Yesterday (17.07.25), Cureus published a research article entitled ‘Assessing Brain Neurophysiology in COVID-19 Patients With Prolonged Cognitive Fatigue: A Comparison With Persistent Post-concussion Symptoms' and Dr Charles Shepherd has provided his comments.
Oakley et al (2025)
Abstract Summary (using AI)
- This study examined if similar electroencephalogram (EEG) markers are present in long COVID to better quantify cognitive impairment.
- Participants: 31 long COVID patients (mean age 45 ± 9; 10 ± 2 months post-infection), 64 PPCS patients (69% female; mean age 42 ± 11) and 70 age-matched healthy controls (mean age 45 ± 5).
- Key findings: Reduced P300 amplitude, altered EEG coherence, biomarker normalization paralleled symptom recovery, supporting clinical utility and EEG/ERP metrics offer objective tools to diagnose and track post-viral cognitive impairment.
- These abnormalities correlate with cognitive fatigue and functional neurological dysfunction.
- Conclusions: ERP deficits common in concussion, persistent post-concussion symptoms (PPCS), and aging are also found in Long Covid symptoms.
Extracts
Abstract
Introduction: Brain fog and cognitive dysfunction are frequently reported in post-viral fatigue syndromes such as long COVID, yet these symptoms remain challenging to quantify objectively. Notably, many individuals with long COVID describe clinical features that overlap with those observed in patients with persistent post-concussion symptoms (PPCS), including cognitive fatigue, exertional intolerance, mood disturbances, visual and balance problems, headaches, and neck pain.
Emerging evidence suggests that PPCS is associated with distinct electrophysiological abnormalities, including altered functional connectivity (measured by electroencephalography (EEG) coherence), spatial changes in EEG amplitude distribution (notably increased frontal alpha and left-right asymmetry), and reduced cognitive evoked potentials (e.g., the auditory P300 response). In this study, we investigated whether these electrophysiological markers of PPCS are also present in individuals experiencing post-viral fatigue following COVID-19, aiming to provide objective measures to better characterize and quantify cognitive impairment in this population.
MEA Comment
We already know that cognitive dysfunction/'brain fog', debilitating fatigue, and other ME/CFS symptoms often occur in a wide range of neurological conditions, especially multiple sclerosis (MS) and Parkinson's disease, and that people who have concussion or a traumatic brain injury often report persisting cognitive dysfunction and fatigue.
So the findings from this research, which compared cognitive dysfunction in people with a persistent post concussion syndrome to people who have cognitive dysfunction linked to post Covid fatigue/ Long Covid, come as no surprise.
At the moment we don't really know what causes cognitive dysfunction in ME/CFS (or in Long Covid). It may involve low level neuroinflammation as a result of a continuing low level immune system activation following a viral infection. It could also involve changes in blood flow to the brain.
Some of the electrophysiological changes being reported here, that occur as a result of a traumatic brain injury, do therefore provide some additional clues about the causation of cognitive dysfunction and possibly what is called central (ie brain) fatigue in ME/CFS. They may also help in developing a more objective way of assessing and confirming cognitive dysfunction in ME/CFS and in Long Covid.
Please see the MEA information leaflet on cognitive dysfunction and ME/CFS below:
Dr Charles Shepherd,
Trustee and Hon. Medical Adviser to the ME Association,
Member of the 2018-2021 NICE guideline on ME/CFS committee,
Member of the 2002 Chief Medical Officer's Working Group on ME/CFS
Information
- The ME Association: Trends in Neurosciences: Cognitive dysfunction/brain fog in various medical conditions – including ME/CFS and Long Covid | March 3, 2025
- The ME Association: MDPI Article: Cognitive Dysfunction in ME/CFS – Aetiology and Potential Treatments | February 25 , 2025
- The ME Association: Research: Novel brain SPECT imaging unravels abnormal cerebral perfusion in patients with PoTS and cognitive dysfunction | January 30 , 2025
- The ME Association: BMJ: Cognitive dysfunction in Long Covid – and in ME/CFS | March 14 , 2024