An MRI or CT scan can detect a silent stroke.
Q. I recently heard the term “silent stroke.” If a stroke is silent, how is it diagnosed?
A. Most strokes occur when a clot blocks a blood vessel that feeds part of the brain. Starved of blood and oxygen, cells in that area may die, causing symptoms such as sudden weakness in an arm or leg, trouble speaking, or vision problems.
But if cells are destroyed in a part of the brain that doesn’t control any vital functions, it’s known as a silent stroke. These strokes may not cause any noticeable symptoms, but research suggests they may lead to thinking and memory problems, especially if several occur over time. It’s also possible that some strokes are “silent” because older people and their families don’t recognize the resulting changes as symptoms of a stroke.
The only way to tell if someone has experienced a silent stroke is if the damage shows up when person has a brain imaging test, like an MRI or CT scan, for another reason. Research suggests that silent strokes are far more common than strokes with symptoms, occurring in about 20% of older people.
People who learn they have had a silent stroke face a higher risk of another—potentially more damaging—stroke. They should keep their blood pressure, cholesterol, and weight in a normal range; exercise regularly; and treat conditions that boost stroke risk, including atrial fibrillation and diabetes.
— Deepak L. Bhatt, MD, MPH
Editor in Chief, Harvard Heart Letter