Acute Disseminated Encephalomyelitis (ADEM)
Last Updated: October 1, 2018
- Peak Age: Childhood (5-8)
- Gender: M > F (1:0.6-0.8)
- Etiology: Post-infectious or post-vaccination immune-mediated demyelination
- Brain/Brain stem: Multifocal subcortical/juxtracortical white matter lesions (commonly involves gray matter too), less common periventricular and callososeptal white matter lesions. Commonly basal ganglia and thalami involved (symmetric)
- Spinal Cord:
- Dorsal cord white matter
- +/- gray matter
- Nerves: +/- cranial nerve involvement
- Flame-shaped lesions in spinal cord
Modality-Specific (Spinal Cord Only):
- CT Myelography:
- Spinal cord not well evaluated. May see spinal cord swelling in acute phase (mimics intramedullary tumor)
- T1: Isointense or hypointense
- T1 + Contrast: +/- Enhancement. Patchy, ring, nodular, or cloud-like/fluffy
- T2: Flame-shaped hyperintense lesions
- STIR: Flame-shaped hyperintense lesions. Increased sensitivity for detection of lesions
- DWI: Acute lesions may have restricted diffusion
- CT Myelography:
Contributor: Jacob A. Eitel, MD
“Diffusion-Weighted Imaging and Proton MR Spectroscopy in the Characterization of Acute Disseminated Encephalomyelitis. - PubMed - NCBI.” Accessed February 7, 2018. https://www.ncbi.nlm.nih.gov/pubmed?term=17131116.
MD, Jeffrey S. Ross, and Kevin R. Moore MD. Diagnostic Imaging: Spine, 3e. 3 edition. Philadelphia: Elsevier, 2015.
“Medline ® Abstracts for References 5,18 of ‘Acute Disseminated Encephalomyelitis in Adults’ - UpToDate.” Accessed February 7, 2018. https://www.uptodate.com/contents/acute-disseminated-encephalomyelitis-in-adults/abstract/5,18.
Singh, S., M. Alexander, and I. P. Korah. “Acute Disseminated Encephalomyelitis: MR Imaging Features.” AJR. American Journal of Roentgenology 173, no. 4 (October 1999): 1101–7. https://doi.org/10.2214/ajr.173.4.10511187.
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