New Study Shows Link Between COVID-19 and Elevated Risks for Neurological Disorders

Patients who tested positive for COVID-19 had significantly elevated risks for developing Alzheimer’s disease, Parkinson’s disease, ischemic stroke, and intracerebral hemorrhage in comparison to people who tested negative for COVID-19, according to the findings of a new study presented recently at the 8th European Academy of Neurology (EAN) Congress in Vienna, Austria.

In the study, which involved over 919,000 people in Denmark who were tested for COVID-19 between February 2020 and November 2021, 43,375 patients tested positive for COVID-19. Researchers found that patients with COVID-19 had 3.5 times the risk of developing Alzheimer’s disease, 2.6 times the risk of having Parkinson’s disease, 2.7 times the risk for suffering ischemic stroke and 4.8 times the risk of having intracerebral hemorrhage in comparison to patients who did not have COVID-19.

While previous research has noted an association between neurological disorders and COVID-19, lead study author Pardis Zarifkar, MD said the new study findings offer more clarity on the impact of COVID-19 on the incidence of neurological disease.

“These findings will help to inform our understanding of the long-term effect of COVID-19 on the body and the role that infections play in neurodegenerative diseases and stroke,” noted Dr. Zarifkar, who is affiliated with the Department of Neurology at Rigshospitalet in Copenhagen, Denmark.

(Editor's note: For a recent video interview with Pardis Zarifkar, MD, click here.)

The study authors also compared patients who tested positive for COVID-19 to patients with influenza or pneumonia and found similar elevated risks for the development of neurological diseases. However, when comparing COVID-19 to influenza and inpatients with pneumonia over the age of 80, the researchers noted a 1.7 times elevated risk of ischemic stroke for patients with COVID-19.