New research from Dr. Helen Tremlett, Canada Research Chair in Neuroepidemiology and Multiple Sclerosis (MS), finds that patients’ lives are already altered in a measurable way in the five years before the first demyelinating event. The research, published this week in the Lancet Neurology, suggests the existence of a prodromal period leading up to the onset of specific MS symptoms.

Researchers in four different provinces looked at Canadian health records over a 20-year period and found that, overall, patients who had been diagnosed with MS presented more often to their physicians, were more frequently admitted to a hospital, and filled prescriptions for a greater number of drug classes in the five years before the first demyelinating event as compared with the general population. There was a particularly notable increase in usage the year before MS-specific symptoms appeared.

Other neurodegenerative disorders, such as Parkinson’s or Alzheimer’s disease, have also been shown to have a prodrome in which symptoms can appear several years before the disease is formally recognized.

“We were inspired to look for a prodrome in MS,” says Dr. Tremlett. “Proving that people with MS had been accessing the healthcare system differently prior to the first demyelinating event is very important because it means we have to look beyond those previous five years to understand how the disease begins to manifest.” Going forward, the researchers intend to look at population data to understand why MS patients had been using the health system differently, and whether there are trends in illnesses reported and prescriptions filled that point to a demonstrable set of symptoms leading up to the first demyelinating event.

“There’s something going on here that makes this population of people unique,” says Dr. Tremlett. “It’s early to say what that might be, but when other degenerative brain diseases have a prodrome, it tells you that something may be happening in MS – we just need to know what to look for.”

This research, funded by the National Multiple Sclerosis Society, a US-based organization, is uniquely Canadian – large-scale access to health administrative data, is necessary in order to collect aggregated data on healthcare system usage across the country.

“It’s the kind of research that really benefits from taking place in Canada,” says José Wijnands, co-author on the paper and MSFHR-supported trainee. “Researchers in Canada have access to an incredible collection of data; without this degree of large-scale anonymized health information, seeing these types of patterns would be impossible.”

Read more: Medical history reveals multiple sclerosis begins to impact patients sooner


JMA Wijnands, E Kingwell, F Zhu, Y Zhao, T Högg, K Stadnyk, O Ekuma, X Lu, C Evans, JD Fisk, RA Marrie, H Tremlett. The multiple sclerosis prodrome: health care utilization increases in the five years before a first demyelinating event in a matched cohort study. Lancet Neurology 2017.


This investigation was supported by a research grant from the National Multiple Sclerosis Society (RG 5063A4/1; PI: Tremlett). José M.A. Wijnands receives salary support from the Michael Smith Foundation for Health Research /The Koehle Family Foundation, Ruth Ann Marrie holds the Waugh Family Chair in Multiple Sclerosis, and Helen Tremlett is funded by the Canada Research Chair Program.