Disappearing lesion - McDonald Criteria

[wennell_dennell]

Hi all,

I recently had an MRI that showed no new lesions from a scan 2 years ago, but one of the original lesions is no longer there. Multiple small lesions in the periventricular, subcortical, and deep white matter.   The radiologist's report stated that this new scan met the McDonald criteria of dissemination in time and space, for the diagnosis of MS. I'm just a bit confused, as I thought you needed new lesions to get the dissemination in time. I know the criteria were updated in 2010, and I'm wondering if the fact that there was change showing that at least one lesion  is a result of an active process constitutes enough proof that it is MS??

Thanks for any input!

[wennell_dennell]

Thanks so much, supermum_ms!

I don't think there were any enhancing lesions, so perhaps it was just the location, and the fact that there was some change.  Perhaps despite his wording, I meet the DIS but not DIT.  I was really sick this summer, but that started in mid-June, and I didn't get the MRI until last week, so I'm not surprised nothing was showing as active in that regard, though I know lesions can be active without a person showing symptoms.  At the very least it has my neurologist reviewing my file again,moving up my appointment, and will probably mean more testing....which is better than the 'wait and see' limbo I have been in!

[supermum_ms]

Hi there,

Usually, the addition of at least one new lesion, will create enough change of MRI evidence to meet the Mcdonald criteria of space and time BUT the latest criteria is simplified and you can be meet the criteria for CDMS  with the following....

DIS - 1 or more T2 lesions in at least 2 or more areas of the CNS
* Periventricular
* Juxtacortical
* infratentorial
* spinal cord

DIT - can be demonstrated
* A new T2 and or gad-enhancing lesion(s) on follow up MRI, with reference to a base line scan, irrespective of the timing of baseline MRI
* Simultaneous presence asymptomatic gad-enhancing and non-enhancing lesions at any time.

http://onlinelibrary.wiley.com/doi/10.1002/ana.22366/full

So technically a person can meet the criteria if they have a) new gad-enhancing lesion(s) AND b) old non-enhancing lesion(s) in at least 2 of the identified CNS areas (listed above).

That meets the criteria because the non-enhancing lesions are from at least one, (older) demyelinating event and the gad-enhancing lesions are from a second (newer) demyelinating event.  

The number and location of the lesions has more significance, because there is a time component to enhancement, off the top of my head its some thing like 30-40 days so if the MRI isn't done at the optimum time, it can miss it. So i'd be of the mind that, the number grater than 1 and specific location of your lesions, could be what makes your MRI meet the criteria.  

Hope that helps

Cheers.....JJ