Bilateral neuralgic amyotrophy – a case report

Introduction: The neuralgic shoulder amyotrophy is characterised by a variety of neurological deficits with variable degrees of severity. Besides the cryptogenic eteology there is a number of causes, such as neuritis after infection or vaccination as well as collagenosis and Hodgin-Lymphoma .

Case report: We report on a 56 year old immune-competent male patient who complained of acute and severe sharp back pain which radiated to his right shoulder. A few hours after spontaneous relief of the pain sensation he experienced acute dyspnoea. Besides a right sided scapula alata there were no further pathological findings upon neurological examination. The chest x-ray revealed an elevation of the left diaphragm. There were no signs of a thoracal mass lesion or a tumor which may have caused a phrenic nerve irritation. Neither serum nor cerebrospinal fluid analyses showed any signs of a systemic or central nervous system infection. On electromyography there were bilaterally mild neurogenic alterations of the muscle unit potentials when the shoulder girdle was examined. There was an emphasis of the pathological findings in the right deltoid, the right anterior serratus, and both rhomboid muscles. The MRI of the cervical spine showed degenerative disease of the cervical vertebrae 3–7 without root irritation or myelopathy.

Conclusion: The medical history, physical examination and laboratory findings indicate a bilateral neuralgic shoulder amyotrophy as cause for the aforementioned symptoms. We postulate that a bilateral cervicobrachial plexus neuritis led to a right sided pain sensation including the typical scapula alata and a left sided painless phrenic nerve lesion causing the dyspnea. In the literature the neuralgic shoulder amyotrophy is described as occurring bilaterally in up to 25% of the cases. We suspect that a bilateral neuralgic shoulder amyotrophy is underdiagnosed, as there may be a number of cases where one side is clinically asymptomatic despite electrophysiological alterations.