Evaluation of possible prognostic factors of fulminant acute disseminated encephalomyelitis (ADEM) on magnetic resonance imaging with fluid-attenuated inversion recovery (FLAIR) and diffusion-weighted imaging.
BACKGROUND
Acute disseminated encephalomyelitis (ADEM) may be a rapidly progressive disease with different clinical outcomes.


OBJECTIVE
To investigate the radiological findings of fulminant ADEM on diffusion-weighted imaging (DWI) and fluid-attenuated inversion recovery (FLAIR) images, and to correlate these findings with clinical outcome.


METHODS
Initial and follow-up magnetic resonance imaging (MRI) scans in eight patients were retrospectively evaluated for distribution of lesions on FLAIR images and presence of hemorrhage or contrast enhancement. DWI of the patients was evaluated as to cytotoxic versus vasogenic edema. The clinical records were analyzed, and MRI results and clinical outcome were correlated.


RESULTS
Four of the eight patients died, three had full recovery, and one had residual cortical blindness. The distribution of the hyperintense lesions on FLAIR sequence was as follows: frontal (37.5%), parietal (50%), temporal (37.5%), occipital (62.5%), basal ganglia (50%), pons (37.5%), mesencephalon (37.5%), and cerebellum (50%). Three of the patients who died had brainstem involvement. Two patients had a cytotoxic edema, one of whom died, and the other developed cortical blindness. Six patients had vasogenic edema: three of these patients had a rapid progression to coma and died; three of them recovered.


CONCLUSIONS
DWI is not always helpful for evaluating the evolution or predicting the outcome of ADEM. However, extension of the lesions, particularly brainstem involvement, may have an influence on the prognosis.
Donmez
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Department of Radiology, Faculty of Medicine, Baskent University, Ankara, Turkey. fuldemyildirim@yahoo.com
Aslan
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Coskun
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D000293:Adolescent; D000328:Adult; D000368:Aged; D019575:Blindness, Cortical / Q000175:diagnosis; D001921:Brain / Q000473:pathology*; D001929:Brain Edema / Q000175:diagnosis; D001933:Brain Stem / Q000473:pathology; D002540:Cerebral Cortex / Q000473:pathology; D002543:Cerebral Hemorrhage / Q000175:diagnosis; D002648:Child; D002675:Child, Preschool; D003337:Corpus Callosum / Q000473:pathology; D038524:Diffusion Magnetic Resonance Imaging; D018450:Disease Progression; D004292:Dominance, Cerebral / Q000502:physiology; D004673:Encephalomyelitis, Acute Disseminated; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007089:Image Enhancement; D007091:Image Processing, Computer-Assisted; D007223:Infant; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009460:Neurologic Examination; D011379:Prognosis; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D013788:Thalamus / Q000473:pathology; D055815:Young Adult