Acute brachial plexus neuritis: An uncommon cause of shoulder pain

Patients with acute brachial plexus neuritis are often misdiagnosed as havi ng cervical radiculopathy. Acute brachial plexus neuritis is an uncommon di sorder characterized by severe shoulder and upper arm pain followed by mark ed upper arm weakness. The temporal profile of pain preceding weakness is i mportant in establishing a prompt diagnosis and differentiating acute branc hial plexus neuritis from cervical radiculopathy. Magnetic resonance imagin g of the shoulder and upper arm musculature may reveal denervation within d ays, allowing prompt diagnosis. Electromyography, conducted three to four w eeks after the onset of symptoms, can localize the lesion and help confirm the diagnosis. Treatment includes analgesics and physical therapy, with res olution of symptoms usually occurring in three to four months. Patients wit h cervical radiculopathy present with simultaneous pain and neurologic defi cits that fit a nerve root pattern. This differentiation is important to av oid unnecessary surgery for cervical spondylotic changes in a patient with a plexitis.