Neuroimaging of Headache Disorders in the Emergency Department

Headaches are a common cause of emergency department visits, encompassing a broad spectrum from benign to life-threatening conditions. While most headaches seen in the emergency department are primary headache disorders, such as migraine, tension-type headache, and cluster headache, a small subset represents secondary headaches associated with serious underlying conditions like intracranial hemorrhage, stroke, or infections. This chapter discusses the critical role of neuroimaging in identifying these secondary causes, enabling timely intervention and improving outcomes. The choice of imaging, often between computed tomography and magnetic resonance imaging, depends on clinical presentation, urgency, and logistical considerations. Headaches present across diverse populations, with distinct needs in children, pregnant women, and older adults, who are at greater risk for secondary headache disorders. To streamline headache diagnosis, red flags can be identified as warning signs for secondary headache disorders and green flags as primary headache disorders. The SNNOOP10 list highlights red flags such as sudden onset or neurological symptoms, which indicate the need for further imaging, although its specificity requires more validation. Balancing these flags improves diagnostic accuracy, minimizes unnecessary imaging, and optimizes resource use. This chapter concludes by underscoring the need for ongoing validation of these diagnostic flags and protocols to enhance headache management and neuroimaging efficiency in emergency medicine.