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When a baby’s crying, it can be difficult to know what’s wrong. Detecting brain signals could provide a more reliable way to tell if babies are in pain.

“Babies can’t talk, so we need other ways to tell if they’re in pain,” says Rebeccah Slater, at the University of Oxford. “Currently, doctors use facial grimaces and squints, but they could be caused by other factors, such as hunger or the desire for a cuddle,” she says.

Now Slater and her team have developed a method that uses an electrode positioned on the midline of the scalp to detect brainwave patterns associated with pain. They did this by analysing EEG readings taken from 18 babies as they had their blood taken as part of routine health screening. The readings showed a distinctive signal half a second after their heels were pricked.


The team then tested the accuracy of this signal in tests on more infants, finding that the size of the pain signal correlated with the degree of facial grimacing, the usual method of judging pain by a baby’s facial expressions.

Pain relief

The signal worked for premature infants too, and it was reduced in babies that had a painkilling gel applied to their heels before taking blood. Slater’s team is now conducting further experiments to determine if the technique is accurate enough to be used to detect if a baby really is in pain.

If it proves reliable, it could assist the team’s research into how best to relieve a baby’s pain during procedures such as eye examinations.

“This method has been investigated for the past half-dozen years, and [it’s] really interesting and good that it’s now been validated,” says Lorenzo Fabrizi, at University College London.

But Fabrizi says we need to know more about how and why a baby’s brain produces this pain signal. Babies’ brainwaves respond to a brief, acute stimulus, but different brain systems may be involved in ongoing, chronic pain, he says.

Journal reference: Science Translational Medicine, DOI: 10.1126/scitranslmed.aah6122