Démarche diagnostique devant des hypersignaux de la substance blanche cérébrale

Abstract

The discovery of cerebral white matter lesions, either by chance or during a workup, is an extremely frequent occurrence and may be related or not to the complaint that prompted the brain MRI. It is therefore important to be able to identify the etiology. In addition to clinical data, analysis of the topography, size and appearance of the lesions (contour, shape, demyelinating front, edematous reaction, microbleeds, etc.) helps to orientate the etiological assessment and thus to differentiate vascular, from inflammatory, infectious, tumoral or metabolic appearance... In this article, we propose a review of the various aspects that point towards inflammatory hypotheses. We will then review the main diagnoses of inflammatory pathologies that may involve the brain: multiple sclerosis, ADEM (acute disseminated encephalomyelitis), cerebral involvement in more general inflammatory pathologies (lupus, sarcoidosis, histiocytosis, SAPL... ), Susac syndrome, CLIPPERS (chronic lymphocytic inflammation with pontine perivascular enhancement responsive to steroids), NMOSD (neuromyelitis optica spectrum disorders), and MOGAD (myelin oligodendrocyte glycoprotein antibody-associated diseases).