So sorry you find yourself here, on this board. Hope you can get some answers and healing.
Yes, there is a known connection between tamoxifen and death of myelin making cells (OPCs), which could potentially look like (or exacerbate) MS lesions on MRI.
http://www.urmc.rochester.edu/news/stor ... fm?id=3935
In the Journal of Neuroscience paper, Noble’s team first identified central nervous system (CNS) cells that are most vulnerable to tamoxifen toxicity. Chief among these were oligodendrocyte-type 2 astrocyte progenitor cells (O-2A/OPCs), cells that are essential for making the insulating sheaths (called myelin) required for nerve cells to work properly. Exposure to clinically relevant levels of tamoxifen for 48 hours killed more than 75 percent of these cells.
I've been writing about chemo and damage to the brain and myelin on my blog.http://ccsviinms.blogspot.com/2014/03/c ... rophy.html
take care--do all you can to help your brain heal with nutrition, exercise, healthy fats, stress reduction. Let us know how it goes. A healthy lifestyle can really make a difference.