Study: Nearly one-third of Covid-19 patients show altered mental state

Nearly a third of hospitalised Covid-19 patients experienced some type of altered mental function - ranging from confusion to delirium to unresponsiveness - in the largest study to date of neurological symptoms among coronavirus patients in a US hospital system. And patients with altered mental function had significantly worse medical outcomes, according to the study, published Monday in Annals of Clinical and Translational Neurology. The study looked at the records of the first 509 coronavirus patients hospitalized, from March 5 to April 6, at 10 hospitals in the Northwestern Medicine health system in the Chicago area.

These patients stayed three times as long in the hospital as patients without altered mental function. After they were discharged, only 32% of the patients with altered mental function were able to handle routine daily activities like cooking and paying bills, said Dr. Igor Koralnik, senior author of the study and chief of neuro-infectious disease and global neurology at Northwestern Medicine. In contrast, 89% of patients without altered mental function were able to manage such activities without assistance. Patients with altered mental function - the medical term is encephalopathy - were also nearly seven times as likely to die as those who did not have that type of problem.

"Encephalopathy is a generic term meaning something's wrong with the brain," Koralnik said. The description can include problems with attention and concentration, loss of short-term memory, disorientation, stupor and "profound unresponsiveness," or a comalike level of consciousness. "Encephalopathy was associated with the worst clinical outcomes in terms of ability to take care of their own affairs after leaving the hospital, and we also see it's associated with higher mortality, independent of severity of their respiratory disease," he said. The researchers did not identify a cause for the encephalopathy, which can occur with other diseases, especially in older patients, and can be triggered by several different factors including inflammation and effects on blood circulation, said Koralnik, who also oversees the Neuro COVID-19 Clinic at Northwestern Memorial Hospital.

There is very little evidence so far that the virus directly attacks brain cells, and most experts say neurological effects are probably triggered by inflammatory and immune system responses that often affect other organs, as well as the brain. "This paper indicates, importantly, that in-hospital encephalopathy may be a predictor for poorer outcomes," said Dr. Serena Spudich, chief of neurological infections and global neurology at Yale School of Medicine, who was not involved in the study. That finding would also suggest that patients with altered mental function in the hospital "might benefit from closer post-discharge monitoring or rehabilitation," she added.

In the study, the 162 patients with encephalopathy were more likely to be older and male. They were also more likely to have underlying medical conditions, including a history of any neurological disorder, cancer, cerebrovascular disease, chronic kidney disease, diabetes, high cholesterol, heart failure, hypertension or smoking.