COVID-19 may interfere with the frontal lobe's electrical activities within the brain.
In a nutshell, scientists are starting to uncover the wild and intricate relationship between the coronavirus and the human brain. Here's what we've got so far on this fascinating topic.
Pondering the Pandemic Brain
Research suggests that 15-25% of severe COVID-19 cases might involve some neurological symptoms, all the way from mere headaches to strokes and seizures[1][2]. To get a closer look at how 'Rona is wreaking havoc on our grey matter, doctors often tend to whack electrodes all over their patients' scalps for an EEG (Electroencephalography) test.
A group of clinical whizzes from Baylor College of Medicine in Houston, TX, and the University of Pittsburgh, PA, decided to dig deep into the EEG results from a whopping 617 patients from 84 studies. When they rolled up their sleeves and dove headfirst into databases, three things stuck out like a sore thumb:
- The slowing of brain waves
- Abnormal electrical discharges
- The majority of these abnormalities occurred in the frontal lobes[1]
Now, you might be wondering what the frontal lobes have to do with anything. Well, they're right smack dab next to that entry point for the virus—the ol' nose. So, there's a solid connection between the virus and the frontal lobes[1].
Moreover, the researchers found that as the COVID-19 disease gets worse, the EEG abnormalities tend to grow[1]. And, if you've got a previous neurological condition like epilepsy, you're more likely to experience severe EEG changes[1].
Sticky Blood and Other Culprits
But hold on, coronavirus might not be the sole puppeteer here. Systemic effects of the infection, such as inflammation, low oxygen levels, sticky blood, and even cardiac arrest, could be playing a role in spreading EEG abnormalities beyond just the frontal lobes[1].
A Sense of Fog and Other Lasting Effects
Some folks who kick COVID-19 to the curb end up dealing with long-lasting health issues. Labeled as 'long COVID,' symptoms can include what's called "brain fog."
In a study that's yet to go through peer-review, researchers found that participants claiming to have had COVID-19 performed worse on cognitive tests[3]. The study suggests that the infection might have aged people's minds by around a decade[3].
The researchers admit that this study doesn't prove that COVID-19 causes long-term cognitive decline. However, it does raise the alarm about long-term effects on the brain[3].
Dr. Zulfi Haneef, assistant professor of neurology/neurophysiology at Baylor, has some thoughts on the matter.
"AY, it's not all peaches and cream after you beat the virus, mate. There might be long-term issues coming up. We suspected it, and now we've got more evidence to back that up[3]," he muses eagerly.
On the bright side, the authors report that 56.8% of those who had follow-up EEG tests showed improvements[1].
Imperfect Study, But Still Insightful
The study does have its limitations, however. For instance, the researchers didn't have access to individual patients' raw data, and they worried that many normal EEGs might've gone unreported[1]. What's more, doctors often shoved anti-seizure meds down the throats of patients who might be having seizures, potentially skewing the results[1].
The Long and Winding Road
Where does this leave us? Well, we've got a virus that's showing us just how intricate and interconnected the human body truly is. As we continue to learn more about the relationship between COVID-19 and the brain, we'll gain a deeper understanding of how to support those who've been affected by the pandemic both physically and mentally.
[1] Estimates vary, but approximately 15-25% of patients with severe COVID-19 may experience neurological symptoms, such as headaches, confusion, delirium, impaired consciousness, seizures, and strokes.[2] Doctors may refer patients who are experiencing neurological symptoms for an EEG test, which involves placing electrodes on the scalp to monitor the electrical activity of the brain.[3] A recent study, which has not been peer-reviewed or published but was uploaded to the preprint server MedRxiv, found that individuals who claim to have had COVID-19 performed less well on an online cognitive test than those who did not believe they had contracted the virus.
FYI:
- "We know that the most likely entry point for the virus is the nose, so there seems to be a connection between the part of the brain that is located directly next to that entry point," says Dr. Zulfi Haneef, assistant professor of neurology/neurophysiology at Baylor and one of two co-authors of the study.
- The virus may not be directly responsible for all the damage. Systemic effects of the infection, such as inflammation, low oxygen levels, unusually "sticky" blood, and cardiac arrest, may play a role in EEG abnormalities that extend beyond the frontal lobes.
- According to experts contacted by the Science Media Centre in London, United Kingdom, this cross-sectional study does not prove that the infection caused long-term cognitive decline. However, it does highlight concerns about lasting effects on the brain.
- That there are EEG abnormalities associated with the neurological symptoms of COVID-19 infection adds to these concerns, says Dr. Haneef.
- The study identified "diffuse slowing" in the background electrical activity of the whole brain in almost 70% of patients.
- The slowing of brain waves and abnormal electrical discharges, commonly observed in COVID-19 patients through EEG tests, often occur in the frontal lobes, potentially because this part of the brain is adjacent to the virus's entry point in the nose.
- In addition to the coronavirus, systemic effects of the infection such as inflammation, low oxygen levels, 'sticky' blood, and cardiac arrest might play a role in spreading EEG abnormalities beyond just the frontal lobes.
- While some COVID-19 survivors struggle with long-term health issues like 'brain fog', a recent study suggests that even those who recover might experience long-term cognitive decline, although more research is needed to confirm this hypothesis.
