Percutaneous phenol block of the musculocutaneous nerve to control elbow flexor spasticity

Twenty-three extremities in 17 brain-injured adults were prospectively studied to evaluate the effectiveness of percutaneous phenol blocks of the musculocutaneous nerve in controlling spasticity of the biceps and brachialis muscles. Twenty-one (93%) of the extremities improved after the initial injection. The mean resting position decreased from 120 degrees of flexion to 69 degrees. Elbow range of motion increased an average of 53 degrees. There were no complications. Two patients did not respond to the initial injection and required repeat nerve blocks. Concomitant phenol motor point block of the brachioradialis muscle further improved elbow motion. The mean duration of the block was 5 months. Follow-up averaged 21 months. This study indicates that percutaneous phenol injection of the musculocutaneous nerve provides reliable, temporary relief of spasticity in patients with potential for further neurologic improvement.