Infants as young as one day old can feel pain, according a first-ever MRI brain-scan study conducted by investigators at Oxford University. The research, published April 21 in the journal eLife, challenges the belief of some experts that babies don’t feel pain.
“Some people have argued that babies’ brains are not developed enough to really ‘feel’ pain – any reaction being just a reflex,” lead author Rebeccah Slater, PhD, an associate professor of neuroimaging in England’s Oxford University department of pediatrics, said in a news release. “Our study provides strong evidence that this is not the case.”
For the small study, researchers used MRI scanners to compare pain responses to the same stimuli in 10 infants aged 1 day to 6 days with that of 10 adults aged 23 to 36.
“Up until recently, people didn’t think it was possible to study pain in babies using MRI because, unlike adults, they don’t keep still in the scanner,” Slater said. “However, as babies that are less than a week old are more docile than older babies, we found that their parents were able to get them to fall asleep inside the scanner so, for the first time, we could study pain in the infant brain using MRI.”
While in the scanner, the babies were given a poke to the bottoms of their feet much like being “being poked with a pencil,” but mild enough not to wake them up. The adults were also “poked” while in the scanner and the reactions of the two groups were compared.
Findings showed that 18 of the 20 brain regions active in adults experiencing pain were active in the infants. The scans also showed that the babies had the same response to weak pokes as the adults had to pokes that were four times stronger, suggesting babies may have a lower pain threshold.
The use of MRI scanning, said Slater, “is particularly important when it comes to pain; obviously babies can’t tell us about their experience of pain and it is difficult to infer pain from visual observations.” Now, she added, it is possible to see pain “happening” inside the infant brain.
With this new evidence, the researchers urge a change in the way babies are treated for pain. According the news release, a 2014 review of neonatal pain management practices in intensive care showed that although NICU patients experienced an average of 11 painful procedures per day, 60 percent of the babies did not receive any kind of pain medication.
“Our study suggests that not only do babies experience pain, but they may be more sensitive to it than adults. We have to think that if we would provide pain relief for an older child undergoing a procedure then we should look at giving pain relief to an infant undergoing a similar procedure.” Slater said.