Aerodynamics and Dysphagia

This study investigated the influence of aerodynamic measures of Maximum Phonation Time (MPT) and the S/Z ratio on swallowing. Twelve individuals were examined, six with a diagnosis of dysphagia, and six as a control group. The study hypothesized that (1) there would be a reduced MPT in the dysphagic group compared to the control (2) there would be an S/Z ratio greater than 1.0 in the dysphagic group. The rationale for this study was that since MPT and S/Z measures are easily administered, they may prove to be useful, non-invasive, inexpensive tools to predict a patient\u27s potential risk for aspiration. The results showed (1) a reduction of MPT values in the dysphagic group compared to the control (2) no significant difference in S/Z ratios between groups (3) a significant decrease in duration of individual /s/ /z/ productions in the dysphagic group and (4) a significant difference in /z/ duration compared to /s/ duration was found in both the dysphagic and control groups. The results suggest that only the MPT may be a useful indicator in detecting patients who may be at risk for aspiration. Contrary to the hypothesis, the S/Z ratio is not a predictor for detecting patients who may be at risk for aspiratio