Thanks for the replies. Yes, warm hands helps. A warm climate helps a LOT. Does exercise help? No one knows. It can't hurt.
It is REALLY great to be able to connect with others that have similar experiences. I'm 71 and clearly the old guy in this group. I am going to post a pretty long set of experiences which I hope will be a sober encouragement to the rest of you.
I think we still need to identify some "centers of excellence", as they say in the medical field, where there is experience in diagnosing and treating Hirayama's disease. I WANT TO PLAY MY GUITAR AGAIN!
One point: Hirayama's and SMA (spinal muscular atrophy) are most likely different: SMA is known to be genetic and there is a genetic test. Google it. The Muscular Dystrophy sites have information. I don't think anyone knows exactly what Hirayama's is.