Reduced Cortical Thickness Correlates of Cognitive Dysfunction in Post-COVID-19 Condition: Insights from a Long-Term Follow-up

Abstract:

Background and purpose: There is a paucity of data on long-term neuroimaging findings from individuals who have developed the post-coronavirus 2019 (COVID-19) condition. Only 2 studies have investigated the correlations between cognitive assessment results and structural MR imaging in this population. This study aimed to elucidate the long-term cognitive outcomes of participants with the post-COVID-19 condition and to correlate these cognitive findings with structural MR imaging data in the post-COVID-19 condition.

Materials and methods: A cohort of 53 participants with the post-COVID-19 condition underwent 3T brain MR imaging with T1 and FLAIR sequences obtained a median of 1.8 years after Severe Acute Respiratory Syndrome coronavirus 2 (SARS-CoV-2) infection. A comprehensive neuropsychological battery was used to assess several cognitive domains in the same individuals. Correlations between cognitive domains and whole-brain voxel-based morphometry were performed. Different ROIs from FreeSurfer were used to perform the same correlations with other neuroimaging features.

Results: According to the Frascati criteria, more than one-half of the participants had deficits in the attentional (55%, n = 29) and executive (59%, n = 31) domains, while 40% (n = 21) had impairment in the memory domain. Only 1 participant (1.89%) showed problems in the visuospatial and visuoconstructive domains. We observed that reduced cortical thickness in the left parahippocampal region (t(48) = 2.28, = .03) and the right caudal-middle-frontal region (t(48) = 2.20, = .03) was positively correlated with the memory domain.

Conclusions: Our findings suggest that cognitive impairment in individuals with the post-COVID-19 condition is associated with long-term alterations in the structure of the brain. These macrostructural changes may provide insight into the nature of cognitive symptoms.

Source: Dacosta-Aguayo R, Puig J, Lamonja-Vicente N, Carmona-Cervelló M, Biaani León-Gómez B, Monté-Rubio G, López-Linfante VM, Zamora-Putin V, Montero-Alia P, Chacon C, Bielsa J, Moreno-Gabriel E, Garcia-Sierra R, Pachón A, Costa A, Mataró M, Prado JG, Martinez-Cáceres E, Mateu L, Massanella M, Violán C, Torán-Monserrat P; Aliança ProHEpiC-19 Cognitiu (The APC Collaborative Group). Reduced Cortical Thickness Correlates of Cognitive Dysfunction in Post-COVID-19 Condition: Insights from a Long-Term Follow-up. AJNR Am J Neuroradiol. 2024 Apr 4. doi: 10.3174/ajnr.A8167. Epub ahead of print. PMID: 38575319. https://pubmed.ncbi.nlm.nih.gov/38575319/

SARS-CoV2 evokes structural brain changes resulting in declined executive function

Abstract:

Background: Several research has underlined the multi-system character of COVID-19. Though effects on the Central Nervous System are mainly discussed as disease-specific affections due to the virus’ neurotropism, no comprehensive disease model of COVID-19 exists on a neurofunctional base by now. We aimed to investigate neuroplastic grey- and white matter changes related to COVID-19 and to link these changes to neurocognitive testings leading towards a multi-dimensional disease model.

Methods: Groups of acutely ill COVID-19 patients (n = 16), recovered COVID-19 patients (n = 21) and healthy controls (n = 13) were prospectively included into this study. MR-imaging included T1-weighted sequences for analysis of grey matter using voxel-based morphometry and diffusion-weighted sequences to investigate white matter tracts using probabilistic tractography. Comprehensive neurocognitive testing for verbal and non-verbal domains was performed.

Results: Alterations strongly focused on grey matter of the frontal-basal ganglia-thalamus network and temporal areas, as well as fiber tracts connecting these areas. In acute COVID-19 patients, a decline of grey matter volume was found with an accompanying diminution of white matter tracts. A decline in executive function and especially verbal fluency was found in acute patients, partially persisting in recovered.

Conclusion: Changes in gray matter volume and white matter tracts included mainly areas involved in networks of executive control and language. Deeper understanding of these alterations is necessary especially with respect to long-term impairments, often referred to as ‘Post-COVID’.

