In 1979, the Centers for Disease Control and Prevention (CDC) was presented with a question: How many children have a developmental disability? Knowing more about the number and characteristics of children with developmental disabilities, such as epilepsy, can help us to understand the magnitude of these conditions and how improvements can be made to help children with developmental disabilities. In 1981, to address this question, CDC began to develop the Metropolitan Atlanta Developmental Disabilities Study (MADDS). We started to think through which developmental disabilities could be tracked and how we would track them, using the CDC birth defects tracking system (started in metropolitan Atlanta in 1967) as a model.
From my perspective as a medical epidemiologist and a developmental pediatrician, I thought that it made sense to include epilepsy tracking along with other serious developmental disabilities. The number of children with epilepsy and the impact that epilepsy has upon their lives is just as important to understand and highlight as many other developmental disabilities. Also, epilepsy and other developmental disabilities tend to cluster together. For example, many children with cerebral palsy also have epilepsy. For these reasons, from 1985-1987 we decided to track the number and characteristics of children with cerebral palsy, epilepsy, hearing loss, intellectual disability, and vision impairment among school-aged children in metropolitan Atlanta.
Because children with developmental disabilities are identified by and receive services from various health, social service, and education systems, we decided to go to multiple sources in the community to collect data from records. These “sources” included schools, hospitals, the health department, and other health service providers. This proved to be an efficient method of tracking the number of children with cerebral palsy, hearing loss, intellectual disability, and vision impairment. In fact, about 95% of the children with one or more of these four developmental disabilities were initially identified through school records (1).[blockquote align=”right”]Knowing more about the number and characteristics of children with developmental disabilities, such as epilepsy, can help us understand the magnitude of these conditions and where improvements can be made to help children.[/blockquote] However, epilepsy proved to be unique. After a preliminary analysis of the data collected from the various health, social service, and education records, we determined that we underestimated the number of children with epilepsy. Our results seemed too low when compared to those of other studies that are based on an entire group of children in a specific geographic area. Through these sources, we seemed mainly to identify children whose epilepsy was particularly severe, and came to the attention of the school system or required significant medical services, including hospitalization.
To identify the children with epilepsy who were being missed, we decided to use laboratories that do electroencephalograms (EEG), or brain wave tests that can help diagnose epilepsy, as an additional source. We identified 20 EEG laboratories in hospitals, clinics, and private physician offices that served children in metropolitan Atlanta, and we reviewed records at these facilities. Luckily at about this same time, an Epidemic Intelligence Service Officer and pediatric neurologist named Dr. Edwin Trevathan joined our team. He was very committed to the project and reviewed each EEG report himself to help determine epilepsy diagnoses.
Through this comprehensive method of data collection, we found that:
- about 1 in every 165 school-aged child in metropolitan Atlanta had epilepsy,
- more boys than girls had epilepsy,
- partial seizures were the most common seizure type, and
- among children with epilepsy, 35% had at least one other developmental disability, including cerebral palsy, hearing loss, intellectual disability, and/or visual impairment (2).
Fast forward almost thirty years, and CDC now funds a group of programs in multiple communities across the United States to track autism and other developmental disabilities using the same methods developed for MADDS. This group of programs is known as the Autism and Developmental Disabilities Monitoring (ADDM) Network. The model for the ADDM Network is the Metropolitan Atlanta Developmental Disabilities Surveillance Program (MADDSP), which was built on MADDS and began to track cerebral palsy, intellectual disability, hearing loss, and vision impairment in 1991 and autism spectrum disorder in 1996. Because tracking the number of children with epilepsy in the 1980s required collecting data from unique data sources and was a very labor intensive process, we were unable to continue tracking epilepsy.
Fortunately, we are able to work within our existing ADDM Network infrastructure to collect information on epilepsy as a co-occurring condition. For example, when reviewing the records of children with cerebral palsy, we also note whether those same children have a documented diagnosis of epilepsy. In 2006, we found that among children with cerebral palsy, 35% also had epilepsy (3). Although this does not paint the full picture of the impact of epilepsy upon children, it can help communities plan and coordinate service delivery for children with both cerebral palsy and epilepsy. It can help inform research into factors that are putting children at risk for both conditions.
Although we do not currently track the number of children with epilepsy, my CDC colleagues are committed to promoting the health and quality of life of people living with epilepsy and decreasing the stigma associated with the condition. Please visit CDC’s website to learn more and access resources, including a tool-kit for parents of teens with epilepsy: www.cdc.gov/Epilepsy.
To learn more about CDC’s tracking of autism and other developmental disabilities, please visit: www.cdc.gov/ADDM
- Yeargin-Allsopp M, Oakley GP, Murphy CC, Sikes RK. A multiple-source method for studying the prevalence of developmental disabilities in children: The Metropolitan Atlanta Developmental Disabilities Study. Pediatrics. 1992;89: 624-630.
- Murphy CC, Trevathan E, Yeargin-Allsopp M. Prevalence of epilepsy and epileptic seizures in 10-year-old children: Results from the Metropolitan Atlanta Developmental Disabilities Study. Epilepsia. 1995;36(9): 866-872.
- Kirby RS, Wingate MS, Van Naarden Braun K, Doernberg NS, Arneson CL, Benedict RE, Mulvihill B, Durkin MS, Fitzgerald RT, Maenner MJ, Patz JA, Yeargin-Allsopp M. Prevalence and functioning of children with cerebral palsy in four areas of the United States in 2006: A report from the Autism and Developmental Disabilities Monitoring Network. Research in Developmental Disabilities. 2011;32(2): 462-469.
Marshalyn Yeargin-Allsopp, MD
DD Branch Chief
CDC, National Center on Birth Defects and Developmental Disabilities[/success]