Hi and welcome,
We've had many people tell of their misdiagnosis stories over the years, some originally dx with MS, others in diagnostic limbo for a lot of years before being dx with MS, others suspected of MS but eventually end up dx with something else. One of our CL's (he's no longer here) had a 20 yr gap between his first and second relapse, he wasn't dx-ed until the second, and i don't believe he had any symptoms suggestive of MS in those 20 years, he was completely unaware but his MRI and clinical evidence on his second though made it obvious he'd had MS for a very long time.
For me there isn't enough diagnostic information to even speculate on if there's potentially been a misdiagnosis or not......the locations of the lesions are significant, as is size, shape, type ie demyelinating, micro vascular etc, if any had ever lit up with contrast, if any new lesions developed or disappeared on any of your brain/spinal MRI's over the 10 yr time frame, if you have any neurological clinical abnormalities showing in your assessments in that time frame....etc
Optic Neuritis (ON) is one of the most common first symptoms of MS, just 1 unspecified brain lesion significantly increases the likelihood of conversion to MS. In the more recent research articles on the ON to MS conversion rate over a longer period than most other research projects, they use to just look at a 5 year window to conversion but longitudinal studies have discovered from presenting with ON to dx of MS is still high after 15 years..
"The 15-year risk of developing MS was 25% in the patient group with no lesions, while the risk was 75% in the patient group with one or more lesions.38 Previously, various studies including the Controlled High Risk Avonex, Multiple Sclerosis Study, the Early Treatment of Multiple Sclerosis Study, the Betaseron in Newly Emerging Multiple Sclerosis for Initial Treatment Trial, the Prevention of Relapses and Disability by Interferon β-1a Subcutaneously in Multiple Sclerosis, and PreCISe trials have all helped to clarify the natural history of CIS including ON and management options for a single demyelinating episode.39–45
These studies suggested that early initiation of disease modification after a first clinical episode including treatment with interferons (IFN beta-1a and IFN beta 1-b) or glatiramer acetate would be beneficial in lowering the risk of conversion to MS as well as decreasing development of new T2 lesions on MRI. It is crucial to diagnose patients accurately and other possible etiologies including NMO, NMO spectrum disorders or vasculitis should be considered while evaluating the patients prior to initiating DMT." https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5398757/
I honestly believe even 'if' you didn't have clinically defined MS when dx-d, the risk of conversion to MS over 15 yrs will likely still be there, so at least discussing things openly and or seeking a second opinion with another MS specialising neuro would definitely be in your best interest.
I hope that helps......JJ
I have not been in your particular situation but had to see more doctors and specialists than I can count with just as many misdiagnoses before the medical riddle was solved. I can say a doctors word is not gospel and will very rarely say they were wrong. In fact statistically one out of seven diagnosis are wrong. To answer your query a second and even third opinion is always a good idea. Hope this helps and best of luck.