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preterm brain scans

Early lipids in micropreemies’ diets can boost brain growth

preterm brain scans

Segmentation of a preterm brain T2-weighted MRI image at 30 gestational weeks [green=cortical grey matter; blue=white matter; grey=deep grey matter; cyan=lateral ventricle; purple=cerebellum; orange=brainstem; red=hippocampus; yellow=cerebrospinal fluid].

Dietary lipids, already an important source of energy for tiny preemies, also provide a much-needed brain boost by significantly increasing global brain volume as well as increasing volume in regions involved in motor activities and memory, according to research presented during the Pediatric Academic Societies 2019 Annual Meeting.

“Compared with macronutrients like carbohydrates and proteins, lipid intake during the first month of life is associated with increased overall and regional brain volume for micro-preemies,” says Catherine Limperopoulos, Ph.D., director of MRI Research of the Developing Brain at Children’s National and senior author. “Using non-invasive magnetic resonance imaging, we see increased volume in the cerebellum by 2 weeks of age. And at four weeks of life, lipids increase total brain volume and boost regional brain volume in the cerebellum, amygdala-hippocampus and brainstem.”

The cerebellum is involved in virtually all physical movement and enables coordination and balance. The amygdala processes and stores short-term memories. The hippocampus manages emotion and mood. And the brainstem acts like a router, passing messages from the brain to the rest of the body, as well as enabling essential functions like breathing, a steady heart rate and swallowing.

According to the Centers for Disease Control and Prevention, about 1 in 10 U.S. babies is born preterm, or before 37 weeks gestation. Regions of the brain that play vital roles in complex cognitive and motor activities experience exponential growth late in pregnancy, making the developing brains of preterm infants particularly vulnerable to injury and impaired growth.

Children’s research faculty examined the impact of lipid intake in the first month of life on brain volumes for very low birth weight infants, who weighed 1,500 grams or less at birth. These micro-preemies are especially vulnerable to growth failure and neurocognitive impairment after birth.

The team enrolled 68 micro-preemies who were 32 weeks gestational age and younger when they were admitted to Children’s neonatal intensive care unit during their first week of life. They measured cumulative macronutrients – carbohydrates, proteins, lipids and calories – consumed by these newborns at 2 and 4 weeks of life. Over years, Limperopoulos’ lab has amassed a large database of babies who were born full-term; this data provides unprecedented insights into normal brain development and will help to advance understanding of brain development in high-risk preterm infants.

“Even after controlling for average weight gain and other health conditions, lipid intake was positively associated with cerebellar and brainstem volumes in very low birthweight preterm infants,” adds Katherine M. Ottolini, the study’s lead author.

According to Limperopoulos, Children’s future research will examine the optimal timing and volume of lipids to boost neurodevelopment for micro-preemies.

Pediatric Academic Societies 2019 Annual Meeting presentation

  • “Early lipid intake improves brain growth in premature infants.”
    • Saturday, April 27, 2019, 1:15-2:30 p.m. (EST)

Katherine M. Ottolini, lead author; Nickie Andescavage, M.D., Attending, Neonatal-Perinatal Medicine and co-author; Kushal Kapse, research and development staff engineer and co-author; and Catherine Limperopoulos, Ph.D., director of MRI Research of the Developing Brain and senior author, all of Children’s National.

newborn in incubator

In HIE lower heart rate variability signals stressed newborns

newborn in incubator

In newborns with hypoxic-ischemic encephalopathy (HIE), lower heart rate variability correlates with autonomic manifestations of stress shortly after birth, underscoring the value of this biomarker, according to Children’s research presented during the Pediatric Academic Societies 2019 Annual Meeting.

Tethered to an array of machines that keep their bodies nourished, warm and alive, newborns with health issues can’t speak. But Children’s research teams are tapping into what the machinery itself says, looking for insights into which vulnerable infants are most in need of earlier intervention.

Heart rate variability – or the variation between heartbeats – is a sign of health. Our autonomic nervous system constantly sends signals to adjust our heart rate under normal conditions. We can measure heart rate variability non-invasively, providing a way to detect potential problems with the autonomic nervous system as a sensitive marker of health in critically ill newborns,” says An N. Massaro, M.D., co-Director of Research for the Division of Neonatology at Children’s National, and the study’s senior author. “We’re looking for validated markers of brain injury in babies with HIE, and our study helps to support heart rate variability as one such valuable physiological biomarker.”

In most newborns, the autonomic nervous system reliably and automatically receives information about the body and the outside world and, in response, controls essential functions like blood pressure, body temperature, how quickly the baby breathes and how rapidly the newborn’s heart beats. The sympathetic part stimulates body processes, while the parasympathetic part inhibits body processes. When the nervous system’s internal auto-pilot falters, babies can suffer.

The Children’s team enrolled infants with HIE in the prospective, observational study. (HIE is brain damage that occurs with full-term babies who experience insufficient blood and oxygen flow to the brain around the time they are born.) Fifteen percent had severe encephalopathy. Mean age of babies in the observational study was 38.9 weeks gestation. Their median Apgar score at five minutes was 3; the 0-9 Apgar range indicates how ready newborns are for the rigors of life outside the womb.

The team analyzed heart rate variability metrics for three time periods:

  • The first 24 to 27 hours of life
  • The first three hours after babies undergoing therapeutic cooling were rewarmed and
  • The first three hours after babies’ body temperature had returned to normal.

