McDonald criteria for diagnosis of Multiple Sclerosis

Clinical Presentation

Additional Data Needed

• 2 or more attacks (relapses)
• Objective clinical evidence of 2 or more lesions, or of 1 lesion with historical evidence of prior attack^a

• 2 or more attacks
• Objective clinical evidence of 1 lesion

• Presence of 1 or more T2 lesions in at least 2 of 4 of the MS typical areas of the CNS: Periventricular, juxtacortical, infratentorial, or spinal cord;^b
• or: Await a further attack implicating a different CNS site.

• 1 attack
• Objective clinical evidence of 2 or more lesions

• Simultaneous presence of asymptomatic gadolinium-enhancing and non-enhancing lesions at any time;
• or: A new T2 and/or gadolinium-enhancing lesion(s) on follow-up MRI, irrespective of its timing with reference to a baseline scan;
• or: Await a second clinical attack. [This allows for quicker diagnosis without sacrificing specificity, while improving sensitivity.]

• 1 attack
• Objective clinical evidence of 1 lesion (clinically isolated syndrome)

• 1 T2 lesion in at least 2 of 4 MS-typical regions of the CNS (periventricular, juxtacortical, infratentorial, or spinal cord);
• or: Await a second clinical attack implicating a different CNS site;and:

For dissemination in time:

• Simultaneous presence of asymptomatic gadolinium-enhancing and non-enhancing lesions at any time;
• or: A new T2 and/or gadolinium-enhancing lesion(s) on follow-up MRI, irrespective of its timing with reference to a baseline scan;
• or: Await a second clinical attack.

• Insidious neurological progression suggestive of MS (primary progressive MS)

1. Evidence for dissemination in space in the brain based on 1 or more T2 lesions in the MS-characteristic regions (periventricular, juxtacortical, or infratentorial)
2. Evidence for dissemination in space in the spinal cord based on 2 or more T2 lesions in the cord
3. Positive CSF (isoelectrical focusing evidence of oligoclonal bands and/or elevated IgG index)