Very interesting indeed, I know exactly what you mean in that you start looking at what seems like a microscopic level across your entire body for any weird sensations when you bend your neck down. And you're 100% right, I bet most people would notice something if they tried it. The first night I read about bending your neck down as a test for MS was the first time I ever felt anything, I tried it multiple times, felt nothing, then a few hours later BAM. I imagine then it had something to do with stretching a muscle too much in my neck or tugging on a nerve that honestly would never have been touched otherwise, how often do you bend your neck down to your chest entirely? I don't think I would ever really do it. And yes, it's very infrequent for me, often I can only feel it the first time I bend my head down then the times after that it fades or doesn't re-appear. I have a good friend who was diagnosed with MS last year and she said it is a very disturbing feeling that ran down her back, that it was very hard to describe.
Needless to say this really screwed me up over the past 6 months, anxiety like I could never believe, and I'm suffering the fallout from it now. I have repetitive stress injury in my right hand and it spasms now and again, which causes me to immediately think parkinsons, etc. Then these little numb spots, as if there couldn't be more going wrong with me, I think to myself. When in reality this neck buzzing thing for me, is very minor, I would probably never notice it unless I had read about it on the net. Often I wonder where I would be if I hadn't!
Thanks for your feedback