Snapshot A 36-year-old male presents with recurrent bouts of left-sided severe lancinating periorbital pain. His symptoms began 20 minutes prior, and appears to occur daily for the past several weeks. During his headache episodes, he constantly tears, and has a “runny nose.” Miosis, ptosis, and conjunctival injection is appreciated on exam. Introduction Primary headache disorder characterized by unilateral periorbital pain ipsilateral cranial autonomic manifestations e.g., lacrimation, rhinorrhea, miosis, ptosis circadian rhythmicity A type of trigeminal autonomic cephalalgias (TACs) Typically lasts 15 - 3 hours occurs in "clusters" (or bouts) Epidemiology more common in men onset typically 10 - 39 years old Presentation Symptoms severe, excruciating, lancinating periorbital pain strictly unilateral restless circadian rhythmicity can occur daily, with or without remission Evaluation Clinical diagnosis Differential Migraine headache Trigeminal neuralgia Treatment Acute (Abortive) Therapy Preventive Prophylactic Therapy 100% O2 Triptans Verapamil Lithium Melatonin Prognosis, Prevention, and Complications Prognosis affects quality of life as a person ages, frequency may decline Complications medication overuse headaches