PRS is more frequent than PUCR, and the 2 reflexes have distinctive characteristics in air and water stimuli. Both PRS and PUCR have implications for the evaluation of swallowing in infants.

OBJECTIVES: Glottal relationships during swallowing dominate the etiology of dysphagia. We investigated the pharyngo-glottal relationships during basal and adaptive swallowing. METHODS: Temporal changes in glottal closure kinetics (frequency, response latency, and duration) with spontaneous and adaptive pharyngeal swallows were defined in 12 infants using concurrent pharyngoesophageal manometry and ultrasonography of the glottis. RESULTS: Frequency, response latency, and duration of glottal closure with spontaneous swallows (n = 53) were 100%, 0.27±0.1 s, and 1±0.22 s, respectively. The glottis adducted earlier (P < 0.0001 vs. upper esophageal sphincter relaxation) within the same respiratory phase as swallow (P = 0.03). With pharyngeal provocations (n = 41), glottal adduction (pharyngo-glottal closure reflex (PGCR)) was noted first and then again with pharyngeal reflexive swallow (PRS). The frequency, response latency, and duration of glottal closure with PGCR were 100%, 0.56±0.13 s, and 0.52±0.1 s, respectively. Response latency to PRS was 3.24±0.33 s; the glottis adducted 97% within 0.36±0.08 s in the same respiratory phase (P = 0.03), and remained adducted for 3.08±0.71 s. Glottal adduction was the quickest with spontaneous swallow (P = 0.04 vs. PGCR), and the duration was the longest during PRS (P < 0.005 vs. PGCR or spontaneous swallow). CONCLUSIONS: Glottal adduction during basal or adaptive swallowing reflexes occurs in either respiratory phase, thus ensuring airway protection against pre-deglutitive or deglutitive aspiration. The independent existence and magnitude (duration of adduction) of PGCR suggests a hypervigilant state of the glottis in preventing aspiration during swallowing or during high gastroesophageal reflux events. Investigation of pharyngeal–glottal relationships with the use of noninvasive methods may be more acceptable across the age spectrum.

The occurrence and frequency of symptoms with AREs depend on the most proximal extent of the ARE and the acid clearance time.

BACKGROUND AND AIMS-Our aims were to identify and characterize the glottal response to esophageal mechanostimulation in human infants. We tested the hypotheses that glottal response is related to the type of esophageal peristaltic response, stimulus volume, and respiratory phase.

OBJECTIVES The changes in esophageal propulsive characteristics during maturation are not known. Our aim was to define the effects of postnatal maturation on esophageal peristaltic characteristics in preterm human neonates. We tested the hypotheses that: (i) maturation modifies esophageal bolus propulsion characteristics, and (ii) the mechanistic characteristics differ between primary and secondary peristalsis. METHODS Esophageal motility in 10 premature neonates (mean 27.5 weeks gestational age) was evaluated twice at 33.8 weeks (time 1, earlier study) and 39.2 weeks (time 2, later study) mean postmenstrual age. Esophageal manometry waveform characteristics (amplitude and duration, peristaltic velocity, and intrabolus pressure domains) were analyzed during spontaneous primary peristalsis and infusion-induced secondary peristalsis. Repeated-measures and unstructured variance–covariance or compound symmetry matrixes were used for statistical comparison. Values stated as least squares means±s.e.m. or percent. RESULTS A total of 200 primary peristalsis and 227 secondary peristalsis events were evaluated. Between time 1 and time 2: (i) proximal esophageal waveform amplitude increased (P < 0.02), with primary peristalsis (38±6 vs. 48±7 mm Hg) and with secondary peristalsis (34±6 vs. 46±5 mm Hg); (ii) distal esophageal waveform amplitude was similar (P = NS), with primary peristalsis (42±4 vs. 43±4 mm Hg) and secondary peristalsis (29±3 vs. 32±4 mm Hg); (iii) proximal esophageal waveform onset to peak duration decreased (P = 0.02) with primary (2.6±0.3 vs. 1.9±0.1 s, P < 0.003) and with secondary peristalsis (2.2±0.2 vs. 1.8±0.1 s); (iv) distal esophageal waveform onset to peak duration decreased (P = 0.01) with primary (2.4±0.3 vs. 1.8±0.1 s) and with secondary peristalsis (1.9±0.2 vs. 1.5±0.1 s); (v) effects of identical stimulus volume on intrabolus pressure were similar (P = NS); however, greater infusion volumes (2 vs. 1 ml) generated higher intrabolus pressure at both time 1 and time 2 (both Ps < 0.05). Between primary and secondary peristalsis (mechanistic variable): (i) no differences were noted at either period, with proximal esophageal waveform amplitudes (P = NS); (ii) differences were noted with distal esophageal waveform amplitudes at each time period (P = 0.0002); (iii) no differences were noted with both esophageal waveforms duration at either period (P = NS); (iv) peristaltic velocity was faster with secondary peristalsis than with primary peristalsis at either period (at earlier study, 7.9±1.4 vs. 2.5±1.4 cm/s and at later study 6.2±1.6 vs. 1.2±1.5 cm/s, both Ps < 0.01). CONCLUSIONS In preterm neonates, longitudinal maturation modulates the characteristics of primary and secondary peristalsis. Differences in proximal striated muscle and distal smooth muscle activity during peristalsis are evident. Peristaltic velocity is faster with secondary peristalsis. These findings may represent maturation of central and peripheral neuromotor properties of esophageal bolus propulsion in healthy preterm hum...