Sorry for delay in replying - on the assumption that question is for me!
No real struggle to get a diagnosis, but that's just down to the good luck (ha! 🙄) of having, what I then learned, was a big relapse (totally lost the use of my legs). The MRI scans showed very clear myelin sheath damage. There was also signs of 'old' damage, which I'm led to believe is a different colour (basically very dark, whereas active current damage is much lighter). So I think the Neurologist didn't take long at all (was the n hospital for 4 days, and it was 10 days in total until diagnosis day.
The reason it's not an immediate diagnosis following MRI is because they have to consider ALL other possible causes (as other conditions can display some of MS characteristics - which I'm sure you know!).
If it is MS for you, don't worry about the fact you've already had the IV steroids before having the MRI. Because the damage to the myelin sheath happens when you are getting the actual symptoms - in your case the neuritis - the signs of the damage caused to the myelin sheath on the MRI don't then disappear, even though, to you, you feel 'cured'. Sadly, it's only your symptoms that are helped by the steroids, they are not able to 'reverse' the damage.
It'll all be clear to the Neurologist.
Really hope the above makes sense. I do have a tendency to waffle 😉
& p.s, I've probably had MS for around 10 years or so. The Neurologist agreed that some of the episodes of lack of balance / staggering / walking into door-frames / difficulty writing, all at various times in the last 10 years that seemed to resolve after 3-4 weeks in each case - which is typical of MS, were MS relapses. But of course, all that damage is accumulating into disability as the years pass
On meds now, so with a view to reducing the chances of more relapses and reducing the rate of disability.