Idiopathic neuralgic amyotrophy: an illustrative case report

To describe the case of a patient diagnosed with neuralgic amyotrophy (NA) illustrating pertinent aspects of differential diagnosis, the use of clinical neurophysiological procedures to aid in establishing the diagnosis, and issues of management.

A 39-year-old male soldier presented with a rapid onset of marked loss of left shoulder movement. This started acutely early one morning as a sharp, severe lower neck pain progressing over the following 2 weeks to a less severe dull ache in the left shoulder and arm. Pain was rapidly replaced with weakness. Physical examination and electrodiagnostic investigation helped establish a diagnosis of NA.

The patient was reassured that this is normally a self-limiting condition. Range of motion exercises progressing to a strengthening program was prescribed. He was progressing well; however, we lost contact because of his commitments in the armed service.

When a patient presents with shoulder and arm pain of neurogenic origin, NA should be a consideration. Differentiating NA from radiculopathy is especially important in making management decisions. With a careful history and physical examination, the diagnosis may be made without the need for ancillary investigations. Neuralgic amyotrophy is a self-limiting condition requiring reassurance and monitoring.