Detection of poststroke oropharyngeal dysphagia with swallowing screening by ultrasonography.

There are currently no standard evaluation tools for poststroke neurogenic oropharyngeal dysphagia. We previously suggested calculating the relative movements of the hyoid bone and larynx by ultrasonography to evaluate swallowing movement. Swallowing movement is altered in neurogenic oropharyngeal dysphagia. Therefore, the present study aimed to verify whether an ultrasonographic evaluation of swallowing movement facilitates the detection of neurogenic oropharyngeal dysphagia. Eighteen healthy male elderly participants (the healthy group) and 18 male stroke patients diagnosed with neurogenic oropharyngeal dysphagia (the dysphagia group) were enrolled. Participants swallowed 5 mL of liquid and water with an adjusted viscosity and the movements of the hyoid bone and larynx were visualized by ultrasonography. The results obtained revealed significant differences in laryngeal duration (static phase), laryngeal displacement (elevation phase), and the hyoid bone-laryngeal motion ratio (HL motion ratio) between the two groups. A multiple regression analysis was performed to adjust for confounding factors, and laryngeal duration (static phase) and the HL motion ratios were identified as factors affecting dysphagia. In the receiver operation characteristic curve of the two variations, the area under the curve for laryngeal duration (static phase) was 0.744 and the cut-off was 0.26 sec with 72.2% sensitivity and 88.9% specificity; the area under the curve for the HL motion ratio was 0.951 and the cut-off was 0.56 with 88.9% sensitivity and 88.9% specificity. Therefore, the objective evaluation of hyoid bone and larynx movements during swallowing by ultrasonography facilitated the detection of neurogenic oropharyngeal dysphagia.

Evaluation of swallowing movement using ultrasonography.

The aim of this study is to develop an index to assess swallowing function by ultrasonography to evaluate the relationship between movements of the hyoid bone and the larynx while swallowing water. Forty-two younger participants (mean age, 20.3 ± 3.4 years) and 42 older participants (mean age, 75.1 ± 10.6 years) with normal swallowing function were included in the study. Movements of the hyoid bone and the larynx while swallowing 5 mL of water were observed using ultrasonography. Two-dimensional distances from the starting points of the hyoid bone and the larynx to their points of maximum movement were measured as displacements. The hyoid bone-laryngeal motion ratio was defined as the hyoid bone displacement divided by the laryngeal displacement. Parameters were compared among four groups: younger male, younger female, older male, and older female. The hyoid bone displacement differed significantly between the younger and older groups, and the laryngeal displacement differed significantly between age groups and sexes. The hyoid bone-laryngeal motion ratio was not significantly correlated with age, height, or body weight, and did not show a significant difference between the four groups. Thus, the hyoid bone-laryngeal motion ratio is an index that evaluates swallowing movement and is independent of physique and physiological changes associated with aging.