What are the McDonald criteria for a diagnosis of multiple sclerosis (MS)?

Updated: Oct 08, 2019
  • Author: Christopher Luzzio, MD; Chief Editor: Jasvinder Chawla, MD, MBA  more...
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Answer

The McDonald criteria, which were developed in 2001 by an international expert panel and revised several times, most recently in 2017, provide recommendations on the diagnosis of MS, including diagnosis after a single attack. [1] The criteria consist of a combination of clinical, imaging, and paraclinical tests (ie, CSF, evoked potentials). [4] (See Table 1, below.)

Table 1. 2017 Revised McDonald Criteria for the Diagnosis of Multiple Sclerosis [1] (Open Table in a new window)

Clinical Presentation

Additional Data Needed for MS Diagnosis

  • Two or more attacks

  • Objective clinical evidence of 2 or more lesions with reasonable historical evidence of a prior attack

None; clinical evidence will suffice. Additional evidence (eg, brain MRI) desirable,

but must be consistent with MS

  • Two or more attacks

  • Objective clinical evidence of 1 lesion

Dissemination in space demonstrated by MRI or

Await further clinical attack implicating a different site

  • One attack

  • Objective clinical evidence of 2 or more lesions

Dissemination in time demonstrated by MRI or second clinical attack or demonstration of CSF-specific oligoclonal bands

  • One attack

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

Dissemination in space demonstrated by

MRI or await a second clinical attack implicating a different CNS site

and

Dissemination in time, demonstrated by MRI or second clinical attack

  • Insidious neurologic progression suggestive of MS

One year of disease progression and dissemination in space, demonstrated by 2 of the following:

  • One or more T2 lesions in brain, in regions characteristic of MS

  • Two or more T2 focal lesions in spinal cord

  • Positive CSF

Notes: An attack is defined as a neurologic disturbance of the kind seen in MS. It can be documented by subjective report or by objective observation, but it must last for at least 24 hours. Pseudoattacks and single paroxysmal episodes must be excluded. To be considered separate attacks, at least 30 days must elapse between onset of one event and onset of another event.

Key changes made to the McDonald Criteria in 2017 include the following:

  • Brain stem and cord lesions can now be counted among the 2 lesions disseminated in space and time.
  • CSF oligoclonal bands can now be used to substitute for demonstration of dissemination in time in some settings.
  • Both asymptomatic and now symptomatic MRI lesions can be considered in determining dissemination in space (optic nerve lesions are still excluded).
  • Cortical lesions have been added to juxtacortical lesions as determinant for dissemination in space.

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