title: Lateralized central facilitation of trigeminal nociception in cluster headache.
abstract: OBJECTIVE
  To investigate whether central facilitation of trigeminal pain processing is part of the pathophysiology of cluster headache (CH).
  
  
  METHODS
  Sixty-six patients with CH (18 episodic CH inside bout, 28 episodic CH outside bout, 20 chronic CH) according to the International Classification of Headache Disorders-II classification, as well as 30 healthy controls, were investigated in a case-control study using simultaneous recordings of the nociceptive blink reflex (nBR) and pain-related evoked potentials (PREP) following nociceptive electrical stimulation on both sides of the forehead (V1).
  
  
  RESULTS
  nBR latency ratio (headache side/nonheadache side) was decreased in all CH patients independent from CH subtype compared with healthy controls indicating central facilitation at brainstem level. Area under the curve ratio was increased in patients with episodic CH inside bout only. PREP showed decreased N2 latency ratio in patients with chronic CH indicating central facilitation at supraspinal (thalamic or cortical) level.
  
  
  CONCLUSIONS
  Asymmetric facilitation of trigeminal nociceptive processing predominantly on brainstem level was detected in patients with CH. This alteration is most pronounced in the acute pain phase of the disease, but appears to persist in remission periods. Only chronic CH patients show additional changes of PREP prompting to supraspinal changes of pain processing related to the chronic state of disease in regard to neuronal plasticity, which exceeds changes observed in episodic CH.
authors.affiliation: Department of Neurology, University of Duisburg-Essen, Essen, Germany. dagny.holle@uk-essen.de
authors.forename: D
authors.initials: D
authors.lastname: Holle
authors.forename: C
authors.initials: C
authors.lastname: Gaul
authors.forename: S
authors.initials: S
authors.lastname: Zillessen
authors.forename: S
authors.initials: S
authors.lastname: Naegel
authors.forename: S
authors.initials: S
authors.lastname: Krebs
authors.forename: H-C
authors.initials: HC
authors.lastname: Diener
authors.forename: H
authors.initials: H
authors.lastname: Kaube
authors.forename: Z
authors.initials: Z
authors.lastname: Katsarava
authors.forename: M
authors.initials: M
authors.lastname: Obermann
mesh_terms: D000328:Adult; D000368:Aged; D016022:Case-Control Studies; D003027:Cluster Headache / Q000175:diagnosis* / Q000453:epidemiology / Q000503:physiopathology*; D005071:Evoked Potentials / Q000502:physiology; D005260:Female; D007839:Functional Laterality / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D010147:Pain Measurement / Q000379:methods*; D014277:Trigeminal Neuralgia / Q000175:diagnosis* / Q000453:epidemiology / Q000503:physiopathology*; D055815:Young Adult