Flu linked to greater risk for neurological disorders than COVID-19, study shows

The flu is more likely to lead to a neurological disorder than COVID-19, according to a new study that surprised its authors.

"While the results were not what we expected to find, they are reassuring in that we found being hospitalized with COVID did not lead to more care for common neurological conditions when compared to being hospitalized with influenza," study co-author Dr. Brian Callaghan of University of Michigan Health in Ann Arbor said in a news release.

The study -- published online in Neurology, the journal of the American Academy of Neurology -- looked at patients who were hospitalized with either COVID-19 or influenza. It did not look at long COVID-19, researchers emphasized.

Researchers used medical claims records to compare more than 77,000 people who were hospitalized for COVID-19 with the same number who were hospitalized with flu.

Then, they zeroed in on how many were treated during the year that followed for any of the most common neurological disorders -- migraine, epilepsy, stroke, neuropathy, movement disorders and dementia.

Here's a by-the-numbers look at the findings:

In all, 3.2% of those with flu and 2% with COVID-19 were treated for migraine, and 2.1% of flu patients and 1.6% of COVID-19 patients received epilepsy care.

Further, 2.4% with flu were treated for stroke, compared to 2% of COVID-19 patients; 3.6% of flu patients and 1.9% of COVID-19 patients were treated for neuropathy; and 2.5% of flu patients and 1.5% of COVID-19 patients were treated for a movement disorder.

Rates for dementia were similar for the two viral infections -- 2.3% of flu patients and 2% of COVID-19 patients received care for the condition.

COVID-19 patients had a 44% lower risk of receiving care for neuropathy, a 36% lower risk for movement disorders, a 10% lower risk for stroke and a 7% lower risk for dementia

In all, 4.9% of flu patients and 2.8% of COVID-19 patients developed a new neurologic condition in the year after their illness.

"Since COVID-19 has now infected the majority of adults in the US, it's good news that it behaves similarly to other respiratory viruses with respect to these common neurologic conditions," said study co-author Dr. Adam de Havenon, an associate professor of neurology at Yale University in New Haven, Conn.

"There was concern that the already limited access to neurologic care would further shrink if we had a dramatic increase in neurologic care after COVID-19 infection," he said in a journal news release.

Both de Havenon and Callaghan are members of the American Academy of Neurology Health Services Research Subcommittee.

They noted in the news release that the data used in the study is not a nationally representative sample, so the findings may not apply to all COVID-19 survivors in the U.S.

The academy supported the study and published the findings in its journal on Wednesday.

More information

The National Institute of Neurological Disorders and Stroke has more about the effects of COVID on the nervous system.