DEAR DOCTOR K: My father just had a lacunar stroke. I’ve never even heard of this. What can you tell me about it?
DEAR READER: The most common kind of strokes, called ischemic (iss-KEE-mick) strokes, occur when an artery supplying oxygen-rich blood to a part of the brain is blocked. This leads to the death of some brain cells. Many strokes are caused by blockages of the largest arteries in the brain.
A lacunar stroke involves smaller arteries deep in the brain that branch off the large arteries. Because the arteries are smaller, the amount of brain tissue they feed is smaller than the amount fed by the large arteries. Still, lacunar strokes can cause significant disability. (I’ve put an illustration of the areas of the brain affected by lacunar stroke on my website, AskDoctorK.com.)
The smaller arteries deep in the brain are vulnerable because they branch directly off of a high-pressure main artery. As a result, high blood pressure can directly damage the walls of these arteries. High blood pressure also can damage the walls of larger arteries and help stimulate the growth of plaques of atherosclerosis, which can block blood flow.
The symptoms of lacunar stroke vary depending on the part of the brain that is deprived of its blood supply. Symptoms may affect the ability to feel things, to move, to see, to speak, and one’s balance and coordination. If a person has multiple lacunar strokes, this can affect emotional behavior and lead to dementia.
Full recovery is possible with early treatment. Ideally, doctors would be able to administer a clot-dissolving medication within three hours after symptoms start. If blood supply is interrupted for longer, there may be more brain damage. In this case, symptoms may last for many weeks or months, requiring physical rehabilitation. There may be permanent disability.
The first person I ever cared for after a lacunar stroke just noticed that his writing hand was suddenly clumsy. Fortunately, there were no other symptoms, and the clumsiness gradually improved with physical therapy.
What probably happens when people recover from the symptoms of a stroke is that some new brain cells grow to take the places of some of the cells that were killed. We used to think that this couldn’t happen, but now research has showed us that it can. Probably more important, other brain cells that are sitting around with not enough to do learn to take on the jobs of the brain cells that were killed by the stroke.
Your father must control his risk factors to prevent another stroke. He will probably need to take a daily aspirin or other blood-thinning medication. He should control his blood pressure and heart disease with lifestyle changes and medication. Exercising regularly, eating plenty of fruits and vegetables, and avoiding saturated fats and cholesterol will help. If he smokes, he should quit. If he has diabetes, he should control his blood sugar.
Dr. Komaroff is a physician and professor at Harvard Medical School. To send questions, go to AskDoctorK.com, or write: Ask Doctor K, 10 Shattuck St., Second Floor, Boston, MA 02115.