Cluster headache: A review of clinical presentation, evaluation, and management

Cluster headache is a primary headache disorder that leads to attacks of excruciating unilateral head pain with ipsilateral cranial autonomic features. These attacks can cluster, with frequent occurrences for weeks or months at a time followed by a period of complete remission. The excruciating pain of these attacks often is accompanied by increased suicidality, delays in diagnosis, and unnecessary invasive interventions. This article reviews the clinical presentation, differential diagnosis, evaluation, and treatment of cluster headache.