Case contributed by A.Prof Frank Gaillard


2 weeks of generalised malaise. Parents recall her developing pharyngitis with fever, prescribed antibiotics by LMO. Shortly after became aphasic, with right hemiparesis, confused.

Patient Data

Age: 25 years
Gender: Female

Multiple white matter regions of high T2 signal with open-ring enhancement and leading edge restricted diffusion. No central restricted diffusion. 


Follow-up scan 5 weeks later demonstrates evolution of the previously demonstrated high T2 signal regions, with some of the larger lesions having reduced in size, whilst others that were merely punctate have increased in conspicuity.

Of note the left caudate and lentiform nucleus are of markedly elevated T2 signal.

Case Discussion

Initially, this case was thought to be fairly typical of ADEM with a cluster of lesions which evolve at variable rates during the one period. 

The presence of basal ganglia high T2 signal suggests that this is indeed post-streptococcal acute disseminated  encephalomyelitis (ADEM) as basal ganglia involvement (with auto-reactive antibasal ganglia antibodies (ABGA)) is far more common (80%) in post-strep ADEM than in non-post-strep ADEM (18%) 1

Unfortunately on further follow-up additional new lesions developed (over one year after the initial presentation) suggesting that in fact this was, or had gone on to become, a relapsing form of ADEM (relapsing disseminated encephalomyelitis (RDEM) and multiphasic disseminated encephalomyelitis - MDEM). The demarcation between these, however, and relapsing-remitting multiple sclerosis is contentious.

Overall when the diagnosis of ADEM is made, progression to MS is not uncommon, reported in up to 35% of cases.

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Case information

rID: 39817
Published: 10th Mar 2016
Last edited: 14th Aug 2019
Inclusion in quiz mode: Included

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