Cognitive decline, dementia common after stroke

(CNN) Up to 60% of all stroke survivors develop memory and thinking problems within a year, and one-third go on to develop dementia within five years, according to a new American Stroke Association scientific statement.

“The numbers are staggering, right?” said Dr. Andrew Freeman, director of cardiovascular prevention and wellness at National Jewish Health in Denver.

“This is a call to action to up our game and focus on prevention,” said Freeman, who was not part of the scientific committee who prepared the statement.

An estimated 9.4 million American adults — about 3.6% of the US adult population — report having had a stroke, according to 2023 statistics from the American Heart Association.

“Cognitive impairment is an often under-reported and under-diagnosed but yet very common condition stroke survivors frequently deal with,” said Dr. Nada El Husseini, an associate professor of neurology at Duke University Medical Center in Durham, North Carolina, in a statement.

About 40% of the survivors of stroke have mild cognitive impairment that does not meet the diagnostic criteria for dementia. Mild or not, the mental difficulties can seriously affect quality of life, said El Husseini, who chaired the writing committee for the statement.

“Cognitive impairment after stroke ranges from mild impairment to dementia and may affect many aspects of life, such as remembering, thinking, planning, language and attention, as well as a person’s ability to work, drive or live independently,” El Husseini said.

Cognitive impairment is most common within the first two weeks after a stroke, the statement said. Mental decline may go hand in hand with other conditions associated with a stroke such as behavioral and personality changes, depression, physical disability and disruption in sleep, all of which can contribute to a lower quality of life.

The American Stroke Association’s statement did offer some good news: About 20% of people who experience mild cognitive impairment after a stroke fully recover their cognitive function, typically within the first six months.

Signs of stroke

People are at higher risk for strokes if they have atrial fibrillation, an irregular heartbeat that sufferers often describe as a quiver, flutter or flip-flop of the heart in the chest. Those with uncontrolled high cholesterol or high blood pressure are also at high risk, as are people who smoke or use drugs or alcohol. Being diabetic or obese can be risk factors, too.

Ischemic strokes, caused by a clot in the blood vessels that feed blood to the brain, account for 87% of all strokes, according to the statement. Brain bleeds caused by a rupture of a weak vessel in the brain, called hemorrhagic strokes, are much less common, accounting for some 13% of all strokes.

The following are signs of a stroke, according to the National Institute of Neurological Disorders and Stroke:

• Sudden numbness or weakness in the face, arm or leg, especially on one side of the body.
• Sudden confusion, trouble speaking or difficulty understanding speech.
• Sudden trouble seeing in one or both eyes.
• Sudden trouble walking, dizziness, loss of balance or lack of coordination.
• Sudden severe headache with no known cause.

Other, less commons symptoms include dizziness, disorientation, nausea, memory loss or vomiting.

Any of the warning signs may last only a few moments and then disappear, which could mean the person is having a minor stroke or a transient ischemic attack, or TIA. Any symptom should not be ignored, experts say, as it can signal a more serious stroke to come.

“One might call a TIA a ‘lucky stroke’ because it’s less serious, but it really is a sentinel event,” Freeman said.

It’s never too late for prevention, but serious effort is needed after even mild stroke to “extinguish the fire if you will, with aggressive change and aggressive medication therapy when appropriate,” Freeman added.

“It should push people to make very drastic lifestyle changes: Eat better, exercise more, go on the appropriate statins or aspirins or whatever their doctor suggests are appropriate so that their risk is as low as possible,” he said.

Quick action is key

Damage to the brain occurs when some cells stop getting oxygen and die, while other brain cells may die due to bleeding in the brain. As a result, permanent brain damage can occur within minutes to hours, according to the institute. “Some brain cells die quickly but many linger in a compromised or weakened state for several hours,” it said.

Immediate medical attention is key to lessening the impact of a stroke. Learning the symptoms of a stroke using the acronym FAST can help identify the signs quickly, according to the US Centers for Disease Control and Prevention.

• F — Face: Ask the person to smile. Does one side of the face droop?
• A — Arms: Ask the person to raise both arms. Does one arm drift downward?
• S — Speech: Ask the person to repeat a simple phrase. Is the speech slurred or strange?
• T — Time: If you see any of these signs, call 911 right away.

Be sure to capture the time when any symptom first appears, the CDC advises, to help medical personnel determine the best course of treatment.

Additional strokes only worsen potential cognitive decline, the scientific statement said, so prevention is key. Stroke risk factors, such as hypertension, high cholesterol and type 2 diabetes, should be treated, as should atrial fibrillation.

Keeping high blood pressure under control has been linked to a reduction in risk for additional strokes as well as mild cognitive impairment, the statement said.

“Stroke survivors should be systematically evaluated for cognitive impairment so that treatment may begin as soon as possible after signs appear,” El Husseini said.

“Perhaps the most pressing need, however, is the development of effective and culturally relevant treatments for post-stroke cognitive impairment,” she said. “We hope to see big enough clinical trials that assess various techniques, medications and lifestyle changes in diverse groups of patients that may help improve cognitive function.”