Objective.—To refine the clinical spectrum of chronic paroxysmal hemicrania (CPH).
Methods.—From 1976 to 1996, 74 patients were diagnosed with CPH by Mayo Clinic neurologists. Data were collected on those cases.
Results.—Of the 74 patients, 62% were women. Most (93%; 69/74) had strictly unilateral pain, 78% (53/68) had daily attacks, and 4% (2/47) had no autonomic features. The mean usual attack duration was 26 minutes, whereas the mean usual attack frequency was six per day. Three-quarters (30/40) had a consistent response to indomethacin, whereas 25% did not. In 34 patients, there were incomplete data concerning indomethacin response. Some (9/13) were able to stop indomethacin without headache recurrence. Few (2/25) stopped indomethacin because of side effects. Two patients had initial responses to indomethacin that did not persist. Oxygen was beneficial in three patients. Three surgically treatable cases of secondary CPH were identified.
Conclusions.—Attack duration is the clinical feature that best distinguishes CPH from other trigeminal autonomic cephalgias. Although long-term therapy with indomethacin is generally well-tolerated, some patients who clinically appear to have CPH do not respond to indomethacin, and tachyphylaxis may develop in some cases. Some patients are able to stop indomethacin without headache recurrence, highlighting the importance of a trial of discontinuation. A consistent clinical profile and treatment response do not exclude the possibility of intracranial pathology.