Long Covid smell loss linked to changes in the brain

People living with long Covid who suffer from loss of smell show different patterns of activity in certain regions of the brain, a new study led by UCL researchers has found. The research used MRI scanning to compare the brain activity of people with long Covid who lost their sense of smell, those whose smell had returned to normal after Covid infection, and people who had never tested positive for Covid-19. Published in  eClinicalMedicine , the observational study found that the people with long Covid smell loss had reduced brain activity and impaired communication between two parts of the brain which process important smell information: the orbitofrontal cortex and the pre-frontal cortex. This connection was not impaired in people who had regained their sense of smell after Covid. The findings suggest smell loss, known as anosmia, caused by long Covid is linked to a change in the brain that stops smells from being processed properly. Because it's clinically reversible, as shown in some subjects, it may be possible to retrain the brain to recover its sense of smell in people suffering the side effects of long Covid. Dr Jed Wingrove (UCL Division of Medicine) the lead author of the study, said: "Persistent loss of smell is just one way long Covid is still impacting people's quality of life - smell is something we take for granted, but it guides us in lots of ways and is closely tied to our overall wellbeing.