I've felt every sensation possible in my extremities as well as down my spine, on my head, my chest, abdomen, etc...
I've felt twitching, burning, cold, hot, electrical shock sensations, buzzing, numbness, you name it!
I also have tremendous worry about MS and ALS but what helped me is looking up actual people who have been diagnosed with MS and seeing what they experienced at the onset of their symptoms. It seems that blurred vision is extremely common as well as localized twitching or buzzing. Most people report feeling numbness/buzzing/twitching in one leg or one hand.
I don't think I have MS and I don't think you do either! Anxiety and constant release of stress hormones can really make your nervous system completely out of sorts. Do you shiver/tremble during episodes of anxiety/panic attacks? I do and afterwards, my muscles and nerves are all tenses up and more likely to buzz or twitch.
Isn't anxiety grand?