Posts

illustration of brain showing cerebellum

Focusing on the “little brain” to rescue cognition

/in , , , , , , , , , , , , , , , , , /by
illustration of brain showing cerebellum

Research faculty at Children’s National in Washington, D.C., with colleagues recently published a review article in Nature Reviews Neuroscience that covers the latest research about how abnormal development of the cerebellum leads to a variety of neurodevelopmental disorders.

Cerebellum translates as “little brain” in Latin. This piece of anatomy – that appears almost separate from the rest of the brain, tucked under the two cerebral hemispheres – long has been known to play a pivotal role in voluntary motor functions, such as walking or reaching for objects, as well as involuntary ones, such as maintaining posture.

But more recently, says Aaron Sathyanesan, Ph.D., a postdoctoral research fellow at the Children’s Research Institute, the research arm of Children’s National  in Washington, D.C., researchers have discovered that the cerebellum is also critically important for a variety of non-motor functions, including cognition and emotion.

Sathyanesan, who studies this brain region in the laboratory of Vittorio Gallo, Ph.D., Chief Research Officer at Children’s National and scientific director of the Children’s Research Institute, recently published a review article with colleagues in Nature Reviews Neuroscience covering the latest research about how altered development of the cerebellum contributes to a variety of neurodevelopmental disorders.

These disorders, he explains, are marked by problems in the nervous system that arise while it’s maturing, leading to effects on emotion, learning ability, self-control, or memory, or any combination of these. They include diagnoses as diverse as intellectual disability, autism spectrum disorder (ASD), attention-deficit/hyperactivity disorder and Down syndrome.

“One reason why the cerebellum might be critically involved in each of these disorders,” Sathyanesan says, “is because its developmental trajectory takes so long.”

Unlike other brain structures, which have relatively short windows of development spanning weeks or months, the principal cells of the cerebellum – known as Purkinje cells – start to differentiate from stem cell precursors at the beginning of the seventh gestational week, with new cells continuing to appear until babies are nearly one year old.  In contrast, cells in the neocortex, a part of the brain involved in higher-order brain functions such as cognition, sensory perception and language is mostly finished forming while fetuses are still gestating in the womb.

This long window for maturation allows the cerebellum to make connections with other regions throughout the brain, such as extensive connections with the cerebral cortex, the outer layer of the cerebrum that plays a key role in perception, attention, awareness, thought, memory, language and consciousness. It also allows ample time for things to go wrong.

“Together,” Sathyanesan says, “these two characteristics are at the root of the cerebellum’s involvement in a host of neurodevelopmental disorders.”

For example, the review article notes, researchers have discovered both structural and functional abnormalities in the cerebellums of patients with ASD. Functional magnetic resonance imaging (MRI), an imaging technique that measures activity in different parts of the brain, suggests that significant differences exist between connectivity between the cerebellum and cortex in people with ASD compared with neurotypical individuals. Differences in cerebellar connectivity are also evident in resting-state functional connectivity MRI, an imaging technique that measures brain activity in subjects when they are not performing a specific task. Some of these differences appear to involve patterns of overconnectivity to different brain regions, explains Sathyanesan; other differences suggest that the cerebellums of patients with ASD don’t have enough connections to other brain regions.

These findings could clarify research from Children’s National and elsewhere that has shown that babies born prematurely often sustain cerebellar injuries due to multiple hits, including a lack of oxygen supplied by infants’ immature lungs, he adds. Besides having a sibling with ASD, premature birth is the most prevalent risk factor for an ASD diagnosis.

The review also notes that researchers have discovered structural changes in the cerebellums of patients with Down syndrome, who tend to have smaller cerebellar volumes than neurotypical individuals. Experimental models of this trisomy recapitulate this difference, along with abnormal connectivity to the cerebral cortex and other brain regions.

Although the cerebellum is a pivotal contributor toward these conditions, Sathyanesan says, learning more about this brain region helps make it an important target for treating these neurodevelopmental disorders. For example, he says, researchers are investigating whether problems with the cerebellum and abnormal connectivity could be lessened through a non-invasive form of brain stimulation called transcranial direct current stimulation or an invasive one known as deep brain stimulation. Similarly, a variety of existing pharmaceuticals or new ones in development could modify the cerebellum’s biochemistry and, consequently, its function.

“If we can rescue the cerebellum’s normal activity in these disorders, we may be able to alleviate the problems with cognition that pervade them all,” he says.

In addition to Sathyanesan and Senior Author Gallo, Children’s National study co-authors include Joseph Scafidi, D.O., neonatal neurologist; Joy Zhou and Roy V. Sillitoe, Baylor College of Medicine; and Detlef H. Heck, of University of Tennessee Health Science Center.

