title: Update on cluster headache.
abstract: OBJECTIVE
  Although cluster headache has traditionally been thought of as a vascular headache disorder, its periodicity suggests an involvement of central areas such as the hypothalamus. This review covers the past 3 years, which have seen remarkable progress in understanding the pathophysiology of circadian headache syndromes and have brought exciting news.
  
  
  RESULTS
  As more cluster headache patients are seen by headache specialists, new forms of this well-defined primary headache syndrome are being identified. In addition, we discuss recent findings with regard to abnormalities in the secretion of hormones, genetic influences, neuroimaging of cluster headache attacks, and the use of newer substances as preventive therapy in cluster headache.
  
  
  CONCLUSIONS
  We have entered a new diagnostic and therapeutic era in primary headache disorders. In recent reports, the use of deep brain stimulation of the hypothalamus has enabled intractable chronic cluster headache patients to be successfully operated upon. Further research in this field is urgently needed and the recent possibility of combining deep brain stimulation with positron emission tomography will certainly help to unravel the brain circuitry implicated in stimulation-produced analgesia. The time has come to use the evidence for a disorder of circadian rhythm in cluster headache to further the development of chronobiotics in the treatment of this disorder.
authors.affiliation: Department of Neurology, University of Regensburg, Regensburg, Germany. arne.may@klinik.uni-regensburg.de
authors.forename: Arne
authors.initials: A
authors.lastname: May
authors.forename: Massimo
authors.initials: M
authors.lastname: Leone
mesh_terms: D003027:Cluster Headache / Q000453:epidemiology / Q000235:genetics / Q000503:physiopathology / Q000628:therapy; D004599:Electric Stimulation Therapy; D005838:Genotype; D006801:Humans; D007031:Hypothalamus / Q000503:physiopathology; D010641:Phenotype