The risk of stroke after cervical artery dissection unaccompanied by ischemia at time of diagnosis seems to be limited to the first 2 weeks, according to a recent study. Researchers performed a crossover cohort study using administrative claims data on all emergency department visits and acute care hospitalizations from 2005 to 2011 in California, 2006 to 2013 in New York, and 2005 to 2013 in Florida. They identified patients with a cervical artery dissection and no previous or concurrent stroke or transient ischemic attack diagnosis (n=2,791). They found:

• The absolute increase in stroke risk was 1.25% in the first 2 weeks after dissection compared with the same time period 1 year later.
• The absolute risk increase was 0.18% during weeks 3 to 4 and was no longer significant during the remainder of the 12-week post-dissection period.
• These findings were similar in a sensitivity analysis identifying patients who presented with typical symptoms of acute dissection.