Longitudinal changes of the swallowing process in subacute stroke patients with aspiration.

The purpose of this study was to evaluate longitudinal changes of the swallowing process in stroke patients with aspiration using kinematic analysis. Twenty-eight subacute stroke patients with aspiration on fluid at initial videofluoroscopic swallowing studies (VFSS) were included. Follow-up VFSS was performed at 2-4 weeks after initial studies that were conducted at an average of 26 days after stroke. Temporal and spatial variables were calculated by two-dimensional motion analysis of hyoid bone and epiglottic movements. Swallowing process delays associated with hyoid bone and epiglottic movements were improved at follow-up studies, whereas spatial variables were not. Fourteen patients had recovered from aspiration at follow-up. Time to the start of the hyoid movement was longer in the nonrecovered patient group at initial studies (1.76 ± 1.07 s) than in the recovered group (0.90 ± 0.82 s, P=0.024). Although time-associated differences between the nonrecovered and recovered groups disappeared at follow-up studies, aspiration persisted in the nonrecovered group. This study shows that recovery from delays in the swallowing process is a conspicuous change during the subacute stage in stroke patients with aspiration. Our findings suggest that delayed swallowing triggering at initial VFSS is a useful predictor of poor recovery from aspiration in stroke patients.