Roberto Cappellani

Robert Zivadinov

Multiple sclerosis (MS) is a chronic inflammatory disease affecting the central nervous system in young people. Conventional MRI is an important tool not only for determining the early diagnosis of MS but also for monitoring disease progression. However, pathology outside of the focal white matter (WM) and gray matter (GM) lesions, in the so-called “normal-appearing” (NA) WM and NAGM, remains largely undetected by the conventional MRI. This motivated us to investigate the alterations in NAGM and in the subcortical deep gray matter (SDGM) in patients with MS in different stages of disease. Diffusion tensor imaging (DTI) was used to investigate the SDGM pathology and its relationship with lesion burden and WM and cortical atrophy in patients with MS and healthy controls. Our findings suggest significant alterations of DTI diffusivity in NAWM, NAGM, total SDGM, caudate, thalamus, and hippocampus. In addition, SDGM alterations were associated with WM lesion burden and atrophy but not with cortical pathology, which may have different origins.

Generally, in clinical practice patients with MS undergo periodic clinical assessments and conventional MRI scans to evaluate the clinical and radiologic progression of the disease. Unfortunately, the lack of standardized protocols among MRI centers and fully validated and automated quantitative techniques do not permit the incorporation of nonconventional MRI techniques in the clinical routine. However, there is an

increasing body of evidence suggesting that correlations between clinical disability and WM and GM microstructural alterations are useful to predict disease progression, compared with conventional MRI methods. In light of evidence from the current study, the fully validated and automated quantitative nonconventional techniques may become useful additions to the clinical routine standard protocols.

Our study stresses the importance of focusing the attention not only on the assessment of lesion burden in the WM but also on the degeneration of the GM, which may improve the therapeutic management of patients with MS.

It would be important to develop new protocols including measurements of DTI GM alterations, especially in the progressive stages of patients with MS, where the neurodegenerative component prevails over the inflammatory process.

Read this article at AJNR.org . . .