Relapsing-remitting multiple sclerosis

**Definition:** Clearly defined disease relapses with full recovery or with sequelae and residual deficit upon recovery. The periods between disease relapses are characterised by a lack of disease progression.

**Long definition:** Diagnostic criteria for Multiple Sclerosis, modified McDonald criteria (2010): A) Clinical presentation-2 or more attacks (relapses); 1 objective clinical lesion. Dissemination in space (DIS), demonstarted by MRI (presence of 1 or more T2 lesions in at least 2 out of 4 of the following areas of the central nervous system: periventricular, juxtacortical, infratentorial, or spinal cord) or positive CSF and 2 or more MRI lesions consistent with MS or further clinical attack involving different site. B) 1 attack (relapse); 2 or more objective clinical lesions. Dissemination in time (DIT) demonstarted by MRI or second clinical attack. DIT can be demonstrated by:the simultaneous presence of asymptomatic gadolinium (Gd)-enhancing and non-enhancing lesions at any time; or new T2 and/or Gd-enhancing lesion(s) on follow-up MRI, irrespective of its timing with reference to baseline scan; or await a second clinical attack. C) 1 attack (relapse); 1 objective clinical lesion (clinically isolated syndrome). DIS and DIT demonstrated by: For DIS: 1 or more T2 lesions in at least 2 of 4 MS-typical regions of the CNS (periventricular, juxtacortical, infratentorial or spinal cord); or await second clinical attack implicating a different CNS site. For DIT: simultaneous presence of asymptomatic Gd-enhancing and nonenhancing lesions at any time; or new T2 and/or Gd-enhancing lesion(s) on follow-up MRI, irrespective of its timing with reference to a baseline scan; or await second clinical attack.