Tethered Cord Syndrome or autoimmune?

Hello @ceciliac, and welcome to Mayo Clinic Connect. Mayo Connect is a patient-to-patient support group, so we cannot answer your medical question about why it affects your facial pain on both sides. This would be a good question to ask your medical provider.

On Connect, we have another discussion on this topic. Here is a link:
https://connect.mayoclinic.org/discussion/i-am-a-senior-male-with-spina-bifida-i-have-managed-to-dodge-most-of/
As you read the posts in this discussion, you will meet others who have this diagnosis.

How long have you had these symptoms? Has your doctor suggested any treatments?

@ceciliac Something I have learned through my experience as a spine patient is that spinal cord compression can cause pain or jumping muscles anywhere in your body below that level. I had a collapsed C5 C6 disc causing pressure on my spinal cord and I had leg pain and pains in my body that changed position with my neck position. Doctors can miss this connection. It's called funicular pain. This literature explains funicular pain.
https://pubmed.ncbi.nlm.nih.gov/20938789/
What also happened in my case was that my C1 & C2 would slip out of alignment and stay like that. It caused my jaw to be out of alignment and that did compress the Trigeminal nerve that travels through a tiny space near the angle of the jaw. The Trigeminal nerve is one of the cranial nerves that are superior to the spinal cord. I have been working with a dentist who treats the temperal mandibular dysfunction with appliances that I wear in my mouth and physical therapy. My spine surgery to correct the spinal cord compression was about 10 years ago with a single level fusion of C5 C6. There is a disc between the jaw and the skull and a small space there. If the jaw is out of alignment it compresses that space and can affect the cervical spline alignment and put wear and tear on the jaw's disc. This can also generate facial, head and neck pain or pain in the jaws.

If your doctor doesn't understand funicular pain, you'll need to seek another opinion. I sounds like they looked at your brain as a potential cause of foot pain instead of spinal cord compression. Is this in your neck? (Please see the medical literature.) I was in that situation and it was missed by 5 spine surgeons. I found the literature I posted and sent it with my application to be seen at Mayo Clinic. I had surgery there and my Mayo surgeon understood this issue. My condition was the result of a whiplash injury and some years of spine deterioration contributing to the dysfunction.