1995 Volume 88 Issue 5 Pages 553-559
In general, esophagography with a VTR system, electromyography and measurement of the pressure of the digestive tract are used for evaluation of the swallowing function. In previous reports a time lag in movement of the bolus was pointed out in many patients with dysphagia. However, a standardized time reference for this lag was not clarified in most cases.
A new concept evaluating dysphagia is introduced in this study to clarify the pathophysiology of swallowing disorders. The movement of the bolus is referred to as a phase, and the time progress of the patterned output from the medullary swallowing center is referred to as a stage. It can, therefore, be considered that dysphagia occurs when the time lag between the phase and stage exceeds the physiologically permissible limits.
The standard point of the phase and stage were determined separately from an analysis of the esophagogram with a VTR system in normal volunteers, and the time lag between the two points was measured in patients with dysphagia. We devised a new instrument to evaluate the swallowing function, which can record simultaneously the pressure of the oral cavity and pharynx and the air flow rate. These methods were useful for detecting the delay of the initiation of pharyngeal swallowing which is observed in patients with dysphagia caused by lesions of the corticobulbar tract.