Source: Deuter D, Hense K, Kunkel K, Vollmayr J, Schachinger S, Wendl C, Schicho A, Fellner C, Salzberger B, Hitzenbichler F, Zeller J, Vielsmeier V, Dodoo-Schittko F, Schmidt NO, Rosengarth K. SARS-CoV2 evokes structural brain changes resulting in declined executive function. PLoS One. 2024 Mar 12;19(3):e0298837. doi: 10.1371/journal.pone.0298837. PMID: 38470899; PMCID: PMC10931481. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10931481/ (Full text)

MEA Review: Grey and white matter differences in chronic fatigue syndrome

The ME Association of Great Britain has provided an excellent review of a recent study on brain matter abnormalities in ME/CFS patients. The study, Grey and white matter differences in Chronic Fatigue Syndrome – A voxel-based morphometry study, was conducted by Julia Newton’s group at Newcastle University. Below is an excerpt from Dr. Shepherd’s summary of the study. To read a full discussion, along with an excellent overview of brain pathology and the implications of these brain abnormalities, go HERE. You can download the full review as a PDF file.

_______________________

Comment from Dr Charles Shepherd, Hon Medical Adviser, ME Association:

This study was carried out in Newcastle by Professor Julia Newton and colleagues – a team who have not only achieved a long and distinguished record in ME/CFS research but also have access to patients who have been very carefully assessed from a clinical point of view. So, the results should be taken seriously.

As has been pointed out in this review, three of the main criticisms of previous neuroimaging studies involving people with ME/CFS is that the numbers involved have often been far too small; there has been a lack of information from other control groups that would be relevant in addition to the use of healthy controls; and that different imaging techniques have been used.  So, not surprisingly, the results are not always consistent.

Despite these caveats, these results clearly add weight to the findings from previous neuroimaging studies describing white matter abnormalities in ME/CFS but also raise the possibility of grey matter involvement in ME/CFS.

There are several possible explanations for these findings but no clear answer has emerged in the paper.  Are they a primary feature of ME/CFS?  Or are they secondary to other factors – e.g. duration of illness, decrease in activity, severity of fatigue – that are related to having ME/CFS?  The only way to find out is through further research into what is clearly an interesting aspect of neuropathology in ME/CFS.

A fully referenced summary of all the key findings from both functional and structural neuroimaging studies in ME/CFS can be found in the Research section of the ME Association ‘An Exploration of the Key Clinical Issues’ available from our online shop.

You can read the rest of this brief summary HERE.

Grey and white matter differences in Chronic Fatigue Syndrome – A voxel-based morphometry study

Abstract:

OBJECTIVE: Investigate global and regional grey and white matter volumes in patients with Chronic Fatigue Syndrome (CFS) using magnetic resonance imaging (MRI) and recent voxel-based morphometry (VBM) methods.

METHODS: Forty-two patients with CFS and thirty healthy volunteers were scanned on a 3-Tesla MRI scanner. Anatomical MRI scans were segmented, normalized and submitted to a VBM analysis using randomisation methods. Group differences were identified in overall segment volumes and voxel-wise in spatially normalized grey matter (GM) and white matter (WM) segments.

RESULTS: Accounting for total intracranial volume, patients had larger GM volume and lower WM volume. The voxel-wise analysis showed increased GM volume in several structures including the amygdala and insula in the patient group. Reductions in WM volume in the patient group were seen primarily in the midbrain, pons and right temporal lobe.

CONCLUSION: Elevated GM volume in CFS is seen in areas related to processing of interoceptive signals and stress. Reduced WM volume in the patient group partially supports earlier findings of WM abnormalities in regions of the midbrain and brainstem.

Source: Finkelmeyer A, He J, Maclachlan L, Watson S, Gallagher P, Newton JL, Blamire AM. Grey and white matter differences in Chronic Fatigue Syndrome – A voxel-based morphometry study. Neuroimage Clin. 2017 Sep 28;17:24-30. doi: 10.1016/j.nicl.2017.09.024. ECollection 2018. https://www.ncbi.nlm.nih.gov/pubmed/29021956

Progressive brain changes in patients with chronic fatigue syndrome: A longitudinal MRI study

Abstract:

PURPOSE: To examine progressive brain changes associated with chronic fatigue syndrome (CFS).

