Age, ethnicity, mental health contribute to post-stroke risk of dementia

Stroke may be linked to an increased risk of dementia, but cognitive decline isn’t an inevitable consequence of the event, researchers reported in the Journal of the American Heart Association this week.

After the fact, stroke survivors can indeed decline mentally, but they can also stabilize or revert to their baseline cognitive function, corresponding author Eugene Y.H. Tang, MSc, and colleagues wrote in the JAHA review. This makes it crucial to map a patient’s cognitive function over time in case intervention is necessary.

“Stroke is the second most common cause of acquired cognitive impairment, which predisposes patients toward institutionalization, disability, increased mortality and poorer quality of life,” Tang and co-authors wrote. “With an aging population and a decline in mortality after stroke, the rates of poststroke cognitive impairment will increase.”

In the wake of a stroke, they said, clinicians tend to focus more on motor and sensory impairment rather than cognitive function. Because of this, patients’ mental decline is often ignored until the condition has progressed to full-fledged dementia.

The researchers drew information from Medline, EMBASE and PsycINFO databases, retrieving nearly 6,000 relevant articles and handpicking 14 for the purposes of their study. The majority of the trials—eight—focused on cognitive decline after stroke, while three each were geared toward cognitive stability and improvement.

Tang et al. found that cognitive outcome following a stroke is heavily dependent on a handful of factors, including age, ethnicity, sociodemographic status, medical history and timing of cognitive assessment. Neuropsychiatric symptoms like depression, poorer baseline cognitive tests, stroke location and genetic factors like APOE*E4 status also contributed to cognitive decline, according to the paper.

“Poststroke patients need to have their cognitive function followed up over time to ensure that cognitive decline is noted early,” the authors wrote. “Known risk factors associated with poststroke cognitive decline could be incorporated into risk scores to ensure timely detection of poststroke cognitive decline.”