Maybe there is no correlation because Lyme disease is severely underreported. A couple years ago, the CDC stated that official numbers were likely underreported by a factor of 10. From 30,000 yearly cases to 300,000 https://www.cdc.gov/media/releases/2013/p0819-lyme-disease.h...

There was also the case of actor/songwriter Kris Kristofferson being misdiagnosed with Alzheimer's for years. He had Lyme. This is anecdotal of course. https://www.cbsnews.com/news/kris-kristofferson-misdiagnosed...