hi LA, yes your spinal lesions can be pure b12 deficiency.
if you only have three lesions on your brain, from what i understand that is not quite enough for them to definitely say ms, if your docs are anything like my neuro. i think he wanted to see at least 9 brain lesions or something like that? does your brain scan write up say anything about 'dawson's fingers'? i have not yet seen those associated in research with anything but ms. and i have tried to find them studied in some other illness, but no luck so far.
they find brain lesions sometimes in people upon autopsy, who never had any symptoms at all so the brain lesion thing is a bit of an iffy diagnostic measure anyway.
if they find O-bands in your spinal fluid, that's a marker for chronic inflammation and they'll say that's not caused by b12 deficiency (i don't actually believe that is true - b12 is anti-inflammatory) and if your case is like mine, that will be the last straw, and they will dx ms.
when i started out at tims i was fixated on b12 because it really was all i knew about as a kind of problem area for strict vegetarians, which i was at the time. so in early 2006 i dug around for studies that would show that my problems could be b12, period. in fact i did find studies where brain lesions and o-bands were seen in b12 deficiency.
of course, i had yet to learn about my d3 deficiency, my zinc deficiency, my sub-optimal uric acid, low magnesium, and all the rest of it 7:P !!!
as for where the lesions are, what does it say in the write-up? i'm kind of looking at what i think is the area adjacent to C7, does it mention C7 at all in the mri report? i can't tell which vertebra is which in the thoracic scan, but i think the area about the 3rd v from the top, and the 7/8th from the top look a bit washed out.
the weirdest thing to me is that you have like NO thecal sac. you're supposed to have a protective layer of fluid around your cord, which is the white outline around the darker cord, that you can see on my scan. do you have any other scans maybe, where you can see that white outline?
where my cervical lesion was worst, my cord looked kind of spread out and the sac was thinner, and that's where it looks most like yours, on the left side at least. in my second scan you can see that the cord kind of looks more put together, and the thecal sac appears to be in better shape.
anyway, enough blabbing for now
JL
