Altered brain connectivity in Long Covid during cognitive exertion: a pilot study

Area of Science:

• Neuroimaging
• Neurology
• Infectious Diseases

Background:

• Long Covid (LCov) is a debilitating condition with frequent neurological symptoms following SARS-COVID-19 infection.
• Understanding the neural underpinnings of LCov is crucial for developing effective treatments.

Purpose of the Study:

• To investigate functional brain connectivity differences between individuals with Long Covid and healthy controls using high-field functional MRI.
• To explore the relationship between brain connectivity patterns and clinical symptoms in Long Covid patients.

Main Methods:

• Functional MRI (7 Tesla) was performed on 10 LCov patients and 13 healthy controls (HC) during a cognitive task.
• Brain connectivity was assessed using region-to-region (ROI-to-ROI) and region-to-voxel analyses, focusing on salience, default-mode, hippocampus, and brainstem networks.
• Regression analyses correlated connectivity with clinical disability and autonomic function scores in LCov.

Main Results:

• Two ROI-to-ROI connections involving the brainstem (rostral medulla) were significantly stronger in LCov than HC.
• ROI-to-voxel analyses revealed widespread connectivity differences across the brain in LCov, mostly weaker than HC.
• LCov brainstem connectivity correlated significantly with disability and autonomic symptom scores.

Conclusions:

• Altered brainstem connectivity is a key feature of Long Covid, potentially reflecting compensatory mechanisms.
• These findings suggest that brainstem dysfunction contributes to the neurological and autonomic symptoms experienced by LCov patients.
• The study highlights the brainstem's role in regulating arousal, autonomic function, and sleep-wake cycles in the context of Long Covid.