MRI scans shortly after birth might help determine which premature babies have sustained a brain injury that will affect their development, a new study reports.
Lack of blood flow or oxygen
It appears that doctors can predict which premature infants will suffer from future motor, thinking and language problems by using MRI scans to identify specific injuries to the white matter in their brain, said senior researcher Dr Steven Miller.
Miller is head of neurology at the Hospital for Sick Children in Toronto, Canada.
Read: Brain problems in premature babies may develop before birth
Fluctuations in blood pressure that occur regularly in preemies might cause a lack of blood flow or oxygen to the brain, damaging the white matter, Miller explained.
In addition, said Dr Gregory Lodygensky, a clinical investigator at the University of Montreal, white matter injuries also occur due to inflammation and infection suffered by the very vulnerable infants.
Specifically, the study found that white matter injuries in the frontal lobes of the brain appear to have the worst impact on a baby's future development, compared with damage to white matter elsewhere in the brain.
For example, preemies with larger frontal lobe injuries were 79 times more likely to develop thinking problems than infants without such injuries. And they had 64 times greater odds of problems with motor development, the researchers reported.
Identifying frontal lobe development problems
The frontal lobe is the area of the brain that regulates problem solving, memory, language skills and voluntary movement skills, the study authors said.
"As a clinician, when I see lesions in the frontal lobe, I am paying much more attention to them," Miller said. "I'm starting to spend time thinking about where the lesions are, not just how big they are."
More than one in 10 babies is born prematurely in the United States – before 37 weeks' gestation, according to the US Centres for Disease Control and Prevention.
And more than 70 percent of babies born before 31 weeks' gestation endure injury to their white matter – vital tissue linking different regions of the brain, Lodygensky noted in an editorial accompanying the study.
However, doctors have so far been unable to prove a direct link between this damage and future developmental problems, Miller said.
Brain scan research has focused primarily on the total volume of white matter injury, but some children with large amounts of brain injury develop normally while others with less injury suffer from developmental problems, Miller noted.
"We've seen these clinical scores are not perfect predictors of how children will subsequently do," he said. "We wanted to move the conversation forward, to not look at how much injury there was to the brain but to understand how the location of the injuries impacts outcomes for the babies."
MRI scans help find problem areas
Miller and his team performed MRI scans on 216 babies born at an average 28 weeks of gestation. The investigators assessed both the volume and location of white matter injury.
The research team then revisited 58 of the babies at 18 months of age, performing motor, thinking and language assessments to determine how their development had proceeded. These assessments revealed that damage in the frontal lobes mattered more than damage in other brain locations.
A greater volume of these small areas of injury in the frontal lobe could predict thinking problems, the researchers found. However, a greater volume of small areas of injury, no matter where they were located in the brain, could predict movement problems at 18 months, the team discovered.
Dr Manikum Moodley, a paediatric neurologist who was not involved with the study, said, "It definitely does provide compelling evidence that doing MRIs is of immense benefit in counselling parents of children born prematurely regarding their neurological status."
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Moodley and Lodygensky added that the MRI itself poses no risk to premature infants.
However, sedating the baby to get a good scan does pose risks, so the scans should be done without sedation, said Moodley, who is with Cleveland Clinic Children's Hospital in Ohio.
Drugs and therapies
In addition, doctors need to be careful moving the fragile baby from the neonatal intensive care unit to the hospital's MRI unit for the brain scans, Miller and Moodley said.
Miller pointed out that such MRI scans will be valuable in detecting children who will need additional education and physical rehabilitation to compensate for developmental problems.
Lodygensky predicted that, in the future, the scans also could help determine which preemies will benefit from any drugs and therapies developed to prevent white matter injuries.
"I am personally convinced that MRI will be part of our ongoing strategy to protect the brains of premature babies," Lodygensky said.
The report was released online in Neurology.
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