302 - The Diagnostic Dilemma of Axillary Neuropathy: Hiding in Plain Sight

Thursday, February 22, 2024

5:00 PM – 6:30 PM EDT

Presenting Author(s)

RB

Russell Boston, MS

Medical Student
Philadelphia College of Osteopathic Medicine
Philadelphia, Pennsylvania, United States

Co-Author(s)

RT

Robert Theiss, MD

Resident
Atrium Health
Charlotte, North Carolina, United States
PA

Puneet K. Aggarwal, MD

Medical Director
Atrium Health
Charlotte, North Carolina, United States

Case Diagnosis: Axillary Neuropathy

Case Description: A 56-year-old female with past medical history of fibromyalgia, right rotator cuff tendinopathy, and subacromial impingement presented with neck and right shoulder pain after being caught in a strong current while swimming. Her symptoms became bilateral in the following months, with new onset left abduction weakness and paresthesias. She also exhibited balance difficulty, urinary incontinence, and hyperreflexia concerning for cervical myelopathy. MRI showed moderate cervical stenosis and disc herniation at C5-6. She was managed with Medrol Dosepak, left C6 transforaminal epidural steroid injection, and trigger point injections with minimal improvement. Electrodiagnostic studies were eventually ordered and demonstrated chronic left axillary neuropathy without evidence of C6 radiculopathy. MRI brachial plexus suggested axillary nerve involvement. In addition to conservative management of her axillary neuropathy, C4/5 and C5/6 anterior cervical discectomy and fusion for decompression of cervical stenosis was performed. She ultimately experienced partial symptom relief but residual left shoulder abduction weakness.

Discussions: Axillary neuropathy typically results from a stretch injury and presents with glenohumeral abduction weakness and altered sensation over the lateral shoulder. Atraumatic etiologies like this patient’s case are relatively rare, which can delay diagnosis and treatment. It is often challenging for clinicians to distinguish atraumatic axillary neuropathy from subacromial impingement, cervical spine pathologies, and other brachial plexopathies. Because imaging demonstrated cervical stenosis and no known trauma preceded the injury, her chronic axillary neuropathy was only discovered after months of treatment for her cervical stenosis.

Conclusions: Axillary neuropathy should be included in the differential diagnosis of shoulder weakness and paresthesias, regardless of the etiology. Electrodiagnostic testing for axillary neuropathy should also be considered in these patients, even if there is confirmed cervical spine pathology.