Severe Covid infections can set the brain’s ‘control centre’ on fire, says study
Severe Covid infections can cause inflammation in the brain’s ‘control center’, researchers say, leading to damage that could explain the long-term shortness of breath, fatigue and anxiety some patients experience.
High-resolution MRI scans of 30 people hospitalized with Covid early in the pandemic, before the introduction of vaccines, found signs of inflammation in the brainstem, a small but crucial structure that supports life-sustaining bodily functions such as breathing, heart rate and blood regulates. Busy.
The scans suggest that severe Covid infections can trigger an immune response that inflames the brain stem, causing damage that causes symptoms that can last for months after the patient is discharged.
“The fact that we see abnormalities in the parts of the brain related to breathing strongly suggests that long-term symptoms are a result of inflammation in the brain stem after a Covid-19 infection,” said Dr. Catarina Rua, a neuroscientist at the University of Cambridge. and first author of the study.
The project was launched before researchers and public health officials were aware of long Covid, the chronic post-viral disease expected to impact 2 million people in England and Scotland and tens of millions worldwide. But many people with long Covid-19 report shortness of breath and fatigue, raising the possibility that encephalitis may also be involved in their symptoms.
“We have not studied people with long-term Covid-19, but they often have long-lasting effects of shortness of breath and fatigue, which are similar to the symptoms these very severely affected people had six months after being admitted to hospital,” Rua said. “It leads us to ask the question: do people with long Covid-19 have brainstem changes?”
Rua and her colleagues used powerful 7 Tesla MRI scanners to image the patients’ brains. These revealed enough detail to see inflammation and microstructural abnormalities in the brainstem tissue. All patients had been hospitalized with severe Covid-19 near the start of the pandemic.
The scans revealed abnormalities linked to inflammation in multiple parts of the brain stem, starting several weeks after patients were admitted to hospital. The damage was still visible on scans more than six months later.
Damage to the brainstem may also contribute to the mental health problems some patients face after a Covid infection. Of the patients in the study, those with the highest levels of brainstem inflammation had the most severe physical symptoms and the highest levels of depression and anxiety, according to the study published in Brain.
“While this study does not conclusively prove the causes of long Covid-19, it does point the finger at a possible suspect for some of the symptoms experienced,” said Paul Mullins, professor of neuroimaging at Bangor University. “It is not clear that this says much about possible treatments for a long Covid-19 epidemic once it has occurred, but it may point to the need to reduce inflammatory responses during the initial Covid infection and response.”