Effects of oral stimulus frequency spectra on the development of non-nutritive suck in preterm infants with respiratory distress syndrome or chronic lung disease, and preterm infants of diabetic mothers

Abstract

The precocial nature of orofacial sensorimotor control underscores the biological importance of establishing ororythmic activity in human infants. The purpose of this study was to assess the effects of comparable doses of three forms of orosensory experience, including a low-velocity spectrally reduced orocutaneous stimulus (NT1), a high-velocity broad spectrum orocutaneous stimulus (NT2), and a SHAM stimulus consisting of a blind pacifier. Each orosensory experience condition was paired with gavage feedings 3x/day for 10 days in the neonatal intensive care unit (NICU). Four groups of preterm infants (N=214), including those with respiratory distress syndrome (RDS), chronic lung disease (CLD), infants of diabetic mothers (IDM), and healthy controls (HI) were randomized to the type of orosensory condition. Mixed modeling, adjusted for gender, gestational age, postmenstrual age, and birth weight, demonstrated the most significant gains in non-nutritive suck (NNS) development among CLD infants who were treated with the NT2 stimulus, with smaller gains realized among RDS and IDM infants. The broader spectrum of the NT2 stimulus maps closely to known response properties of mechanoreceptors in lip, tongue, and oral mucosa and is more effective in promoting NNS development among preterm infants with impaired oromotor function compared to the low-velocity, spectrally reduced NT1 orosensory stimulus.

Patterned frequency-modulated oral stimulation in preterm infants: A multicenter randomized controlled trial

“…In contrast, the PFOS provides consistent oral-somatosensory stimuli which mimic the amplitude and frequency of mature NNS bursts [36]. The efficacy of PFOS also critically depends on the characteristics of its frequency modulation (0–16 Hz) [38], which targets the touch frequency spectrum of orofacial mechanoreceptors (0–100 Hz) [69, 70]. This broader stimulation spectrum may generate more effective sensory inputs in inducing neuroplastic changes in brainstem feeding centers and sensory and motor cortices [71.…”

“…These infants were capable of taking sufficient oral feeds at a mean PMA of 35 weeks, a feeding competence comparable to infants born at 35 weeks’ gestation [73]. The previous studies of PFOS have mainly focused on the efficacy of PFOS on NNS development [36–38]. This multicenter RCT evaluated the effect of PFOS on nutritive feeding competency.…”

“…The pneumatic stimulator in the NTrainer system generates a series of pulses patterned as 6-cycle bursts followed by 2-second pause periods (Fig 2A), which transforms the pacifier into a pulsating nipple. Each NTrainer pulse was frequency modulated (0 to 16 Hz) through the dynamic intraluminal pressure changes to stimulate oral facial nerves [38]. A PFOS training session lasted 20 minutes and consisted of three 3-minute PFOS epochs and two 5.5-minute non-stimulation epochs during which the pneumatic stimulator was switched off (Fig 2B).…”

Automatic Nonnutritive Suck Waveform Discrimination and Feature Extraction in Preterm Infants

“…Adoption of the NTrainer is expected to double in 2019 to include new NICUs in the US and international settings. The NTrainer has been and is currently used in randomized controlled trials (RCTs) to study the neurobiology of feeding [9, 10, 30, 33].…”

“…This section briefly describes the computational methods and analysis parameters implemented in NeoNNS. The algorithms, notations, and parameter specifications for time- and frequency-domain analysis routines described herein are based on previous research in preterm suck development [1, 4, 5, 8, 10, 15, 30, 32, 36, 37].…”