Figure 14.

Illustrative examples from MND patients. (A) An early stage MND patient (Female 69 years) who still swallows well. (B) A patient with more advanced MND (Male 62 years) in whom the mechanical state of Passive-Isometric Pressure Increase (PIPI) is predicted by the model to occur with luminal closure. Spatio-temporal pressure plots show the pressures of UES high pressure zone during a 5 ml liquid swallow. Pmax defines the position of maximum axial pressure. A representation of the UES mechanical states predicted for the swallows is shown below each plot (color scheme identical to previous Figures, PIPI in colored purple). Admittance-pressure Orbit plots for each swallow are shown right. Videofluoroscopy images from a barium swallow investigation of Patient B performed within 1 week of the high resolution impedance manometry study are shown at the bottom of the figure. The images captured during 5 ml liquid barium swallow show UES closure onto, rather than behind, the swallowed bolus. Hence the bolus is divided into two as the UES closes and bolus is retained in the pharynx above the UES as residue (yellow arrow in magnified image). Residual bolus material is most likely also trapped within the UES lumen.