Pediatric Patients Have Higher Disease Burden at Time of MS Onset

Allison Gandey

September 26, 2008

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Dr. Emmanuelle Waubant discusses the study findings.

September 26, 2008 (Salt Lake City, Utah) — Magnetic resonance imaging findings for pediatric patients with multiple sclerosis (MS) can look misleadingly different from adult patients. These are the findings of a new study presented at the American Neurological Association 133rd Annual Meeting.

While the clinical course of MS is often similar between pediatric and adult patients, lead investigator Emmanuelle Waubant, MD, from the University of California, San Francisco, told the meeting that disease onset may be distinct. Childhood MS is estimated to represent up to 10% of cases.

"Children have a higher disease burden with more frequent posterior fossa involvement at MS onset than adults," Dr. Waubant noted.

"We expect diseases to follow a specific course regardless of age — otherwise, we start questioning whether these are separate disease entities," Dr. Waubant told Medscape Neurology & Neurosurgery during an interview. "But the truth is that in our patients, the clinical course is actually very similar to what we know happens in MS, but the onset can be different."

Dr. Waubant proposes that the brain may react differently to inflammation at younger vs older ages.

Investigators studied the brain MRI scans of 31 pediatric-onset and 31 adult-onset MS patients. They evaluated initial MRI scans for lesions that were T2-bright, ovoid, well-defined, large (1 cm or more), or enhancing. Pediatric patients were 18 years of age or younger.

Findings from MRI Scans In Pediatric vs Adult MS Patients

Outcome Children Adults P
Median number total T2 21 6 <0.0001
Large T2-bright areas 5 1 <0.0001
T2-bright foci (posterior fossa) (%) 74 48 0.037
Enhancing lesions (%) 70 25 0.0008

While it is unknown whether these differences are explained by age or ethnicity, the researchers note, these characteristics have been associated with worse disability in adults.

"This challenges the notion that pediatric MS is benign," Dr. Waubant pointed out. "I think what's exciting is to try now to understand what this means at a biological level. Does this bring new understanding to the disease processes and how best to treat patients?"

Pediatric MS Not Benign

During the question period following the presentation, an attendee asked about the genetic cause of disease. Dr. Waubant explained that about 10% of patients had a first-degree relative with MS, but the number may actually be higher considering many of the families were youngand may not yet have developed disease.

Another attendee wanted to know the age of the youngest patients. Dr. Waubant said that patients were as young as 3 or 4 years old.

It was 1 such patient that inspired the present study, Dr. Waubant tells Medscape Neurology & Neurosurgery. Her team saw a 4-year-old girl with very severe bilateral optic neuritis. The patient's symptoms and workup were consistent with a first episode of MS, but her MRI results were not typical.

"Then her spinal tap started to really look like what we know happens in MS," Dr. Waubant explained. "We were then really convinced that she had MS. She's now been symptom-free for a year since she started interferon."

The research team plans to continue exploring this issue and intends to implement more sophisticated imaging sequences. They hope to better capture the underlying mechanisms for MS and perhaps add some immunology to the study as well.

Investigators point to a number of limitations to the current work, including a potential referral bias, a longer length of time between disease onset and first scan for adults, and no standardized MRI protocol for pediatric patients.

The study was funded by the National MS Society.

American Neurological Association 133rd Annual Meeting: Derek Denny-Brown New Member Symposium. Presented September 23, 2008.


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