Neurological complications of COVID-19

Scientists report that the neurological complications of COVID-19 can include delirium, brain inflammation, stroke and nerve damage. They highlight a concerning rise in the number of adult cases of potentially fatal acute disseminated encephalomyelitis (ADEM) could be a result of the pandemic.

In the paper published in Brain, the team report that some patients did not experience severe respiratory symptoms, instead neurological disorders were the first and main presentation of COVID-19.

Joint senior author of the study, Dr Michael Zandi, University College London (UCL) Queen Square Institute of Neurology and University College London Hospitals (UCLH) National Health Service (NHS) Foundation Trust, said: “We identified a higher than expected number of people with neurological conditions such as brain inflammation, which did not always correlate with the severity of respiratory symptoms.

“We should be vigilant and look out for these complications in people who have had COVID-19. Whether we will see an epidemic on a large scale of brain damage linked to the pandemic – perhaps similar to the encephalitis lethargica outbreak in the 1920s and 1930s after the 1918 influenza pandemic – remains to be seen.”

The study provides detailed accounts of the neurological symptoms experienced by 43 people, aged 16 to 85, treated at the National Hospital for Neurology and Neurosurgery, UCLH, UK, who either had either confirmed or suspected Covid-19.

These include 10 cases of transient encephalopathies (temporary brain dysfunction) with delirium, 12 cases of brain inflammation, eight cases of strokes and eight others with nerve damage, mainly Guillain-Barré syndrome (which usually occurs after a respiratory or gastrointestinal infection).

Other studies have also reported delirium with agitation in some COVID-19 patients.

The team highlighted that nine of the 12 cases of brain inflammation were further diagnosed with acute disseminated encephalomyelitis (ADEM), a rare and sometimes fatal inflammatory condition typically presented by children and triggered a viral infection. According to the researchers, the National Hospital for Neurology and Neurosurgery usually sees one adult with ADEM per month; however, during the study period this increased to at least one per week, a concerning pattern said the team.

SARS-CoV-2, the virus causing the COVID-19 pandemic, was not detected in any of the cerebrospinal fluid samples taken from the patients in the study. Therefore, the team suggest the cause of the neurological disorders is not due to coronavirus directly attacking the brain, instead they suggest the cases of brain inflammation are caused by the immune response to the disease.

This paper adds clinical descriptions to a previous study (by the same researchers and some colleagues) which identified 153 people with neurological complications from COVID-19. This paper also reported a higher than expected number of patients with stroke, attributing it to the excessive stickiness of the blood in COVID-19 patients.

Joint first author Dr Ross Paterson, UCL Queen Square Institute of Neurology, said: “Given that the disease has only been around for a matter of months, we might not yet know what long-term damage Covid-19 can cause.

“Doctors needs to be aware of possible neurological effects, as early diagnosis can improve patient outcomes. People recovering from the virus should seek professional health advice if they experience neurological symptoms.”

Joint senior author Dr Hadi Manji, UCL Queen Square Institute of Neurology, said: “Our study amalgamates, for the first time, the clinical presentations of patients with COVID-19 neurological disease with MRI (magnetic resonance imaging) and laboratory features including, in one case, a brain biopsy.

“This now sets up a template for other researchers around the world, facilitating coordinated research to optimise the diagnosis and treatments of these complications, which to date, has proved difficult. In addition, patients are going to require long term follow up.”