@snowmass Hello and I wanted to welcome you to Connect. I have the same diagnoses; a cervical spine issue that has been operated on resulting in a C5/C6 fusion and I have had thoracic outlet syndrome for years as this spine condition developed.

I have done years of physical therapy for TOS, and too much working of muscles tends to tighten my neck and shoulders and kick up pain symptoms. I don't do injections. What works well is myofascial release therapy with a John Barne's trained therapist to stretch out the tight fascia. I have had tightness that generates pain or tingling all the way from my jaw to my ankles from tight fascia. Before spine surgery, I had cervical central canal stenosis that was also generating pain all over my body and it confused a bunch of surgeons. The really smart one was at Mayo, and the Mayo surgeon removed the bones spurs and ruptured disc that was impinging on my spinal cord.

The thing that confused the surgeons was all over body pain being caused only by canal stenosis in my neck, and there was no lumbar spine pathology to cause the pain into my legs. It was all coming from my neck. If fact, the very first symptom that linked to my cervical spine was that I got a pain in my ankle when I turned my head to the side. That was when I was at a physical therapy session laying on a table, and when I turned my head forward again, the pain stopped. It was reproducible and I could turn it on and off at least in the early stages. My spine surgery solved all of that, and I do not have that pain anymore. I do still stretch fascia to deal with tightness, and tight surgical scar tissue that can link to the rest of it.

I did have an epidural injection as diagnostic when I was consulting surgeons and had a bad reaction to it, perhaps because of an allergy to a component in it. Often these injections are done to try to determine what surgery may fix. They reduce inflammation and can buy a little bit of space. That may take some pressure off a spinal nerve or the spinal cord temporarily until the steroid wears off and is cleared out by the body. In my case, the injection gave me new pain I didn't have prior and I had burning electric pains gong into my hand randomly for about 6 weeks which is the time it takes the body to clear the injected material.

You may be interested in this discussion about myofascial release.

Neuropathy - "Myofascial Release Therapy (MFR) for treating compression and pain"
https://connect.mayoclinic.org/discussion/myofascial-release-therapy-mfr-for-treating-compression-and-pain/
Is your physical therapist doing myofascial release?

Jennifer