Clinical policy: Critical issues in the evaluation and management of patients presenting to the emergency department with acute headache

This clinical policy focuses on critical issues in the evaluation and management of patients with acute headache. A MEDLINE search was performed, abstracts were reviewed, and appropriate full-text articles were read; references from reviewed articles were searched for additional material. This policy focuses on 4 areas of current interest and/or controversy in acute headache management: (1) response to headache therapy as an indicator of underlying pathology, (2) clinical findings predictive of increased intracranial pressure, (3)indications for emergent neuroimaging in patients with a complaint of headache, and (4) indications to pursue emergent diagnostic studies in patients with thunderclap headache but with normal findings on a head computed tomography (CT) scan and negative findings on a lumbar puncture. Recommendations for patient management are provided for each of these 4 topics based on strength of evidence. Level A recommendations represent patient management principles that reflect a high degree of clinical certainty, Level B recommendations represent patient management principles that reflect moderate clinical certainty, and Level C recommendations represent other patient management strategies based on preliminary, inconclusive, or conflicting evidence, or based on panel consensus. This guideline is intended for physicians working in hospital-based emergency departments.