Imaging of gray matter lesions in multiple sclerosis

Abstract

© Cambridge University Press 2011. Introduction Multiple sclerosis (MS) is the most common immune-mediated chronic inflammatory disease of the central nervous system affecting young adults. MS is characterized by inflammation, demyelination, and neuroaxonal degeneration. In early histopathological studies, it was demonstrated that MS pathology occurs both in the white and in the gray matter. However, since demyelination in gray matter structures is difficult to visualize with conventional histochemistry, or with conventional magnetic resonance imaging (MRI) techniques, gray matter pathology in MS has until recently been disregarded. As a consequence, MS has been traditionally considered a “white matter disease”. The introduction of newer histopathological staining methods such as myelin protein immunohistochemistry, as well as the implementation of more advanced and quantitative MRI techniques, has shed light on the importance of gray matter pathology in MS in many respects (Fig. 13.1)., In particular, the clinical relevance of gray matter lesions has become more obvious. For example, while global white matter damage have been attributed to more general clinical outcome measures, gray matter changes could also be related to more specific clinical manifestations including cognitive impairment within several different domains and to epilepsy. Gray matter pathology can be observed in early stages of MS, but generally grows more prominent with increasing disease duration.