I had a C3-4 fusion just under a year after yours. I fell and broke my neck, big chunk off C3 and a broken bone spur that damaged my cord. At least my fusion "took" after nearly a year, but C4-5 fused by itself also.
I know we don't have the same diagnosis, but a lot of your symptoms are the same as mine.
I have dx "central cord syndrome." I have most of the symptoms of CRPS, just no muscle wasting or skin thinning.
I have problems from C3 and below, plus headaches. I didn't have the gastric bypass, but I had a stomach surgery that did much the same (Nissen fundoplication for stomach pushed into chest), resulting in stomach much smaller than before. I have constant muscle spasms that never relax, worse in the lower legs. My left shoulder has a bone chip and some torn stuff, needs surgery. When I try to get up in the morning my whole body is in spasm, shaking, jerking, stiff but I can work it out. After I get a pill and move for a couple of hours I can work a little.
There is nothing that does anything for the leg pain (worst waist down, but everywhere below neck), extreme sensitivity to touch, and cold, as far as I have experienced. I have to wear long pants and fluffy socks in 80 degrees. I get some relief from Norco for the shoulder and back pain (arthritic bone spurs, etc.) and headaches. I get a little serotonin help from tramadol. My docs to worry about
addiction way too much for my old age, and I don't tolerate most pain meds and none of the muscle relaxants except Valium, which they won't give me for fear of addiction. I'm one of those people who don't react at all to morphine. Most recently I've been trying Klonopin, which helps the leg spasms some and stops the body jerking all night, but it's not really worth bothering with because I'm too tired and not spastic enough to walk the next day. One good thing about
spasticity is no muscle wasting and being able to walk, even if poorly.
Since my damage is mostly at C3, there's no use getting a stim unit. The messages to the brain are garbled there, not from my legs. I've had the nerves tested. External back stim (TENS) relieves my back muscle spasms.
I have loads of dysautonomia - no sweat below C3, bladder and bowels not working right, orthostatic hypotension and blood pressure fluctuations, autonomic dysreflexia episodes. www.apparelyzed.com/
I'm sure you've read everything already.
But enough about
me. I'm just suggesting getting tested before jumping into scs. Get second opinion, maybe more.
Blessings. Keep posting. I'm anxious to hear your progress.