CHICAGO — In what is thought to be the first study of its kind, Northwestern doctors found high levels of neurological symptoms among patients who developed long-term COVID-19 symptoms after a relatively mild initial illness that did not require hospitalization.
Eight-five percent of patients reported four or more neurological symptoms, problems such as “brain fog” (or attention and memory problems), loss of taste or smell, headache and blurred vision. In addition, patients experienced non-neurologic symptoms, such as fatigue (85%) and depression or anxiety (47%).
About half of patients in the study missed more than 10 days of work, due to what doctors call long COVID syndrome, or symptoms lasting more than six weeks.
“Long COVID syndrome affects probably millions of people in the world, and people have persistent (neurological) symptoms, and some have cognitive dysfunction that significantly impairs their quality of life,” said study co-author Igor Koralnik, chief of neuro-infectious diseases at Northwestern Medicine.
COVID-19 will probably have a “serious impact” on the U.S. workforce, Koralnik said.
The study, published Tuesday in the Annals of Clinical and Translational Neurology, focused on 100 patients who sought care at Northwestern Memorial Hospital’s neuro-COVID-19 clinic between May and November 2020.
The authors found brain fog in 81% of the patients, headache in 68%, numbness or tingling in 60%, loss of taste in 59%, problems with smell in 55%, muscle pain in 55%, dizziness in 47%, blurred vision in 30% and ringing in the ears in 29%.
Patients experienced decreased quality of life, with some suffering from brain fog, headache and dizziness, and others from different constellations of symptoms.
“When everything you eat tastes like metal and everything you smell smells like bleach, your quality of life is altered in a completely different way,” Koralnik said.
The average age for the patients in the study was 43, younger than the average for hospitalized COVID-19 patients, which is 55, Koralnik said.
People with long COVID syndrome are known as COVID long-haulers.
Interestingly, 70% of the patients were female, and 16% had a history of autoimmune disease. Those findings are consistent with the hypothesis that long COVID is an autoimmune problem. Immune diseases such as multiple sclerosis and rheumatoid arthritis also disproportionately affect women.
The pace of recovery varied widely, with some patients reporting they were 95% recovered after two months, and others saying they were less than 10% recovered after nine months, Koralnik said.
“The light at the end of the tunnel is that people tend to improve over time,” he said. “But we can’t tell you the percent chance of 100% recovery at three months or six months.”
