Neurological complications of Covid-19 can include delirium, brain inflammation, stroke and nerve damage, according to a new study led by University College London (UCL) and University College London Hospitals (UCLH). Published in the journal Brain, the study provided an account of the 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. According to a UCL release, The researchers identified 10 cases of transient encephalopathies (temporary brain dysfunction) with delirium. 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). Some patients in the study did not experience severe respiratory symptoms, and the neurological disorder was the first and main presentation of Covid-19, according to the release. Most (nine out of 12 cases) of those with brain inflammation conditions were diagnosed with acute disseminated encephalomyelitis (ADEM), what the researchers described in the release as a "rare and sometimes fatal inflammatory condition." While the research team in London would normally see about one adult patient with ADEM per month, that number increased to at least one per week during the study period, which the researchers say is a concerning increase. Joint senior author Dr Michael Zandi (UCL Queen Square Institute of Neurology and University College London Hospitals 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." At the same time, the virus causing Covid-19, SARS-CoV-2, 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. In some patients, the researchers found evidence that the brain inflammation was likely caused by an immune response to the disease, suggesting that some neurological complications of Covid-19 might come from the immune response rather than the virus itself. Further research is needed to identify why patients were developing these complications, the researchers concluded.