A diverse set of disorders that respond often exquisitely to indomethacin (25 mg two to three times daily). Includes:

• Paroxysmal hemicrania: Frequent unilateral, severe, short-lasting episodes of headache that are often retroorbital and associated with autonomic phenomena such as lacrimation and nasal congestion.
• Hemicrania continua: Moderate and continuous unilateral pain associated with fluctuations of severe pain that may be associated with autonomic features.
• Primary stabbing headache: Stabbing pain confined to the head or rarely the face lasting from 1 to many seconds or minutes.
• Primary cough headache: Transient severe head pain with coughing, bending, lifting, sneezing, or stooping; lasts for several minutes. Usually benign, but posterior fossa mass lesion in some pts; therefore consider brain MRI.
• Primary exertional headache: Features similar to cough headache and migraine, but precipitated by any form of exercise.