Updated: Jul 13, 2021
I recently attended the International Society of Neurofeedback Research (www.isnr.org) Virtual Conference where much of the research done in this past year has centred around how COVID-19 affects the brain.
Presentation by Dr David Cantor was of particular interest as it showed how these changes can be seen in EEG and Quantitative EEG recordings - Covid: Effects on the Brain, Behaviours and the QEEG correlates (David Cantor PHD, Susan Blank MD, Guiseppe Chiarenza MD, Harry Kerasidis MD, Britt Paramore MA, Leslie Sherlin PHD, Tanju Surmeli MD, Ron Swatzyna PHD, Robert Turner MD, Adrian van Deusen).
We know that two general pathways influence the brain:
Direct infection of brain cells via the blood-brain barrier or trans-synaptic transmission along axons through cranial nerves and along the olfactory nerve.
Indirect transmission to the brain can occur as a result of neuroinflammatory mechanisms and organ feedback via the Vagus Nerve or demyelination of Vagus Nerve tracts.
Professor Thomas Hartung and colleagues at Johns Hopkins University discovered that SARS-COV 2 can invade brain cells via the ACE2 human protein. It is not yet known whether the SARS-COV2 virus itself passes the blood-brain barrier but it is known that severe inflammations, such as observed in Covid-19 patients, makes the barrier disintegrate. Prof Hartung highlighted particular concern on the possible effects of the virus on the foetal brain during pregnancy as some research has shown that the virus crosses the placenta and that embryos lack the blood-brain barrier during early development.
While long-term effects of COVID-19 are not yet known we do know that Neurons have significant levels of ACE-2 receptors, which allows SARS-COV2 to penetrate them disrupting the mitochondria and protein folding. Theoretically, this may make patients vulnerable to dementing neurodegenerative diseases decades after the acute illness.
Helms et al, 2020 found that on Neuroimaging and Neuropsychological testing of 58 patients, 84% had neurological symptoms and at discharge, 33% showed features of Dysexecutive Syndrome, ADHD features and poor coordination of movement. On EEG disorganised coherence was seen in the frontotemporal regions.
Batty et al, 2020 found lower cognitive functioning was the highest risk factor with differences noted in semantic problem solving, visual attention and spatial working memory. Couzin-Frankel, 2020 noted Brain Fog in 10-15% of patients in a UK sample while this was seen in 87% in the Italian Population 2-3 months post-recovery. Zhou et al., 2020 noted significantly poorer performance on tasks of continuous performance (attention) with a positive correlation between the degree of inflammation and reaction time.
Psychiatric symptoms have also been identified including confusion, memory impairment, depression, fatigue and insomnia (Rogers et al, 2020). Elevated signs of anxiety and depression have also been identified (Duan et al. 2020).
The Vagus Nerve also plays a role because this is essentially the highway between the brain and peripheral organs, a body-wide system of nerves and hormones which travel from nearly every internal organ to the base of the brain and back again. Peter Strick, a neuroscientist at the University of Pittsburgh, found that viral infection in the stomach leads via vagal pathways to the rostral insula in the brain that is thought to process sensations from internal organs and regulate emotions (Bohorquez, 2018). Hippocampal (memory storage) function was also seen to be affected.
QEEG results show an increase in Delta and Theta Power – both slow brain wave frequencies associated with impaired concentration, poor memory and are implicated in sleep:
Time1: Intake assessment in 2018
Time 2: after 10 sessions of Neurofeedback (2018)
Time 3: After 20 sessions of Neurofeedback (2019)
Time 4: Post-infection with COVID-19 (2020) – Note significantly elevated Delta and Theta amplitude almost back to pre-treatment findings
Time 5: Following Neurofeedback treatment in the Frontal regions of the brain (post COVID19 treatment)
Assessment using the Central Nervous System Vital Signs Test showed difficulties in sustained and simple attention 90 days post-covid infection. All metrics fell within the normal range following 10 sessions of Neurofeedback training.
There is a large body of developing research and anecdotal evidence suggesting that the COVID-19 virus does indeed impact neurocognitive functioning but how long-lasting these effects are is not yet understood.
If you have experienced a severe COVID-19 infection and are concerned about lingering side effects such as brain fog, inattention, memory difficulties, sleep difficulties or mood regulation difficulties take our quiz to find out if further investigation is indeed warranted.