Key opinion leaders in the management of MS comment on the current diagnostic criteria and discuss the importance of ruling out other common mimics in pediatric patients.
Tanuja Chitnis, MD: MS [multiple sclerosis] is diagnosed using the McDonald criteria; these are a set of guidelines that started developing in 2001, and there have been several iterations, with the most recent being in 2017. In general, MS can be defined by a couple of different ways. One must first show that there is dissemination in space, meaning there are different lesions in different parts of the brain. The McDonald criteria say you have to have at least 2 areas of the brain affected. The other part that needs to be confirmed is dissemination in time; there has to be different lesions of different periods. Now, this might be fulfilled by having 2 attacks at different times, having a follow-up MRI that shows a new MRI lesion, or having 1 MRI that shows both nonenhancing and gadolinium-enhancing lesions. The most recent iteration of the McDonald criteria also said that you could substitute in for some of these MRI criteria CSF [cerebrospinal fluid] oligoclonal bands; that is now included in the diagnostic criteria for MS. These have largely been adopted for pediatric MS, and it’s important to note that it should be the best diagnosis fitting the clinical scenario. We recognize that there are some scenarios where you can have MRI lesions in these different areas, but really the clinical syndrome has to also fit.
The differential diagnosis of pediatric MS is fairly broad; one of the most important areas to differentiate are other autoimmune diseases. This includes, but is not limited to, the emerging disease MOGAD [myelin oligodendrocyte glycoprotein–associated disease], which can be tested for by MOG antibodies; as well as neuromyelitis optica, which can also be tested for using aquaporin-4 antibodies. There are a number of other autoimmune syndromes, including lupus, antiphospholipid antibody syndrome, and others that can mimic pediatric MS; these are important to consider and take into account. The other areas that one should consider are infectious diseases; rarely some infectious diseases can mimic pediatric MS. I would examine the CSF very carefully for any evidence of viruses and/or bacteria or fungus infections. Another entity to also consider is tumors. Sometimes we do see large tumefactive lesions, and it’s very important to rule out any sort of malignancies. There is a very broad differential; we also have to think about nutritional disorders, including B-12 deficiency, and other ischemic disorders. Sometimes ischemic stroke-like syndromes caused by autoimmune conditions can also be mimics of MS.
Lauren B. Krupp, MD: The diagnosis of MS in the pediatric age group shares many similarities with how one makes the diagnosis in adults, with the exception being that pediatric patients with MS almost never present with a progressive course. This is a big difference between pediatric and adult MS; if you get a history of progressive decline, either in school performance, walking or dexterity, and there’s no break or improvement, while that could be the history of an adult with primary progressive MS, that subtype in the pediatric age is extraordinarily rare. You want to rule out diagnosis like leukodystrophy or a genetic disorder that could present in that kind of fashion.
Transcript Edited for Clarity