Financial support for research described in this post was provided by the National Institute of Neurological Disorders and Stroke under grant numbers 5R01NS099461, R01NS089664, R01NS100874, R01NS105138 and R37NS109478; the Hamill Foundation; the Baylor College of Medicine Intellectual and Developmental Disabilities Research Center under grant number U54HD083092; the University of Tennessee Health Science Center (UTHSC) Neuroscience Institute; the UTHSC Cornet Award; the National Institute of Mental Health under grant number R01MH112143; and the District of Columbia Intellectual and Developmental Disabilities Research Center under grant number U54 HD090257.

preterm brain scans

Early lipids in micropreemies’ diets can boost brain growth

/in , , , , , , , , , /by

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.

Stat Madness 2019

Vote for Children’s National in STAT Madness

/in , , , , , , , , /by

Stat Madness 2019

Children’s National Health System has been selected to compete in STAT Madness for the second consecutive year. Our entry for the bracket-style competition is “Sensitive liquid biopsy platform to detect tumor-released mutated DNA using patient blood and CSF,” a new technique that will allow kids to get better treatment for an aggressive type of pediatric brain tumor.

In 2018, Children’s first-ever STAT Madness entry advanced through five brackets in the national competition and, in the championship round, finished second. That innovation, which enables more timely diagnoses of rare diseases and common genetic disorders, helping to improve kids’ health outcomes around the world, also was among four “Editor’s Pick” finalists, entries that spanned a diverse range of scientific disciplines.

“Children’s National researchers collaboratively work across divisions and departments to ensure that innovations discovered in our laboratories reach clinicians in order to improve patient care,” says Mark Batshaw, M.D., Children’s Executive Vice President, Chief Academic Officer and Physician-in-Chief. “It’s gratifying that Children’s multidisciplinary approach to improving the lives of children with brain tumors has been included in this year’s STAT Madness competition.”

Pediatric brain cancers are the leading cause of cancer-related death in children younger than 14. Children with tumors in their midline brain structures have the worst outcomes, and kids diagnosed with diffuse midline gliomas, including diffuse intrinsic pontine glioma, have a median survival of just 12 months.

“We heard from our clinician colleagues that many kids were coming in and their magnetic resonance imaging (MRI) suggested a particular type of tumor. But it was always problematic to identify the tumor’s molecular subtype,” says Javad Nazarian, Ph.D., MSC, a principal investigator in Children’s Center for Genetic Medicine Research. “Our colleagues wanted a more accurate measure than MRI to find the molecular subtype. That raised the question of whether we could actually look at their blood to determine the tumor subtype.”

Children’s liquid biopsy, which remains at the research phase, starts with a simple blood draw using the same type of needle as is used when people donate blood. When patients with brain tumors provide blood for other laboratory testing, a portion of it is used for the DNA detective work. Just as a criminal leaves behind fingerprints, tumors shed telltale clues in the blood. The Children’s team searches for the histone 3.3K27M (H3K27M), a mutation associated with worse clinical outcomes.

“With liquid biopsy, we were able to detect a few copies of tumor DNA that were hiding behind a million copies of healthy DNA,” Nazarian says. “The blood draw and liquid biopsy complement the MRI. The MRI gives the brain tumor’s ZIP code. Liquid biopsy gives you the demographics within that ZIP code.”

Working with collaborators around the nation, Children’s National continues to refine the technology to improve its accuracy. The multi-institutional team published findings online Oct. 15, 2018, in Clinical Cancer Research.

Even though this research technique is in its infancy, the rapid, cheap and sensitive technology already is being used by people around the globe.

“People around the world are sending blood to us, looking for this particular mutation, H3K27M, ” says Lindsay B. Kilburn, M.D., a Children’s neuro–oncologist, principal investigator at Children’s National for the Pacific Pediatric Neuro-Oncology Consortium, and study co-author. “In many countries or centers, children do not have access to teams experienced in taking a biopsy of tumors in the brainstem, they can perform a simple blood draw and have that blood processed and analyzed by us. In only a few days, we can provide important molecular information on the tumor subtype previously only available to patients that had undergone a tumor biopsy.”

“With that DNA finding, physicians can make more educated therapeutic decisions, including prescribing medications that could not have been given previously,” Nazarian adds.

The STAT Madness round of 64 brackets opened March 4, 2019, and the championship round voting concludes April 5 at 5 p.m. (EST).

In addition to Nazarian and Dr. Kilburn, study co-authors include Eshini Panditharatna, Madhuri Kambhampati, Heather Gordish-Dressman, Ph.D., Suresh N. Magge, M.D., John S. Myseros, M.D., Eugene I. Hwang, M.D. and Roger J. Packer, M.D., all of Children’s National; Mariam S. Aboian, Nalin Gupta, Soonmee Cha, Michael Prados and Co-Senior Author Sabine Mueller, all of University of California, San Francisco; Cassie Kline, UCSF Benioff Children’s Hospital; John R. Crawford, UC San Diego; Katherine E. Warren, National Cancer Institute; Winnie S. Liang and Michael E. Berens, Translational Genomics Research Institute; and Adam C. Resnick, Children’s Hospital of Philadelphia.

