Yes, it sounds familiar, but with some variation. After prolonged very high dose shots or sublingual (without swallowing for 1/2 hour or so) methylcobalamin and adenosylcobalamin, the tremors and odd nerve sensations became intermittent until the doses were lowered, then it crept up again. Yes, laying flat and still and waiting it out is the only short-term way I know of to relieve it without the help of a doctor whenever it comes up again, and for long-term without the help of a doctor is raising the OTC b12 doses. Also, when it gets to be intermittent, keep a watchful eye on any factors that may trigger a worsening - drug reactions, exertion, etc. You are fortunate that your doctors are taking you seriously so soon and actually doing test after test until they find what's wrong instead of brushing you off to psych. I hope you find that the MG treatments help these symptoms better and faster than the above methods.

Just an aside, but I've heard that 'electric shock' sensations are seen in MS, but it sounds like you're in good hands so your Neuro will pick up what's happening over time and has already been on top of MRI's. Diagnoses are harder with atypical things and things in early stages, but it's great you're getting tested early, so you're likely to get treatment to slow, stop, or reverse symptom progression.