My GP had thought MS as a possibility when I first hurt my back... Or rather when my back became injured. 'I' didn't hurt it, no fall, accident, impact, slouching, excessive sitting or standing, or even toting excessive weight. No signs of any back problems until "Wham!" Broke a vertebra, bulged and herniated a disk in the lumbar spine. My muscles had ripped my back apart.

So MS could be a possibility, but considering the info, I would likely agree with your doctors towards the neuropathy. Though I am surprised they have not tried any medications to help control the involuntary muscle movements, or injections to reduce swelling of the herniated disks, unless your herniated disks are infringing upon the spinal cord, in which case, if your a good candidate they may opt for surgery.

The only reason my GP had thought of MS for me, was because of my history prior to the snapping of my back. Lots and lots of little, seemingly insignificant things that added up to a much larger picture. Constant muscle spasms that I ignored, weird falls, chronic headaches, heat intolerance, insomnia, catching every bug, sniffle and cold going around... A multitude of things that when younger and 'healthier' I largely ignored, or had for so long I didn't know it wasn't normal.