(Medical Xpress)—Multiple sclerosis (MS) patients sometimes experience "natural" improvements in disability at least over the short term, according to a new study led by researchers at the University of British Columbia and Vancouver Coastal Health Research Institute.
The study, published this month in the Multiple Sclerosis Journal, is the first to quantify improvements in disability in patients who are not taking immunomodulatory drugs such as beta interferon drugs or glatiramer acetate.
"Many people assume that MS patients experience only disease progression and an increasing disability," says Helen Tremlett, the study's lead author, an associate professor in the UBC Faculty of Medicine. "While we did observe that no change or a worsening in disability was most common, up to 30 per cent of patients did experience an improvement, and this was often sustained over one to two years."
While there were some patient characteristics more associated with a greater chance of improvement – including being female, younger, and having the relapse-remitting form of the disease – a wide spectrum of patients experienced episodes of improvement.
"To date, no disease modifying drugs for MS that have gained licensed approval for specifically improving or reducing disability in MS," adds Prof. Tremlett, who is also a member of the Brain Research Centre at UBC and VCH Research Institute. "However, we know that these drugs can be very helpful in reducing relapses, so our research provides additional important context for interpreting the findings of clinical trials."
Further research is needed to understand the biological mechanisms underlying these improvements in order to pinpoint possible drug targets, and to determine the potential capacity for drug intervention to enhance and prolong this natural, innate improvement for the benefit of patients.
Canada has one of the highest rates of MS in the world. MS can cause a loss of balance, impaired speech, extreme fatigue, and vision problems, among other symptoms. There are four types of disease progression in MS, which can be characterized as relapsing remitting, primary progressive, secondary progressive, or progressive relapsing.
Anonymized clinical data of 2961 patients with MS residing in British Columbia who visited a B.C. MS clinic between 1980 and 2004 were accessed. Disability in MS patients is measured by the Expanded Disability Status Scale (EDSS) in eight functional systems, including sensory, visual, and cerebellar systems. Consecutive immunomodulatory drug-free EDSS scores one and two years apart were examined. EDSS scores were assessed and recorded after a face-to-face consultation with an MS specialist neurologist. EDSS scores were excluded once an immunomodulatory, immunosuppressant, or MS clinical trial drug was started, or if the score was recorded within one month post-relapse ('attack').
In this study, published first online in June, improvements in disability were measured on the EDSS scale and classified in three ways: any improvement greater than or equal to 0.5 points; an improvement greater than or equal to 1 point; and an improvement greater than or equal to 2 points.