Table 2.
2017 McDonald criteria for the diagnosis of multiple sclerosis in patients with an attack at onset3
| Number of attacks at clinical presentation | Number of lesions with objective clinical evidence | Additional data needed for diagnosis of multiple sclerosis |
|---|---|---|
| ≥2 | ≥2 | Nonea |
| ≥2 | 1 (as well as clear-cut historical evidence of a previous attack involving a lesion in a distinct anatomical location) | Nonea |
| ≥2 | 1 | Dissemination in space demonstrated by an additional clinical attack implicating a different CNS site |
| Or by MRI | ||
| 1 | ≥2 | Dissemination in time demonstrated by an additional clinical attack |
| Or by MRI | ||
| Or demonstration of CSF-specific oligoclonal bands | ||
| 1 | 1 | Dissemination in space demonstrated by an additional clinical attack implicating a different CNS site |
| Or by MRI | ||
| And dissemination in time demonstrated by an additional clinical attack | ||
| Or by MRI | ||
| Or demonstration of CSF-specific oligoclonal bands |
a= no additional tests are required to demonstrate dissemination in space and time. However, unless MRI is not possible, brain MRI should be obtained in all patients in whom the diagnosis of multiple sclerosis is being considered. In addition, spinal cord MRI or CSF examination should be considered in patients with insufficient clinical and MRI evidence supporting multiple sclerosis, with a presentation other than a typical clinically isolated syndrome, or with atypical features. If imaging or other tests (eg CSF) are undertaken and are negative, caution needs to be taken before making a diagnosis of multiple sclerosis, and alternative diagnoses should be considered. CNS = central nervous system; CSF = cerebrospinal fluid; MRI = magnetic resonance imaging.