Brain microstructural changes and fatigue after COVID-19

Abstract:

Background: Fatigue and cognitive complaints are the most frequent persistent symptoms in patients after severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. This study aimed to assess fatigue and neuropsychological performance and investigate changes in the thickness and volume of gray matter (GM) and microstructural abnormalities in the white matter (WM) in a group of patients with mild-to-moderate coronavirus disease 2019 (COVID-19).

Methods: We studied 56 COVID-19 patients and 37 matched controls using magnetic resonance imaging (MRI). Cognition was assessed using Montreal Cognitive Assessment and Cambridge Neuropsychological Test Automated Battery, and fatigue was assessed using Chalder Fatigue Scale (CFQ-11). T1-weighted MRI was used to assess GM thickness and volume. Fiber-specific apparent fiber density (FD), free water index, and diffusion tensor imaging data were extracted using diffusion-weighted MRI (d-MRI). d-MRI data were correlated with clinical and cognitive measures using partial correlations and general linear modeling.

Results: COVID-19 patients had mild-to-moderate acute illness (95% non-hospitalized). The average period between real-time quantitative reverse transcription polymerase chain reaction-based diagnosis and clinical/MRI assessments was 93.3 (±26.4) days. The COVID-19 group had higher total CFQ-11 scores than the control group (p < 0.001). There were no differences in neuropsychological performance between groups. The COVID-19 group had lower FD in the association, projection, and commissural tracts, but no change in GM. The corona radiata, corticospinal tract, corpus callosum, arcuate fasciculus, cingulate, fornix, inferior fronto-occipital fasciculus, inferior longitudinal fasciculus, superior longitudinal fasciculus, and uncinate fasciculus were involved. CFQ-11 scores, performance in reaction time, and visual memory tests correlated with microstructural changes in patients with COVID-19.

Conclusions: Quantitative d-MRI detected changes in the WM microstructure of patients recovering from COVID-19. This study suggests a possible brain substrate underlying the symptoms caused by SARS-CoV-2 during medium- to long-term recovery.

Source: Bispo DDC, Brandão PRP, Pereira DA, Maluf FB, Dias BA, Paranhos HR, von Glehn F, de Oliveira ACP, Regattieri NAT, Silva LS, Yasuda CL, Soares AASM, Descoteaux M. Brain microstructural changes and fatigue after COVID-19. Front Neurol. 2022 Nov 10;13:1029302. doi: 10.3389/fneur.2022.1029302. PMID: 36438956; PMCID: PMC9685991. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9685991/ (Full text)

Chronic fatigue: electromyographic and neuropathological evaluation

Abstract:

Single fibre electromyography of extensor digitorum communis muscle (EDC) was performed on 35 patients with chronic fatigue, the majority of whom also had creatine kinase estimation and biopsy of EDC.

The subjects were categorised as having an acute-onset post-viral fatigue syndrome, a non-specific chronic fatigue or possible muscle disease in view of pronounced myalgia.

Of 11 subjects who had myalgia as a significant symptom, abnormalities in fibre density were found in 6, and 5 of these had some non-specific abnormalities on muscle biopsy, with creatine kinase levels being normal in all cases. Fibre density estimation may be a useful way of identifying a subgroup of chronic fatigue sufferers with a possible primary muscle disorder.

 

Source: Connolly S, Smith DG, Doyle D, Fowler CJ. Chronic fatigue: electromyographic and neuropathological evaluation. J Neurol. 1993 Jul;240(7):435-8. http://www.ncbi.nlm.nih.gov/pubmed/8410086