Towards understanding seasonal variability in cervical artery dissection (CeAD)

Cervical artery dissection (CeAD) occurs more often in autumn or winter than in spring or summer. We searched for clinical variables associated with this seasonality by comparing CeAD patients with onset of symptoms in autumn–winter (September 22–March 21) versus those with first CeAD symptom in spring–summer (March 22–September 21). We performed a cross-sectional study using data from the multicenter CADISP (Cervical Artery Dissection and Ischemic Stroke Patients) registry. Age- and sex-matched patients with ischemic stroke attributable to a cause other than CeAD (non-CeAD patients) were analyzed to study the specificity of our findings. Autumn–winter CeAD patients had a higher median brachial pulse pressure at admission (55 vs. 52 mmHg; p = 0.01) and more recent infections (22.0% vs. 16.6%; p = 0.047), but prevalence of trauma was not associated with seasonal onset. Multivariable logistic regression analysis revealed that higher pulse pressure was significantly associated with autumn–winter CeAD (p = 0.01), while age, gender, history of hypertension, recent infection, and recent trauma were not. No association between pulse pressure and seasonal occurrence was found in non-CeAD ischemic stroke patients. Increased pulse pressure was associated with the higher frequency of CeAD in autumn or winter.