Diagnosing a newborn baby’s pain can prove baffling when infants broadly express discomfort or unhappiness through scrunched faces and wails. That could change with a new project that uses brain activity patterns to help figure out when babies experience pain. It’s an encouraging step toward helping clinical trials that test certain drugs or treatments as pain relief for babies.
Parents and even physicians have been forced to interpret pain in young infants based on their behavior such as crying and facial grimacing. That’s not the most objective measure because babies often show similar behavior if they are hungry or want a cuddle, says Rebeccah Slater, associate professor of pediatric neuroimaging at the University of Oxford in the U.K. Instead, Slater and her colleagues turned to electroencephalography (EEG) technology as a way to identify and quantify brain activity patterns that reflect actual pain when babies experience certain medical procedures. Their efforts have yielded an easily deployable method of measuring pain in even the most uncooperative, wriggling newborns.
“The importance of this measure is that it is sensitive to analgesic treatment and therefore can be used to quantify whether pain medication is effective for acutely painful procedures in infants,” Slater says.
Slater made the first recording of pain-related brain activity in babies during her Ph.D. research almost 10 years ago. Since that time, researchers have been able to use technologies such as near-infrared spectroscopy, EEG, and more recently fMRI brain scans, to observe brain activity related to pain among infants. That work became the basis for the latest research by Slater and her colleagues detailed in the 3 May 2017 issue of the journal Science Translational Medicine.
The EEG recordings involved placing individual electrodes on the babies’ heads and holding them in place with a net cap. Unlike other fMRI brain scans, EEG cannot show specific areas of the brain that activate because of painful stimuli. But the researchers used EEG because it’s easily performed at the bedside, is less sensitive to the movement of wriggling babies, and can even work for infants born prematurely (“preemies”).
Through their research, the U.K. researchers showed that EEG could distinguish between pain and other stimuli involving sight, sound, or touch. They also compared the brain activity recordings with backup measures involving heart rate and observations of pain-related behavior such as facial grimacing.
The University of Oxford team—alongside colleagues from Great Ormond Street Hospital for Children in London and the John Radcliffe Hospital in Oxford—also demonstrated how they could detect pain-related brain activity even among preemies.
During routine procedures for drawing blood from newborns, the EEG method correctly identified pain-related brain activity in each individual baby about 64 percent of the time. By comparison, the EEG method correctly did not identify pain-related brain activity 65 percent of the time when a non-painful stimulus was tested on each individual baby.
That means the method is currently not suitable for determining pain among individual infants, says Caroline Hartley, a postdoctoral researcher at the University of Oxford and leader author on the recent paper. But she added that it could still help research studies or clinical trials that examine how groups of babies respond to certain treatments or interventions.
Crucially, the EEG recordings were able to show differences in pain-related brain activity and normal brain activity when 12 babies received local anesthetic treatment prior to getting blood drawn for the usual medical procedures. That became a proof-of-concept for the researchers to use the EEG method in a larger clinical trial called the Poppi Trial (Procedural Pain in Premature Infants).
The researchers have already recruited the first 13 infants out of a planned 156 infants who will be studied over the course of three years.
“We will test whether babies who are given morphine experience less pain, and whether reducing pain during a painful eye exam improves the stability of the babies heartbeat and breathing after the procedure,” Hartley says.
Other groups of researchers have begun looking at AI based on machine learning and computer vision that could track the facial expressions of infants—another possible way of detecting pain among preverbal babies. Those could also prove useful, but will face the challenge of distinguishing facial expressions unique to pain rather than similar grimaces related to being hungry.
Jeremy Hsu has been working as a science and technology journalist in New York City since 2008. He has written on subjects as diverse as supercomputing and wearable electronics for IEEE Spectrum. When he’s not trying to wrap his head around the latest quantum computing news for Spectrum, he also contributes to a variety of publications such as Scientific American, Discover, Popular Science, and others. He is a graduate of New York University’s Science, Health & Environmental Reporting Program.