..I wish years ago when I asked my familly dr if it could be vagus nerve, especially with ibs-d and before every rush to bathroom head would tingle and he bluntly, as usual, said: no! Also said no when asked if I had Sojerns (sp?) and he just said no (even tho 2 dentists and optometrist said to ask dr as mouth and eyes so dry, like a desert); and also when I asked if had milk/dairy sensitivity, answer was no. This was at different appointments for other things and just asked the question. Few years later after an antibiotic, and change in meds got the shaking inside and Neurologist even though did interview over zoom based on symptoms and he had me draw a spiral on paper and show it to him said: Internal Tremours, but not why. So I would think could be a variety of reasons? Now I have a laundry list of problems I think I am a "hot potato" with drs and even Nurse Practitioner office I eventually ended up with told me too many contacts/visits: nice way to treat someone almost 80 now!! Glad over the years did meet some amazing doctors!