Pre-pharyngeal Swallow Effects of Recurrent Laryngeal Nerve Lesion on Bolus Shape and Airway Protection in an Infant Pig Model.
*Aspiration; *Deglutition; *Deglutition disorders; *Infant; *Oro-pharyngeal pathophysiology; *Recurrent laryngeal nerve; Animal Studies; Animals; Aspiration – Etiology; Aspiration/etiology; Deglutition – Physiology; Deglutition Disorders – Etiology; Deglutition Disorders – Physiopathology; Deglutition Disorders/*etiology/physiopathology; Deglutition/physiology; Laryngeal Nerve Injuries/*complications; Laryngeal Nerves – Injuries; Newborn; Pneumonia; Swine
Recurrent laryngeal nerve (RLN) damage in infants leads to increased dysphagia and aspiration pneumonia. Recent work has shown that intraoral transport and swallow kinematics change following RLN lesion, suggesting potential changes in bolus formation prior to the swallow. In this study, we used geometric morphometrics to understand the effect of bolus shape on penetration and aspiration in infants with and without RLN lesion. We hypothesized (1) that geometric bolus properties are related to airway protection outcomes and (2) that in infants with RLN lesion, the relationship between geometric bolus properties and dysphagia is changed. In five infant pigs, dysphagia in 188 swallows was assessed using the Infant Mammalian Penetration-Aspiration Scale (IMPAS). Using images from high-speed VFSS, bolus shape, bolus area, and tongue outline were quantified digitally. Bolus shape was analyzed using elliptical Fourier analysis, and tongue outline using polynomial curve fitting. Despite large inter-individual differences, significant within individual effects of bolus shape and bolus area on airway protection exist. The relationship between penetration-aspiration score and both bolus area and shape changed post lesion. Tongue shape differed between pre- and post-lesion swallows, and between swallows with different IMPAS scores. Bolus shape and area affect airway protection outcomes. RLN lesion changes that relationship, indicating that proper bolus formation and control by the tongue require intact laryngeal sensation. The impact of RLN lesion on dysphagia is pervasive.
Gould Francois D H; Yglesias B; Ohlemacher J; German R Z
Dysphagia
2017
2017-06
Article information provided for research and reference use only. All rights are retained by the journal listed under publisher and/or the creator(s).
<a href="http://doi.org/10.1007/s00455-016-9762-2" target="_blank" rel="noreferrer noopener">10.1007/s00455-016-9762-2</a>
LVC Timing in Infant Pig Swallowing and the Effect of Safe Swallowing.
*Animal model; *Aspiration; *Deglutition; *Deglutition disorders; *Dysphagia; *Infant; *Laryngeal vestibule closure; *Recurrent laryngeal nerve; Animal; Animal Population Groups; Animals; Aspiration – Etiology; Aspiration/*etiology; Biological; Deglutition – Physiology; Deglutition Disorders – Etiology; Deglutition Disorders/*etiology; Deglutition/*physiology; Disease Models; Humans; Laryngeal Nerve Injuries/*complications; Laryngeal Nerves – Injuries; Larynx; Models; Newborn; Oropharynx; Pneumonia; Questionnaires; Swine
Recurrent laryngeal nerve (RLN) injury in neonates, a complication of head and neck surgeries, leads to increased aspiration risk and swallowing dysfunction. The severity of resulting sequelae range from morbidity, such as aspiration pneumonia, to mortality from infection and failure to thrive. The timing of airway protective events including laryngeal vestibule closure (LVC) is implicated in aspiration. We unilaterally transected the RLN in an infant pig model to observe changes in the timing of swallowing kinematics with lesion and aspiration. We recorded swallows using high-speed video-fluoroscopic swallow studies (VFSS) and scored them using the Infant Mammalian Penetration and Aspiration Scale (IMPAS). We hypothesized that changes would occur in swallowing kinematics (1) between RLN lesion and control animals, and (2) among safe swallows (IMPAS 1), penetration swallows (IMPAS 3), and aspiration swallows (IMPAS 7). We observed numerous changes in timing following RLN lesion in safe and unsafe swallows, suggesting pervasive changes in the coordination of oropharyngeal function. The timing of LVC, posterior tongue, and hyoid movements differed between pre- and post-lesion in safe swallows. Posterior tongue kinematics differed for post-lesion swallows with penetration. The timing and duration of LVC and posterior tongue movement differed between aspiration swallows pre- and post-lesion. After lesion, safe swallows and swallows with aspiration differed in timing of LVC, laryngeal vestibule opening, and posterior tongue and hyoid movements. The timing of thyrohyoid muscle activity varied with IMPAS, but not lesion. Further study into the pathophysiology of RLN lesion-induced swallowing dysfunction is important to developing novel therapies.
Gross Andrew; Ohlemacher Jocelyn; German Rebecca; Gould Francois
Dysphagia
2018
2018-02
Article information provided for research and reference use only. All rights are retained by the journal listed under publisher and/or the creator(s).
<a href="http://doi.org/10.1007/s00455-017-9832-0" target="_blank" rel="noreferrer noopener">10.1007/s00455-017-9832-0</a>