Lateral pharyngeal outpouchings: A comparison of dysphagic and asymptomatic patients

Videofluoroscopic pharyngeal timings of individuals with dysphagia were compared with timings from individuals without dysphagia to determine if any abnormal pharyngeal movements were associated with dysphagia. Sixteen lateral pharyngeal outpouchings were seen in 50 dysphagic volunteers, whereas 71 were noted in 138 asymptomatic individuals. The outpouchings appeared just after oral delivery of the bolus into the pharynx after onset of the swallow at approximately 500 ms, as compared to the initial appearance during the mid-pharyngeal swallow at 750 ms in asymptomatic individuals (P<0.01). The outpouchings disappeared during mid-pharyngeal swallow in symptomatic volunteers, at approximately 800 ms compared to disappearance during pharyngeal relaxation in asymptomatic volunteers at approximately 1100 ms (P<0.01). No other timing event was delayed nor event duration prolonged when the two groups were compared. This observation of earlier appearance followed by earlier disappearance of lateral pharyngeal outpouchings in dysphagic individuals may be caused by inner longitudinal pharyngeal muscles that are inhibited and then contract earlier than those seen in asymptomatic individuals. Outpouchings appearing later at the onset of pharyngeal contraction were not associated with dysphagia.