Quantification of the Burst Phase during Non-Nutritive Suck Production in Preterm Infants

Abstract

Premature birth places infants at increased risk for learning disabilities, delayed development of speech, language and motor skills, and mortality. The premature infant often has difficulties with respiration and feeding and therefore may remain in the hospital for prolonged periods of time. The non-nutritive suck (NNS) is a motor behavior which can be observed and used to make inference about brain development and organization in this young population. The purpose of this study was to quantify the frequency modulation of the NNS burst in two groups of preterm infants, including those with and those without respiratory distress syndrome (RDS). Thirty-two (32) preterm infants were consented and distributed into one of the following groups: Control (N=17) and RDS (N=15). Digitized samples of NNS compression pressure waveforms were collected 15 minutes prior to scheduled feedings on a weekly basis. Quadratic regression analysis revealed that healthy preterm infants produced longer NNS bursts and the mean burst initiation cycle periods were shorter when compared to the RDS group. Moreover, NNS burst initiation shows a prominent frequency modulated (FM) segment upon initiation which appears to be a significant feature of the suck central pattern generator (sCPG) and is markedly different for RDS preterm infants as compared to their healthy preterm counterparts. Identification of such characteristics provides specific criteria and description of the NNS CPG which may offer a new diagnostic criterion which can be used to gauge the developmental status of oromotor control systems among these fragile infants.