Hi
I can't say FOR SURE,but I have an idea what it means. I have neck problems and bad discs/arthritis in my neck. The last MRI I had done said that there was a bone spur encroaching on the spinal column slightly. THat is what they are saying when they say "bilateral neural forminal narrowing." It means a disc or something is pushing into the spinal canal area. Spinal stenosis also means narrowing of the spinal canal. These are not indicative of MS, but they can cause you plenty of troubles though as far as your spine goes with pain, etc. Sometimes a person needs surgery to correct this if they are in a lot of pain.
Mine isn't too bad right now, but if the disc/bone spur starts to push into the canal far enough, it can cause pain and possible other problems. If you are having any sort of tingling/numbness it is almost 100% being caused by this, not MS.
Good luck