Trial Report Persistent fatigue in post-acute COVID syndrome is associated with altered T1 MRI texture in subcortical structures, 2024, Churchill

[Dolphin]

https://www.sciencedirect.com/science/article/abs/pii/S0166432824002018

Behavioural Brain Research
Available online 9 May 2024, 115045


Research article
Persistent fatigue in post-acute COVID syndrome is associated with altered T1 MRI texture in subcortical structures: a preliminary investigation

Nathan W. Churchill, Eugenie Roudaia, J. Jean Chen, Allison Sekuler, Fuqiang Gao, Mario Masellis, Benjamin Lam, Ivy Cheng, Chris Heyn, Sandra E. Black, Bradley J. MacIntosh, Simon J. Graham, Tom A. Schweizer,

Received 20 February 2024, Revised 3 May 2024, Accepted 6 May 2024, Available online 9 May 2024.


https://doi.org/10.1016/j.bbr.2024.115045Get rights and content

ABSTRACT

Post-acute COVID syndrome (PACS) is a global health concern and is often associated with debilitating symptoms.

Post-COVID fatigue is a particularly frequent and troubling issue, and its underlying mechanisms remain incompletely understood.

One potential contributor is micropathological injury of subcortical and brainstem structures, as has been identified in other patient populations.

Texture-based analysis (TA) may be used to measure such changes in anatomical MRI data.

The present study develops a methodology of voxel-wise TA mapping in subcortical and brainstem regions, which is then applied to T1-weighted MRI data from a cohort of 48 individuals who had PACS (32 with and 16 without ongoing fatigue symptoms) and 15 controls who had cold and flu-like symptoms but tested negative for COVID-19.

Both groups were assessed an average of 4-5 months post-infection.

There were no significant differences between PACS and control groups, but significant differences were observed between those with and without fatigue symptoms in the PACS group.

This included reduced texture energy and increased entropy, along with reduced texture correlation, cluster shade and profile in the putamen, pallidum, thalamus and brainstem.

These findings provide new insights into the neurophysiological mechanisms that underlie PACS, with altered tissue texture as a potential biomarker of this debilitating condition.

https://twitter.com/user/status/1790193065354776891

 

[SNT Gatchaman]

Magnetic resonance imaging (MRI) can provide an important probe for neuroinjury in PACS cohorts. However, tissue abnormalities are often subtle and difficult to identify by visual inspection of images, particularly in non-hospitalized cohorts where the acute disease course tends to be less severe, but post-COVID fatigue remains highly prevalent. A promising solution to this issue is through texture-based analysis (TA) of anatomical MRI scans

Although a relatively new field of research in clinical neuroimaging, promising results have been reported for multiple neurological conditions, including glioma, multiple sclerosis and Alzheimer’s disease

One of the most well-established TA approaches involves the extraction of “Haralick features” from grey level co-occurrence matrices (GLCMs), with the goal of quantifying subjective image qualities, such as “smoothness”, “granularity”, and “complexity”

In practise, intensity values from neighbouring voxels in MR images are collected and used to form a bi-variate histogram. The Haralick features then summarize the “shape” of the histogram, with sets of features usually examined in a single study, such as energy, contrast, entropy, homogeneity, correlation, cluster shade, and cluster prominence.

The present study applies TA to subcortical structures of T1-weighted MRI data

 

[SNT Gatchaman]

Prior literature has shown that unenhanced T1weighted MRI is sensitive to neuronal loss and neuroinflammation, manifesting as signal hypointensities

[Authors] predicted that differences between COVID-19 and control groups will manifest as a greater range of variability in pairwise intensity values (decreased energy, increased entropy), stronger regional changes in signal intensity (increased contrast, decreased homogeneity) and reduced spatial correlations (decreased correlation); the effects are also expected to disrupt signal gradients in tissue (reduced cluster shade and prominence). It is also predicted that effects on subcortical texture will be more strongly expressed in the COVID-positive group with persistent fatigue symptoms, compared to COVID-positive individuals without ongoing fatigue.

The main study findings partially support our hypotheses, as differences between the combined COVID-19 group and controls were non-significant, but COVID-19 patients with persistent fatigue showed significant texture differences relative to both COVID-19 patients without fatigue and nonCOVID controls. The effects were also in the hypothesized direction, with clusters of significantly decreased ENE and increased ENT in the left putamen, pallidum, ventral DC [diencephalon] and brainstem, along with decreased COR, SHA and PRO in the left thalamus and ventral DC. The predicted effects for CTR and HOM, however, were non-significant.

 

[Ash]

Worse and worse.
Almost makes you think about dusting off that old saying..Oh how does it go now…’An ounce of prevention is better than a cure that doesn’t exist’ huh?