Changes in episodic and working memory are found in patients with long COVID. 

People with SARS-CoV-2 infection may have persistence of symptoms for several months after acute illness. Estimates of persistence rates range from 2.5% to 28%. Initially many of the cognitive and emotional symptoms were attributed to the psychological trauma after the health crisis rather than to impairment of the central nervous system, but data were sparse. In this single-centre, cross-sectional study, researchers assessed patients with COVID-19 during the first wave, comparing those without persistent symptoms with those who had persistent neurological symptoms for longer than 14 months (neurologic long COVID). Patients had an extensive and thorough neuropsychological assessment and neuroimaging analysis with special attention to grey- and white-matter changes.

Eighty-three patients with neurologic long COVID and 22 COVID-19 controls without long COVID were included. Patients with long COVID symptoms reported memory failure and poor concentration (90%), asthenia (82%), headache (72%), anxiety (58%), limb paresis (57%), insomnia (57%) and depression (46%). However, the key findings were the alterations detected by neuropsychological testing, compared with population norms, in episodic memory, including verbal and visual memory, in 48% of patients with long COVID and deficits compared with both population norms and controls in attention, verbal working memory, processing speed and verbal fluency in 27% of patients. Some degree of deficit was found in 24% to 34% of patients, and up to 20% had severe impairment. Regarding neuroimaging findings, long COVID patients had significantly thinner cortex in the left superior temporal gyrus. White matter also was affected, with poor integrity located near the cluster of the thinner cortex. Brain regions affected in long COVID correlated with the cognitive dysfunction, and more patients with long COVID had a severe initial infection.

Comment: This well-carried-out study shows that long COVID or persistence of symptoms for months after acute illness can produce important cognitive dysfunction, especially affecting episodic memory, attention, working memory, processing speed and verbal fluency. 

Note to readers: At the time we reviewed this paper, its publisher noted that it was not in final form and that subsequent changes might be made.

Jaime Toro, MD, Chief, Section of Neurology, Fundación Santa Fe de Bogotá; Professor and Director of the Program of Neurology, University of El Bosque, Santa Fe de Bogotá, Colombia.

Serrano del Pueblo VM, et al. Brain and cognitive changes in patients with long COVID compared with infection-recovered control subjects. Brain 2024 Apr 2; e-pub (https://doi.org/10.1093/brain/awae101).

This summary is taken from the following Journal Watch title: Neurology.