Parsonage-Turner Syndrome Resulting in Spinal Accessory Nerve Lesion After COVID-19 Vaccine: A Case Report

ABSTRACT

Case Diagnosis A patient presenting with right shoulder pain and weakness after COVID-19 vaccination is found to have Parsonage-Turner syndrome (PTS) of the spinal accessory nerve. Case Description or Program Description An 18-year-old male patient with no significant medical history presented to the Physiatry clinic for evaluation of right shoulder pain and protrusion of his right scapula. He denied any trauma or known inciting events. He received his two doses of the COVID-19 vaccine on the contralateral deltoid one month and one week prior. Two days after the 2nd dose, he woke up with 8/10 pain in his right shoulder and displayed right scapular protrusion. He also had self-limiting chills and myalgia. His pain improved, but the scapular protrusion persisted. On examination, there was right trapezius atrophy, right scapula lateral winging, and dyskinesis of right scapulothoracic motion. Right shoulder shrug strength was 4/5, but upper extremity strength otherwise remained 5/5 bilaterally. Electrodiagnostic studies approximately 1 month after symptom onset revealed an acute spinal accessory nerve lesion with ongoing denervation potentials in the superior portion of the mid trapezius muscle. Setting(s) Outpatient Physiatry clinic in Northeast health system. Assessment/Results: The patient's clinical presentation, history, and electrodiagnostic findings were consistent with Parsonage-Turner syndrome of the right spinal accessory nerve. One month after onset, his pain resolved, but he had residual right shoulder shrug weakness and right trapezius atrophy. He had not yet started physical therapy at the time of follow-up. Discussion (relevance) This is the first reported case, to our knowledge, of Parsonage-Turner syndrome resulting in spinal accessory nerve palsy from COVID- 19 vaccination. Conclusion(s) While the risk of complications, such as Parsonage-Turner syndrome, remains rare with COVID-19 vaccination, it is important to be mindful of vaccination history in patients with unexplained neurological injuries. However, data continues to show that the risk of complications of COVID-19 infection greatly exceed those of the vaccine.