Two leading neurology experts have called for increased research into the underlying causes of Long Covid and possible ways to treat the wide variety of symptoms in the brain and nervous system.

In a new viewpoint published in Science, Avindra Nath, clinical director of the National Institutes of Health’s National Institute of Neurological Disorders and Stroke (NINDS), and Serena Spudich, Yale School of Medicine, highlight what is currently known about the effects of Covid-19 on the brain.

Neurological symptoms that have been reported with acute Covid-19 include loss of taste and smell, headaches, stroke, delirium, and brain inflammation. There does not seem to be extensive infection of brain cells by the virus, but the neurological effects may be caused by immune activation, neuroinflammation, and damage to brain blood vessels.

Acute Covid-19 infection can sometimes lead to long-lasting effects, that have collectively been termed “Long Covid,” and can include a wide variety of symptoms in the brain and nervous system that range from a loss of taste and smell, impaired concentration, fatigue, pain, sleep disorders, autonomic disorders and/or headache to psychological effects such as depression or psychosis.

Long Covid is an ever-increasing public health concern

In the commentary, Nath and Spudich outline the current scientific understanding of the potential body responses to acute Covid-19 infection and how those responses could lead to Long Covid symptoms. They also draw parallels between the symptoms experienced by individuals with Long Covid to those living with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) or post-Lyme disease, which suggests there could be common risk factors involved.

They said: "The full extent of the long-term neurological complications of Covid-19 has not been realised. Observations of neuroinflammation and neuronal injury in acute Covid-19 have raised the possibility that infection may accelerate or trigger future development of neurodegenerative diseases such as Alzheimer’s or Parkinson’s diseases."

Owing to the significant variability in symptoms from person to person and the fact that many individuals with Long Covid were healthy prior to a relatively mild Covid-19 infection, the authors added that there was an urgent need for significant research efforts into identifying the full extent of Long Covid complications and their causes.

They said that this kind of research, which would include the careful study of individuals with Long Covid categorised by their specific symptoms, is crucial to the development of diagnostic and therapeutic tools to identify and treat what is becoming an ever-increasing public health concern.