They correlated the relationship between heart rate variability for 68 infants during at least one of these time periods with the stress z-score from the NICU Network Neurobehavioral Scale. The scale is a standardized assessment of newborn’s neurobehavioral integrity. The stress summary score indicates a newborn’s overall stress response, and six test items specifically relate to autonomic function.

“Alpha exponent and root mean square in short timescales, root mean square in long timescales, as well as low and high frequency powers positively correlated with stress scores and, even after adjusting for covariates, remained independently associated at 24 hours,” says Allie Townsend, the study’s lead author.

Pediatric Academic Societies 2019 Annual Meeting presentation

  • “Heart rate variability (HRV) measures of autonomic nervous system (ANS) function relates to neonatal neurobehavioral manifestations of stress in newborn with hypoxic-ischemic encephalopathy (HIE).”
    • Monday, April 29, 2019, 5:45 p.m. (EST)

Allie Townsend, lead author; Rathinaswamy B. Govindan, Ph.D., staff scientist, Advanced Physiological Signals Processing Lab and co-author; Penny Glass, Ph.D., director, Child Development Program and co-author; Judy Brown, co-author; Tareq Al-Shargabi, M.S., co-author; Taeun Chang, M.D., director, Neonatal Neurology and Neonatal Neurocritical Care Program and co-author; Adré J. du Plessis, M.B.Ch.B., MPH, chief of the Division of Fetal and Transitional Medicine and co-author; An N. Massaro, M.D., co-Director of Research for the Division of Neonatology and senior author, all of Children’s National.

Robin Steinhorn in the NICU

Coming together as a team for the good of the baby

Robin Steinhorn in the NICU

Children’s National has a new program to care for children who have severe bronchopulmonary dysplasia, a serious complication of preterm birth.

Around the 1-year-old’s crib is a tight circle of smiling adults, and at the foot of his bed is a menagerie of plush animals, each a different color and texture and shape to spark his curiosity and sharpen his intellect.

Gone are the days a newborn with extremely complex medical needs like Elijah would transfer from the neonatal intensive care unit (NICU) to the pediatric intensive care unit and transition through a couple of other hospital units by the time he was discharged. Gone are the days when he’d see a variety of new physician faces at every stop. And gone are the days he’d be confined to his room, divorced from the sights and sounds and scents of the outside world, stimulation that helps little baby’s neural networks grow stronger.

Children’s National has a new program designed to meet the unique needs of children like Elijah who have severe bronchopulmonary dysplasia (BPD), a common complication of preterm birth.

“It’s more forward-thinking – and I mean thinking for the future of each individual baby, and it’s allowing the baby to have one team and one location to take advantage of a deep knowledge of and relationship with that baby and family,” says Robin Steinhorn, M.D. Dr. Steinhorn is senior vice president of the Center for Hospital-Based Specialties and one of Children’s multidisciplinary team members who visited Elijah’s bed twice weekly during his lengthy hospitalization and who continues to see him regularly during outpatient visits.

“The pulmonologist, the neonatologist, the respiratory therapist, the physical therapist, the dietitian, the cardiologist – we all come as a team to work together for the good of the baby,” Dr. Steinhorn adds. “We stick with these babies through thick and thin. We will stick with that baby with this team and this location until they are ready to go home – and beyond.”

BPD, a serious lung condition, mostly affects extremely low birthweight preterm babies whose lungs were designed to continue developing inside the womb until the pregnancy reaches full term. Often born months before their due dates, these extremely vulnerable newborns have immature organs, including the lungs, which are not ready for the task of breathing air. Children’s program targets infants who experience respiratory failure from BPD. The respiratory support required for these infants ranges from oxygen delivered through a nasal cannula to mechanical ventilators.

Robin Steinhorn and Colleague

“It’s more forward-thinking – and I mean thinking for the future of each individual baby, and it’s allowing the baby to have one team and one location to take advantage of a deep knowledge of and relationship with that baby and family,” says Robin Steinhorn, M.D.

About 1 percent of all preterm births are extremely low birthweight, or less than 1,500 grams. Within that group, up to 40 percent will develop BPD. While they represent a small percentage of overall births, these very sick babies need comprehensive, focused care for the first few years of their lives. And some infants with severe BPD also have pulmonary hypertension which, at Children’s National, is co-managed by cardiology and pulmonary specialists.

Children’s BPD team not only focuses on the child’s survival and medical care, they focus on the neurodevelopmental and social care that a baby needs to thrive. From enhanced nutrition to occupational and physical therapy to a regular sleep cycle, the goal is to help these babies achieve their full potential.

“These babies are at tremendous risk for long-term developmental issues. Everything we do is geared to alleviate that,” adds John T. Berger III, M.D., director of Children’s Pulmonary Hypertension Program.

“Our NICU care is more focused, comprehensive and consistent,” agrees Mariam Said, M.D., a neonatologist on the team. “We’re also optimizing the timing of care and diagnostic testing that will directly impact health outcomes.”

Leaving no detail overlooked, the team also ensures that infants have age-appropriate developmental stimuli, like toys, and push for early mobility by getting children up and out of bed and into a chair or riding in a wagon.

“The standard approach is to keep the baby in a room with limited physical or occupational therapy and a lack of appropriate stimulation,” says Geovanny Perez, M.D., a pulmonologist on the team. “A normal baby interacts with their environment inside the home and outside the home. We aim to mimic that within the hospital environment.”

Dr. Steinhorn, who had long dreamed of creating this comprehensive team care approach adds that “it’s been so gratifying to see it adopted and embraced so quickly by Children’s NICU caregivers.”