Presentation
Middle aged male off shore oil worker no past history 1 week history of alteration in cognition mild fever. No recent vaccination.
Patient Data
Extensive ill-defined foci of low attenutation in throughout both cerebral hemispheres in the deep white matter, juxta-cortical regions and left thalamus.
Normal posterior fossa.
Huge number of well delineated high T2/FLAIR, non restricting enhancing lesions of variable size throughout both cerebral hemispheres in the deep white matter, juxta-cortical regions and left thalamus.
No perilesional edema.
Normal posterior fossa.
Case Discussion
Acute disseminated encephalomyelitis (ADEM) is a monophasic acute inflammation and demyelination of white matter typically following a recent viral infection or vaccination.
Appearances vary from small punctate lesions to tumefactive regions, which have less mass effect than one would expect for their size, distributed in the supratentorial or infratentorial white matter. Compared to multiple sclerosis, involvement of the callososeptal interface is unusual. Lesions are usually bilateral but asymmetrical. Involvement of cerebral cortex, subcortical grey matter, especially the thalami.
Lumbar puncture and a multitude of other laboratory investigations were undertaken with no indicative findings. This combined with the clinical history led to the presumptive diagnosis of ADEM.