Nearly a third of coronavirus patients who were hospitalised have experienced some kind of altered mental function, from confusion, delirium to unresponsiveness, according to a study published in peer review journal Annals of Clinical and Translational Neurology.
It is said to be one of the largest studies conducted on the neurological symptoms among COVID-19 patients in an American hospital system.
"The patients suffering from altered mental function had experienced the worst medical results," the study said. The records of the first 509 COVID-19 patients who were admitted from March 5 to April 6 at 10 hospitals in the Northwestern Medicine health system in Chicago were analysed while conducting the study.
These patients were hospitalised three times as long in the hospital as patients without any altered mental function.
Dr Igor Koralnik, senior author of the study and chief of neuro-infectious disease and global neurology at Northwestern Medicine stated that after the patients were released, only 32 per cent of them with altered mental function were able to perform daily activities such as paying bills, cooking, cleaning and others. On the other hand, 89 per cent of patients who were not detected with the altered mental function was able to handle all the activities without any help.
The medical term for the altered mental function is encephalopathy and patients detected with the disease were seven times as likely to die compared to those who do not have such problems.
"Encephalopathy is a generic term meaning something's wrong with the brain," Koralnik told The Indian Express. The disease cause issues in 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 the severity of their respiratory disease," Koralnik added.
Scientists are yet to identify the source of ecephalopathy. Koralnik who also looks after the Neuro COVID-19 Clinic at Northwestern Memorial Hospital said, "It can affect a person with other diseases, especially older people, and can get worse due to inflammation and blood circulation effects." However, there is no evidence that suggests the virus attacks the brain cells directly.
Dr Serena Spudich, chief of neurological infections and global neurology at Yale School of Medicine, who was not involved with the study said, "This paper indicates, importantly, that in-hospital encephalopathy may be a predictor for the poorer outcome. That finding would also suggest that patients with altered mental function in the hospital might benefit from closer post-discharge monitoring or rehabilitation."
The study revealed that 162 patients with encephalopathy were mostly male or older people having underlying diseases like cancer, neurological problems, chronic kidney disease, smoking, hypertension, diabetes and other medical conditions.
Some experts have said that US President Donald Trump who was tested COVID-19 positive and has been hospitalised is of the same age and gender of the patients who have detected encephalopathy since he also has a history of high cholesterol. But there has been no confirmation from his doctors yet.
The study not only found altered mental function as the only neurological disorder but also that 82 per cent of the patients admitted in hospitals have neurological symptoms at some point which is higher than the rates reported in China and Spain.
Among the neurological symptoms, muscle pain was common in 45 per cent of patients followed by the headache which was noticed in around 38 per cent while 30 per cent of them experienced dizziness while a few had problems with smell and taste.
The study also stated that younger patients would develop neurological symptoms overall except for encephalopathy which was more common in older patients.
A quarter of the patients experienced critical respiratory problems to require ventilators while the others were treated in the COVID ward or in intensive care.
The study also revealed that Black and Latino patients were less likely to develop neurological symptoms than other groups. Patients at the Northwestern Memorial Hospital were mostly younger, Black residents and had preexisting medical problems compared to the patients in suburban hospitals.
The patients at the Northwestern Memorial were likely to develop overall neurological symptoms but not encephalopathy. They also had low mortality rates and were better after being discharged. This shows that patients at the academic hospital may have received specialised care or better resources.
Dr Avindra Nath, chief of the section on infections of the nervous system at the National Institute of Neurological Disorders and Stroke said, "It is also interesting but concerning that, they found differences in the outcome of patients between the various hospitals, which they attribute to differences in the quality of care provided. This means that hospitalised patients require a high level of care, which is not readily available in most places."