As the number of confirmed Covid-19 cases worldwide reaches 2 million, clinicians are realizing the disease doesn’t just ravage the lungs and hurt the heart. It also can, in a significant proportion of cases, affect the nervous system in myriad little-understood ways.
Through a growing number of papers, doctors around the globe are chronicling Covid-19’s lesser-known neurological manifestations including brain inflammation, hallucinations, seizures, cognitive deficits and loss of smell and taste. It is unknown whether these are caused directly by the virus infiltrating the nervous system, or by the body’s immune response to infection.
The hope is these reports could speed up diagnosis. Some patients say they were going out in public, potentially exposing others, due to lack of awareness of these symptoms. The reports could also open avenues of research that elucidate whether the virus gets into the brain, how long neurological symptoms might persist, and whether a full recovery can be expected.
The range of effects could take decades to play out. Some epidemiological studies and lab experiments with other viruses suggest severe infections could set in motion molecular events that might increase the risk of developing neurodegenerative disorders, like Alzheimer’s or Parkinson’s, many years later.