This could be unrelated, but I am reminded of my condition (Brachia radial Puritis) which is similar in that it begins in the C spine with vertebrae disc making contact with the Brachial nerve (like sciatica from lumbar disc contacting the sciatic nerve). My wife also suffers from chronic pain involving the same nerve but results in pain from her neck down the shoulder into the arm.
All to say, if it was a similar scenario with another nerve.
We find some relief ( complete relief for me partial relief for her). Using traction to separate the vertebrae and allowing the disc to pull back from contacting the nerve. See my post in Brachia radial puritis