Thank you very much for the link to the testing.
The thyroid issue came up about 7 years after he was diagnosed with the PN, so not a cause. I wish it was that easy!!
We live in Canada so no payment required for the "standard" tests. His GP is very good so I think he would help us narrow it down.
Someone else on the list has referred us to a local neurologist that they feel is good so I'm going to pursue that too.
Thanks again, Linda