Related Experiment Video
Updated: Apr 5, 2026
Neurodevelopmental Reflex Testing in Neonatal Rat Pups
Published on: April 24, 2017
Effects of birth asphyxia on the modulation of pharyngeal provocation-induced adaptive reflexes
Ish K Gulati1, Theresa R Shubert2, Swetha Sitaram2
1Sections of Neonatology, Pediatric Gastroenterology, and Nutrition, Department of Pediatrics, The Ohio State University College of Medicine, The Research Institute at Nationwide Children's Hospital, Columbus, Ohio; The Neonatal and Infant Feeding Disorders Program, The Research Institute at Nationwide Children's Hospital, Columbus, Ohio; and.
Insights
Infants with hypoxic ischemic encephalopathy (HIE) show altered aerodigestive reflexes, including upper and lower esophageal sphincter dysfunction, increasing aspiration risk. These findings highlight potential neural pathway deficits affecting swallowing and airway protection in HIE infants.
Area of Science:
- Neonatal neurology and gastroenterology
- Pediatric respiratory and swallowing disorders
- Perinatal medicine and neurodevelopmental outcomes
Background:
- Perinatal asphyxia leading to hypoxic ischemic encephalopathy (HIE) is a significant concern in newborns.
- Aerodigestive symptoms, including feeding difficulties and aspiration, are common in infants with HIE.
- Understanding the coordination and kinetics of aerodigestive reflexes is crucial for managing these complications.
Purpose of the Study:
- To investigate whether pharyngeal provocation alters aerodigestive reflex coordination and kinetics in infants with HIE compared to controls.
- To characterize the sensory-motor properties of pharyngeal provocation-induced effects on upper esophageal sphincter (UES) and lower esophageal sphincter (LES) reflexes.
- To explore the potential pathophysiological basis for observed aerodigestive issues in HIE.
Main Methods:
- Evaluated 25 infants with HIE and 10 healthy controls using water-perfusion micromanometry.
- Assessed pharyngo-esophageal reflexes, including pharyngeal reflexive swallow (PRS), pharyngo-UES-contractile reflex (PUCR), and pharyngo-LES-relaxation reflex (PLESRR).
- Analyzed UES and LES basal tone, esophageal body-waveform kinetics, and reflex frequency and amplitude.
Main Results:
- Infants with HIE exhibited more frequent PUCR, increased UES basal tone, and decreased LES basal tone compared to controls.
- HIE infants showed decreased LES relaxation frequency, reduced proximal esophageal contractile amplitude, and prolonged proximal esophageal contractile duration.
- Significant differences in APGAR scores were noted between HIE infants and controls at 1 and 5 minutes.
Conclusions:
- Infants with HIE demonstrate significant dysregulation of pharyngo-esophageal reflexes, including UES and LES dysfunction.
- Altered UES tonicity and LES reactivity may contribute to secretion pooling, impaired bolus clearance, and increased aspiration risk in HIE.
- Deficits in glossopharyngeal, vagal neural networks, and respiratory regulatory pathways likely underlie these aerodigestive protective impairments.
Abstract:
Perinatal asphyxia and aerodigestive symptoms are troublesome. We tested the hypothesis that pharyngeal provocation alters proximal and distal aerodigestive reflex coordination and kinetics in infants with hypoxic ischemic encephalopathy (HIE), compared with healthy controls. Specifically, we characterized the sensory-motor properties of pharyngeal provocation-induced effects on upper esophageal sphincter (UES) and lower esophageal sphincter (LES) reflexes. Ten orally fed controls (32.0 ± 1.5 wk gestation) and 25 infants with HIE (38.1 ± 0.4 wk gestation) were evaluated at 39.7 ± 0.9 and 41.9 ± 0.6 wk postmenstrual age respectively. Pharyngo-esophageal reflexes evoked upon graded water stimuli were tested using water-perfusion micromanometry methods. Analysis included sensory-motor characteristics of pharyngeal reflexive swallow (PRS), pharyngo-UES-contractile reflex (PUCR), esophageal body-waveform kinetics, and pharyngo-LES-relaxation reflex (PLESRR). For controls vs. infants with HIE, median appearance, pulse, grimace, activity, respiration (APGAR) scores were 6 vs. 1 at 1 min (P < 0.001) and 8 vs. 3 at 5 min (P < 0.001). Upon pharyngeal- stimulation, HIE infants (vs. controls) had frequent PUCR (P = 0.01); increased UES basal tone (P = 0.03); decreased LES basal tone (P = 0.002); increased pharyngeal-waveforms per stimulus (P = 0.03); decreased frequency of LES relaxation (P = 0.003); and decreased proximal esophageal contractile amplitude (P = 0.002), with prolonged proximal esophageal contractile duration (P = 0.008). Increased tonicity and reactivity of the UES and dysregulation of LES may provide the pathophysiological basis for pooling of secretions, improper bolus clearance, and aspiration risk. Deficits in function at the nuclear or supranuclear level involving glossopharyngeal and vagal neural networks and respiratory regulatory pathways involved with aerodigestive protection may be contributory.
