It's been ongoing for about 6 months. It began one night reading in bed, my neck was resting at a very awkward angle, twisted to one side while I held the book up to my face. That night it started hurting and I got some brief (2-3 seconds) visual darkness, and numbness in the back and top of my head. I soon developed numbness in the front of my neck, and serious blurriness in my right eye. The numbness has largely resolved itself, so has my eye. (Though I'm pretty sure it's not back to normal, it's slower to focus but does at least focus now.
I had a brain MRI that ruled out any congenital stuff, MS, cancer etc. Came back normal. I had another cervical spine MRI only recently, about a month ago. It also came back normal, ruling out pinched nerves etc. Recently the pain has progressed to my collarbones and the front and sides of my neck (it was mostly in the back of my neck before). The sides of my neck, especially the right side, have been very sore and tender, and this usually is accompanied by ear pressure and popping/clicking. ('ve had repeated ear infections throughout this ordeal, and some TMJ problems. Recently I've also developed some annoying twitching in my right thumb and upper arm.
I'm getting worried as to what might be causing this and my GP has recommended physical therapy, but they've closed those services in my country due to coronavirus. I'd still like to know the root cause of this. I don't know whether to press my GP to see further specialists for more tests.
I've read some things about thoracic outlet syndrome causing neck pain, but it usually affects the arms more.