior interosseous distributions are often affected, but lesions are multifocal and need not respect one plexus segment.
Key red flags
New orthopnoea, sleep-related breathlessness, weak cough or an elevated hemidiaphragm after the pain syndrome indicates potentially important diaphragmatic neuropathy.
Investigation priorities
Localise weakness across roots, plexus trunks, fascicles and named nerves.
Management branches
Severe new shoulder or arm pain appears without a clear joint injury.
- Ask about chest and vascular symptoms, trauma, fever, cancer, rash, neck provocation and recent immune triggers, then perform cardiac, vascular, cervical and neurological examination.
- Document baseline scapular, shoulder, elbow, wrist and finger strength even if pain limits effort, arranging urgent alternative imaging for red flags.
Key medicines
NaproxenA time-limited adult oral regimen may be used from the current BNF with the lowest effective dose and gastroprotection selected by gastrointestinal risk.
AmitriptylineStart a low oral night dose, often 10 mg, and titrate slowly under the BNF if persistent neuropathic pain disrupts sleep and function.