The Physiologic Impact of Unilateral Recurrent Laryngeal Nerve (RLN) Lesion on Infant Oropharyngeal and Esophageal Performance.
Recurrent laryngeal nerve (RLN) injury in neonates, a complication of patent ductus arteriosus corrective surgery, leads to aspiration and swallowing complications. Severity of symptoms and prognosis for recovery are variable. We transected the RLN unilaterally in an infant mammalian animal model to characterize the degree and variability of dysphagia in a controlled experimental setting. We tested the hypotheses that (1) both airway protection and esophageal function would be compromised by lesion, (2) given our design, variability between multiple post-lesion trials would be minimal, and (3) variability among individuals would be minimal. Individuals' swallowing performance was assessed pre- and post-lesion using high speed VFSS. Aspiration was assessed using the Infant Mammalian Penetration-Aspiration Scale (IMPAS). Esophageal function was assessed using two measures devised for this study. Our results indicate that RLN lesion leads to increased frequency of aspiration, and increased esophageal dysfunction, with significant variation in these basic patterns at all levels. On average, aspiration worsened with time post-lesion. Within a single feeding sequence, the distribution of unsafe swallows varied. Individuals changed post-lesion either by increasing average IMPAS score, or by increasing variation in IMPAS score. Unilateral RLN transection resulted in dysphagia with both compromised airway protection and esophageal function. Despite consistent, experimentally controlled injury, significant variation in response to lesion remained. Aspiration following RLN lesion was due to more than unilateral vocal fold paralysis. We suggest that neurological variation underlies this pattern.
Department of Anatomy and Neurobiology, Northeast Ohio Medical University, 4209 State Route 44, PO Box 95, Rootstown, OH, 44272, USA. fgould@neomed.edu.
Francois D H
FD
Gould
School of Health Sciences, Cleveland State University, Cleveland, OH, USA.
Andrew R
AR
Lammers
Department of Anatomy and Neurobiology, Northeast Ohio Medical University, 4209 State Route 44, PO Box 95, Rootstown, OH, 44272, USA.
Jocelyn
J
Ohlemacher
Department of Anatomy and Neurobiology, Northeast Ohio Medical University, 4209 State Route 44, PO Box 95, Rootstown, OH, 44272, USA.
Ashley
A
Ballester
Department of Anatomy and Neurobiology, Northeast Ohio Medical University, 4209 State Route 44, PO Box 95, Rootstown, OH, 44272, USA.
Luke
L
Fraley
Department of Anatomy and Neurobiology, Northeast Ohio Medical University, 4209 State Route 44, PO Box 95, Rootstown, OH, 44272, USA.
Andrew
A
Gross
Department of Anatomy and Neurobiology, Northeast Ohio Medical University, 4209 State Route 44, PO Box 95, Rootstown, OH, 44272, USA.
Rebecca Z
RZ
German
D000818:Animals; D003679:Deglutition / Q000502:physiology*; D003680:Deglutition Disorders / Q000209:etiology* / Q000503:physiopathology; D004195:Disease Models, Animal; D004947:Esophagus / Q000503:physiopathology*; D009960:Oropharynx / Q000503:physiopathology*; D012009:Recurrent Laryngeal Nerve / Q000503:physiopathology*; D061226:Recurrent Laryngeal Nerve Injuries / Q000150:complications* / Q000503:physiopathology; D013552:Swine
Aspiration; Deglutition; Deglutition disorders; Esophagus; Infant; Recurrent laryngeal nerve