I haven't been diagnosed yet, but let me tell you what's been going on and see what you think.
about a month ago, I had that buzzing sensations all over my body and some extremely painful muscle spasms along with stiffness. I could barely walk. Two weeks ago, at my request, my PCP prescribed baclofen. I started taking it and it worked great. No more spasms or buzzing.
Two nights ago, the buzzing started again in my hands, arms, legs, feet, and face. I didn't think much about it, but last night, the muscle spasms came back with a vengence! I am in so much pain today, I could almost scream. I increased my dosage of baclofen (I'm currently taking 20 mg, but can raise it to 40 mg if I need it), but it's not helping much. These spasms are much worse than before, and I'm also having blurred vision again.
If I do have MS and this is another flare, then I'd say yes, the buzzing can indicate an impending relapse. Just my opinion, of course.