Long-Term Cognitive Monitoring Warranted After First Stroke

A first stroke in older adults is associated with substantial immediate and accelerated long-term cognitive decline, suggested a new study that underscores the need for continuous cognitive monitoring in this patient population.

Results from the study, which included 14 international cohorts of older adults, showed that stroke was associated with a significant acute decline in global cognition and a small, but significant, acceleration in the rate of cognitive decline over time.

Cognitive assessments in primary care are “crucial, especially since cognitive impairment is frequently missed or undiagnosed in hospitals,” lead author Jessica Lo, MSc, biostatistician and research associate with the Center for Healthy Brain Aging, University of New South Wales, Sydney, Australia, told Medscape Medical News.

She suggested clinicians incorporate long-term cognitive assessments into care plans, using more sensitive neuropsychological tests in primary care to detect early signs of cognitive impairment. “Early detection would enable timely interventions to improve outcomes,” Lo said.

She also noted that poststroke care typically includes physical rehabilitation but not cognitive rehabilitation, which many rehabilitation centers aren’t equipped to provide.

The study was published online on October 2 in JAMA Network Open.

Mapping Cognitive Decline Trajectory

Cognitive impairment after stroke is common, but the trajectory of cognitive decline following a first stroke, relative to prestroke cognitive function, remains unclear.

The investigators leveraged data from 14 population-based cohort studies of 20,860 adults (mean age, 73 years; 59% women) to map the trajectory of cognitive function before and after a first stroke.

The primary outcome was global cognition, defined as the standardized average of four cognitive domains (language, memory, processing speed, and executive function).

During a mean follow-up of 7.5 years, 1041 (5%) adults (mean age, 79 years) experienced a first stroke, a mean of 4.5 years after study entry.

In adjusted analyses, stroke was associated with a significant acute decline of 0.25 SD in global cognition and a “small but significant” acceleration in the rate of decline of −0.038 SD per year, the authors reported.

Stroke was also associated with acute decline in all individual cognitive domains except for memory, with effect sizes ranging from −0.17 to −0.22 SD. Poststroke declines in Mini-Mental State Examination scores (−0.36 SD) were also noted.

In terms of cognitive trajectory, the rate of decline before stroke in survivors was similar to that seen in peers who didn’t have a stroke (−0.048 and −0.049 SD per year in global cognition, respectively).

The researchers did not identify any vascular risk factors moderating cognitive decline following a stroke, consistent with prior research. However, cognitive decline was significantly more rapid in individuals without stroke, regardless of any future stroke, who had a history of diabetes, hypertension, high cholesterol, cardiovascular disease, depression, smoking, or were APOE4 carriers.

“Targeting modifiable vascular risk factors at an early stage may reduce the risk of stroke but also subsequent risk of stroke-related cognitive decline and cognitive impairment,” the researchers noted.

A ‘Major Step’ in the Right Direction

As previously reported by Medscape Medical News, last year the American Heart Association (AHA) issued a statement noting that screening for cognitive impairment should be part of multidisciplinary care for stroke survivors.

Commenting for Medscape Medical News, Mitchell Elkind, MD, MS, AHA chief clinical science officer, said these new data are consistent with current AHA guidelines and statements that “support screening for cognitive and functional decline in patients both acutely and over the long term after stroke.”

Elkind noted that the 2022 guideline for intracerebral hemorrhage states that cognitive screening should occur “across the continuum of inpatient care and at intervals in the outpatient setting” and provides recommendations for cognitive therapy.

“Our 2021 scientific statement on the primary care of patients after stroke also recommends screening for both depression and cognitive impairment over both the short- and long-term,” said Elkind, professor of neurology and epidemiology at Columbia University Irving Medical Center in New York City.

“These documents recognize the fact that function and cognition can continue to decline years after stroke and that patients’ rehabilitation and support needs may therefore change over time after stroke,” Elkind added.

The authors of an accompanying commentary called it a “major step” in the right direction for the future of long-term stroke outcome assessment.

“As we develop new devices, indications, and time windows for stroke treatment, it may perhaps be wise to ensure trials steer away from simpler outcomes to more complex, granular ones,” wrote Yasmin Sadigh, MSc, and Victor Volovici, MD, PhD, with Erasmus University Medical Center, Rotterdam, the Netherlands.

The study had no commercial funding. The authors and commentary writers and Elkind have declared no conflicts of interest.