Hi Everyone.

I wanted some guidance if possible, I have been looking at the McDonald Criteria to see where I fit in. Can anyone explain the following

2 or more attacks (relapse)

2 or more objective clininal lesions

Can anyone explain to fit the critera do you need to have both of these or just one. Im not entirely sure how it works

I can only assume both, as one (relapses) means that the second (damage)is present too.


The Criteria are usually interpreted as being:

An attack and a subsequent relapse that are sufficiently separated in time to be unconnected (as in part of the same attack)
Two lesions that are in different parts of the brain but are clearly related to your symptoms. That’s the MRI bit.

Obviously, both are better than one, but sometimes other data is also required. This is where the LP comes in. A good neuro can usually do a diagnosis of a spinal lesion by physical examination alone. In a private consultation this could take an hour, but I have known a trainee do some of it in 20 minutes and come to the same conclusion as the consultant. A brain and a spinal lesion meet the two lesions criteria, but again it is better if they are separated in time as well.

Just remember that the McDonald Criteria are a guide, and only a guide.


Ok but what if there are no leisons. I had a neurologist appointment yesterday and even though I’ve not yet had any other tests my neurologist is sure I have ms

One thing I have learned is that neurologists sometimes say they ‘think’ or they are ‘sure’ it is MS… but unless they tell you it is an official diagnosis, and write a letter confirming it - it may just be their initial impressions, rather than an final conclusions / official diagnosis. It sounds like he is pretty certain it is MS, but I’d imagine he might possibly need to do MRIs to confirm.

Do you have any follow-up tests / MRIs?