MATERIALS AND METHODS: We investigated progressive brain changes with longitudinal MRI in 15 CFS and 10 normal controls (NCs) scanned twice 6 years apart on the same 1.5 Tesla (T) scanner. MR images yielded gray matter (GM) volumes, white matter (WM) volumes, and T1- and T2-weighted signal intensities (T1w and T2w). Each participant was characterized with Bell disability scores, and somatic and neurological symptom scores. We tested for differences in longitudinal changes between CFS and NC groups, inter group differences between pooled CFS and pooled NC populations, and correlations between MRI and symptom scores using voxel based morphometry. The analysis methodologies were first optimized using simulated atrophy.

RESULTS: We found a significant decrease in WM volumes in the left inferior fronto-occipital fasciculus (IFOF) in CFS while in NCs it was unchanged (family wise error adjusted cluster level P value, PFWE < 0.05). This longitudinal finding was consolidated by the group comparisons which detected significantly decreased regional WM volumes in adjacent regions (PFWE< 0.05) and decreased GM and blood volumes in contralateral regions (PFWE < 0.05). Moreover, the regional GM and WM volumes and T2w in those areas showed significant correlations with CFS symptom scores (PFWE < 0.05).

CONCLUSION: The results suggested that CFS is associated with IFOF WM deficits which continue to deteriorate at an abnormal rate. J. Magn. Reson. Imaging 2016;44:1301-1311.

© 2016 The Authors Journal of Magnetic Resonance Imaging published by Wiley Periodicals, Inc. on behalf of International Society for Magnetic Resonance in Medicine.

 

Source: Shan ZY, Kwiatek R, Burnet R, Del Fante P, Staines DR, Marshall-Gradisnik SM, Barnden LR. Progressive brain changes in patients with chronic fatigue syndrome: A longitudinal MRI study. J Magn Reson Imaging. 2016 Nov;44(5):1301-1311. doi: 10.1002/jmri.25283. Epub 2016 Apr 28. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5111735/ (Full article)

 

Regional grey and white matter volumetric changes in myalgic encephalomyelitis (chronic fatigue syndrome): a voxel-based morphometry 3 T MRI study

Abstract:

OBJECTIVE: It is not established whether myalgic encephalomyelitis/chronic fatigue syndrome (CFS) is associated with structural brain changes. The aim of this study was to investigate this by conducting the largest voxel-based morphometry study to date in CFS.

METHODS: High-resolution structural 3 T cerebral MRI scanning was carried out in 26 patients with CFS and 26 age- and gender-matched healthy volunteers. Voxel-wise generalised linear modelling was applied to the processed MR data using permutation-based non-parametric testing, forming clusters at t>2.3 and testing clusters for significance at p<0.05, corrected for multiple comparisons across space.

RESULTS: Significant voxels (p<0.05, corrected for multiple comparisons) depicting reduced grey matter volume in the CFS group were noted in the occipital lobes (right and left occipital poles; left lateral occipital cortex, superior division; and left supracalcrine cortex), the right angular gyrus and the posterior division of the left parahippocampal gyrus. Significant voxels (p<0.05, corrected for multiple comparisons) depicting reduced white matter volume in the CFS group were also noted in the left occipital lobe.

CONCLUSION: These data support the hypothesis that significant neuroanatomical changes occur in CFS, and are consistent with the complaint of impaired memory that is common in this illness; they also suggest that subtle abnormalities in visual processing, and discrepancies between intended actions and consequent movements, may occur in CFS.

 

Source: Puri BK, Jakeman PM, Agour M, Gunatilake KD, Fernando KA, Gurusinghe AI, Treasaden IH, Waldman AD, Gishen P. Regional grey and white matter volumetric changes in myalgic encephalomyelitis (chronic fatigue syndrome): a voxel-based morphometry 3 T MRI study. Br J Radiol. 2012 Jul;85(1015):e270-3. doi: 10.1259/bjr/93889091. Epub 2011 Nov 29. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3474083/ (Full article)

 

A brain MRI study of chronic fatigue syndrome: evidence of brainstem dysfunction and altered homeostasis

Abstract:

To explore brain involvement in chronic fatigue syndrome (CFS), the statistical parametric mapping of brain MR images has been extended to voxel-based regressions against clinical scores.

