Functional near-infrared spectroscopy to assess pain in neonatal circumcisions.

Anaesthetists may not know that near infrared spectroscopy (NIRS) is used to map brain activation in real-time, in a very wide variety of neuroscience applications. It is best described as a highly portable, cheap, research friendly, cortex specific version of BOLD imaging (usually in a clunky, expensive MRI scanner). The brain during anaesthesia isn’t completely asleep, and this group at CHOP used fNIRS to look at brain responses to the pain of circumcision, showing significant detectable signal changes, that were influenced by local anaesthesia. Perhaps the brain whilst anaesthetised is not quite the black box we think it is, and perhaps we can tease out useful information related to analgesia using optical methods, whilst our patients sleep? See the accompanying editorial for more opinion on this topic and paper (

Reviewed by Dr Justin Skowno