Financial support for the research described in the report was provided by the V Foundation for Cancer Research, Goldwin Foundation, Pediatric Brain Tumor Foundation, Smashing Walnuts Foundation, The Gabriella Miller Kids First Data Resource Center, Zickler Family Foundation, Clinical and Translational Science Institute at Children’s National under award 5UL1TR001876-03, Piedmont Community Foundation, Musella Foundation for Brain Tumor Research, Matthew Larson Foundation, The Lilabean Foundation for Pediatric Brain Cancer Research, The Childhood Brain Tumor Foundation, the National Institutes of Health and American Society of Neuroradiology.

Chima Oluigbo examines a patient

Eradicating epilepsy with Visualase

/in , /by
Chima Oluigbo examines a patient

Chima Oluigbo, M.D., and his team are using Visualase to identify and eliminate seizure foci and provide patients with a minimally invasive procedure for treating epilepsy.

About one in 26 people will be diagnosed with epilepsy in their lifetime. That adds up to about 3.4 million people in the U.S., or about 1 percent of the population nationwide. This condition can have huge consequences on quality of life, affecting whether children will learn well in school, eventually drive a car, hold down a job or even survive into adulthood.

For most of those that develop epilepsy, medications can keep seizures in check. However, for about a third of patients, this strategy doesn’t work, says Chima Oluigbo, M.D., an attending neurosurgeon at Children’s National Health System. That’s when he and his team offer a surgical fix.

Epilepsy surgery has come a long way, Dr. Oluigbo explains. When he first began practicing in the early 2000s, most surgeries were open, he says – they involved making a long incision in the scalp that can span half a foot or more. After drilling out a window of skull that can be as long as five inches, surgeons had to dig through healthy brain to find the abnormal tissue and remove it.

Each part of this “maximally invasive” procedure can be traumatic on a patient, Dr. Oluigbo says. That leads to significant pain after the procedure, extended hospital stays of at least a week followed by a long recovery. There are also significant risks for neurological complications including stroke, weakness, paralysis, speech problems and more.

However, open surgery isn’t the only option for epilepsy surgery anymore. Several new minimally invasive alternatives are now available to patients and the most promising, Dr. Oluigbo says, is called Visualase. He and his team are the only surgeons in the region who perform this procedure.

In Visualase surgeries, Dr. Oluigbo and his colleagues start by making a tiny incision, about 5 millimeters, on the scalp. Through this opening, they bore an even tinier hole into the skull and thread a needle inside that’s about 1.6 millimeters wide. “The brain barely notices that it’s there,” he says.

The tip of this wire holds a laser. Once this tip is placed directly at the seizure foci – the cluster of nerve cells responsible for generating a seizure – the patient is placed in an intraoperative magnetic resonance imaging (MRI) device. There, after checking the tip’s precise placement, the surgeons turn the laser on. Heat from the laser eradicates the foci, which the surgeons can see in real time using MRI thermography technology. The margins of the destroyed tissue are well-defined, largely sparing healthy tissue.

After the wire is removed, the incision is closed with a single stitch, and patients go home the next day. The majority of patients are seizure free, with rates as high as 90 percent for some types of epilepsy, Dr. Oluigbo says. Although seizure-free rates are also high for open procedures, he adds, Visualase spares them many of open surgeries’ painful and difficult consequences.

“Having done both open surgeries and Visualase,” Dr. Oluigbo says, “I can tell you the difference is night and day.”

Although open procedures will still be necessary for some patients with particularly large foci that are close to the surface, Dr. Oluigbo says that Visualase is ideal for treating medication-resistant cases in which the foci are buried deep within the brain. A typical example is a condition called hypothalamic hamartoma, in which tumors on the hypothalamus lead to gelastic seizures, an unusual seizure type characterized by uncontrollable laughing. He also uses Visualase for another condition called tuberous sclerosis, in which waxy growths called tubers develop in the brain, and for cancerous and benign brain tumors.

It’s gratifying to be able to help these children become seizure-free for the rest of their lives, says Dr. Oluigbo – even more so with the numerous updates he receives from families telling him how much this procedure has improved their children’s lifestyle.

