Figure 5.

Swallow coordination in myogenic compared with neurogenic dysphagia. Shown are the timing of three major swallow events: upper oesophageal sphincter (UOS) relaxation onset (A), UOS opening (B), and UOS closure (C). Times are referenced to the onset of the oral phase, marked by initial motion of the tongue tip against the maxillary incisors. The shaded segments represent the normal range for healthy controls (mean ± 2 SD). Note that the timing of these swallow events in those with myogenic dysphagia is clustered very closely with that of healthy aged controls. The timing of these events in a large number of patients with neurogenic dysphagia falls well outside the normal range. +, one neurogenic control in whom timing of sphincteric events occurred at +30−32 seconds.