McDonald criteria

The McDonald criteria are diagnostic criteria for multiple sclerosis (MS). These criteria are named after neurologist W. Ian McDonald. In April 2001 an international panel in association with the National Multiple Sclerosis Society (NMSS) of America recommended revised diagnostic criteria for MS. They discourage the previously used terms such as "clinically definite" and "probable MS", and propose as diagnostic either "MS", "possible MS", or "not MS."^[1]

They make use of advances in MRI imaging techniques and are intended to replace the Poser criteria and the older Schumacher criteria. The new criteria facilitate the diagnosis of MS in patients who present with signs and symptoms suggestive of the disease. These include monosymptomatic disease, disease with a typical relapsing-remitting course or insidious progression but no clear attacks and remissions.

The McDonald criteria for the diagnosis of multiple sclerosis were revised in 2005 to clarify exactly what is meant by an "attack," "dissemination," a "positive MRI," etc.^[2]

Any diagnostic criteria relies on definition or another more basic criteria. The original article of McDonald states that "MS is a clinical entity and therefore should be diagnosized with clinical and paraclinical criteria"^[1]. Nevertheless they acknowledge the existence of lesion-based MS definition saying that some other groups consider that "the only proved diagnosis of MS can be made upon autopsy, or occasionally upon biopsy, where lesions typical of MS can be directly detected through standard histopathological techniques".^[1]

Currently, McDonald criteria is regarded as the gold standard for MS diagnosis.

Diagnostic Criteria

Clinical Presentation	Additional Data Needed
* 2 or more attacks (relapses) * 2 or more objective clinical lesions	None; clinical evidence will suffice (additional evidence desirable but must be consistent with MS)
* 2 or more attacks * 1 objective clinical lesion	Dissemination in space, demonstrated by: * MRI * or a positive CSF and 2 or more MRI lesions consistent with MS * or further clinical attack involving different site
* 1 attack * 2 or more objective clinical lesions	Dissemination in time, demonstrated by: * MRI * or second clinical attack
* 1 attack * 1 objective clinical lesion (monosymptomatic presentation)	Dissemination in space demonstrated by: * MRI * or positive CSF and 2 or more MRI lesions consistent with MS and Dissemination in time demonstrated by: * MRI * or second clinical attack
Insidious neurological progression suggestive of MS (primary progressive MS)	One year of disease progression (retrospectively or prospectively determined) and Two of the following:    a. Positive brain MRI (nine T2 lesions or four or more T2 lesions with positive VEP)    b. Positive spinal cord MRI (two focal T2 lesions)    c. Positive CSF

Criticism

McDonald criteria have been shown to have a low sensitivity and specificity (respect the presence of lesions) in Asiatic populations.^[3] They present instead a good behaviour (respect CIS to CDMS conversion) when evaluated in non-selected populations^[4].

Some other authors consider McDonald criteria as an attempt for a clinical definition and propose a pathological definition instead. According to Hans Lassmann, the pathological definition should be preferred because the clinical definitions have problems with differential diagnosis.^[5]. Besides, subclinical MS cases would not be accepted as MS cases by this criteria^[6]

Finally McDonald also states "objective evidence of dissemination in time and space of lesions typical of MS is essential in making a secure diagnosis, as is the exclusion of other, better explanations for the clinical features". Therefore, when used as a definition, the McDonald criteria is defining MS just by exclusion of other diseases.

2010 Revisions

In 2010, the International Panel on Diagnosis of MS met in Dublin, Ireland for a third time to discuss and revise the McDonald diagnostic criteria above.^[7] Reasons for revisions to the criteria included the simplification of demonstration of CNS lesions in space and time via imaging, and the above criticisms that the previous criteria did not appropriately apply to non-Western Caucasian populations.^[7]

Revised Diagnostic Criteria (2010)

Clinical Presentation	Additional Data Needed
* 2 or more attacks (relapses) * 2 or more objective clinical lesions	None; clinical evidence will suffice (additional evidence desirable but must be consistent with MS)
* 2 or more attacks * 1 objective clinical lesion	Dissemination in space, demonstrated by: * MRI * or a positive CSF and 2 or more MRI lesions consistent with MS * or further clinical attack involving different site. New criteria: Dissemination in Space (DIS) can be demonstrated by the presence of 1 or more T2 lesions in at least 2 of 4 of the following areas of the CNS: Periventricular, Juxtacordial, Infratentorial, or Spinal Cord.
* 1 attack * 2 or more objective clinical lesions	Dissemination in time (DIT), demonstrated by: * MRI * or second clinical attack New criteria: No longer a need to have separate MRIs run; Dissemination in time, demonstrated by: Simultaneous presence of asymptomatic gadolinium-enhancing and nonenhancing 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 * 1 objective clinical lesion (clinically isolated syndrome)	New criteria: Dissemination in space and time, demonstrated by: For DIS: 1 or more 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 DIT: Simultaneous presence of asymptomatic gadolinium-enhancing and nonenhancing 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)	New criteria: One year of disease progression (retrospectively or prospectively determined) and two or three of the following: 1. Evidence for DIS in the brain based on 1 or more T2 lesions in the MS-characteristic (periventricular, juxtacortical, or infratentorial) regions 2. Evidence for DIS in the spinal cord based on 2 or more T2 lesions in the cord 3. Positive CSF (isoelectric focusing evidence of oligoclonal bands and/or elevated IgG index)

References

1. ^ ^{a b c} McDonald WI, Compston A, Edan G et al. (2001). "Recommended diagnostic criteria for multiple sclerosis: guidelines from the International Panel on the diagnosis of multiple sclerosis". Ann. Neurol. 50 (1): 121–7. doi:10.1002/ana.1032. PMID 11456302. http://www.msdiagnosed.org/McDonald.pdf. 
2. ^ Polman CH, Reingold SC, Edan G et al. (2005). "Diagnostic criteria for multiple sclerosis: 2005 revisions to the "McDonald Criteria"". Ann. Neurol. 58 (6): 840–6. doi:10.1002/ana.20703. PMID 16283615. 
3. ^ Proposed modifications to McDonald diagnostic criteria for Asians with multiple sclerosis, HT Chong et al, Neurology Asia 2006; 11 : 87 – 90
4. ^ Alexandre S. Fortini, Cerebrospinal Fluid Oligoclonal Bands in the Diagnosis of Multiple Sclerosis, Immunopathology, DOI: 10.1309/Y5VFF2UAW0RK5W63
5. ^ H. Lassmann, Acute disseminated encephalomyelitis and multiple sclerosis, doi: 10.1093/brain/awp342, [1]
6. ^ G V McDonnell et al, Clinical presentation of primary progressive multiple sclerosis 10 years after the incidental finding of typical magnetic resonance imaging brain lesions, Mult Scler April 2003 vol. 9 no. 2 204-209, doi: 10.1191/1352458503ms890cr
7. ^ ^{a b} Polman, Chris et al. (2011). Annals of Neurology. Diagnostic criteria for multiple sclerosis: 2010 Revisions to the McDonald criteria. doi: 10.1002/ana.22366