title: Preservation of the greater occipital nerve during suboccipital craniectomy results in a paradoxical increase in postoperative headaches.
abstract: BACKGROUND
  Injury to the greater occipital nerve (GON) during suboccipital/retrosigmoid craniectomy (SOC) has been postulated as an etiology of postoperative headaches (HAs). We hypothesized that severe postoperative HAs may be due to the division of the GON during dissection.
  
  
  OBJECTIVE
  To determine whether the GON plays an important role in the development of postoperative HAs.
  
  
  METHODS
  A retrospective review of prospectively accrued patients undergoing SOC by 1 neurosurgeon at Johns Hopkins from 1995 to 2009 was performed. A total of 280 patients were included in the study. HA was categorized into 3 groups according to the severity and impact on daily activities. Data were analyzed using a stepwise multivariate logistic regression analysis to identify independent factors associated with HA development. Patients with a history of preoperative HAs and migraine were excluded from the analysis.
  
  
  RESULTS
  In this cohort, new postoperative severe HAs at last follow-up visit were found in 19% of patients. By multivariate analysis, only GON preservation (relative risk: 1.49; 95% confidence interval: 1.00-2.34; P = 0.05) and wound infection (relative risk: 2.29; 95% confidence interval: 0.91-4.25; P = 0.07) were statistically significant. By univariate analysis, positive dependent associations included GON preservation (P < .01), reconstruction of the porus with hydroxyapatite cement (P = 0.02), and wound infection (P < 0.01). Statistically significant differences in the incidence of HA after surgery were found in patients in whom the GON was preserved compared with patients in whom the GON was divided (P = 0.035).
  
  
  CONCLUSIONS
  Postoperative debilitating HAs are a common complication after SOC. Although these HAs are probably multifactorial in nature, preservation of the GON during SOC is independently associated with postoperative debilitating HAs.
authors.affiliation: *Department of Neurosurgery, Johns Hopkins University School of Medicine, Baltimore, Maryland; ‡Department of Neurosurgery, University of Maryland School of Medicine, Baltimore, Maryland.
authors.forename: Tomas
authors.initials: T
authors.lastname: Garzon-Muvdi
authors.forename: Christopher
authors.initials: C
authors.lastname: Jackson
authors.forename: Alfred P
authors.initials: AP
authors.lastname: See
authors.forename: Graeme F
authors.initials: GF
authors.lastname: Woodworth
authors.forename: Rafael J
authors.initials: RJ
authors.lastname: Tamargo
mesh_terms: D000368:Aged; D015331:Cohort Studies; D003399:Craniotomy / Q000009:adverse effects* / Q000379:methods*; D005260:Female; D006261:Headache / Q000453:epidemiology / Q000209:etiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000453:epidemiology / Q000209:etiology*; D012189:Retrospective Studies; D013127:Spinal Nerves / Q000601:surgery*