Damage to the brain’s “control centre” might be behind the long-term breathlessness, fatigue and anxiety experienced by long Covid sufferers.
Researchers from the universities of Cambridge and Oxford used ultra-high-resolution scanners to study the brains of 30 people who had been admitted to hospital with severe Covid-19 early in the pandemic, before vaccines were available.
The results, published in the journal Brain, may help scientists and clinicians understand the long-term effects of Covid-19 on the brain and the rest of the body. They could also improve treatments for other conditions such as MS and dementia.
What did the study find?
Powerful MRI scanners, known as 7-Tesla or 7T, were able to study in fine detail the brains of those suffering from Covid, and compare them with the scans of 51 people with no history of infection.
Researchers found signs of inflammation in the brainstem, a “small but critical structure that governs life-sustaining bodily functions such as breathing, heart rate and blood pressure”, said The Guardian.
What does it mean?
The scans suggest that severe Covid infections can provoke an “immune reaction” that inflames the brainstem, “with the resulting damage producing symptoms that can last for months after patients have been discharged”.
The fact that these “abnormalities” were in the parts of the brain associated with breathing “strongly suggests that long-lasting symptoms are an effect of inflammation in the brainstem following Covid-19 infection”, said Dr Catarina Rua, a neuroscientist at the University of Cambridge and first author on the study.
The condition known as long Covid or post-Covid syndrome (PCS) can cause extreme tiredness, shortness of breath, brain fog, dizziness, heart palpitations and muscle aches lasting for 12 weeks or more, according to the Nice guidelines.
Those with the highest levels of brainstem inflammation were also found to have the highest levels of depression and anxiety – another key symptom of long Covid – “because of the tight connection between physical and mental health”, said Professor James Rowe, also from Cambridge, who co-led the research.
Does it change how Covid should be treated?
There is still a lot to be learned about long Covid. This study doesn’t “conclusively prove” the causes, but it does “point a finger at one possible suspect for some of the symptoms experienced”, said Paul Mullins, a professor in neuroimaging at the University of Bangor. The results suggest it might be useful to “reduce inflammatory responses during initial Covid infection and response”.
The researchers said the study might also be useful in understanding other conditions such as MS and dementia that are associated with brainstem inflammation.