I am NOT a doctor or person to read such MRIs, but it sounds to me like it is past time for you to stop seeing a chiropractor and get to a neurosurgeon. You might have pinched nerves that could be causing both symptoms and putting you at risk, so I'd get to see some form of spine surgeon post haste. I would not go to a chiropractor because in your condition, spinal manipulation could be dangerous.

These are the parts of your report that concern me:

"possible impingement on the existing roots." as well as "there is signal change"