Using ultrasound to investigate intrapersonal variability in durational aspects of tongue movement during swallowing.

The purpose of this study was to determine the extent of intrapersonal variability in durational aspects of tongue movement during swallowing. Using ultrasound, the entire duration of tongue movement and the duration of the oral transport stage during swallowing was measured in a group of patients with neurogenic swallowing disorder and a group of matched healthy control subjects. The results indicate considerable intrapersonal variability in both groups. The patient group performed significantly more variably in terms of the duration of the transport stage. However, when looking at individual results, this finding can not be generalized, in that some patients showed rather decreased variability. Other differences between patient the group and control subjects were not statistically significant. Ultrasound was found to be a highly suitable technique for the purpose of this study.