Stage transition and laryngeal closure in poststroke patients with dysphagia.

Timely hyolaryngeal excursion and laryngeal closure are essential for safe transfer of the bolus during the pharyngeal swallow. The temporal measures stage transition duration (STD) and laryngeal closure duration (LCD) represent these physiological events. The purpose of this investigation was to determine whether small changes in bolus consistency and volume affect these temporal measures in poststroke patients who aspirate, poststroke patients who do not aspirate, and nonneurologically impaired control subjects. STD and LCD were obtained by frame-by-frame analysis of the videofluoroscopic examinations of 5 and 10 ml thin and nectar thick liquids. Using a three-way analysis of variance, STD was significantly different between the control group and the two poststroke groups; however there was no difference between the two stroke groups. There was no difference among the three groups on LCD. Bolus consistency and bolus volume had no effect. Clinical implications of these findings are discussed.