title: Suboccipital nerve blocks for suppression of chronic migraine: safety, efficacy, and predictors of outcome.
abstract: BACKGROUND
  Approximately 1 in 50 Americans is afflicted by chronic migraine (CM). Many patients with CM describe cervicogenic headache. Options for treating CM effectively are at present quite limited.
  
  
  OBJECTIVE
  To determine the safety and efficacy of occipital nerve blocks (ONBs) used to treat cervicogenic chronic migraine (CCM) and to identify variables predictive of a positive treatment response.
  
  
  METHODS
  Using a uniform dose and injection paradigm, we performed ONBs consecutively on a series of patients presenting with CCM. Patients were stratified according to specific findings found to be present or absent on physical examination. A positive treatment outcome was defined as a 50% or greater reduction in headache days per month over the 30 days following treatment relative to the 30-day pre-treatment baseline. We used a 5-point Likert scale as one of the secondary outcome variables.
  
  
  RESULTS
  We treated 150 consecutive patients with unilateral (37) or bilateral (113) ONBs. At the 1-month follow-up visit 78 (52%) exhibited evidence of a positive treatment response according to the primary outcome variable, and 90 (60%) reported their headache disorder to be "better" (44; 29%) or "much better" (46; 30%). A total of 8 (5%) patients reported adverse events within the ensuing 72 hours, and 3 (2%) experienced adverse events that reversed spontaneously but required emergent evaluation and management.
  
  
  CONCLUSIONS
  For suppression of CCM, ONBs may offer an attractive alternative to orally administered prophylactic therapy.
authors.affiliation: University of Alabama Headache, Treatment and Research Program, University of Alabama School of Medicine, Birmingham, AL, USA.
authors.forename: Silvia
authors.initials: S
authors.lastname: Weibelt
authors.forename: Diane
authors.initials: D
authors.lastname: Andress-Rothrock
authors.forename: Wesley
authors.initials: W
authors.lastname: King
authors.forename: John
authors.initials: J
authors.lastname: Rothrock
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D008881:Migraine Disorders / Q000628:therapy*; D009407:Nerve Block / Q000009:adverse effects*; D016896:Treatment Outcome