Neuromuscular function monitoring comparing the flexor hallucis brevis and adductor pollicis muscles

Abstract

To monitor the response to muscle relaxants, the adductor pollicis muscle response to ulnar nerve stimulation is commonly observed or recorded. Occasionally, because of inaccessibility, the hand muscles are difficult to monitor in the operating room. The orbicularis oculi and flexor hallucis brevis muscles have been described as alternative sites for neuromuscular function monitoring. Previous studies, however, have demonstrated that the evoked response of the orbicularis oculi muscle does not correlate well with that of the adductor pollicis muscle. The purpose of our study was to compare the response of the flexor hallucis brevis muscle to stimulation of the posterior tibial nerve with that of the adductor pollicis muscle to stimulation of the ulnar nerve.