Identifying and Treating Disparate Causes of MS
In the past few years, vitamin D has been the focus of many MS researchers. Some studies have found evidence of an interaction between low vitamin D and a common MS genetic variant, called DRB1*1501. The combination appears to boost the risk of getting the disease.
Low vitamin D is viewed by some experts as a potential environmental trigger. "About 35% of all North Americans have low vitamin D," Weiner says. There is some evidence, he says, that MS patients have even lower vitamin D than the general population.
''If you measure vitamin D during an acute [MS] attack, the vitamin D levels go way down," Weiner says. When a patient is in remission, the levels are closer to normal, says Weiner, who has received grants from Teva for basic science research and consulted for Biogen Idec and Merck Serono.
''Clinically, we treat everyone the same," Weiner says. ''We need to think more broadly." MS, he says, maybe caused by multiple factors -- low vitamin D in one person, something else in another person, and understanding the various causes could lead to targeted treatments.
Perhaps the most controversial idea about the potential cause of MS is one proposed by Paolo Zamboni, MD, of the University of Ferrara. He suggests that an abnormality in blood drainage may contribute to the nervous system damage of MS. The condition, called chronic cerebrospinal venous insufficiency or CCSVI, may cause changes in blood flow patterns within the brain, in turn causing brain tissue injury and neuron degeneration, he proposes.
The ''fix" is inserting a tiny balloon or stent in the vessel to improve blood flow. The technique continues to be studied by researchers, including scientists at Stanford University and the University of Buffalo.
But many MS experts are skeptical. ''I can't see how anyone can claim this is what is causing MS," Calabresi tells WebMD. In the ongoing Buffalo research, more than half of MS patients were found to have the condition. But so did more than 20% of the healthy patients, Calabresi says.