Long-term impact of neonatal intensive care and surgery on somatosensory perception in children born extremely preterm.

Alterations in neural activity due to pain and injury in early development may produce long-term effects on sensory processing and future responses to pain. To investigate persistent alterations in sensory perception, we performed quantitative sensory testing (QST) in extremely preterm (EP) children (n=43) recruited from the UK EPICure cohort (born less than 26 weeks gestation in 1995) and in age and sex matched term-born controls (TC; n=44). EP children had a generalized decreased sensitivity to all thermal modalities, but no difference in mechanical sensitivity at the thenar eminence. EP children who also required neonatal surgery had more marked thermal hypoalgesia, but did not differ from non-surgical EP children in the measures of neonatal brain injury or current cognitive ability. Adjacent to neonatal thoracotomy scars there was a localized decrease in both thermal and mechanical sensitivity that differed from EP children with scars relating to less invasive procedural interventions or from those without scars. No relationship was found between sensory perception thresholds and current pain experience or pain coping styles in EP or TC children. Neonatal care and surgery in EP children are associated with persistent modality-specific changes in sensory processing. Decreases in mechanical and thermal sensitivity adjacent to scars may be related to localized tissue injury, whereas generalized decreases in thermal sensitivity but not in mechanical sensitivity suggest centrally mediated alterations in the modulation of C-fibre nociceptor pathways, which may impact on responses to future pain or surgery.