Electroglottographic evaluation of the swallow.

The feasibility of using the electroglottograph (EGG) to record and measure aspects of the swallow was tested in six nonimpaired, two parkinsonian, and two dysphagic subjects. Low-frequency changes in tissue impedance across the neck were recorded with an EGG during deglutition. On six nonimpaired subjects, EGG waveforms were consistently monophasic and appeared to be well timed with laryngeal height changes. The waveforms of the two dysphagic subjects differed markedly from those of the nonimpaired subjects, and their timing and shapes were consistent with videofluoroscopic descriptions of those of the dysphagic subjects. The two parkinsonian patients also showed aberrant waveform patterns. These observations suggest that use of the EGG has strong potential as a quantitative technique for swallowing evaluation, therapy, and research.