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William Gaillard

Putting childhood epilepsy in the spotlight at American Epilepsy Society Meeting

William Gaillard

“We aim to build the evidence base for treatments that are effective specifically for children with epilepsy,” says William D. Gaillard, M.D., chief of Child Neurology, Epilepsy and Neurophysiology, and director of the Comprehensive Pediatric Epilepsy Program.

While epilepsy affects people of all ages, the unique way it manifests in infants, children and adolescents can be attributed in part to the complexities of the growing and developing brain. Researchers from the Children’s National Comprehensive Pediatric Epilepsy Program brought their expertise on the challenges of understanding and treating epilepsy in children to the recent American Epilepsy Society Annual Meeting, the largest professional gathering on epilepsy in the world.

“We aim to build the evidence base for treatments that are effective specifically for children with epilepsy,” says William D. Gaillard, M.D., chief of Child Neurology, Epilepsy and Neurophysiology, and director of the Comprehensive Pediatric Epilepsy Program. “We have learned much from studies in adult populations but technologies like functional MRI allow us to get in-depth understanding, often in non-invasive ways, of precisely how epilepsy is impacting a child.”

Dr. Gaillard was also recently elected to serve as the Second Vice President of the American Epilepsy Society. “The AES is the largest multidisciplinary professional and scientific society dedicated to the understanding, treatment and eradication of epilepsy and associated disorders, and I am honored to serve as the new Second Vice President,” he said.

The team’s presentations and poster sessions focused on several key areas in pediatric epilepsy:

Better ways to see, measure and quantify activity and changes in the brain for children with epilepsy before, during and after surgery

  • Novel applications of fMRI for children with epilepsy
    • Evaluation of an fMRI tool that tracks verbal and visual memory in children with epilepsy – one of the first to capture memory functions in this population of children using noninvasive fMRI;
    • Early study of the use of “resting-state” fMRI to map language skills before epilepsy surgery – an important first step toward noninvasively evaluating children who are too young or neurologically impaired to follow tasks in traditional MRI studies;
  • A study of whether intraoperative MRI, i.e. imaging during neurosurgery, allows for more complete removal of abnormal brain tissue associated with focal cortical dysplasia in children, which is a common cause of intractable epilepsy;
  • A preliminary case review of existing data to see if arterial spin labeling MRI, which measures blood flow to the brain, has potential to identify blood flow changes in specific locations of the brain where seizures occur;
  • An analysis of language laterality – the dominant side of the brain controlling language –  questioning the true reasons that the brains of children with epilepsy have differences in the hemisphere that predominantly controls language;
  • A review of some common assessments of language and working memory that are used pre- and post-operatively to gauge the impacts of pediatric epilepsy surgery. The study found that using multiple assessments, and studying results individually rather than as a group average, resulted in a more complete picture of the outcomes of surgery on these areas of brain function;
  • A preliminary study examining whether continuous EEG monitoring of neonates with hypoxic ischemic encephalopathy, or lack of oxygen to the brain, can be a reliable predictor of neurodevelopmental outcomes while the infant is undergoing therapeutic hypothermia.

“In order to expand our understanding of causes, impacts and outcomes, the range of research is broad given the complexity of epilepsym,” says Madison M. Berl, Ph.D. “This is the only way we can contribute to the goal of providing our colleagues and the families they serve with better resources to make informed decisions about how best to assess and treat pediatric epilepsy.”

The molecular, genetic and biological factors that contribute to onset and severity of pediatric epilepsy

  • A retrospective study of young patients with malformations in cortical development that are important causes of childhood epilepsy;
  • Investigation of a simple saliva test to effectively identify the presence of two common viral infections, human herpesvirus-6B and Epstein-Barr virus, that may be contributors to onset of epilepsy in otherwise normally functioning brains;
  • A preliminary review of the possible relationship between febrile infection-related epilepsy syndrome and the co-occurrence of another neuro-inflammatory condition – hemophagocytic lymphohistiocytosis.

Madison Berl, Ph.D., director of research in the Division of Pediatric Neuropsychology, and a pediatric neuropsychologist in the Comprehensive Pediatric Epilepsy Program, adds, “In order to expand our understanding of causes, impacts and outcomes, the range of research is broad given the complexity of epilepsy. This is the only way we can contribute to the goal of providing our colleagues and the families they serve with better resources to make informed decisions about how best to assess and treat pediatric epilepsy.”

