HealthDay News — Influenza-like illness (ILI) is associated with an increased risk for ischemic stroke and cervical artery dissection (CeAD), according to two studies presented at the American Stroke Association International Stroke Conference, held from Feb. 6 to 8 in Honolulu.
Trevor Alvord, M.P.H., from Columbia University in New York City, and colleagues conducted a case-crossover analysis of the 2012 to 2014 inpatient and outpatient New York Statewide Planning and Research Cooperative System to estimate the odds of hospitalization for ischemic stroke after ILI hospitalization. The time period preceding stroke for each patient was compared to their control window constructed using the same dates from the previous two years. The researchers included 30,912 patients with ischemic stroke in 2014 in the study. The odds of stroke were increased with ILI in the 15 days before stroke (odds ratio, 1.39); this correlation persisted over time.
In a second study, Madeleine D. Hunter, also from Columbia University, and colleagues compared ILI and influenza in sequential, mutually exclusive intervals preceding nontraumatic CeAD and overlapping intervals to ILI and influenza exactly one and two years earlier. The final sample included 3,861 CeAD cases. The researchers found that compared with the same time period one and two years earlier, patients were more likely to have ILI within 30 days of CeAD (0 to 15 days: adjusted odds ratio, 1.53; 0 to 30 days: adjusted odds ratio, 1.60).
“Our results suggest that the risk of dissection fades over time after the flu,” Hunter said in a statement. “This trend indicates that flu-like illnesses may indeed trigger dissection.”