Hi, Thanks for writing in. White matter lesions in frontal lobe are seen in many people in the elderly age group. Since your age is not mentioned, I guess you are in your middle age or elderly. The frontal lobes are most severely affected by sub cortical vascular ischemia. In this there is reduced blood supply in the specific areas of the brain and these are more abundant in the frontal region. It is not a serious finding and your doctor might have considered it as a part of normal aging changes in your brain and therefore mentioned it as normal. Such findings have been associated with frontal hypometabolism and executive dysfunction. There is reduced nutrition to these parts with decreased cognitive functions and probably speech at times. The memory problem relating to saying your old zip code shows that you have an intact long term memory but your recent memory is affected at times. Please discuss this with your doctors and you might like to remember things using other methods like writing down important things on a piece of paper.