Boorman G I, Hoffer J A, Kallesoe K, Viberg D, Mah C
Department of Clinical Neurosciences, University of Calgary, Alberta.
Can J Neurol Sci. 1996 Nov;23(4):264-70. doi: 10.1017/s0317167100038208.
When H-reflexes are recorded during movement in human subjects, the stimulator current output is not a good indicator of sensory stimulation efficacy because of unavoidable nerve movement relative to the stimulus electrodes. Therefore, the M-wave amplitude has been used by researchers as an indicator of the efficacy of the stimulus. In this study we have examined the general validity of the hypothesis that the M-wave amplitude is directly proportional to the group I sensory afferent volley evoked by the stimulus.
A nerve recording cuff, stimulating electrodes, and EMG recording electrodes were implanted in cats. Nerve cuff recordings of centrally propagating volleys evoked by electrical stimuli were directly compared to M-waves produced by the same stimuli. Compound action potentials (CAPs) recorded in the sciatic nerve were compared with soleus M-waves during either tibial nerve or soleus muscle nerve stimulation. CAPs in the ulnar nerve were correlated with flexor carpi ulnaris M-waves during ulnar nerve stimulation.
Our findings indicate that for mixed nerve stimulation (e.g., tibial or ulnar nerve) the M-wave can be a reliable indicator of the centrally propagating sensory volley. Due to the high correlation between CAP and M-wave amplitude in these nerves, a small number of M-waves can give a good estimate of the size of the group I sensory volley. On the other hand, when nerves with only partially overlapping fibre diameter populations are stimulated (e.g., the soleus muscle nerve), the M-wave is not well correlated with the group I sensory volley and thus may not be used as a measure of the size of the input volley for H-reflex studies.
在人体受试者运动过程中记录H反射时，由于神经相对于刺激电极不可避免地发生移动，刺激器的电流输出并非感觉刺激效果的良好指标。因此，研究人员使用M波幅度作为刺激效果的指标。在本研究中，我们检验了M波幅度与刺激诱发的I类感觉传入冲动成正比这一假设的普遍有效性。
在猫体内植入神经记录袖带、刺激电极和肌电图记录电极。将电刺激诱发的向中枢传播的冲动的神经袖带记录与相同刺激产生的M波直接进行比较。在胫神经或比目鱼肌神经刺激期间，将坐骨神经记录的复合动作电位（CAP）与比目鱼肌M波进行比较。在尺神经刺激期间，将尺神经的CAP与尺侧腕屈肌M波进行相关性分析。
我们的研究结果表明，对于混合神经刺激（如胫神经或尺神经），M波可以作为向中枢传播的感觉冲动的可靠指标。由于这些神经中CAP与M波幅度之间的高度相关性，少量的M波就能很好地估计I类感觉冲动的大小。另一方面，当刺激仅部分纤维直径群体重叠的神经时（如比目鱼肌神经），M波与I类感觉冲动的相关性不佳，因此可能不能用作H反射研究中输入冲动大小的测量指标。
