Electrophysiological Measurements and Analysis of Nociception in Human Infants

Abstract

Pain is an unpleasant sensory and emotional experience. Since infants cannot verbally report their experiences, current methods of pain assessment are based on behavioural and physiological body reactions, such as crying, body movements or changes in facial expression. While these measures demonstrate that infants mount a response following noxious stimulation, they are limited: they are based on activation of subcortical somatic and autonomic motor pathways that may not be reliably linked to central sensory processing in the brain. Knowledge of how the central nervous system responds to noxious events could provide an insight to how nociceptive information and pain is processed in newborns.The heel lancing procedure used to extract blood from hospitalised infants offers a unique opportunity to study pain in infancy. In this video we describe how electroencephalography (EEG) and electromyography (EMG) time-locked to this procedure can be used to investigate nociceptive activity in the brain and spinal cord.This integrative approach to the measurement of infant pain has the potential to pave the way for an effective and sensitive clinical measurement tool.

Assessing pain objectively: the use of physiological markers

“…Magneto‐encephalography directly measures magnetic fields generated by intracellular dendritic activity, whereas EEG directly measures scalp voltage fluctuations due to extracellular ionic currents . Both techniques detect increases in brain activity related to noxious stimulation , that correspond with data obtained with functional magnetic resonance imaging (fMRI) . They have a temporal resolution in the order of milliseconds, which is superior to indirect neuroimaging methods such as functional near‐infrared spectroscopy and MRI.…”

Translation and cultural adaptation of an objective pain assessment tool forFinnishICUpatients

“…There is some evidence that this technique is capable of detecting cerebral hemodynamic changes associated with sensory stimuli . NIRS is still new, but it has been demonstrated to be effective with infants with nociceptive procedures and adults undergoing cardiac surgery . The results are promising, but further research is needed.…”

A review of important electroencephalogram features for the assessment of brain maturation in premature infants

“…Similarly, in the somatosensory cortex, spontaneously generated twitches and body movements in immature rats and human preterm infants produce somatosensory feedback, eliciting delta brushes and organise the broad layout of the cortical somatosensory topographic body map, necessary for sensorimotor coordination. On the EEG, delta brushes have been recognised as not only spontaneous activity or in response to endogenously generated movements, but as EEG waveforms that can also be induced by different sensory stimuli in infants <35 weeks GA . Different stimuli evoke delta brushes in the relevant cortical regions: visual inputs evoke delta brushes in occipital regions , auditory inputs in temporal regions , tactile stimuli to hand and foot in lateral and medial regions of the contralateral central cortex respectively , and noxious stimuli to the heel can elicit delta brushes in the mid‐temporal regions .…”