When mri show multiple foci of increased t2 weighted flair signal intensity in the deep white matter tracts, is nortriptyline 10mg the best medicine?

Unclear: The findings you describe are radiological and generally don't represent active brain pathology. Infrequently they may associated with inflammatory processes or small vessel vascular disease. I would discuss it with a neurologist. Radiological findings are not usually treated unless there is a clear disease process associated with them.