I stopped getting new lesions in 2013. It is 2017 and my cognition and fatigue is worse. Why would my cognition be worse than when I was still getting lesions? I had to go on disability in 2015. I don't get it?
Conventional MRI doesn't see all lesions caused by MS. We have known for sometime that much of the disease burden of MS occurs in the gray matter of the brain (as opposed to the white matter that is more readily seen on standard MRI scanners). Gray matter damage from MS likely explains the situation you are describing. However, many external factors can affect cognition also (medication side effects, sleep fragmentation from MS or other medical causes, MS related cognitive fatigue, metabolic problems such as thyroid dysfunction which is seen in a higher association with MS, etc.). A thorough review with your neurologist can help tease apart potential causes in your case and potential treatment options based on the cause could be considered.
A. Scott Nielsen MD MMSc
Neurologist and MS Specialist at Kaiser Permanente