COVID-19 Alters Brain Blood Flow!

Medical News: COVID-19's Impact on Brain Blood Flow: A New Study Finds Key Changes
As the world continues to study the long-term impacts of COVID-19, researchers have uncovered an alarming connection between the virus and brain function. A recent systematic review reveals that COVID-19 survivors may experience significant changes in brain blood flow, leading to neurological and cognitive challenges. Using advanced imaging technology, this research highlights how the virus affects various parts of the brain, potentially contributing to long-term symptoms such as memory issues, fatigue, and difficulty concentrating.


Brain perfusion alterations in ASL MRI. ASL, Arterial spin labeling; MRI, Magnetic resonance imaging.

The study, conducted by researchers from the Neuromuscular Research Center at Shariati Hospital in Tehran, Iran, and the University Hospitals of Leicester NHS Trust in the UK, used a non-invasive brain imaging method called arterial spin labeling (ASL). ASL allows scientists to measure cerebral blood flow (CBF), providing a window into how COVID-19 may alter brain function. The findings offer critical insights into post-COVID conditions and open up new avenues for diagnosis and treatment.
 
How COVID-19 Affects Brain Blood Flow
COVID-19, while primarily known as a respiratory illness, can have far-reaching effects on other parts of the body, including the brain. This Medical News report highlights that survivors often report persistent neurological symptoms, even after recovering from the acute phase of the infection. Symptoms such as brain fog, difficulty focusing, and forgetfulness have become common in what is now referred to as "long COVID."
 
The researchers analyzed data from multiple studies involving ASL and brain perfusion in COVID-19 patients. They observed that the virus can lead to hypoperfusion, where certain brain regions receive less blood flow than normal. Hypoperfusion was especially evident in the frontal lobes - an area of the brain associated with cognitive functions like problem-solving, memory, and behavior control.
 
In some cases, the researchers also identified hyperperfusion, where areas of the brain experience excessive blood flow. This abnormality was often linked to inflammation or damage to the brain’s blood vessels. Hyperperfusion was more commonly seen in the leptomeninges, the delicate membranes surrounding the brain and spinal cord.
 
Key Findings from the Research
The findings of this systematic review were based on the analysis of several studies that utilized ASL to examine brain perfusion in individuals affected by COVID-19. Some of the key highlights of the research include:
 
-Hypoperfusion in Critical Brain Regions: The study consistently found that patients with COVID-19 or those recovering from it experienced reduced blood flow in various parts of the brain, particularly in the frontal, parietal, and temporal lobes. These areas are crucial for cognitive functions such as memory, attention, and emotional reg ulation.
 
-Potential Link to Cognitive Impairment: Reduced blood flow in these regions may explain why many COVID-19 survivors report cognitive difficulties, often referred to as "brain fog." The frontal lobes, which play a role in executive function and memory, were notably affected, suggesting that COVID-19 may cause lasting damage that impairs these cognitive abilities.
 
-Hyperperfusion and Inflammation: Some studies reported instances of hyperperfusion, particularly in areas surrounding the brain, suggesting that inflammation caused by COVID-19 might lead to abnormal increases in blood flow. This may be the body’s way of trying to compensate for damage caused by the virus, but it could also result in additional complications.
 
-Brain Imaging Shows Persistent Changes: Even after recovering from the virus, survivors showed evidence of lasting changes in brain blood flow, suggesting that the effects of COVID-19 on the brain may be long-lasting. ASL imaging revealed that these changes were not detectable using more conventional imaging techniques, underscoring the importance of advanced imaging methods in understanding the full impact of the virus.
 
The Role of Arterial Spin Labeling in COVID-19 Research
Arterial spin labeling (ASL) is a specialized imaging technique that provides detailed information about brain blood flow without the need for radiation or contrast agents. By using magnetically labeled arterial blood water as a tracer, ASL allows researchers to non-invasively measure cerebral perfusion - making it an ideal tool for studying the subtle changes in brain function that may result from COVID-19.
 
The study article that ASL has proven invaluable in uncovering how the virus affects the brain. Traditional imaging methods, such as structural MRI, focus on identifying physical damage to the brain, but they may miss functional changes, such as alterations in blood flow. ASL offers a way to detect these functional changes, providing a more complete picture of how COVID-19 disrupts brain function.
 
What Does This Mean for COVID-19 Survivors?
The study findings suggest that even after recovering from COVID-19, many survivors may experience lasting neurological symptoms due to altered brain blood flow. The reduced blood flow in key cognitive regions could explain why some individuals struggle with memory, focus, and executive function long after the virus has cleared their system.
 
Additionally, the researchers found that these changes in brain blood flow could be linked to the severity of the initial infection. Individuals who experienced severe COVID-19 symptoms were more likely to show significant changes in cerebral perfusion, highlighting the importance of monitoring brain function in these patients as part of their long-term recovery.
 
Although much more research is needed to fully understand the relationship between COVID-19 and brain function, these findings underscore the importance of early intervention and treatment for those experiencing lingering neurological symptoms. The use of ASL in future studies could also help researchers develop better diagnostic tools and treatment strategies for post-COVID conditions.
 
Conclusion: A New Approach to Understanding COVID-19’s Long-Term Impact
This review of existing research highlights the potential of arterial spin labeling (ASL) to shed light on the long-term effects of COVID-19 on the brain. The findings suggest that the virus can cause lasting changes in brain blood flow, which may contribute to the persistent cognitive symptoms reported by many survivors.

ASL provides a non-invasive and effective way to measure cerebral perfusion, offering new insights into how COVID-19 affects brain function. By continuing to study these changes, researchers hope to develop better treatments for those suffering from long COVID and improve outcomes for all patients recovering from the virus.
 
The study findings were published in the peer-reviewed journal: Brain-X. (Wiley)
https://onlinelibrary.wiley.com/doi/10.1002/brx2.70007
 
For the latest COVID-19 News, keep on logging to Thailand Medical News.
 
Read Also:
https://www.thailandmedical.news/news/american-scientists-discover-lower-white-matter-cerebral-blood-flow-in-those-who-have-recovered-from-mild-covid-19
 
https://www.thailandmedical.news/news/sars-cov-2-alters-brain-oxygen-levels-and-causes-sleepiness-and-attention-issues-in-post-covid-phase