Brachial Plexopathy Following Rapid Weight Loss from Tirzepatide: A Case Report.

BACKGROUND: Weight reduction and metabolic changes have been associated with the development of compressive peripheral neuropathies. CASE REPORT: We present the case of a right-handed 60-year-old man who had a medical history of hypertension and hypercholesterolemia and developed neuromuscular symptoms after being treated with tirzepatide. During a 6-month course of tirzepatide use, the patient lost 60 pounds. However, the treatment was complicated by right-sided brachial plexopathy symptoms, including scapular pain, paresthesia, and progressive triceps weakness. Electromyography and nerve conduction studies confirmed denervation potentials at the right C5-C7 roots. Imaging studies were unremarkable. Symptoms persisted despite conservative interventions but improved gradually after the tirzepatide regimen was ended. At 2 months after the cessation, the patient's pain decreased from a 5/10 score to a score of one-2/10, and his strength improved. The follow-up EMG/NCV demonstrated the resolution of the denervation-caused changes. CONCLUSION: This case highlights a possible association between the rapid weight loss caused by GLP-1 RAs and the development of brachial plexopathy. In this patient's case, the latter condition improved after his medication was discontinued.