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Early detection and treatment are crucial to help minimize damage and cognitive impairment after a stroke, according to the American Heart Association. Yoshiyoshi Hirokawa/Getty Images
  • A stroke occurs when the blood supply is stopped or reduced to part of the brain, depriving cells of oxygen and nutrients.
  • It is the second most common cause of death worldwide and the leading cause of disability.
  • Many stroke survivors are left with some cognitive impairment, and as many as 1 in 3 develop dementia following a stroke.
  • A new scientific statement from the American Heart Association highlights the need for early cognitive impairment screening and treatment following stroke to help prevent long-term disability.

According to the World Health Organization (WHO), stroke — a reduction or stoppage of blood supply to the brain — will affect 1 in 4 people during their lifetime. And the lifetime risk of developing a stroke has doubled since 1990.

With improvements in medical care, more people are now surviving strokes. While 10% will recover fully, most will be left with some form of impairment. For example, 40% of stroke survivors have moderate to severe disabilities, while 10% require long-term care in a nursing home or similar facility.

These disabilities may include:

  • Paralysis in part of the body
  • Numbness and pain in areas of the body
  • Speech and language issues
  • Cognitive issues, such as problems with thinking and memory.

Now, the American Heart Association and the American Stroke Association have published a scientific statement highlighting that more than half of those who survive a stroke are left with some post-stroke cognitive impairment (PSCI). Their statement stresses the importance of screening to identify cognitive impairment and allow early treatment.

The statement is published in Stroke, a journal of the American Heart Association.

“This is an important study, reviewing an important area. Drawing important conclusions on the size of the problem — PSCI is common after stroke, especially in the first year, and ranges from mild to severe. Although cognitive impairment is reversible in some cases early after stroke, up to one-third of individuals with stroke develop dementia within 5 years.”

– Dr. Steve Allder, consultant neurologist at Re:Cognition Health.

Strokes may be ischemic — a blood clot blocks an artery leading to part of the brain — or hemorrhagic, where bleeding occurs in the brain. The consequences depend on which part of the brain is affected by the stroke.

PSCI and memory loss are common after stroke, with stroke being the second most common cause of cognitive impairment and dementia.

According to an AHA press release, 87% of strokes are ischemic, and 13% are hemorrhagic. Both may lead to cognitive impairment immediately after the stroke or some years later.

Most commonly, PSCI occurs within 2 weeks of a stroke, so to minimize lasting damage, the AHA recommends screening both immediately following a stroke and thereafter to assess any cognitive changes.

In the report, Dr. Nada Husseini, chair of the scientific stroke writing committee and an associate professor of Neurology at Duke University Medical Center, North Carolina, said: “Cognitive impairment is an often under-reported and under-diagnosed — yet very common condition that stroke survivors often deal with.”

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

According to the AHA statement, cognitive impairment can be reversed if detected and treated soon after a stroke. However, most people will show improvement rather than complete recovery to pre-stroke cognitive levels, and up to one-third of people develop dementia within five years of a stroke.

One study found that stroke doubled the risk of dementia even after adjustment for age, sex, education, and stroke risk factors.

In older stroke survivors, stroke accelerates cognitive decline, and subsequent strokes will accelerate it. The statement, therefore, stresses the importance of stroke prevention in those who have had one stroke or who are at risk of stroke.

The statement also highlights that: “Risk factors for PSCI reflect prestroke cognitive decline, preexisting cerebral vulnerability/reduced reserve, and the impact of the stroke; a minor stroke may precipitate dementia in an older person with a vulnerable brain.”

Dr. Adi Iyer, neurosurgeon and interventional neuroradiology of Pacific Neuroscience Institute at Providence Saint John’s Health Center in Santa Monica, CA, highlighted the importance of therapy to help stroke survivors regain their cognitive abilities:

“Cognitive impairment after stroke is common within the first year and not well studied. Given its prevalence, cognitive therapy should be a necessary adjunct to physical therapy during recovery.”

“Like physical exercise, mental exercise is essential for patients to make a complete recovery,” he added.

PSCI is not the only adverse outcome of stroke. Others may include physical disability, sleep disorders, depression and anxiety, personality and behavioral changes, and fatigue. Although rehabilitation can be effective in treating many of these effects, cognitive impairment may prevent a person from benefiting fully from rehabilitation programs.

The statement highlights the need for joined-up after-stroke care to help stroke survivors regain quality of life:

“A streamlined, interdisciplinary model of care beyond the acute and subacute phases after stroke is needed for optimal monitoring and management of cognitive deficits.”

Key to managing the cognitive and other effects of stroke is minimizing the likelihood of further strokes. According to the American Stroke Association, 25% of people with one stroke will go on to have another, but the risk of subsequent strokes can be reduced.

By adopting healthful habits, such as a healthy diet, regular physical activity, and taking medication as prescribed, stroke survivors can reduce their risk of experiencing a second stroke by as much as 80%.

The statement stressed that more research is needed to help identify which stroke survivors are most at risk of cognitive impairment and to help develop culturally relevant screening and management techniques.

And Dr. Iyer explained it is important to recognize the impact of a stroke to ensure the greatest benefit from therapy:

“Before patients who have suffered from strokes return to work or start driving, for example, it is critical for clinicians to understand their functional limitations.”

“Additionally the cognitive sequelae of stroke may lead to subsequent depression and overall worse outcomes. This study statement illustrates the need for more guided cognitive therapy to give patients the best chance of meaningful recovery,” he added.