Using SPM5 we performed voxel-based morphometry (VBM) and analysed T(1) – and T(2) -weighted spin-echo MR signal levels in 25 CFS subjects and 25 normal controls (NC). Clinical scores included CFS fatigue duration, a score based on the 10 most common CFS symptoms, the Bell score, the hospital anxiety and depression scale (HADS) anxiety and depression, and hemodynamic parameters from 24-h blood pressure monitoring. We also performed group × hemodynamic score interaction regressions to detect locations where MR regressions were opposite for CFS and NC, thereby indicating abnormality in the CFS group.

In the midbrain, white matter volume was observed to decrease with increasing fatigue duration. For T(1) -weighted MR and white matter volume, group × hemodynamic score interactions were detected in the brainstem [strongest in midbrain grey matter (GM)], deep prefrontal white matter (WM), the caudal basal pons and hypothalamus. A strong correlation in CFS between brainstem GM volume and pulse pressure suggested impaired cerebrovascular autoregulation.

It can be argued that at least some of these changes could arise from astrocyte dysfunction. These results are consistent with an insult to the midbrain at fatigue onset that affects multiple feedback control loops to suppress cerebral motor and cognitive activity and disrupt local CNS homeostasis, including resetting of some elements of the autonomic nervous system (ANS).

Copyright © 2011 John Wiley & Sons, Ltd.

 

Source: Barnden LR, Crouch B, Kwiatek R, Burnet R, Mernone A, Chryssidis S, Scroop G, Del Fante P. A brain MRI study of chronic fatigue syndrome: evidence of brainstem dysfunction and altered homeostasis. NMR Biomed. 2011 Dec;24(10):1302-12. doi: 10.1002/nbm.1692. Epub 2011 May 11. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4369126/ (Full article)

 

Gray matter volume reduction in the chronic fatigue syndrome

Abstract:

The chronic fatigue syndrome (CFS) is a disabling disorder of unknown etiology. The symptomatology of CFS (central fatigue, impaired concentration, attention and memory) suggests that this disorder could be related to alterations at the level of the central nervous system. In this study, we have used an automated and unbiased morphometric technique to test whether CFS patients display structural cerebral abnormalities.

We mapped structural cerebral morphology and volume in two cohorts of CFS patients (in total 28 patients) and healthy controls (in total 28 controls) from high-resolution structural magnetic resonance images, using voxel-based morphometry. Additionally, we recorded physical activity levels to explore the relation between severity of CFS symptoms and cerebral abnormalities.

We observed significant reductions in global gray matter volume in both cohorts of CFS patients, as compared to matched control participants. Moreover, the decline in gray matter volume was linked to the reduction in physical activity, a core aspect of CFS. These findings suggest that the central nervous system plays a key role in the pathophysiology of CFS and point to a new objective and quantitative tool for clinical diagnosis of this disabling disorder.

 

Source: de Lange FP, Kalkman JS, Bleijenberg G, Hagoort P, van der Meer JW, Toni I. Gray matter volume reduction in the chronic fatigue syndrome. Neuroimage. 2005 Jul 1;26(3):777-81. Epub 2005 Apr 7. http://www.ncbi.nlm.nih.gov/pubmed/15955487

 

Mechanisms underlying fatigue: a voxel-based morphometric study of chronic fatigue syndrome

Abstract:

BACKGROUND: Fatigue is a crucial sensation that triggers rest, yet its underlying neuronal mechanisms remain unclear. Intense long-term fatigue is a symptom of chronic fatigue syndrome, which is used as a model to study the mechanisms underlying fatigue.

METHODS: Using magnetic resonance imaging, we conducted voxel-based morphometry of 16 patients and 49 age-matched healthy control subjects.

RESULTS: We found that patients with chronic fatigue syndrome had reduced gray-matter volume in the bilateral prefrontal cortex. Within these areas, the volume reduction in the right prefrontal cortex paralleled the severity of the fatigue of the subjects.

CONCLUSION: These results are consistent with previous reports of an abnormal distribution of acetyl-L-carnitine uptake, which is one of the biochemical markers of chronic fatigue syndrome, in the prefrontal cortex. Thus, the prefrontal cortex might be an important element of the neural system that regulates sensations of fatigue.

 

Source: Okada T, Tanaka M, Kuratsune H, Watanabe Y, Sadato N. Mechanisms underlying fatigue: a voxel-based morphometric study of chronic fatigue syndrome. BMC Neurol. 2004 Oct 4;4(1):14. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC524491/