I feel like this is a common problem in neuro diseases. If only we could get an earlier diagnosis, we would have fewer people seriously disabled by these diseases at a young age, while they visit their doctors over and over begging for some sort of help.
MS is very common in Western New York… home of Love Canal and plenty of less-publicized toxic dumping.
Apparently Syracuse is the chart-topper: https://cnycentral.com/news/local/the-ms-mystery-in-syracuse-why-do-we-have-highest-rate-of-multiple-sclerosis-nationwide
Old data (2010), but the 7th page of this pdf shows the northeast generally highest US-wide: https://n.neurology.org/content/neurology/92/10/e1029.full.pdf
“Old data” because a 2019 study doubled the estimate of people living with MS: https://www.nationalmssociety.org/About-the-Society/MS-Prevalence