[What do we know about the pathology of gray matter in multiple sclerosis].

The emergence of modern methods of immunohistochemistry and further development of MRI has led to a deeper understanding of gray matter (GM) pathology in multiple sclerosis (MS). GM involvement can be extensive including both demyelination (cortical lesions) and neuroaxonal damage. The mechanisms of GM damage in MS remain insufficiently studied. There are two concepts: the lesion of GM is primary and is paralleled by changes in white matter (WM), or secondary, i.e. it is a consequence of the pathological process in WM. More research into GM pathology using the latest MRI techniques will contribute to the understanding of pathological changes in both cortical and subcortical GM.