information:classification
McDonald criteria

The McDonald criteria, which focus on clinical, laboratory, and radiologic evidence of lesions at different times and in different areas, is the most commonly used method of diagnosis with the Schumacher and Poser criteria being of mostly historical significance. The McDonald criteria states that patients with multiple sclerosis should have lesions which are disseminated in time (DIT) and disseminated in space (DIS), i.e. lesions which have appeared in different areas in the brain and at different times. Below is an abbreviated outline of the 2017 McDonald Criteria for diagnosis of MS.

As of 2017, no single test (including biopsy) can provide a definitive diagnosis.