NEW ORLEANS (FRONTLINE MEDICAL NEWS) – Changes are coming to the current McDonald Criteria for diagnosing multiple sclerosis, primarily because of advances in the understanding of MS since the criteria were last updated in 2010.

Such advances include the availability of new data regarding the relationship between MS and other spectrum disorders and data concerning the performance of the 2010 McDonald Criteria in several patient populations, according to Jeffrey A. Cohen, MD , who cochaired the effort known as the International Panel on Diagnosis of Multiple Sclerosis. “There also were new data concerning the utility of cerebrospinal fluid evaluation and increasing recognition that the role of cerebrospinal fluid (CSF) examination perhaps needs increased emphasis,” Dr. Cohen said at the annual meeting of the Consortium of Multiple Sclerosis Centers. “It’s been somewhat de-emphasized in previous versions of the criteria. Then, there was identification of subsets of patients that were felt to have a high likelihood of MS but in whom the diagnosis could not be made by the current criteria – patients who fell through the cracks. There was also increasing recognition of the frequency and important consequences of misdiagnosis.”

The International Panel on Diagnosis of Multiple Sclerosis was organized under the auspices of the International Advisory Committee on Clinical Trials in MS , and it was funded by the National MS Society and the European Committee for Treatment and Research in Multiple Sclerosis ( ECTRIMS ). Dr. Cohen, director of the Mellen Center for MS at the Cleveland Clinic, cochaired the panel along with Alan J. Thompson, MD . The duo led panel meetings that convened in Philadelphia in November 2016 and in Berlin in May 2017. While Dr. Cohen was unable to provide details about proposed revisions to the 2010 McDonald criteria, he shared some general points that panelists agreed on. The revised criteria currently are being prepared for publication.

The panel emphasized that evidence supporting the McDonald criteria is predominately based on patients with a typical clinically isolated syndrome (CIS) at onset. It also acknowledged the difficulty of confirming a diagnosis of MS, the importance of addressing alternative diagnoses and absence of atypical features and red flags, and the rigor necessary for interpreting clinical, imaging, and laboratory studies. “Misdiagnosis is common,” Dr. Cohen told meeting attendees. “In some series, upwards of 50%-60% of patients referred to a specialized MS center turn out to have some other diagnosis. Our panel had discussions related to the tradeoff between sensitivity of the criteria and trying to make the diagnosis earlier and in a broader range of patients but counterbalancing that against the risk of a misdiagnosis. Our conclusion was that, although some of that might be created by the criteria, it’s mostly a problem of misapplying the criteria. One needs to remember that to make the diagnosis of MS does not merely require demonstrating that the patient has a disease process that involves potentially multiple places in the CNS and as recurrent events over time, but one has to apply the diagnostic data with rigor.”

Another emphasis expected to be included in updated McDonald criteria is the use of CSF and spinal cord imaging, as well as the notion that a history, examination, and synthesis of a patient’s overall clinical picture “needs to be made by a clinician with MS-related expertise,” Dr. Cohen said. “One cannot merely use the criteria as a checklist.”

The panelists also discussed modifying the term “possible MS,” which is already in the McDonald criteria, to include patients with CIS who do not (yet) fulfill the diagnostic criteria for MS; radiologically isolated syndrome (RIS); solitary sclerosis; and patients with clinical manifestations, imaging, and other features that are compatible with MS but not typical for those who may or may not be determined to have MS or in the future.

Dr. Cohen noted that additional data concerning the applicability of the McDonald criteria to Asian and Latin populations have been published since 2010 but are modest. “There is no indication the McDonald criteria cannot be used in these populations,” he said. “Care is needed to address alternative diagnoses, particularly neuromyelitis optica spectrum disorder (NMOSD) in both and also infectious diseases in Latin America.” Several studies also support the applicability of the McDonald criteria in children, with certain caveats. “One needs to be careful in diagnosing MS in people younger than 11 years of age,” Dr. Cohen said. “If the initial event is [acute disseminated encephalomyelitis], they also need to have a typical clinically isolated syndrome.”

Panelists also agreed that the McDonald criteria apply to older patients, with caveats that a new diagnosis of MS is rarely considered in older adults. “They are more likely to have a progressive course, either progressive from onset or following previous unrecognized relapses,” Dr. Cohen said. “There needs to be careful consideration of alternative diagnoses and, particularly, comorbidities. This represents an example of a diagnostic scenario for which CSF examination is advised.”

Panel members found that the recognized range of potential clinical manifestations of NMOSD is becoming wider and is still being defined. “Emerging data suggests a substantial proportion of AQP-4 seronegative patients with NMOSD features (about 20%) have anti–myelin oligodendrocyte glycoprotein antibodies,” he said. “Although some features of MS and NMOSD overlap, they are now understood to be distinct disorders.”

Other points under consideration for the 2017 revision of the McDonald Criteria included incorporating the revised phenotype categories (relapse-remitting, secondary progressive, primary progressive, and progressive relapsing), expanding the role of CSF to allow diagnosis of MS with CIS plus DIS plus oligoclonal bands, determining whether to accept 2016 Revised Magnetic Resonance Imaging in Multiple Sclerosis MRI criteria in aggregate or in part, and incorporating optic nerve involvement.

Dr. Cohen disclosed that he has received compensation as a consultant for Adamas, Celgene, Merck, Mallinckrodt, and Novartis.