While there are some similarities to adult populations, there are also unique considerations providers must keep in mind when diagnosing and treating multiple sclerosis (MS) in pediatric patients.

Neurology Learning Network caught up with Scott Otallah, MD, director, Pediatric MS and Demyelinating Clinic, Wake Forest School of Medicine, Salem, North Carolina, on-site at the 52nd Child Neurology Society Annual Meeting to discuss where the field stands and where it may be headed.

In Part 1 of this Q&A, Dr Otallah walks us through some of the factors to keep in mind when diagnosing pediatric MS, as well as some of the “wonderful” therapies available for treatment.

Find Part 2 of this interview here, and visit our Multiple Sclerosis Excellence Forum for more expert insights and research updates.

Brionna Mendoza, Associate Digital Editor, Neurology Learning Network: Could you walk us through some of the key differences in diagnosing MS in pediatric versus adult patients?

Scott Otallah, MD: There are a lot of differences that are very relevant for people who are pediatric demyelinating disease experts versus adult MS experts. That being said, the diagnostic criteria are actually the same. We use the McDonald criteria, which were originally created with pediatric MS expert input for adults and then validated in children, and the most recent version of those criteria are from 2017.

The McDonald criteria do have to be applied with quite a bit of caution for both adult and pediatric patients. The biggest area of danger is that you have to exclude mimics, and excluding mimics can be very difficult. In pediatric MS, there are multiple other pediatric demyelinating diseases that can potentially meet criteria for pediatric MS and lead to misdiagnosis.

In addition, because we are seeing more and more kids get imaging performed for headaches or unrelated symptoms, if you are not aware of what a true demyelinating syndrome should look like clinically, it’s easy to misdiagnose because you might find changes associated with migraine or changes that are congenital or changes from a birth injury that are in the white matter and technically meet criteria. They're in what we call the ‘juxtacortical area,’ the area between the gray and the white matter, or the periventricular area right around the ventricles, or in the brain stem or in the spinal cord.

Those are the 4 areas required for dissemination in space—the different parts of the nervous system that need to be involved in order for to diagnose MS.

So, if you hear a clinical symptom like tingling or fatigue or something of that sort, and don't recognize that it's not necessarily a subacute demyelinating attack, and then you see those lesions, you could think that you meet criteria. The most important thing is to be assessing cases that are consistent with demyelination.

Then, we have mimics that are common, especially in younger kids, like acute disseminated encephalomyelitis (ADEM), where there's a single attack with multifocal lesions. Sometimes those lesions can enhance, they can take contrast, and others won't. If you aren't careful, you could make a single attack of ADEM meet McDonald criteria for pediatric multiple sclerosis.

But I think that making sure that you are including the right patients from the start before applying those criteria is one of the difficult things, and then distinguishing between some of our other demyelinating diseases is also very challenging because pediatric MS patients have lesions on MRI that look more like ADEM than they do like adult MS sometimes.

You have to act and move cautiously when making the diagnosis, especially because our patients with pediatric-onset MS have so many more years of disease in front of them. We're usually talking about lifelong therapy.

Mendoza, NLN: What are some of the most promising therapies available for pediatric MS treatment?

Dr Otallah: Promising is tricky here because we have some wonderful therapies. It's always unfortunate when I have to make a diagnosis of pediatric-onset MS, but I do get to say that the positive thing about even from 15 to 20 years ago when I was going through training, if you ever had to be diagnosed with MS in the history of the world, this would be the time to be diagnosed, because we do have some highly effective treatments. We have our first FDA-approved therapy for MS, fingolimod, which has recently gone generic. That creates its own issues, and I'll discuss this more later.

I think that we have done pretty well at this point with our infusion therapies and with our oral therapies at controlling the inflammatory, relapsing-remitting aspects in the white matter in pediatric-onset multiple sclerosis. Where there is the most room for improvement is for patients who don't respond to any of our current therapies, but thankfully those patients are getting fewer and farther between.

Elsewhere, we are just starting to make an impact is on the neurodegenerative aspect of multiple sclerosis. We've got our first couple [therapies] (which are not so relevant to kids because kids almost always have relapsing-remitting MS). Even at the time of diagnosis, kids with pediatric-onset MS have smaller brain volume than their age match controls. Although their brains continue to grow, their brains peak at a lower point and begin to atrophy earlier.

So, addressing that challenge is, I think, the next important phase. We've got our first couple of drugs for progressive MS in adults. Thankfully, progressive MS almost never happens in kids, but when it does, the risk of secondary progressive MS is very real. Even though the kids thankfully accumulate morbidity more slowly than adults, because they start so much earlier, they are more prone to accumulate morbidity at a younger age than adult MS patients. They are also more likely to go on to secondary progressive MS at a younger age as well.

Editor's Note: This conversation continues in Part 2: Navigating Challenges in Pediatric Multiple Sclerosis Care--find it here!

Scott Otallah, MD, is the Director of the Pediatric Multiple Sclerosis and Demyelinating clinic at Wake Forest School of Medicine in Winston Salem NC.  He is also the Program Director for Child Neurology and the Clerkship Director for the Department of Neurology.