Chandelier
Senior Member (Voting Rights)
Identifying EEG biomarkers of fatigue and brain fog in long COVID: insights from rest and movement-related brain activity
• Slower sensorimotor alpha frequency at rest reflected fatigue-linked excitability.
• EEG changes tied to fatigue and brain fog suggest disrupted E/I balance.
In this context, we aimed to identify neural correlates associated with LC symptoms.
A sample of twenty LC participants reporting fatigue, brain fog, and post-exertional malaise (PEM) was analyzed, along with 20 age- and sex-matched controls.
All participants were right-handed, and EEG activity was recorded on the dominant left hemisphere over motor and somatosensory areas.
The main LC symptoms were assessed using the Fatigue Severity Scale (FSS), the Cognitive Failures Questionnaire (CFQ), and the DePaul Symptom Questionnaire for PEM (DSQ-PEM).
They also showed a slower alpha central frequency (CF) at rest (electrode C5, p = 0.003), which correlated with fatigue (r = −0.264, p = 0.019).
Together, these features, which were associated with fatigue and brain fog, highlight altered dynamics in the sensorimotor cortex of LC individuals.
These findings offer preliminary mechanistic insight into LC symptoms and suggest that PMBR and alpha CF warrant further investigation as candidate EEG markers of this condition.
Web | DOI | Journal of Clinical Neuroscience | Open Access
Casado Sánchez, M.; Morales Fajardo, K.; Long, S.; Janaudis-Ferreira, T.; Duclos, C.; Boudrias, M.H.
Highlights
• Long COVID showed reduced post-movement beta rebound in somatomotor cortex.• Slower sensorimotor alpha frequency at rest reflected fatigue-linked excitability.
• EEG changes tied to fatigue and brain fog suggest disrupted E/I balance.
Abstract
Background
Fatigue and brain fog are among the most reported symptoms in Long COVID (LC), yet their underlying neural mechanisms remain unclear.In this context, we aimed to identify neural correlates associated with LC symptoms.
Methods
Electroencephalography (EEG) was used to quantify brain oscillatory activity during sustained handgrips and rest in the left central region overlying the primary hand motor (C3) and somatosensory areas (C5).A sample of twenty LC participants reporting fatigue, brain fog, and post-exertional malaise (PEM) was analyzed, along with 20 age- and sex-matched controls.
All participants were right-handed, and EEG activity was recorded on the dominant left hemisphere over motor and somatosensory areas.
The main LC symptoms were assessed using the Fatigue Severity Scale (FSS), the Cognitive Failures Questionnaire (CFQ), and the DePaul Symptom Questionnaire for PEM (DSQ-PEM).
Results
LC participants showed a smaller post-movement beta rebound (PMBR) during handgrips in the left central region (electrode C3, p = 0.02) compared to controls, which negatively correlated with cognitive symptoms (r = −0.35, p = 0.02).They also showed a slower alpha central frequency (CF) at rest (electrode C5, p = 0.003), which correlated with fatigue (r = −0.264, p = 0.019).
Conclusions
Both the lower PMBR and slower alpha CF suggest impaired inhibitory control and reduced excitability in the sensorimotor cortex of LC individuals.Together, these features, which were associated with fatigue and brain fog, highlight altered dynamics in the sensorimotor cortex of LC individuals.
These findings offer preliminary mechanistic insight into LC symptoms and suggest that PMBR and alpha CF warrant further investigation as candidate EEG markers of this condition.
Web | DOI | Journal of Clinical Neuroscience | Open Access