No known cause yet. I had EMG's , MRI, Blood tests for vitamin B6 and B12. My B6 and B12 were both high due to supplements. I stopped both of them as told by the neurologist who I had on a telemedicine visit. I am still looking for a neurologist (not satisfied with the one I saw who is 3 hours away and spent 30 minutes with me). AC1 was also normal. No lead or arsenic detected. ANA was abnormal, but was repeated by rheumatologist who found nothing in bloodwork to indicate autoimmune. X-Rays show degenerative arthritis in neck and lumbar, but I was told by PA for neurosurgeon that I did not need surgery. I am worried about the nerve block.