Prevalence and characteristics of aggressive MS identified

A recent study has found that older men with primary progressive multiple sclerosis may have a higher risk for developing an aggressive form of the disease. The discovery was led by Dr. Suresh Menon, Dr. Helen Tremlett and Dr. Tony Traboulsee, researchers with the Brain Research Centre at UBC Hospital and VCH Research Institute (VCHRI).

This study is one of the first to identify and describe patients with aggressive MS through the use of three clearly defined, unambiguous criteria*. Based on Expanded Disability Status Scale (EDSS) scores, the study criteria for aggressive MS may be used by others to assess a patient’s health status.

“We identified between 4-14% of patients as having aggressive MS, depending on which definition we used,” says Dr. Suresh Menon. “We also found that one in seven patients who developed MS before age 40 required assistance to walk by the time they reached 40 years old.”

Aggressive MS has a rapid disease course, leading to significant disability in multiple neurologic systems in a relatively short time after disease onset. There are typically three disease courses in MS—relapsing remitting, primary progressive, and secondary progressive. The classification of MS as aggressive or benign is largely based on the speed at which the disease progresses.

“Very little is known about the prevalence or incidence of aggressive MS, despite it being the most challenging type to deal with,” says Dr. Tony Traboulsee, also Head of the MS and Neuromyelitis Optica Programs at UBC Hospital and VCHRI. “This study will help us better understand the treatment needs of patients with aggressive MS, as well as help to better inform the planning of future experimental clinical trials and other research studies.”

While older men initially diagnosed with primary progressive MS might have higher odds of developing the aggressive form of the disease, the research team also found that three out of every five patients with aggressive MS were younger women initially diagnosed with the relapsing remitting form. This highlights the variability of MS in affecting a broad demographic.

The study was published online June 6, 2013 in the Journal of Neurology, Neurosurgery, and Psychiatry.


* The EDSS measures levels of disability in patients by assessing eight functional systems, and provides a score between 0 and 10. The researchers accessed clinical data of 5891 anonymous patients with MS residing in BC who visited a BC MS Clinic between 1980 and 2009. Using this data the research team developed three criteria for aggressive MS: 1. patients who reached an Expanded Disability Status Scale (EDSS) score ≥ 6 within five years of MS onset; 2. patients who reached an EDSS score ≥ 6 by age 40; and 3. patients who reached secondary progressive MS within three years of a relapsing onset-course.

Disability in MS patients is measured by EDSS in eight functional systems, and provides a score between 0 and 10. A score of six means a walking aid is required. In this study, patients without an EDSS score were excluded.

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