[Electroglottographic evaluation of swallowing in Parkinson's disease]

The feasibility of using electroglottography (EGG) to record and measure aspects of swallowing was tested in 31 patients with Parkinson's disease (72.8 +/- 4.8 years) and 10 control subjects (74.6 +/- 4.4 years). The patients were divided into three groups: those feeling dysphagia frequently (D(+), n = 9), those feeling dysphagia occasionally (D(+/-), n = 8), and those not feeling dysphagia (D(-), n = 14). The instrument delivered a 250 microA, 52 kHz carrier signal to a pair of surface electrodes on each side of the larynx at the level of the thyroid lamina. Tissue impedance across the neck was recorded via EGG while the swallowing of 10 ml of water. Four trials were performed for each subject. Based on the analysis of EGG waveform, latency, number of phases and duration were measured. In the EEGs of D(+) group, the reproducibility of waveforms was poor, while the waveforms of D(-) group and control group showed higher reproducibility. The waveforms of D(+) group had significantly longer latency and more phases than those of D(-) and control groups. In D(+), the duration was significantly longer than that of control group. These results suggest that the EGG is a quantitative and noninvasive technique for analysis of swallowing in patients with Parkinson's disease.