Abstract
Dysphagia has been conventionally evaluated primarily by mechanical functions, while the evaluation of sensory functions has been largely neglected. A newly developed flexible laryngoscopic laryngopharyngeal sensory test was performed in 35 patients with dysphagia in whom pharyngeal bolus retention was demonstrated by a videofluorographic study of swallowing. The flexible laryngoscope (XENF-DP) and the probes used in the test were jointly developed with the Olympus Corporation. There were 4 types of probes, and the test sites were touched beginning with the one with the smallest diameter, and thereafter the probes were serially changed to larger ones. The response was judged to be positive when the patient felt a sensation, which supported the objective confirmation of the laryngeal adductor reflex. The test sites included the laryngeal surface of the epiglottis, and, if possible, the bilateral arytenoid regions. The interrelations among the sensory threshold of the larynx, the perception of pharyngeal retention, food aspiration, salivary aspiration, and a history of pneumonia were all examined. The correlation between the laryngeal sensibility and the perception of pharyngeal retention and salivary aspiration were also probed. According to the type of dysphagia, laryngeal sensibility was reduced in all subjects with pseudobulbar palsy. A larger number of subjects should be examined in the future and the findings should then be clinically applied to determine the correlation between a reduced laryngeal sensibility and either aspiration or pneumonia from a preventive viewpoint.
