I have been studying two maps concerning the prevalence of MS globally. One had been produced by a group in the UK about five or more years ago and i had studied it at that time. The second is recent and by an international research group.
The maps show that MS is more common nearer to the Poles as indicated by Bombardier about six or seven years ago. This explains to me why sufferers endure more pain and other manifestations of MS during winter months when the Earth has tilted on it’s axis toward the North or South Poles. I am surprised that the international researchers have not spotted environmental changes that are so often mentioned by other research groups.