Can cortical responses following noxious stimulation inform us about pain processing in neonates?

The measurement of pain in neonates presents a unique challenge. Infants, unable to describe pain verbally, rely on caregivers to assess and manage pain on their behalf. Behavioral and physiological indicators, often used in pain assessment in this population, are assumed surrogate measures of pain processing; however, it has not been proven that these outcome measures correlate with perceived pain, which requires higher cortical processing. Recent studies in neonates have used near-infrared spectroscopy to measure the cortical responses to nociception. The magnitude of these responses can be compared with current clinical pain assessment measures, which provides the opportunity to assess whether these measures are a true reflection of cortical pain processing. This review discusses the use of near-infrared spectroscopy and compares it with alternative pain assessment measures in this vulnerable population.