Pathophysiology and Imaging Diagnosis of Demyelinating Disorders

The spectrum of "demyelinating disorders" is broad and it includes various disorders with central nervous system (CNS) demyelination[...].

growing evidence that comorbidities may increase relapse rate and disability progression [10][11][12][13][14]. Painful paresthesias are part of the MS symptomatology; however painful sensations can be seen in other conditions co-existing with MS and may lead to diagnostic confusion. The review article by Purvis et al. focuses on the concurrent presence of cervical spondylotic myelopathy in MS patients that is commonly seen in everyday clinical practice and evaluates the results of decompressive surgery on pain management and quality of life in this population. The need for a comprehensive approach and multidisciplinary collaboration is emphasized [15].
Pathophysiology of demyelinating disorders is complex and not very well understood. The contribution of B-lymphocytes has been increasingly acknowledged, in addition to the traditional view regarding the role of T-lymphocytes in demyelinating pathophysiology. There are various B and T subsets, as well as different cell populations that are key players in the immune response and their involvement has been further investigated.
In this special issue, three review articles discuss MS pathogenesis and address old and new knowledge. In a very comprehensive review by Dargahi et al., the pathophysiology of MS is explained and the role of specific cells, including T and B-lymphocytes and their subsets, macrophages, microglia, natural killer and dendritic cells, in the pathogenesis of demyelination is further analyzed [16]. Kinzel et al. review the role of humoral immunity in demyelinating disorders and further explore the role of peripheral CNS-specific antibodies in initiating a cascade of events that lead to CNS demyelination [17]. As MS encompasses both an inflammatory and a neurodegenerative component, with neurodegeneration being more prominent later in the disease course and especially during the progressive stage and associated with disability, Salapa et al. discuss the role of neuronal and axonal damage in MS, emphasize the multifactorial nature of neurodegeneration and summarize potential mechanisms that contribute to neuro-axonal injury. [18].
A new, deep insight into MS pathogenesis may promote novel neuroprotective and remyelinating therapeutic strategies. The review by Bose focuses on a very specific population of cells in MS pathophysiology, the T, B and resident memory cells, their role in MS pathophysiology, the effect of the disease modifying agents on this cell population and their potential of being a therapeutic target [19]. Lisak and Benjamins review melanocortins and their receptors (MCR), and analyze the direct effect of melanocortins on the CNS (neurons and glia) as well as their effect on the immune cells in the periphery. The role of adrenocorticotropic hormone (ACTH) in treating MS relapses is discussed and comparative efficacy results between ACTH and intravenous steroids from clinical trials are presented. In this review article, future research targets are explored and the potential for developing innovative neuroprotective therapies involving MCR agonists is highlighted [20]. As there is growing interest in cell-based therapeutic strategies for MS [21], more research is needed. Emerging immunotherapeutic approaches, such as stem cells, nanoparticles, mannan, DNA vaccines, altered peptide ligands and cyclic peptides, are presented by Dargahi et al. [16], after reviewing current and approved disease-modifying agents.

Conflicts of Interest:
The author declares no conflict of interest.