Spinal cord lesion cause

I started having symetric pain, tingling, and numbness in the ulnar nerve path (fingers, hands, wrists, elbows) three years ago. An MRI showed a bulging disk at C5-C6 and spinal cord lesion adjacent to it, had a laminectomy w/ fusion to correct it. This didn't help, neurologist suspected MS, several tests ruled this out. The lesion continued to grow, several experts agreed it was an astrocytoma. Had a very painful surgery to remove it. No tumor was found, only gliosis and Rosenthal fibers, recovery has been difficult. Symptoms continued to worsen, and incredibly painful spasms/seizures started. Tested again 9 months ago with every imaginable test for MS at a very reputable clinic, all negative or inconclusive. Recent MRI shows lesion size is reduced, but symptoms now include weakening legs, back pain (like stretched rubber bands), and finger pain and numbness continue to worsen. Seizures were relieved by Baclofen and Tegretol, but no meds help the pain. I have no history of trauma that would cause an SCI. Please help!