Tag: cognitive dysfunction

Microstructural brain abnormalities, fatigue, and cognitive dysfunction after mild COVID-19

Abstract:

Although some studies have shown neuroimaging and neuropsychological alterations in post-COVID-19 patients, fewer combined neuroimaging and neuropsychology evaluations of individuals who presented a mild acute infection. Here we investigated cognitive dysfunction and brain changes in a group of mildly infected individuals.

We conducted a cross-sectional study of 97 consecutive subjects (median age of 41 years) without current or history of psychiatric symptoms (including anxiety and depression) after a mild infection, with a median of 79 days (and mean of 97 days) after diagnosis of COVID-19. We performed semi-structured interviews, neurological examinations, 3T-MRI scans, and neuropsychological assessments. For MRI analyses, we included a group of non-infected 77 controls. The MRI study included white matter (WM) investigation with diffusion tensor images (DTI) and functional connectivity with resting-state functional MRI (RS-fMRI).

The patients reported memory loss (36%), fatigue (31%) and headache (29%). The quantitative analyses confirmed symptoms of fatigue (83% of participants), excessive somnolence (35%), impaired phonemic verbal fluency (21%), impaired verbal categorical fluency (13%) and impaired logical memory immediate recall (16%). The WM analyses with DTI revealed higher axial diffusivity values in post-infected patients compared to controls.

Compared to controls, there were no significant differences in the functional connectivity of the posterior cingulum cortex. There were no significant correlations between neuropsychological scores and neuroimaging features (including DTI and RS-fMRI).

Our results suggest persistent cognitive impairment and subtle white matter abnormalities in individuals mildly infected without anxiety or depression symptoms. The longitudinal analyses will clarify whether these alterations are temporary or permanent.

Source: Scardua-Silva, L., Amorim da Costa, B., Karmann Aventurato, Í. et al. Microstructural brain abnormalities, fatigue, and cognitive dysfunction after mild COVID-19. Sci Rep 14, 1758 (2024). https://doi.org/10.1038/s41598-024-52005-7  https://www.nature.com/articles/s41598-024-52005-7 (Full text)

Exploring the neurocognitive consequences of post-exertional malaise in myalgic encephalomyelitis

Background and aims:

Myalgic encephalomyelitis (ME) is a complex, debilitating and heterogeneous disorder. It affects over 500,000 people in Canada but remains poorly understood. People are affected with multi-systemic symptoms such as fatigue that is not alleviated by rest, pain, cognitive impairment and post-exertional malaise (PEM), which is considered as the hallmark symptom of ME. PEM is triggered by minimal mental or physical effort and exacerbates other symptoms. Our aim was to measure how individuals’ cognition can be impacted by the induction of PEM, and investigate the difference in cognitive response.

Section snippets:

Methods
A prospective cohort of people with ME (n = 42) and matched healthy controls (n = 15) was recruited and subjected to PEM induction through a 90-minutes mechanical arm stimulation. BrainCheck test (BrainCheck, Inc., TX, USA) was used at baseline (T0) and after 90 minutes of stimulation to evaluate six cognitive domains for which each participant received a score and a population percentile based on their performance.

Results
Comparison between both groups was significant (p < 0.05) at T90, but not at T0, in four out of six cognitive domains. We then classified our ME cohort in three clusters by k-means method based on the Δ percentile (T90-T0) for each cognitive task. This stratification allowed us to notice how some cognitive domains seem more affected depending on the cluster, namely memory and attention.

Conclusions
These results showed the impact of PEM on the disturbance of cognition in the context of ME as well as the variability of cognitive domains affected in people with ME.

Source: Corinne Leveau, Iurie Caraus, Anita Franco, Alain Moreau. Exploring the neurocognitive consequences of post-exertional malaise in myalgic encephalomyelitis. Journal of the Neurological Sciences, Volume 455, Supplement, December 2023, 122590. https://www.sciencedirect.com/science/article/abs/pii/S0022510X23020518