The McDonald criteria are the most widely used diagnostic criteria for multiple sclerosis (MS). They combine clinical findings, MRI, and cerebrospinal fluid (CSF) analysis to show that inflammatory lesions in the central nervous system are disseminated in space (DIS) and disseminated in time (DIT)—and that there is no better alternative diagnosis.
Originally introduced in 2001 under the leadership of W. Ian McDonald, the criteria were revised in 2005, 2010 and most recently in 2017 (with additional updates proposed in 2024). The 2017 McDonald criteria remain the core standard in many guidelines and clinical tools, especially for patients with a typical clinically isolated syndrome (CIS)—a first demyelinating neurological event suggestive of MS.
McDonald Criteria for Multiple Sclerosis Diagnosis
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The McDonald Criteria are diagnostic guidelines for Multiple Sclerosis (MS) that incorporate clinical presentation, MRI findings, and cerebrospinal fluid analysis to demonstrate dissemination of lesions in both time and space. First established in 2001 and revised several times (most recently in 2017), these criteria allow for earlier diagnosis of MS while maintaining high specificity.
Key Principles of McDonald Criteria
Dissemination in Space (DIS)
Evidence of MS lesions in at least two of four CNS areas:
- Periventricular
- Cortical/Juxtacortical
- Infratentorial
- Spinal Cord
Dissemination in Time (DIT)
Evidence that new lesions are forming over time, demonstrated by:
- Simultaneous presence of gadolinium-enhancing and non-enhancing lesions
- New T2 or gadolinium-enhancing lesion on follow-up MRI
Note: The presence of oligoclonal bands in CSF can substitute for dissemination in time in patients with clinical evidence of dissemination in space.
