According to a recent scientific statement from the American Stroke Association, up to 60% of stroke survivors may develop memory and thinking problems within a year, and one-third of those may go on to develop dementia within five years. Dr. Andrew Freeman, director of cardiovascular prevention and wellness at National Jewish Health in Denver, called the numbers "staggering" and emphasized the importance of prevention. The statement's writing committee chair, Dr. Nada El Husseini, noted that cognitive impairment is frequently under-diagnosed among stroke survivors and can range from mild to severe, affecting a range of activities from remembering to driving to living independently.
The first two weeks after a stroke are the most common time frame for cognitive impairment, which may be accompanied by other conditions associated with stroke such as depression, physical disability, and sleep disruption. However, the statement also offers some good news: about 20% of stroke survivors who experience mild cognitive impairment fully recover within six months.
Although anyone can have a stroke, people with certain risk factors are more likely to experience one. Those with atrial fibrillation, high cholesterol, high blood pressure, a history of smoking or alcohol or drug use, diabetes, or obesity are all at increased risk. Ischemic strokes, which occur when a clot blocks blood flow to the brain, are by far the most common type of stroke, accounting for 87% of all strokes, with hemorrhagic strokes making up most of the remainder.
The National Institute of Neurological Disorders and Stroke provides the acronym FAST to help identify the signs of a stroke: Face, Arms, Speech, and Time. If you notice drooping on one side of someone's face, arm weakness, slurred speech, or difficulty understanding speech, it's important to call 911 immediately.
Prevention is key to reducing the impact of strokes, as additional strokes can worsen cognitive decline. Stroke risk factors such as hypertension, high cholesterol, and type 2 diabetes should be treated, as should atrial fibrillation. Keeping blood pressure under control can reduce the risk of additional strokes as well as cognitive impairment. "Stroke survivors should be systematically evaluated for cognitive impairment so that treatment may begin as soon as possible after signs appear," said Dr. El Husseini. Moving forward, she hopes to see clinical trials of a variety of techniques, medications, and lifestyle changes in diverse groups of patients to help improve cognitive function.