title: Stimulation of the sphenopalatine ganglion (SPG) for cluster headache treatment. Pathway CH-1: a randomized, sham-controlled study.
abstract: BACKGROUND
  The pain and autonomic symptoms of cluster headache (CH) result from activation of the trigeminal parasympathetic reflex, mediated through the sphenopalatine ganglion (SPG). We investigated the safety and efficacy of on-demand SPG stimulation for chronic CH (CCH).
  
  
  METHODS
  A multicenter, multiple CH attack study of an implantable on-demand SPG neurostimulator was conducted in patients suffering from refractory CCH. Each CH attack was randomly treated with full, sub-perception, or sham stimulation. Pain relief at 15 minutes following SPG stimulation and device- or procedure-related serious adverse events (SAEs) were evaluated.
  
  
  RESULTS
  Thirty-two patients were enrolled and 28 completed the randomized experimental period. Pain relief was achieved in 67.1% of full stimulation-treated attacks compared to 7.4% of sham-treated and 7.3% of sub-perception-treated attacks ( P  < 0.0001). Nineteen of 28 (68%) patients experienced a clinically significant improvement: seven (25%) achieved pain relief in ≥50% of treated attacks, 10 (36%), a ≥50% reduction in attack frequency, and two (7%), both. Five SAEs occurred and most patients (81%) experienced transient, mild/moderate loss of sensation within distinct maxillary nerve regions; 65% of events resolved within three months.
  
  
  CONCLUSIONS
  On-demand SPG stimulation using the ATI Neurostimulation System is an effective novel therapy for CCH sufferers, with dual beneficial effects, acute pain relief and observed attack prevention, and has an acceptable safety profile compared to similar surgical procedures.
authors: Headache Research Unit, Department of Neurology, CHR Citadelle, Liège University, B-4000 Liège, Belgium. jschoenen@ulg.ac.be
authors: Jean
authors: J
authors: Schoenen
authors: Rigmor Højland
authors: RH
authors: Jensen
authors: Michel
authors: M
authors: Lantéri-Minet
authors: Miguel J A
authors: MJ
authors: Láinez
authors: Charly
authors: C
authors: Gaul
authors: Amy M
authors: AM
authors: Goodman
authors: Anthony
authors: A
authors: Caparso
authors: Arne
authors: A
authors: May
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D003027:Cluster Headache / Q000503:physiopathology / Q000628:therapy*; D004599:Electric Stimulation Therapy / Q000295:instrumentation / Q000379:methods*; D004567:Electrodes, Implanted; D005260:Female; D005726:Ganglia, Parasympathetic / Q000502:physiology*; D006801:Humans; D008297:Male; D008839:Microelectrodes; D008875:Middle Aged; D010147:Pain Measurement / Q000379:methods*; D056739:Pterygopalatine Fossa / Q000502:physiology; D016896:Treatment Outcome; D055815:Young Adult
keywords: Cluster headache; neurostimulation; randomized controlled trial; sphenopalatine ganglion