By Laura Eggertson

When Dr. Ruth Ann Marrie entered medical school, no therapies existed to treat Multiple Sclerosis.

The chronic autoimmune disease, which interrupts the connection between the brain and body by destroying the protective coating around nerve fibres and the fibres themselves, affects up to 100,000 people in Canada.

“On a per capita basis, Canada has one of the highest prevalences in the world,” says Dr. Marrie, who graduated from Dalhousie’s medical school in 1996.

Today, as Dr. Marrie assumes the Multiple Sclerosis Clinical Research Chair at Dalhousie’s Faculty of Medicine and becomes the university’s first Gillian’s Hope MSologist, there are more than 15 therapies available to help people with MS, including the first disease-modifying drugs.

On-going work to change the diagnostic criteria for the disease means people are getting their diagnoses more quickly, and researchers have identified more than 230 genes that contribute to the risk of MS.

Clinicians now also know that people’s co-existing conditions are also critical to the way they experience MS, and how severe its effects can be.

That realization is due to Dr. Marrie, whose effect on the field of MSology – the study of MS – has been transformational.

Twenty years ago, when Dr. Marrie had finished her neuroimmunology training at the Cleveland Clinic, she was treating a patient at an MS clinic.

Terrible fatigue

The man, who was about 50, had terrible fatigue.

“I was trying to sort out what drove that, because fatigue can be related to the MS or other factors,” she remembers.

Looking at his chart reminded Dr. Marrie that her patient had severe emphysema, a lung disease that was likely worsening his fatigue. But there was almost no information in the literature surrounding MS about the impact of emphysema or any other co-existing conditions on patients, or any strategies around holistic treatment.

She wondered how many of the symptoms and variation in outcomes she was seeing in people with MS was related to the influence of their other conditions on MS.

That question spawned Dr. Marrie’s PhD dissertation and the next two decades of her work on the frequency and effects of co-existing conditions. Her research is paving the way for personalized medicine approaches that could stop disease progression or even prevent MS altogether.

Dr. Marrie’s research showed that depression, diabetes, high blood pressure, heart disease and high cholesterol increase both the amount of disability people with MS experience at diagnosis, and the disease’s progression, as well as shortening people’s lifespans.

Her recent collaboration analysing 17 clinical trials in MS indicates that 25 percent of people have at least 1 other condition, another 11 percent had two other co-existing conditions, and six percent had three or four co-existing illnesses.

“It becomes a bigger and bigger issue as people age with their disease,” she says.

MS is also associated with higher rates of depression and anxiety disorders.

Warning phase

Thanks to Dr. Marrie and her team, neurologists are now also recognizing that before people experience typical symptoms, they may have a 5- to 10-year warning phase that consists of worsening mood, fatigue, pain, and other sensory symptoms.

“The opportunity that warning phase offers if we can fully characterize and pick it out, is to potentially intervene before people have a first typical symptom of MS,” Dr. Marrie says. “We’re in the early stages, but that is a very important finding.”

The National Multiple Sclerosis Society recognized Dr. Marrie’s impact in 2023, when the Society awarded her the Barancik Prize for Innovation in MS Research.

“Dr. Marrie brings her perspective as a neurologist to ask research questions that are very relevant to improving people’s quality of life and providing answers that will increase our ability to stop and even prevent MS in the future,” Dr. Bruce Bebo, the Society’s Executive Vice-President of Research Programs, said when announcing the award.

“She is also incredibly generous and very effective as a volunteer who provides critical leadership to MS research initiatives on a global scale.”

Dr. Marrie, who grew up in Halifax and earned her undergraduate as well as her medical degree at Dalhousie, returned to take up the Chair in September after spending 17 years at the University of Manitoba.

The Chair is supported through the Gillian’s Hope Fund, which philanthropist Margot Spafford established in 2014 to honour her friend Gillian Morrow’s decades-long journey with multiple sclerosis.

Becoming the Gillian’s Hope MSologist will enable Dr. Marrie to pursue her research full-time, rather than splitting her research time and clinical practice.

In addition to developing her work on MS and co-existing conditions, Dr. Marrie wants to explore the role other factors, such as social determinants of health and aging, play in the variation of symptoms people with MS experience. Her findings could also help tailor treatments.

She’s also passionate about informing people that smoking, childhood obesity, vitamin D deficiency, and the Epstein-Barr virus, which may also result in infectious mononucleosis, heighten people’s risk of developing MS.

Through her work at Dalhousie, Dr. Marrie will collaborate with Nova Scotia Health and other research partners around the world to continue to explore the impact of MS, the factors that lead to the disease and its expression in individuals, and the improvements in health services required to better diagnose, treat, and prevent the disease.

She’ll do it all from her new home in Chester, closer to her parents and extended family.

“It’s good to be home,” she says.