July 9 (UPI) -- Up to one in four people infected with the new coronavirus experience brain damage, according to the findings of a small study published Wednesday by the journal Brain.
In an analysis of 43 patients hospitalized with confirmed or suspected COVID-19 showed signs of brain inflammation or encephalitis, 10 had symptoms of delirium or psychosis and eight suffered a stroke, the researchers said.
All but one of the patients included in the study survived, overcoming the disease and the neurological symptoms following treatment in a hospital intensive care unit, they 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," study co-author Dr. Michael Zandi said in a statement.
"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," said Zandi, a neurologist at the Queen Square Institute of Neurology and University College London Hospitals NHS Foundation Trust in England.
All 43 patients in the study were treated at the National Hospital for Neurology and Neurosurgery. They ranged in age from 16 to 85, the researchers said.
Several of the patients did not develop severe respiratory symptoms from COVID-19, with the neurological disorder acute disseminated encephalomyelitis, or ADEM, being "the first and main presentation" of the disease, they said.
Nine of the 12 patients with brain inflammation were diagnosed with ADEM, which is rare and most often seen in children, according to the researchers.
Their clinic typically sees about one adult patient with ADEM per month, but that increased to at least one per week during the study period, which ran from April 9 to May 15, they said.
In addition, eight patients in the study experienced nerve damage, mainly Guillain-Barré syndrome, a rare neurological disorder in which the body's immune system attacks the nerves, causing severe muscle weakness. Guillain-Barré most often occurs after a respiratory or gastrointestinal infection, the researchers said.
They also found evidence that brain inflammation in some patients was caused by an immune response to COVID-19, rather than the disease itself.
SARS-CoV-2, the virus that causes the disease, was not detected in the cerebrospinal brain fluid of any of the patients tested, the researchers 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," study co-author Dr. Ross Paterson, also a neurologist at the UCL Queen Square Institute of Neurology, said in a statement.
"Doctors need to be aware of possible neurological effects, as early diagnosis can improve patient outcomes," he said. "People recovering from the virus should seek professional health advice if they experience neurological symptoms."