Health (Commonwealth Union) – Influenza, commonly known as the flu, and COVID-19, caused by the novel coronavirus SARS-CoV-2, are both respiratory illnesses that can lead to severe outcomes. While they share similarities in symptoms and transmission routes, there are crucial differences between the two viruses that affect their impact, treatment, and prevention strategies. Both influenza and COVID-19 can cause fever, cough, fatigue, body aches, and respiratory symptoms such as shortness of breath. However, COVID-19 has been associated with a broader range of symptoms, including loss of taste or smell, gastrointestinal issues, and blood clotting disorders.
A study published in the March 20, 2024, online edition of Neurology, the medical journal of the American Academy of Neurology, reveals that individuals who contract influenza are more prone to requiring medical attention for neurological disorders within the subsequent year compared to those who contract COVID-19. Funded by the American Academy of Neurology, the research examined hospitalized individuals with either influenza or COVID-19, though it did not specifically analyze outcomes related to long COVID.
“It’s important to note that our study did not look at long COVID outcomes, and our results do not necessarily conflict with the findings in other research showing an increase in neurologic symptoms in people with long COVID,” explained the study author and Chair of the American Academy of Neurology, Health Services Research Subcommittee Brian C. Callaghan, MD, MS, FAAN, of the University of Michigan Health in Ann Arbor. “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 neurologic conditions when compared to being hospitalized with influenza.”
In their study, researchers utilized healthcare claims data to contrast 77,272 individuals hospitalized with COVID-19 against an equivalent number of individuals hospitalized with influenza. Subsequently, they examined the incidence of medical care within the subsequent year for the six most prevalent neurologic disorders—migraine, epilepsy, stroke, neuropathy, movement disorders, and dementia—among these cohorts.
Additionally, the researchers investigated individuals without these conditions at the study’s onset to ascertain the development of new diagnoses for any of the six conditions during the subsequent year.
Individuals afflicted with COVID-19 exhibited a reduced likelihood of requiring care for common neurologic conditions in the following year compared to those affected by influenza. Among COVID patients, 2.0% received care for migraine, as opposed to 3.2% of influenza patients; for epilepsy, the figures were 1.6% and 2.1%, respectively. Similarly, for neuropathy, the percentages stood at 1.9% for COVID patients and 3.6% for influenza patients; for movement disorders, they were 1.5% and 2.5%; for stroke, 2.0% and 2.4%; and for dementia, 2.0% and 2.3%.
Upon adjusting for various factors influencing the need for care, such as age, gender, and other medical conditions, researchers found that individuals with a COVID infection had a 35% lower risk of receiving care for migraine compared to those with influenza. Similarly, they had a 22% lower risk for epilepsy, a 44% lower risk for neuropathy, a 36% lower risk for movement disorders, a 10% lower risk for stroke, as well as a 7% lower risk for dementia.
Upon examining the development of new neurologic conditions in the year following infection, researchers discovered that 2.8% of individuals with COVID developed one of the six neurologic conditions, in contrast to 4.9% of those who were known to have influenza.
“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,” added the study author Adam de Havenon, MD, MSc, of Yale University in New Haven, Connecticut, who is also a member of the American Academy of Neurology Health Services Research Subcommittee. “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.”
Researchers of the study pointed out that a constraint of the study stems from the non-nationally representative nature of the data platform utilized by the researchers. Consequently, the findings cannot be universally extrapolated to all COVID-19 survivors across the United States. The study received support from the American Academy of Neurology.
