Hi!
These indicate small vessel ischemic disease or changes of brain blood vessels. These changes are seen in multiple sclerosis, Alzheimer's or Wilson's Disease, migraine headaches, diabetes, high blood pressure and high cholesterol. Though they are of no immediate threat, all these causes, and the presence of ischemic changes can be a risk factor for future stroke. Hence, prevention methods should include a healthy lifestyle, and a combination of diet, exercise, and medicines.