Acute Disseminated Encephalomyelitis (ADEM): Past, Present, and Future

Cynthia Wang, MD

James T. Lubin Fellow at the University of Texas Southwestern Medical Center in Dallas

Acute disseminated encephalomyelitis (ADEM) is a rare, autoimmune neurological condition that often occurs in young children following an infection. Initial symptoms of ADEM may be quite variable and non-specific, including headache, fever, irritability, confusion, sleepiness, and weakness. Over the years, our understanding of ADEM has matured, though many aspects of the condition remain mysterious. What leads some individuals to develop the condition in the first place? Could it happen again? Why do some individuals make a full recovery while others have lasting impairment?

ADEM is thought to develop when the body mounts a response to an infection, but rather than solely attacking the invading organism, it mistakenly targets parts of the nervous system as well. ADEM is primarily a clinical diagnosis, meaning that we do not have a perfect test that can tell us definitively whether a child or adult has ADEM. Laboratory studies of blood and spinal fluid, and MRIs of the brain and spine can help rule out other conditions and support the diagnosis of ADEM. If ADEM is suspected, children and adults often receive steroid medications during their hospitalization to help reduce inflammation and suppress the body’s confused immune system.

For the vast majority of those affected by ADEM, it is a one-time illness and does not recur. Many children make excellent recoveries and largely seem to return to normal. However, episodes of new neurological symptoms, especially those that develop 3 months or more after the initial event, raise concern for an alternate diagnosis, such as multiple sclerosis or neuromyelitis optica spectrum disorder. In our clinic at UTSW Dallas, our practice has been to repeat MRI brain scans at 3-4 months after ADEM to establish a baseline for future comparison. Any new clinical events or MRI brain lesions occurring after this period of time would lead to scrutiny of the ADEM diagnosis

Another practice in our clinic is to perform neuropsychological testing on our patients who have had ADEM. Increasing research highlights that children with ADEM may have subtle cognitive deficits involving processing speed, visual-motor integration, executive functioning, language processing, and behavioral regulation that may not be evident until they get older and are faced with increasing academic and social demands. Neuropsychological testing is geared toward uncovering areas of weakness and may be helpful in guiding school accommodations for children affected by ADEM.

We are just beginning to study the long-term outcomes of children with ADEM, particularly their cognitive potential, academic achievement, social functioning, and quality of life. In the past couple of years, we have also learned more about a subset of ADEM patients who make antibodies toward a protein on the outer surface of certain cells called myelin oligodendrocyte glycoprotein (MOG). Over time, our ability to test for this antibody has improved, along with increasing understanding that this group of MOG positive ADEM patients may have similarities in their clinical presentation, neuroimaging, and prognoses that may impact their care.

 

Introducing APERTURE: Assessment of Pediatric and Adult Encephalomyelitis Related Outcomes: Understand, Reveal, Educate

To help address gaps in our understanding about ADEM, our group at University of Texas Southwestern Medical Center will be conducting a study examining the long-term outcomes of individuals with ADEM. We aim to collect data on a large group of children and adults diagnosed with ADEM and review their presenting history, laboratory studies, neuroimaging, treatment course, and recovery from ADEM. Individuals between ages 0-64 with the initial diagnosis of ADEM are welcome to participate. People who cannot travel to our center in Dallas can participate remotely by providing medical records, MRI studies, completing questionnaires, and in some cases, neuropsychological testing. Enrollment will begin in June 2017.

We are eager to learn more about this rare neurological condition, and with your help, work toward improving our ability to better care for those affected by ADEM.

Please email PEDICONQUER@UTSouthwestern.edu for more details.

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