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.

KEYWORDS: Tirzepatide, brachial plexopathy, case report, neuropathy, weight loss