@jan64
I am sorry to hear of your suffering and can empathize.

Don’t let your neurologist discourage you from getting answers, diagnoses, and treatment. I have small fiber neuropathy confirmed by biopsy that started in my feet (burning/pins and needles).

It sounds like your accident may have contributed to your cervical spine issues and is aggravating your arthritis in your hands. How did you injure your thumb? Do your arms and hands feel weak and clumsy (do you drop things and is it hard to write/write legibly)? I had spinal cord and nerve root compression affecting my arms/hands (weakness/clumsiness/dropped things/handwriting worsened) plus I had bladder control issues and walking was hard (felt like I salad wearing cement boots). I even noticed swallowing/speaking issues.

I had seen a neurologist, rheumatologist and multiple spine specialists but it took me time to finally get properly diagnosed with cervical spondylotic myelopathy by my 3rd spine specialist. I, too, had a car accident where I had some whiplash plus a desk job over 30 years which contributed to neck problems. Many of my symptoms improved after ACDF surgery on C5-C6 to relieve compression and stop further injury to my spinal cord. I still have some weakness in my wrists/hands and I have hurt my thumb joint multiple times as a result.

Have you been to an orthopedic spine specialist to review symptoms and get an updated MRI of your cervical spine to see if surgery would help you?