PHARYNGEAL EFFECTS OF BOLUS VOLUME, VISCOSITY, AND TEMPERATURE IN PATIENTS WITH DYSPHAGIA RESULTING FROM NEUROLOGIC IMPAIRMENT AND IN NORMAL SUBJECTS

The oropharyngeal swallow of 10 patients with mild dysphagia at 3 week s after a cerebrovascular accident (stroke), 10 normal subjects, and 8 neurologically impaired patients with moderate to severe dysphagia wa s studied videofluorographically to examine the effects of 2 bolus tem peratures (room temperature and 33-degrees-F), 2 volumes, and 2 viscos ities on the durations of pharyngeal stage swallow events and the freq uency and nature of oropharyngeal swallowing problems and bolus transi t. Normal subjects exhibited significantly longer pharyngeal response times and longer laryngeal elevation only for 1 ml cold liquid. The st roke patients and the 8 significantly dysphagic neurologically impaire d patients exhibited very few significant effects of temperature on sw allowing disorders or swallow measures. Increases in bolus volume and viscosity decreased pharyngeal delay times in both neurologically impa ired patient groups. Stroke patients exhibited significantly longer ph aryngeal delay times but shorter pharyngeal response times, laryngeal closure, cricopharyngeal opening, and laryngeal elevation than normal subjects on some bolus volumes and viscosities. Results are discussed in terms of the potentially therapeutic effects of bolus volume and vi scosity.