Assessment of Hyoid Bone Movement by Simultaneous Ultrasound and Videofluoroscopic Imaging.

About one third of the recordings that were successfully lined up in time (28 of 84) could not be used, mostly because the hyoid moved out of the ultrasound image or was too blurred to track. Only 56 of the 92 possible 5 ml swallows were analyzable, so the ultrasound method failed on a large share of attempts. The probe was placed after the bolus was already in the mouth, so the hyoid's earliest movement as it prepared for the bolus was probably missed. Only 19 people were analysed, all referred for a clinical swallow study at one centre, with a wide range of swallowing problems and severities; most were not aspirating. The motion correction that made ultrasound accurate depended on the videofluoroscopy images to measure the probe, so this is not yet a method that stands alone at the bedside. The comparison between people who aspirated and those who did not rests on very few participants and the authors themselves call it exploratory and say it should be read with caution. Hyoid velocity numbers cannot be compared directly between studies, because different ways of calculating and smoothing the data give different values.

Funding came from the National Institute on Aging and the College of Medicine, University of Cincinnati. The text provided contains no other declaration of competing interests, and nothing stating a sponsor's role in the design, analysis or writing.

Do not turn the finding that people who aspirated had larger hyoid excursions and faster hyoid movement into a clinical rule. Only 3 of the 19 participants aspirated, the authors describe it as an exploratory trend, and the opposite pattern has been reported in conditions such as myopathy. This study does not show that bigger hyoid movement means safer or less safe swallowing.