Introduction: Cluster headache is characterized by severe attacks of unilateral pain, but many patients experience symptoms more commonly associated with migraine such as persistent pain.
Patients and methods: We evaluated cluster headache patients using a questionnaire and chart review to determine clinical characteristics.
Results: Twenty-four of 50 subjects reported interictal pain outside of their acute attacks. Sixteen reported persistent pain more than half the time while in cycle. Unlike acute attacks, this pain was generally mild.
Conclusions: Subjects with persistent interictal pain were more likely to have chronic cluster, allodynia, and suboptimal response to sumatriptan, suggesting that interictal pain in cluster headache may predict a more severe disease process.