fig7

Figure 7. Bottom four tracings - Triggered EMG recordings demonstrating large amplitude, polyphasic compound muscle action potentials (CMAPs) in the orbicularis oculi and oris muscles during facial nerve stimulation within the surgical field. The top four tracings show the corresponding free-running EMGs with superimposed stimulation artifacts. Please note the different time bases for the recordings, i.e., 400 ms/division for the four top tracings and 1.5 ms/division for the bottom four tracings.Amplitude is 20 µV per division.