I just skimmed the "causes" and stopped. It is too depressing for me.
My Dad died of secondary complications to Parkinson's which has its own dementia with it. It has the same causes. We suspect farm chemicals/pesticides to be a cause. When I grew up, way back in the 50's we used a ton of pesticides,\. The safety equipment/gear was non-existent.
Every time I forget where I put my keys, I stumble or feel a little vertigo, I worry I am getting Parkinson or Alzheimer's. What will be will be, but I am not going to over worry it, if I can. I know what you are going through. BTW if I was to get it I would try any cure Mexico or Europe has to offer. Whether our FDA says it is legal, helpful or not. I do not want to live and die the way my Dad did. It was terrible, He died 8 years before his body stopped functioning.
Sorry to throw a bummer on everyone's morning, I know what you are going through. Try to live for the day and not let it get you down. I know easier said than done. I pray he does not get it.
Note I grew up in the 50's proving I am way older than you,,,,