Bicep jerk

Hi

I have a jerk in my right bicep.  That is, my arm has a jerky movement.  It is only in vertical motion and is much less severe in horizontal motion.  Brain MRI is clear,  cervical MRI shows osteophytes at C4/5 and C6/7 with some disc bulging, Blood tests shows B12 deficiency, brachial plexus MRI is clear.  There is no pain, tingling or numbess and it is worse after physical stress (ie bicep curls at gym) and emotional stress.  One neuro put me on Topomax (topamax) which did nothing apart from bad side effects.  Currently having acupuncture as he suspects it is nerve impingement in the arm itself.  Any help would be appreciated.