“Visualase has completely changed the way that we approach these patients,” Dr. Oluigbo says. “It’s extraordinary to see the effects that this one procedure can have on the quality of life for patients here at Children’s National.”

newborn in incubator

Tracking oxygen saturation with vital signs to identify vulnerable preemies

/in , , , , , , , /by

 

Khodayar-Rais-Bahrami

PDF Version

What’s known

Critically ill infants in neonatal intensive care units (NICU) require constant monitoring of their vital signs. Invasive methods, such as using umbilical arterial catheters to check blood pressure, are the gold standard but pose significant health risks. Low-risk noninvasive monitoring, such as continuous cardiorespiratory monitors, can measure heart rate, respiratory rate and blood oxygenation. A noninvasive technique called near-infrared spectroscopy (NIRS) can gauge how well tissues, including the brain, are oxygenated. While NIRS long has been used to monitor oxygenation in conditions in which blood flow is altered, such as bleeding in the brain, how NIRS values relate to other vital sign measures in NICU babies was unknown.

What’s new

A research team led by Khodayar Rais-Bahrami, M.D., a neonatologist at Children’s National Health System, investigated this question in 27 babies admitted to Children’s NICU. The researchers separated these subjects into two groups: Low birth weight (LBW, less than 1.5 kg or 3.3 pounds) and moderate birth weight (MBW, more than 1.5 kg). Then, they looked for correlations between information extracted from NIRS, such as tissue oxygenation (specific tissue oxygen saturation, StO2) and the balance between oxygen supply and consumption (fractional tissue oxygen extraction, FTOE), and various vital signs. They found that StO2 increased with blood pressure for LBW babies but decreased with blood pressure for MBW babies. Brain and body FTOE in LBW babies decreased with blood pressure. In babies with abnormal brain scans, brain StO2 increased with blood pressure and brain FTOE decreased with blood pressure. Together, the researchers suggest, these measures could give a more complete picture of critically ill babies’ health.

Questions for future research

Q: Can NIRS data be used as a surrogate for other forms of monitoring?

Q: How could NIRS data help health care professionals intervene to improve the health of critically ill infants in the NICU?

Source: “Significant correlation between regional tissue oxygen saturation and vital signs of critically ill infants.” B. Massa-Buck, V. Amendola, R. McCloskey and K. Rais-Bahrami. Published by Frontiers in Pediatrics Dec. 21, 2017.

Children’s National Fetal Medicine Institute hosts 2nd annual International Symposium on the Fetal Brain

/in , , , , /by


The Children’s National Health System Fetal Medicine Institute hosted the 2nd annual International Symposium on the Fetal Brain in August 2017 in Washington, D.C.

Speakers at this year’s symposium focused on the following four areas:

  • Brain Development in an Unsupportive In Utero Environment – Diagnosis and Consequences
  • Supporting Brain Development in the Ex Utero Fetus: How Far Are We From Optimal?
  • Genomic and Epigenomic Mechanisms Underlying Differences in Brain Development
  • The Emergence of Consciousness and Pain Sensation

Adré J. du Plessis, M.B.Ch.B., M.P.H., Director of the Fetal Medicine Institute and Division Chief of Fetal and Transitional Medicine hosted the conference. In his opening remarks Dr. du Plessis noted “Our goal has been to gather together a diverse group from across the spectrum of disciplines focused on the well-being of the fetal brain and to engage all disciplines together.”

Diana-Bianchi-at-ISFB

Diana Bianchi, MD gives her keynote presentation on non-invasive fetal testing at the second annual International Symposium on the Fetal Brain.

Invited, internationally renowned speakers presented on diverse topics, including Diana Bianchi, Director of the Eunice Kennedy Shriver National Institute of Child Health and Human Development who spoke on the “Non-Invasive Fetal Testing Beyond Karyotype: What’s in it for the Fetal Brain?”

A new component to the symposium was the clinically-focused breakfast breakout sessions, created based on feedback from attendees of the 2016 Symposium. Sessions covered varied topics such as “Fetal Ultrasound: the Cornerstone of Fetal Neurodiagnosis,” “The Essentials of Neurogenetic Testing,” “Developing a Transitional Fetal-Neonatal Program” and “Using MRI to Advance Fetal Neurodiagnosis.”

The conference started with an exciting discussion by Alistair Gunn, M.B.Ch.B., Head of the Department of Physiology at the University of Auckland. His presentation “Fetal Heart Rate: What It Does and Does Not Tell Us” explored the considerable body of evidence that essentially all decelerations are mediated by chemoreflex responses to repeated hypoxia and that the parasympathetic autonomic nervous system is the critical regulator of both fetal heart rate and heart rate variation in labor.

Following a voting process from the symposium’s external speakers, the inaugural Andrea Poretti Abstract Award was presented to Katherine Ottolini for her poster titled: Breastmilk Feeds Improve Brain Microstructural Development in Very Premature Infants.

For more information about the sessions and speakers at the 2017 Symposium, please visit our website.