OC06: Naturally occurring tactile stimulation augments cortical activity in pre-term human infants with acquired brain injury

Introduction: Neonatal animal studies show that cortical activity is necessary for typical development. This suggests that the suppression of activity following brain injury in human infants could mediate their adverse outcomes. In healthy infants, cortical activity can be augmented by stimulation in up to 100% of infants. Here, we evaluated whether cortical activity can also be augmented in infants with acquired brain injury by tactile stimulation. Methods: We analysed 5 EEG recordings from 4 pre-term infants with a unilateral intra-parenchymal lesion (IPL) associated with intra-ventricular haemorrhage (24-30 weeks gestational age; 7-69 postnatal days at EEG). We evaluated whether naturally occurring tactile stimulation of the hand contralateral to the IPL, e.g. caregiver touch, increased EEG power using video synchronised to the EEG. Results: Time-frequency analysis showed that stimulation evoked a broadband increase in power in 3 of 5 datasets from 2 of the 4 infants. This included a pronounced widespread delta energy increase, maximal in the contralateral temporal region (up to 10dB). Conclusion: These preliminary results show that naturally occurring tactile stimulation can augment cortical activity in infants with IPL, to a comparable extent to that reported in healthy infants. This could support healthy development. Nevertheless, this finding was not present in all infants, and future work will examine whether this heterogeneity relates to factors such as sleep states, or the location and extent of the parenchymal lesion. Additionally, it will be important to compare these brain responses to those following tactile stimulation contralateral to the healthy brain hemisphere.