As the second wave of flu infections sweeps across the United States, it is important to take note of how the virus can impact several aspects of your well-being. The mild symptoms of influenza are fever, body ache, headache, cough, sore throat, and fatigue, and it’s known to attack the respiratory system. However, research shows that the flu can also impact your brain, leading to short term trouble like brain fog, mood changes and sluggishness. In some cases, it can also cause long-term neuroinflammation that could impair cognitive function and memory. Flu brain is an informal term for all the ways the infection can impact your brain.
Let’s under flu’s impact on brain:
Why flu makes us feel sluggish
Scientists have discovered that a cluster of nerve cells in the throat detects the flu virus and sends signals to the brain, triggering symptoms like fatigue, loss of appetite, and sluggishness.
A study published in Nature, aimed to find out why this happened. Scientists discovered it is because the infection leads to the production of chemicals called prostaglandins, which help the body fight illness but also make you feel unwell. Researchers found that these chemicals don’t need to travel to the brain through the bloodstream. Instead, nerve cells in the throat detect them directly and send signals to the brain. Blocking these signals in mice prevented sickness behaviors and even improved survival rates.
The deadly impact of flu on brain
In rare cases, the flu virus can reach the brain and cause a severe condition called influenza-associated encephalopathy (IAE), which can lead to serious symptoms or even death.
A new study from Osaka University found that the virus enters the brain through endothelial cells, which form a protective barrier between the blood and the brain. Once inside, the virus doesn’t multiply but instead builds up viral proteins, damaging the brain’s defense system.
Researchers discovered that common antiviral drugs that stop virus growth may not work for IAE. However, drugs that block viral protein production showed promising results in mice, reducing brain damage and improving survival rates.
What is long flu?
A study from the University of Michigan has found that people hospitalized with severe flu infections may face a higher risk of long-term brain damage compared to those hospitalised with Covid.
Similar to long Covid, long flu can persist in some people after the initial viral infection fades, leaving behind a range of uncomfortable symptoms including brain fog, persistent headaches, crushing fatigue, and changes in mood. As per this study, severe flu can leave a longer-lasting impact on the brain than a comparably severe Covid infection.
The study reveals that patients hospitalized with the flu were nearly twice as likely to seek medical help for neurological issues in the year after their illness compared to those hospitalized with Covid. This included a 44% raised chance of nerve pain, a 35% higher chance of battling persistent migraines, and up to a 10% greater risk of stroke or dementia.
The reason for this could be the widespread inflammation throughout the body triggered by the infection, which can harm blood vessels.
(Picture courtesy: iStock)
