How do I test for longterm (9 years) suspected nerve avulsion in neck?

HI there, thank you for helping if you can. I am desperate for help. I was hit by a drunk driver from behind 9 years ago and the seat belt caught me across the neck. I had immediate loss of the use of my left arm, had temporary loss of both legs. the nerve pain went from the top of my head to the bottom of my feet and I was on fire, could not think, could not function (lift anything), my left eye bulged and my left ear pain was horrendous. (horners syndrome in right eye diagnosed years later) I have been a ball of electrical fire since that day, have completed every type of therapy (most to gain use of left arm which took a year to be able to lift but always with terrible pain) , seen way too many doctors and had two major surgeries when my spine collapsed (lost control of bladder and couldn't walk-being forced to retire ultimately from 30 year career). One surgery in the neck. I have said from the beginning that I "broke" a nerve in my neck. I could feel it, I have had MRI's, CT's, seizure EEGs, nerve conduction studies and more. Most nerve studies showed nerve damage but it just showed what it was affecting not where it was. I recently learned from my own research of brachial plexus injuries and that CT myleograms and MR neurographies can "see" nerves coming off spinal cord. My pain doctor is in agreement with me that I probably suffered a nerve evulsion but said it is too late to do anything about it except manage the pain. I become partially paralyzed every day depending on how much I use my left arm and how much movement, standing or sitting upright that I have. I cannot escape the intolerable pain. I finally got a neurologist to agree to give me a brachial plexus study but understand that it is not a neurography, only a regular MRI (just looking in different place). How can I expect to find this nerve evulsion with a regular MRI? Why wouldn't other MRI's have shown it? By the way, I have been tested for stroke many times especially since I feel faint when my central nervous system is overwhelmed and my symptoms worsen. Do you know anyone that has ever heard of a person having a nerve evulsion in the neck area that immediately took out the entire left side and ultimately affected the whole body? I really want to improve. I have living to do and I am barely able to function for more than minutes at a time. I don't know what else it could be and I am tired.