Surprising consensus on pediatric anti-epilepsy meds

A study that includes William D. Gaillard, M.D., among its authors indicates that U.S. doctors appear to have reached an unexpected consensus about which anti-seizure medicine to prescribe to their pediatric patients.

The number of available anti-seizure medications has exploded in the past two decades, going from just a handful of medicines available in the 1990s to more than 20 now. Once the Food and Drug Administration (FDA) approves each new medicine based on trials in adults, it’s available for clinicians to prescribe off-label to all age groups. However, says William D. Gaillard, M.D., division chief of Child Neurology and Epilepsy, Neurophysiology and Critical Care Neurology at Children’s National Health System, trials that lead to FDA approval for adults do not provide any information about which medications are best for children.

“With so many medications and so little data,” Dr. Gaillard says, “one might think doctors would choose a wider variety of medicines when they prescribe to children with epilepsy.”

However, the results from a recent study that included Dr. Gaillard and colleagues, published online in Pediatric Neurology on June 27, 2017, show otherwise. The study indicates that doctors in the United States appear to have reached an unexpected consensus about which medication to prescribe for their pediatric patients.

The study is part of a broader effort to collect data on the youngest epilepsy patients – those younger than 3 years old, the age at which epilepsy most often becomes evident. As part of this endeavor, researchers from 17 U.S. pediatric epilepsy centers enrolled in the study 495 children younger than 36 months old who had been newly diagnosed with non-syndromic epilepsy (a condition not linked to any of the commonly recognized genetic epilepsy syndromes).

The researchers mined these patients’ electronic medical records for information about their demographics, disease and treatments. About half of the study participants were younger than 1 year old when they were diagnosed with epilepsy. About half had disease marked by focal features, meaning that their epilepsy appeared to originate from a particular place in the brain. Nearly all were treated with a single medication, as opposed to a cocktail of multiple medicines.

William Gaillard

“This study identifies current practices, but whether those practices are correct is a separate question,” explains Dr. Gaillard. “Just because a medication is used commonly doesn’t mean it is the best medication we should be using.”

Of those treated with a single medication, nearly all were treated with one of five medicines: Levetiracetam, oxcarbazepine, phenobarbital, topiramate and zonisamide. However, the data showed a clear prescribing preference. About 63 percent of the patients were prescribed levetiracetam as a first choice. By contrast, oxcarbazepine and phenobarbital, the next most frequently prescribed medicines, were taken by patients as a first choice by a mere 14 percent and 13 percent respectively.

Even more striking, of the children who were not prescribed levetiracetam initially but required a second medication due to inadequate efficacy or unacceptable side effects, 62 percent also received this medication. That made levetiracetam the first or second choice for about 74 percent of all the children in the study, despite the availability of more than 20 anti-seizure medications.

It’s not clear why levetiracetam is such a frequent choice in the United States, says Dr. Gaillard. However, in its favor, the drug is available in a liquid formulation, causes no ill effects medically and can be started intravenously if necessary. Studies have shown that it appears to be effective in controlling seizures in about 40 percent of infants.

Yet, levetiracetam’s market dominance appears to be a North American phenomenon, the study authors write. A recent international survey that Dr. Gaillard also participated in suggests that outside of this continent, carbazepine and oxcarbazepine were the most frequently prescribed medications to treat focal seizures.

What’s really necessary, Dr. Gaillard says, is real data on efficacy for each of the medications commonly prescribed to pediatric epilepsy patients – a marked vacuum in research that prevents doctors from using evidence-based reasoning when making medication choices.

“This study identifies current practices, but whether those practices are correct is a separate question,” he explains. “Just because a medication is used commonly doesn’t mean it is the best medication we should be using.”

To answer that question, he says, researchers will need to perform a head-to-head clinical trial comparing the top available epilepsy medications in children. This study sets the stage for such a trial by identifying which medications should be included.

“Uncontrolled pediatric epilepsy can have serious consequences, from potential problems in development to a higher risk of death,” Dr. Gaillard says. “You want to use the optimal medicine to treat the disease.”