Towards the implementation of 'no evidence of disease activity' in multiple sclerosis treatment: the multiple sclerosis decision model.

Objective: The introduction of new and potent therapies for the treatment of relapsing remitting multiple sclerosis (MS) has increased the desire for therapeutic success. There is growing doubt that the mere reduction of relapse rate, Expanded Disability Status Scale (EDSS) progression and magnetic resonance imaging (MRI) markers are exclusive and appropriate factors to monitor the new aim of 'no evidence of disease activity' (NEDA). However, there is no generally accepted definition so far.

Methods: To achieve the therapeutic aim of NEDA, a panel of MS experts searched the available literature on clinical and paraclinical outcomes to propose a test battery that is sensitive to detect disease activity in an everyday clinical setting.

Results: The panel proposed to include, besides relapse rate, disability progression and MRI, neuropsychological outcome measures such as cognitive status, fatigue, depression and quality of life. To standardize the examinations in an economic and schematic way, a multifactorial model [multiple sclerosis decision model (MSDM)] that includes the domains 'relapse', 'disability progression', 'MRI', and 'neuropsychology' is proposed. The scheme reflects the complexity of the disease even in the early stages when scales such as the EDSS are not able to distinguish low levels of progression.

Conclusion: The MSDM aims to support early treatment decisions and uncover timely treatment failure. Prospective investigations are required to prove that such a disease-monitoring concept leads to an early and effective silencing of disease activity.