Risk for cognitive decline associated with older COVID-19 survivors

An increased risk for cognitive decline was associated with adults aged 60 years and older, following severe cases of COVID-19, in Wuhan, China, experts reported in JAMA Neurology.

Yu-Hui Liu, MD, PhD, of the Center for Clinical Neuroscience at Third Military Medical University in Chongqing, China, and colleagues recruited 3,233 COVID-19 survivors who were discharged from three COVID-19-designated hospitals from Feb. 10 through April 10, 2020.

Researchers recruited participants’ uninfected spouses (n = 466) as the study’s control population and conducted cognitive interviews at baseline, 6 months and 12 months.

Cognitive statuses were rated using a questionnaire and the Chinese version of the Telephone Interview of Cognitive Status-40 (TICS-40), which included 10 variables and graded on a 40-point scale. A score of 20 or lower was indicative of mild cognitive impairment (MCI), while a score of 12 or lower was indicative of dementia.

The authors categorized study participants’ cognitive scores in four groups — stable cognition, early-onset cognitive decline, late-onset cognitive decline and progressive cognitive decline.

Following 6- and 12-month follow-up periods, a total of 1,438 COVID-19 survivors (747 female [51.95%]; median age, 69 years) and 438 spouses (222 male [50.68%]; median age, 67 years) were included in the study. Of the 1,438 COVID-19 cases, 260 were classified as severe.

COVID-19 survivors had lower TICS-40 scores than control participants at the 6-month interval (median [interquartile range], 29 [24-32] vs. 30 [26-33]; P < .001) and at the 12-month interval (median [IQR], 29 [24-32] vs. 31 [26-33]; P < .001), following discharge.

After 6 months, those with severe COVID-19 had lower TICS-40 than those with non-severe cases (median [IQR], 24 [18.25-29] vs. 30 [26-33]; P < .001). Likewise, this was also seen after 12 months (median [IQR], 22.5 [16-28] vs. 30 [26-33]; P < .001).

Among those with severe COVID-19 cases, 26 (10%) had dementia and 69 (26.54%) had MCI, after 6 months. This increased to 39 (15%) for dementia at 12 months; MCI remained the same. Survivors of non-severe COVID-19 and control patients had comparable frequencies of dementia and MCI at both 6- and 12-month intervals.

Severe COVID-19 (OR = 9.1; 95% CI, 5.61-14.75) was associated with a higher risk for cognitive impairment, 12 months post-discharge. Non-severe cases were not (OR = 1.1; 95% CI, 0.69-1.76).

“These findings suggest that COVID-19, especially severe COVID-19, may be associated with long-term cognitive impairment,” the authors wrote.