Non-traumatic headache is a common complaint seen in the emergency department (ED), accounting for 2.3% of ED visits per year in the United States (Munoz-Ceron et al., 2019). When approaching the workup and management of headache, an emergency medicine physician is tasked with generating a deadly differential by means of a thorough history and physical exam to determine the next best steps.

A 21-year-old male presented to the emergency department with a debilitating new-onset headache, preceded by an isolated vertiginous event 3 days prior. He was found to have a normal neurologic examination. A non-contrast CT scan of the head revealed a large hypodensity within the left cerebellum with a subsequent MRA of the brain and neck notable for a left vertebral artery dissection, complicated by an ischemic cerebellar stroke.

With an estimated incidence of 1–5 per 100,000, vertebral artery dissection is a rare cause of stroke within the general population and carries with it a high degree of morbidity and mortality (Rodallec et al., 2008). Vertebral artery dissection is a result of blood penetrating the intimal wall of the artery to form an intramural hematoma. Diagnosis can be difficult in cases presenting subacutely but a thorough history evaluating for red flags and using simple but highly sensitive exams such as the bedside HINTS exam can increase pretest probability of stroke. Clinical syndromes, red flags, and time from onset of symptoms should guide imaging modalities such as CT, CTA, MRI, and MRA in detection of small ischemic changes, intimal flaps, and luminal thromboses.

Vertebral artery dissection should remain high on the differential for an emergency medicine physician when history is suggestive of a new onset headache, preceded by vertiginous symptoms. An absence of recent trauma and a normal neurologic examination does not eliminate the diagnosis.