That's interesting, I hadn't considered it being psychological, it feels far too real. I think it's not psychological because

(a) I didn't expect it to happen after my concussion, so why would I imagine it

(b) it seems to be improving with my other symptoms, though admittedly at a slower pace

(c) when I did get a big jolt last June, it caused a massive relapse, even though the person who jolted me didn't touch my head and the jolt was not bad enough to cause concern amongst the people who saw it. SO in effect I have 'tested' it and found that jolts do in fact cause me more damage than they should.

(d) it seems to be a fairly common experience and I doubt we would all share the same delusion