Ultrasound-Guided Botulinum Toxin Injection for the Treatment of Teres Major Fasciculations.

This case study presents a 31-yr-old male weightlifter without known neuromuscular disease who presented with 5 wks of atraumatic, constant fasciculations of his right teres major muscle without recent injury. Electromyography identified fasciculation potentials within the teres major and pronator teres, suggesting an acute C6 radiculopathy, although a cervical magnetic resonance imaging demonstrated no significant neuroforaminal stenosis. Trigger point injections and multiple medications failed to stop the fasciculations. Under electromyography and ultrasound guidance, he was focally injected with botulinum toxin to the teres major 10 wks from initial onset with subsequent complete resolution of the symptoms and no side effects.