A third of patients hospitalized with COVID-19 experience various forms of encephalopathy, or altered mental states, including an inability to reason, difficulty concentrating, or memory loss, according to a study published October 5 in the Annals of Clinical and Translational Neurology.
The prevalence of encephalopathy could spell long-term trouble for patients, wrote a team led by Dr. Eric Liotta of Northwestern University Feinberg School of Medicine in Chicago.
"COVID-19 is unique in its ability to cause a multiorgan disease, with involvement of the central and peripheral nervous system in some individuals," the group wrote. "Indeed, a wide range of neurologic manifestations of SARS-CoV-2 infection have been recognized, and evidence of their severity and persistence is increasing ... neurologic manifestations, especially encephalopathy, have been associated with worse clinical outcomes in other systemic illnesses and may even lead to significant disability."
COVID-19 is mostly characterized by respiratory and flu-like symptoms, but it has increasingly been shown to also cause complications in the nervous system, the group noted. Liotta and colleagues conducted a study that investigated these neurologic complications, their risk factors, and associated outcomes in a group of 509 patients hospitalized for COVID-19. Patients' neurologic symptoms were diagnosed with a combination of clinical consultation, brain CT, brain MRI, electroencephalograms, and lumbar punctures.
The researchers noted neurological symptoms in 42.2% of these patients at disease onset, 62.7% at hospitalization, and 82.3% at any time during the disease course. Of the patient cohort, 26.3% required mechanical ventilation, the group found. Patients with neurologic manifestations of the illness had longer hospital stays compared with those who did not (eight days versus five); those with encephalopathy remained in the hospital three times as long as patients without the condition (17 days versus five).
The authors noted the following neurologic manifestations of COVID-19, with encephalopathy representing a third:
- Myalgias (44.8%)
- Headaches (37.7%)
- Encephalopathy (31.8%)
- Dizziness (29.7%)
- Loss of taste (15.9%)
- Loss of smell (11.4%)
Risk factors for developing any neurologic manifestations of the disease included having a more severe form and being younger, while risk factors for developing encephalopathy included being older, having severe COVID-19 disease, and having a history of any neurological disorder or chronic kidney disease.
Of all the patients, 71.1% were discharged with favorable function, but those with encephalopathy had higher odds of worse functional outcome (odds ratio, 0.22) and higher mortality rates within 30 days of discharge (21.7% compared with 3.2%) than those without, Liotta's group wrote.
COVID-19-induced encephalopathy appears to pose long-term danger to patients, according to the authors.
"Our results suggest that, of all neurologic manifestations, encephalopathy is associated with a worse functional outcome in hospitalized patients with COVID-19, and may have lasting effects," the team concluded. "Prospective cognitive and neurologic-focused evaluations through specialized clinics dedicated to further diagnostic assessment and tailored rehabilitation needs could play a significant role in recovery from this pandemic."
