MRI Shows Minor Microvascular Ischemic Change Around The Frontal Horn Of Right Ventricle. Why Is It ?

I had an acoustic neuroma surgically removed in 1994. A recent MRI revealed very minor microvascular ischemic change also seen aroud the frontal horn of the ventricle the right and superiorly in the left frontal lobe . No convincing new or acute intraparenchymal mass, hemorrhage or infarct has developed, The tumor was on the right side of my head. I had a mild stroke durring surgery. It was a tweve hour proceedure followed by three hours of closing ( 15hr s total ) I ve lost fine motor skills in my left hand and have mild facial peresis on the right side of my face. what are the implications of very minor microvascular ischemic change ? I am 55, 165lbs, 5 10 , 62bpm, 120/80, good / appropriate diet...I cycle 2000-2500 miles per yr., camp /back pack, skate...I m in pretty good shape. I m concerned my body is not getting adequate oxygen to my brain?...not sure what to make of the aforementioned observation? How should I veiw this non-event? Is this a function of older age? Will this impact my potential for dimentia in the future?