[Theoretical approach and prognostic significance of high disease activity in multiple sclerosis]

Multiple sclerosis (MS) is an autoimmune inflammatory disease of the central nervous system with demyelination and neurodegeneration. In addition to the inflammatory immune processes that characterise the onset of the disease with relapses, chronic inflammation is also present from the onset of the disease. The catabolic processes induced by chronic inflammation are responsible for the axonal degeneration that causes the progression of the disease. The activity of the disease is well defined, an important prognostic factor, and a determining factor in the indication of disease-modifying therapies. It is important to establish disease activity at the time of diagnosis and to monitor it continuously during patient care, both clinically and radiologically, as it is the basis for deciding on the current treatment. If detected on the basis of the professional guideline, it is necessary to start or switch to a highly effective therapy.