Color electromyographic topographic analysis of facial movements

To determine the precise amount of facial function present in patients with facial palsy, color electromyographic (EMG) topograms of the facial movements were made using a computerized system, newly designed and manufactured by the authors. During mimetic movements, such as wrinkling the forehead, closing the eyes, blinking, grinning, and blowing out the cheeks, EMGs from 16 monopolar disk electrodes were concurrently recorded from the frontalis, orbicularis oculi, and orbicularis oris muscles on both sides. The amplitude values of the integrated EMG spikes from each electrode were calculated by an interpolation formula in the computer, and the color topographic figures derived from these calculations were displayed on a ten-color computer monitor. The colors ranged from blue to dark red, and they were related to the amount of muscular activity. This technique was applied to patients with facial palsy to document their degree of mimetic movement loss and the time course of the palsy evolution. The results obtained were reliable and reproducible, and the technique made it easy to quantify the loss of mimetic movements in patients with facial palsy.