COVID-19 poses a threat to the entire nervous system of infected individuals, according to a review of studies which may help better manage the neurological symptoms of the disease such as headaches, seizures, and strokes. According to the research, published in the journal Annals of Neurology, nearly half of hospitalised COVID-19 patients have neurological manifestations like headache, dizziness, decreased alertness, difficulty concentrating, disorders of smell and taste, seizures, strokes, weakness, and muscle pain.
"It's important for the general public and physicians to be aware of this, because a SARS-COV-2 infection may present with neurologic symptoms initially, before any fever, cough or respiratory problems occur," said study lead author Igor Koralnik from Northwestern University in the US.
In the analysis, the scientists describe the different neurological conditions that may occur in COVID-19 patients and how to diagnose them, as well as likely pathogenic mechanisms. Koralnik believes that this understanding is key to direct appropriate clinical management and treatment for COVID-19 patients.
There are many different ways COVID-19 can cause neurological dysfunction, he said. According to the study, the disease may affect the entire nervous system, including the brain, spinal cord, nerves, and the muscles. The researchers noted that the brain may also suffer from a lack of oxygen, or from clotting disorders that may lead to strokes.
In addition, they said the virus may cause direct infection of the brain, meninges -- a connective tissue lining several parts of the nervous system -- and the cerebrospinal fluid (CSF) which acts as a shock absorber for the skull.
The reaction of the immune system to the infection may also cause inflammation that can damage the brain and nerves, the scientists added.
Since knowledge about the long term outcome of neurologic manifestations of COVID-19 is limited, the researchers plan to follow some patients prospectively to determine if neurological problems are temporary or permanent.
The scientists said careful studies of the inflammatory and immune cell response within the CSF to SARS-CoV-2, as well as post mortem studies including the nervous system and muscle tissues are urgently needed to better understand the neurological manifestations of COVID-19.
They said such studies can provide the foundation on how to diagnose, manage and treat the many neurologic symptoms of COVID-19.