My breakthrough on muscle tension was "The Quieting Reflex" by Charles Stroebel. Since you have a lesion, I don't think it would be a permanent fix, but if it works then its something you can apply as a counter measure. This is what it's like for me. Rinse and repeat.

My muscle tension is primarily on the left side of my body. Forehead, intercostals, upper back, waist, hamstring, calf ... are all tighter on the left. Makes me wonder if I have a similar lesion in the right hemisphere.

Once you have a lesion can they do anything for it other than trying to prevent more?