September 19, 2003
By Joene Hendry
The risk of increased disease exacerbation is doubled in patients with multiple sclerosis after they experience a non-disease related stressful event, according to the findings of a prospective study of adults with relapsing-remitting multiple sclerosis.
"The knowledge that stressful events are associated with disease activity adds important information to the limited insight that patients and their caregivers have on this unpredictable disease," writes R. Q. Hintzen, MD, of Erasmus MC, Rotterdam, the Netherlands and colleagues. They analysed the relationship between self reported stressful events and disease exacerbation and infections in 73 patients, aged 18 to 55 years, with relapsing-remitting multiple sclerosis. The patients were mobile (at most required a cane for walking) and had a score of 0 to 6.0 on the expanded disability status scale. The cohort reported at least 2 exacerbations within 24 months prior to inclusion in the study but had no other serious conditions. The cohort's mental health scores were comparable with a group of individuals with relapsing-remitting multiple sclerosis who were not study participants.
The investigators defined an exacerbation as a worsening of existing symptoms or the appearance of new symptoms lasting more than 24 hours after a minimum of 30 days of improvement or stability. Over an average follow up of 1.4 years, 70 of the 73 participants reported at least one stressful event, as tallied in weekly diaries, for an overall total of 457 events.
A total of 134 disease exacerbations occurred in 56 patients and a total of 136 episodes of infections occurred in 57 patients, for an average of 1.3 exacerbations or 1.3 infections per year. A Cox univariate regression analysis revealed that the risk of exacerbation was 2.2 times higher during the 4-week period after a stressful event. The risk for a second exacerbation was increased 2.7 times after a 4-week period in which a stressful event occurred.
Analysis of the increased risk of exacerbations related to infections shows a relative risk of 2.9 for the first exacerbation, 2.7 for the second, and 3.2 for a third exacerbation related to infection. The period of high risk related to infection begins 2 weeks prior to the onset of infection and continues until 5 weeks post infection.
The investigators note that in this study the patients were regularly evaluated at close intervals, additional evaluations were arranged in cases of infection or exacerbation, and all relapses were confirmed by a physician. Their findings indicate that stress and infection were independently associated with an increased risk of disease exacerbation.
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