You mention that your son had a heart surgery at age 3 ½ months, and has evidence of an old stroke
in the left basal ganglia. Babies born with heart
problems (congenital heart defects) may be at an increased risk of having strokes before, during, or after surgery, for a variety of reasons. MRIs can show evidence of old brain injuries, such as strokes, but do not give an exact time/date that the injury occurred.