Thanks Jo and Mark for your replies.

Indeed, I saw a chiro for several sessions before I first went to my family doctor, when my cognitive symptoms were getting worse. I've been regularly seeing an osteopath. Though perhaps it would be wise to see an upper spine and neck specialist as you suggest.

I decided not to go to Asia. It was a difficult decision as going was congruent with my previous values. But now health is taking on much more importance. As I read this forum and the Brainlash book, I get the sense that wisdom lies in taking very good care of oneself, even when symptoms abate (and they are, slowly), and that this will pay dividends later on.

Best wishes,
Henry