Inflammation of the Brachial Plexus *AND* BFS?

[taylorspam]

Almost four months ago, I had pain in my neck radiating down my arm - and a numb thumb. I thought maybe I had slept funny, but it did not resolve itself.

In the week or two after that, the pain got worse, weakness and muscle spasms began, so I sought medical attention.

I visited a Spine Specialist (orthopedic surgeon) who performed basic neurological tests (mostly pushing/pulling with my arms) and reasonably presumed a pinched/obstructed nerve in the cervical spine. Treated with corticosteroids, pain meds, and muscle relaxer - in hopes it would resolve itself.

Two months later - pain, spasms continue - weakness is getting worse and arm is noticeably atrophied. Cervical spine MRI is unremarkable. No issues with the nerve there. Still might be inflammation, so give it another month.

A month later, visit the neurologist. Exam is normal, except noticeable weakness in the right arm. EMG/NCV reflects weakness in same muscles as neuro exam (great, so I paid all that money just to confirm that I am not making this all up?) EMG/NCV also results in "probably anomalous" readings of the left ulnar nerve - in my good arm.

Neuro believes it is some kind of inflammation of the brachial plexus, possibly brought on by a chest cold I had around the time this all began. (Wish I'd never mentioned the cold, as it was minor.) "Patchwork" symptoms are often a result of brachial plexus injuries, I was told - though normally there is a distinct injury that initiates the problems.

Neuro also believes the spasms are due to BFS, on account of my formerly high levels of activity (weights mostly)
My only problem with this is that the spasms didn't start when I became significantly less active (about a year ago) - they started right in line with this pain/numbness/weakness/atrophy.

Is it worth seeking a second opinion? Or perhaps getting an MRI of the brachial plexus to confirm existing "suspicions"? (It seems like a lot of this is a guessing game - the first doc was pretty convinced of a pinched nerve in the cervical spine, which it definitely is not - so I'm hoping for something conclusive, though aware that's not too common when it comes to the nervous system.)

I'm not convinced I'm dying (any more than everyone else is dying) but I am displeased with having shelled out a lot of cash for no conclusive answers.
"It's probably your brachial plexus" and "it should resolve itself completely in 6 months to a few years" do not qualify.