Midbrain lesion changing size and demyelination?

I had symptoms last year (a few bouts of vertigo, tingling in my extremities) that led to tests for MS.    

I had spinal and brain MRIs. Spinal were normal, but I had two problems in brain, an area of focus in the left occipital white matter and one on the right midbrain. This was April 2005, and the occipital one was 7mm and the midbrain lesion was 7.4 mm. I was told either MS or low grade glioma.

Lumbar puncture in late April 2005 was normal.

Another MRI in May 2005 showed the same thing as the April one, save the midbrain lesion was measured as 12 mm.

MRI in June 2005 showed that the midbrain abnormality was 9 mm. Occipital one stable.

My first doc said it was MS, but the Cleveland Clinic doc said it wasn't MS. I was advised to see a brain tumor doc.  

I then had a PET/MRI fusion test. The two areas in question did not display increased uptake of the radiotracers. This was consistent with the lack of enhancement with contrast on all of the MRIs I have had done.

The PET showed low chance for neoplasm and the lesions didn't seem to be active.

I had another MRI in November 2005, and the midbrain area was 9.5 mm.

My current doc says I had some sort of demyelination in the past that caused my lesions. Current dx: Benign MS, ADEM, or gliosis.

My only ongoing symptom is sporadic tingling in my left hand/foot. I am not on meds.

Two questions:

1. Do you concur with this diagnosis?

2. If the lesions are inactive, why does the midbrain one change size? The MRIs were all done at different places -- could that lead to slightly different measurements?

Thanks!

[CCF-Neuro-M.D.-PW]

I cannot give you a formal clinical diagnosis over the internet as this forum is purely educational

Without seegin the MRI its hard to judge whether the symptoms ie vertigo were red herrings for the MRI lesions. While a white matter lesion is non-specific, a midbrain lesion could fit a diagnosis of MS. You do not seem to fulfill formal diagnostic criteria for MS at this point.

There is some subjectivity in measuring a lesion , they will just point and click on the diameter usually, and the computer calculates the distance. The exact cut can also differ from MRI to MRI - so depending on the slice chosen, they could be different.

Good luck

[arunlnaik]

I think the description given in MRI is typical of MS. This is a degenerative process probably triggered by immune methods. It is well known that the lesions of MS waxe and wane from time to time. Essentially these lesions are active. They are unlikely to be tumors because tumors do not show such a rapid changes in morphology.
cheers