Objective: Controlled somatosensory stimulation strategies have demonstrated merit in developing oral feeding skills in premature infants who lack a functional suck, however, the effects of orosensory entrainment stimulation on electrocortical dynamics is unknown. The objective of the study was to determine the effects of servo-controlled pneumatic orocutaneous stimulation presented during gavage feedings on the modulation of amplitude-integrated electroencephalogram (aEEG) and range electroencephalogram (rEEG) activity.
Study design: Two-channel EEG recordings were collected during 180 sessions that included orocutaneous stimulation and non-stimulation epochs among 22 preterm infants (mean gestational age=28.56 weeks) who were randomized to treatment and control 'sham' conditions. The study was initiated at around 32 weeks post-menstrual age. The raw EEG was transformed into aEEG margins, and rEEG amplitude bands measured at 1-min intervals and subjected to a mixed models statistical analysis.
Result: Multiple significant effects were observed in the processed EEG during and immediately following 3-min periods of orocutaneous stimulation, including modulation of the upper and lower margins of the aEEG, and a reorganization of rEEG with an apparent shift from amplitude bands D and E to band C throughout the 23-min recording period that followed the first stimulus block when compared with the sham condition. Cortical asymmetry also was apparent in both EEG measures.
Conclusion: Orocutaneous stimulation represents a salient trigeminal input, which has both short- and long-term effects in modulating electrocortical activity, and thus is hypothesized to represent a form of neural adaptation or plasticity that may benefit the preterm infant during this critical period of brain maturation.