[Detection of axillary nerve multisegment motor nerve conduction using magnetic stimulation].

Objective: To establish a method for detecting multi-segmental motor nerve conduction of axillary nerve using magnetic stimulation technique, and to preliminarily discuss its clinical application value. Methods: From April 2017 to February 2018, 80 healthy volunteers, 40 male and 40 female, were included and divided into five groups according to age and gender (groupⅠwere <35 years old; groupⅡwere 35-44 years old; group Ⅲ were 45-54 years old; groups Ⅳ were 55-64 years old; groups Ⅴ aged 65-74). Axillary nerve recording electrodes were placed in the deltoid muscle belly, reference electrode was placed in the deltoid muscle check point. Using the magnetic stimulation coil, stimulation was released at spots which were, respectively, 2 fingers from the lateral side of subscapular fossa, 2 fingers from the lateral side of infraclavicular fossae, and Erb's point. The latency, amplitude, detection distance (stimulation to recording electrode) were recorded at each spot, and the height and arm length were also measured. Results: The detection rate of axillary nerve waveform in healthy volunteers was 97.2%. There were no statistically significant differences in latency and amplitude in the different sides, gender ( P> 0.05).The latency corresponding to different detection distances was compared, and the difference was statistically significant ( P< 0.05).Height and arm length in different age groups were significantly increased in groupsⅠ, Ⅱ and Ⅲ compared with groups Ⅳ and Ⅴ, with statistical significance ( P< 0.05). When compared among different age groups, the latency and amplitude of group Ⅳand Ⅴ (more than 55 years old and over) were significantly prolonged and decreased, with statistically significant differences ( P< 0.05). Conclusions: The method of detecting multi-segmental magnetic stimulation of axillary nerve is stable and the result is reliable, which makes the evaluation of the proximal nerve of upper limbs be possible. However, the biological effects of age on nerve conduction should be carefully considered.