RT Book, Section A1 Wu, Helen A1 Fisher, Kristen A2 Hershey, Andrew D. SR Print(0) ID 1195237730 T1 Demyelinating Diseases of the Central Nervous System T2 CURRENT Diagnosis & Treatment Pediatric Neurology YR 2023 FD 2023 PB McGraw Hill Education PP New York, NY SN 9781260457520 LK neurology.mhmedical.com/content.aspx?aid=1195237730 RD 2024/11/03 AB Acute disseminated encephalomyelitis (ADEM) is a central nervous system (CNS) inflammatory syndrome characterized by rapid-onset encephalopathy along with multifocal neurologic deficits. While ADEM is frequently thought to occur in the context of preceding illness, the specific microbial trigger is rarely identified, and the pathophysiology of the disorder is thought to be immune-mediated.1 Magnetic resonance imaging (MRI) of the brain typically demonstrates large, diffuse, and poorly demarcated T2-hyperintense lesions predominantly affecting white matter. These lesions are apparent during the initial acute to subacute phase (typically 3 months, by definition) and can resolve in the weeks following. Further clinical workup includes lumbar puncture (LP), which is typically remarkable for cerebrospinal fluid (CSF) pleocytosis with lymphocytic predominance and elevated protein. Additional findings may include elevated immunoglobulin (Ig) G index, but oligoclonal bands are rarely positive in ADEM.