MEDICAL RESEARCH vs. MEDICAL REPORTING
—a continuing series—
Science is a search for proofs; journalism aims to get attention. Exaggerated claims increase readership; research studies are more finely nuanced. We seek the common ground.
Multiple sclerosis, a disease that tends to surface in young adulthood, is dependent on the weather, or at least the seasons. A study by a group at Boston, Massachusetts’ Brigham and Women’s Hospital and elsewhere discovered that the illness is less active in the colder months.
The research team found, wrote senior author Dr Dominik Meier for the August 31, 2010 scholarly journal Neurology, that the number of MS lesions to be “two to three times higher in the months of March to August..."
These lesions—scar tissue—in the brain, optic nerve and spinal cord disrupt messages sent through the body’s electrical network. The sclerosed material interrupts the signals both coming and going through the central nervous system. When they can’t make it through, the result can be everything from mild numbness, to blindness and paralysis.
The scarring can be seen on an MRI. This group of researchers looked at almost a thousand of these brain scans saved from the 1990s. This was before present-day treatments that slow the progression of MS. The forty-four 25 to 52 year-old MS-patients living in the Boston area back then were an uncontaminated group.
Each had an average of 22 scans over a two-year period. The scientists tracked the level of scar tissue against seasons, daily temperatures, solar radiation, rainfall. While there was no tie-in with rainy days, there was a parallel between warm weather, season and solar radiation and the number of lesions. “The observed activity pattern,” they wrote, “is suggestive of a modulating role of seasonally changing environmental factors or season-dependent metabolic activity."
The results don't comment on the seemingly contrasting fact that, of the 2.5 million people with the condition, most live in colder climes. MS shows up most in geography far from the Equator; worldwide it's less frequent in the tropics and sub-tropics.
Yet on an individual basis, for a reason still to be discovered, lesions and warm weather seem to go together.
"Seasonal prevalence of MS disease activity." D.S. Meier, K.E. Balashov, B. Healy, H.L. Weiner, and C.R.G. Guttmann. Neurology, 31 August 2010, Volume 75, Issue 9, pp 799-806. Neurology, 31 August 2010, Volume 75, Issue 9, pp 799-806.