Neurological complications of COVID-19 can include delirium, brain inflammation, stroke and nerve damage, finds a new University College London (UCL) and UCLH-led study that is now published in the journal Brain. The research team also identified a rare and sometimes fatal inflammatory condition, known as acute disseminated encephalomyelitis (ADEM), which appears to be increasing in prevalence due to the pandemic.
Some patients in the study did not experience severe respiratory symptoms, and the neurological disorder was the first and main presentation of COVID-19, revealed the researchers.
“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,” said senior author Dr Michael Zandi (UCL Queen Square Institute of Neurology and University College London Hospitals NHS Foundation Trust).
“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,” avers Dr Zandi.
The study provides a detailed account of neurological symptoms of 43 people (aged 16-85) treated at the National Hospital for Neurology and Neurosurgery, UCLH, who had either confirmed or suspected COVID-19.
The researchers identified 10 cases of transient encephalopathies (temporary brain dysfunction) with delirium, which corresponds with other studies finding evidence of delirium with agitation. There were also 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).
Nine out of the 12 cases of those with brain inflammation conditions were diagnosed with acute disseminated encephalomyelitis (ADEM) which is a rare condition typically seen in children and can be triggered by viral infections.
However, the SARS-CoV-2 virus was not detected in the cerebrospinal brain fluid of any of the patients tested, suggesting the virus did not directly attack the brain to cause the neurological illness.
The researchers suggest that some neurological complications of COVID-19 might come from the immune response rather than the virus itself. In some patients, the team found evidence that the brain inflammation was likely caused by an immune response to the disease.
Another recent study conducted by the team also identified an increase in the number of neurological complications in COVID-19 patients showing a spike in stroke cases. The paper which is published in The Lancet Psychiatry also confirmed the previous findings of a higher occurrence of patients with a stroke which resulted from the excessive stickiness of the blood in these patients. The study was co-authored by Dr Zandi identifying 153 people with neurological complications from the viral infection.
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, say the researchers.
“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,” said first author Dr Ross Paterson (UCL Queen Square Institute of Neurology).
“Our study amalgamates, for the first time, the clinical presentations of patients with COVID-19 neurological disease with MRI and laboratory features including, in one case, a brain biopsy,” said joint senior author Dr Hadi Manji.
“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,” he added.