i'm surprised your mri came back clean if you had lhermitte's.. did they do both brain and spine mri?
as for moving forward, from where i sit i'd have to know more about history, dietary preferences/habits and lifestyle, and any other symptoms or health issues that you may have but have not mentioned specifically when you mention the tingling burning issues.
other than that, if you don't already, i'd start keeping a journal of symptoms and timing, so that you have something to take to appointments with any other specialists you might visit.
has your neuro ruled out a peripheral cause for your symptoms, as opposed to central?
bahaha world without zinc https://www.youtube.com/watch?v=U1iCZpFMYd0