“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.
Some experts said that President Trump, who was hospitalized with Covid since Friday, is of the age and gender of the patients in the study who were more likely to develop altered mental function and therefore could be at higher risk for such symptoms. He also has a history of high cholesterol, one of the pre-existing conditions that appear to increase risk. But the president’s doctors have given no indication that he has had any neurological symptoms; the White House has released videos of him talking to the public about how well he is doing. And Mr. Trump announced on Monday that he would be discharged from Walter Reed military hospital in the evening.
Dr. Koralnik urged caution in drawing inferences from the study to Mr. Trump’s condition. “I think we should be careful trying to ascribe a risk to an individual, based on this retrospective study,” he said. “We need to know more about that individual’s health records, which are not public.”
Altered mental function was not the only neurological complication the Northwestern study found. Over all, 82 percent of the hospitalized patients had neurological symptoms at some point in the course of the disease from symptom onset through hospitalization, the study found. That is a higher rate than what has been reported in studies from China and Spain, but the researchers say that may be because of genetic factors or that the Northwestern hospitals may have had more time to identify neurological issues because they were not as overwhelmed with patients as the other hospitals.
“This is an important study, since the neurological complications of the infection seem to be frequent and in many cases long lasting, but yet have not received much attention,” said Dr. Avindra Nath, chief of the section on infections of the nervous system at the National Institute of Neurological Disorders and Stroke, who was not involved in the study.
Among the neurological symptoms, muscle pain occurred in about 45 percent of patients and headaches in about 38 percent. About 30 percent had dizziness. Smaller percentages had disorders of taste or smell.