Speech Language Pathologist Medical University of South Carolina College of Medicine Charleston, South Carolina, United States
Background: Preterm birth or brain injury can lead to a disruption in neural development and swallowing mechanics, contributing to feeding delays. Branches of the vagus nerve regulate neuromuscular control of swallowing and airway protection, and coordination of suck/swallow. For infants with feeding/swallowing difficulties failing to meet feeding goals at term age, transcutaneous auricular vagus nerve stimulation (taVNS) has shown promise in improving oral feeding volumes. In this study, we have added subjects to our previously presented cohort to determine early indices of safety related to acute taVNS effects on specific components of oropharyngeal swallowing and airway protection. Objective: Our objective is to determine early indices of safety related to acute taVNS effects on specific components of oropharyngeal swallowing and airway protection. Design/Methods: With parental consent, we enrolled 18 infants >39 weeks gestation failing oral feeds to participate in an IRB-approved, prospective open-label study of twice daily taVNS-paired feedings. They received a videofluoroscopic swallow study (VFSS) with taVNS before starting two weeks of taVNS-paired feeding. The Penetration-Aspiration Scale (PAS) and Baby Videofluoroscopic Swallow Study Impairment Profile (BaByVFSSImP) were used to evaluate swallow function and safety. Results: Eighteen infants underwent pre-treatment VFSS. Five BaByVFSSImP swallow components were included for analysis: location of initiation, timing of initiation, frequency of penetration, frequency of aspiration, and PAS scores. When comparing taVNS ‘off’ to taVNS ‘on’ during the pre-intervention VFSS, there were no statistically significant changes in BaByVFSSImP or PAS scores (p values>0.5). For infants with a change in function with taVNS ‘on,’ the change was minimal and not clinically significant.
Conclusion(s): There does not appear to be a detrimental effect on airway protection from acute taVNS. While these safety results are encouraging, we intend to continue to study effects of taVNS on infants’ oral feeding, particularly in infants with greater swallow dysfunction.
