New treatment measurements for treatment effects on relapses and progression.

Multiple sclerosis (MS) is considered to be a two stage disease: a first stage in which inflammatory phenomena are crucial and a later one in which degenerative processes become the hallmark. The role of magnetic resonance imaging (MRI) is nowadays of great help both to establish the diagnosis and to rule out other conditions. At the clinically isolated syndrome (CIS) stage, MRI is an important tool both to predict the appearance of a second attack or the development of disability at long term. In the relapsing-remitting (RR) phase of the disease conventional MRI is probably less helpful to predict future relapses and disability. Cross sectional and longitudinal studies have shown very weak correlations between lesion burden on brain T2 and disability in the progressive forms of MS. Regarding T2 burden of disease, a plateau effect for EDSS values greater than 4.5 has been observed. Measures related to brain or spinal cord atrophy together with MR Spectroscopy, Magnetization Transfer Imaging and Diffusion Tensor Imaging may be useful in the future to better monitor disease progression in the late degenerative phase of the condition. MRI has also been of great help in monitoring the effect of immunomodulatory drugs in CIS or RRMS clinical trials. Its role to predict treatment response is still controversial on an individual basis.