Decline in spontaneous cervical artery dissection incidence during COVID-19 public health measures: Evidence for a role of upper respiratory infections in pathogenesis

BACKGROUND: Upper respiratory infections have been suggested as a risk factor for spontaneous cervical artery dissection (sCeAD). If this is the case, public health measures implemented to contain the spread of SARS-CoV-2, which also reduced other communicable diseases such as influenza, might be associated with a reduction in cervical artery dissection incidence. AIMS: We determined the incidence of sCeAD before, during and after the COVID-19 pandemic, and the associated public health measures. METHODS: All patients suffering an sCeAD and seen in Innsbruck Austria, between January 2002 to December 2016 (pre-COVID comparators) and between January 2020 to August 2022 were recorded through two individual prospective cohort studies. We compared admission rates, demographic, and clinical characteristics of sCeAD patients in pre-COVID-19 and COVID-19 times. RESULTS: In total, 249 sCeAD patients were admitted prior to the COVID-19 pandemic compared to 20 during its course. Baseline characteristics of sCeAD subjects did not differ in subjects admitted during and prior to the pandemic. Following the introduction of public health measures for the pandemic, there was a marked decrease of sCeAD admissions from 16.5 per year to 6.3 per year (p = 0.012). Since the measures were ended the number of sCeAD admissions increased again. In contrast, the number of all ischemic stroke patients treated at the Medical University of Innsbruck did not alter during the pandemic. (N per year: 633 in 2015, 687 in 2017, 684 in 2019, 731 in 2020, and 717 in 2021). CONCLUSION: The incidence of sCeAD fell markedly during the pandemic and this may have resulted from the public health measures introduced and a subsequent reduction in upper respiratory infections. Our study provides indirect evidence for a role of infection in the pathogenesis of sCeAD. DATA ACCESS STATEMENT: Anonymized data not published within this article will be made available by request from any qualified investigator.