Investigation of BOLD signal activation in Long COVID patients using 7T MRI
Poster No:
1060
Submission Type:
Abstract Submission
Authors:
Maira Inderyas1, Kiran Thapaliya1, Sonya Marshall-Gradisnik1, Leighton Barnden1
Institutions:
1NCNED, Griffith University, Southport, Queensland
First Author:
Co-Author(s):
Introduction:
Blood oxygenation level-dependent (BOLD) functional magnetic resonance imaging (fMRI) can probe brain functions by measuring haemodynamic responses to neuronal oscillations (Hillman, 2014). Long COVID is a chronic condition characterised by fatigue, light-headedness, and neurocognitive symptoms, of which the exact underlying mechanism is yet to be identified. We investigated BOLD differences between long COVID and COVID-19 recovered healthy individuals (HC-R) using 7 Tesla (7T) fMRI.
Methods:
19 long COVID patients, and 12 COVID-19 recovered healthy controls were included in the study. All participants were asked to perform a Stroop colour-word task. We acquired 80 sagittal slices with 225 volumes of fMRI data on a multiband EPI pulse sequence (Inderyas et al., 2024). The acquisition parameters were repetition time (TR) = 2000ms, echo time (TE) = 22.4ms, flip angle = 70 degrees, multi-slice mode = interleaved, acquisition matrix 192X192 and voxel size = 1.25mm3. Sagittal T1-weighted data was acquired using a Magnetization Prepared 2 Rapid Acquisition Gradient Echo Sequence with TR = 4,300ms, TE = 2.45ms, first inversion time (TI1) = 840ms, second inversion time (TI2) = 2,370ms, first flip angle (FA1) = 5 degrees, second flip angle (FA2) = 6 degrees, and resolution = 0.75mm3 with matrix size = 256X300X320. MRI data were pre-processed using SPM12 (Statistical Parametric Mapping) for realignment and unwarping, slice time correction, and co-registration to anatomical images (Friston et al., 1994). Resampling was performed at isotropic 1 mm, followed by normalisation in MNI space. Smoothing was performed at 5 mm FWHM. Functional MRI model specifications and estimations were performed while regressing for motion correction and framewise displacement measures, and White matter and cerebrospinal fluid time series for whole-brain voxel analysis.
Results:
We found significantly lower BOLD activation in paracingulate gyrus (p=0.002, cluster size= 650, Z-value=4.67) and precuneus (p=<0.001, cluster size=1893, Z-value=4.67) for long COVID patients compared with HC-R (see Figures 1 and 2).
Conclusions:
BOLD fMRI signal responses to the Stroop test were significantly lower in long COVID patients than in COVID-19 recovered individuals. Decreased BOLD signals in the paracingulate gyrus, and precuneus cortex regions may explain altered cognition and metabolic and mentally stimulating operations. This complex interplay between the BOLD signal, changes in cerebral blood volume, cerebral blood flow, and metabolic activity could be associated with underlying inflammation and its pathophysiology.
Disorders of the Nervous System:
Neurodegenerative/ Late Life (eg. Parkinson’s, Alzheimer’s) 2
Modeling and Analysis Methods:
Activation (eg. BOLD task-fMRI) 1
Keywords:
Cerebral Blood Flow
FUNCTIONAL MRI
HIGH FIELD MR
Neurological
1|2Indicates the priority used for review
·Figure 1 shows lower BOLD activation in the paracingulate gyrus of long COVID patients compared with healthy controls
·Figure 2 shows lower BOLD activation in the precuneus cortex of long COVID patients compared with healthy controls.
Abstract Information
By submitting your proposal, you grant permission for the Organization for Human Brain Mapping (OHBM) to distribute your work in any format, including video, audio print and electronic text through OHBM OnDemand, social media channels, the OHBM website, or other electronic publications and media.
The Open Science Special Interest Group (OSSIG) is introducing a reproducibility challenge for OHBM 2025. This new initiative aims to enhance the reproducibility of scientific results and foster collaborations between labs. Teams will consist of a “source” party and a “reproducing” party, and will be evaluated on the success of their replication, the openness of the source work, and additional deliverables. Click here for more information. Propose your OHBM abstract(s) as source work for future OHBM meetings by selecting one of the following options:
Please indicate below if your study was a "resting state" or "task-activation” study.
Healthy subjects only or patients (note that patient studies may also involve healthy subjects):
Was this research conducted in the United States?
Were any human subjects research approved by the relevant Institutional Review Board or ethics panel? NOTE: Any human subjects studies without IRB approval will be automatically rejected.
Were any animal research approved by the relevant IACUC or other animal research panel? NOTE: Any animal studies without IACUC approval will be automatically rejected.
Please indicate which methods were used in your research:
For human MRI, what field strength scanner do you use?
Which processing packages did you use for your study?
Provide references using APA citation style.
Hillman, E. M. C. (2014). Coupling Mechanism and Significance of the BOLD Signal: A Status Report. Annual Review of Neuroscience, 37, 161–181. https://doi.org/10.1146/annurev-neuro-071013-014111
Inderyas, M., Thapaliya, K., Marshall-Gradisnik, S., Barth, M., & Barnden, L. (2024). Subcortical and default mode network connectivity is impaired in myalgic encephalomyelitis/chronic fatigue syndrome. Frontiers in Neuroscience, 17. https://www.frontiersin.org/articles/10.3389/fnins.2023.1318094