hi and welcome

i'm not one to argue with docs' dx, except when it comes to my own which i know tons about, naturally.
i can't imagine anyone here being able to suggest no your docs are wrong, ie that is so definitely MS, and not AS. i could be wrong, we could have a lurking as pro in our midst.
my suggestion is always to ensure nutritional status is optimized to ensure least likelihood of conforming to an ms profile. so not the best person to commiserate with if gunning for an ms dx.
at least there's a heap of science on the nutritional aspects of ms, vs not as much so far for as. i had to resort to a 20+ yr old book which i remembered had an entry on as, just bc at the time the name of it made an impression. it says it's an inflammatory illness, 'bamboo spine', with pain in spine pelvis and sometimes rib cage. bone fusion.
recommendations given: cut sugars, minimize simple carbs and boost complex carbs like various peas lentils and beans. also says if on painkillers, increase intake of vits a and c.
also says long term use of painkillers can cause iron loss due to bleeding in the stomach, and that docs may prescribe anti-inflammatory drugs, steroids etc.
so, we're probably looking for developments over the last couple decades re vit d3, so sure enough there it is from 2013, albeit out of africa, and using resources from my ms clinic's institution no less

woot. now that is interesting. is there an ethnic component to as? bc the only person i know personally who has been dxd with AS is african american.
Seasonal disease activity and serum vitamin D levels in rheumatoid arthritis, ankylosing spondylitis and osteoarthritis
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3645084/
"The mean Bath Ankylosing Spondylitis Disease Activity Index score was significantly higher in winter than in summer "
if there is an ethnic connection there, it seems like it could be related to the fact that darker skin, and even more so darker + covered skin, is susceptible to reduced cutaneous vit d3 synthesis. otherwise, just some lifestyle factors leading to low d3 levels. either way, that's a pretty straight line to bone pain. would be exacerbated by any low dietary magnesium and other d3 cofactors. low mag and d3 are also seen in ms, so there would be potential symptom overlap regardless of the ultimate dx either way.
similarly, lhermitte's sign (the shock feeling) is not unique to ms.
https://www.hindawi.com/journals/crinm/2015/707362/
some of your other symptoms also suggest potential mineral issues. can you describe any nutritional testing that's been done in your case?
there are excellent newer resources out there to help balance diet to the anti-inflammatory side of things. the IF rating web site provides a limited food search tool. when working on inflammatory illness, you want to balance out healthy food sources while aiming for a +100 overall score each day.
also this from 2014:
"We reviewed the literature for studies assessing vitamin D level as a marker of AS disease activity and those examining vitamin D levels in AS in comparison to healthy controls. Four of 7 studies found a significant negative correlation between vitamin D levels and Bath Ankylosing Spondylitis Index (BASDAI), erythrocyte sedimentation rate (ESR) and
C-reactive protein (CRP). In a review of 8 case-control studies, the
mean level of 25-hydroxyvitamin D3 was 22.8 ± 14.1 ng/mL in 555 AS patients versus 26.6 ± 12.5 ng/mL in 557 healthy controls."
those serum d3 levels are all bad, but the AS patients worse off on average. 40 ng/ml is a better level, and should be worked on using cofactors not d3 alone. basically allows your body to create anti-inflammatory steroid hormone treatment for itself.
1,25(OH)2-vitamin D3, a steroid hormone that produces biologic effects via both genomic and nongenomic pathways
https://www.ncbi.nlm.nih.gov/pubmed/1314073
The Anti-Cancer and Anti-Inflammatory Actions of 1,25(OH)2D3
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3164534/
Vitamin D or hormone D deficiency in autoimmune rheumatic diseases, including undifferentiated connective tissue disease
https://arthritis-research.biomedcentra ... 186/ar2552
active members shape site content. if there is a problem, speak up!
use the report button to flag problematic post content to volunteer moderators' attention.