CONTEXT AND OBJECTIVE: Patients undergoing the same neuromodulation protocol may present different responses. Computational models may help in understanding such differences.

Multiple sclerosis is the most common autoimmune inflammatory demyelinating disease of the central nervous system, and its etiology is believed to have both genetic and environmental components. Several viruses have already been implicated as triggers and there are several studies that implicate members of the Herpesviridae family in the pathogenesis of MS. The most important characteristic of these viruses is that they have periods of latency and exacerbations within their biological sanctuary, the central nervous system. The Epstein-Barr, cytomegalovirus, human herpesvirus 6 and human herpesvirus 7 viruses are the members that are most studied as being possible triggers of multiple sclerosis. According to evidence in the literature, the herpesvirus family is strongly involved in the pathogenesis of this disease, but it is unlikely that they are the only component responsible for its development. There are probably multiple triggers and more studies are necessary to investigate and define these interactions.

This article describes the clinical and radiological evolution of a stable group of patients with relapsing-remitting multiple sclerosis that had their disease-modifying therapy (DMT) withdrawn. Forty patients, which had made continuous use of one immunomodulator and had remained free of disease for at least 5 years, had their DMT withdrawn and were observed from 13 to 86 months. Out of the followed patients, 4 (10%) patients presented with new attacks. In addition to these patients, 2 (5%) patients had new lesions revealed by magnetic resonance imaging that did not correspond to clinical attacks. Despite these results, the difficult decision to withdraw medication requires careful analysis. Withdrawal, however, should not be viewed as simply the suspension of treatment because these patients should be evaluated periodically, and the immunomodulators should be readily reintroduced if new attacks occur. Nonetheless, medication withdrawal is an option for a select group of patients.