Epiglottic retroflexion seems to be an important mechanism of airway protection during swallowing. Although epiglottic dysfunction has been correlated with aspiration, the kinematics alterations underlying this condition remain unclear. Two distinct movements of epiglottic inversion were described in videofluoroscopic swallowing studies (VFSS). The first epiglottic movement brings the epiglottis to a horizontal position and the second consists of its full inversion.

Retrospective cohort study of 28 patients with post-stroke dysphagia admitted to our institution in 2017. Based on VFSS images, and in regard with the epiglottic mobility, two groups were assigned for comparison: one group with complete epiglottic inversion and other with partial inversion. Other parameters of VFSS were also compared.

Of the 28 patients in the study, 68% were male (19) and 32% female (9); 28.6% of the patients had hemorrhagic stroke, 67.9% ischemic, and 3.5% ischemic stroke with hemorrhagic transformation. We found significant statistical correlation between epiglottic mechanics alterations and risk of laryngeal penetration (Fisher's exact-test; P=0.036). Regarding other evaluated parameters, only the absence of the cough reflex was shown to statistically correlate with the risk of laryngeal penetration (Pearson's Chi²; P=0.007).

The results suggest that epiglottis movement is an important mechanism to avoid penetration-aspiration. The absence of cough reflex in patients with laryngeal penetration (silent aspiration) emphasizes the importance of the VFSS. We are also of the opinion that this result may be related to the pre selection of patients with suspected silent aspiration. Further studies are needed to better understand the influence of these epiglottic movement alterations in the swallowing process.