title: Risk factors for cranial nerve deficits during carotid endarterectomy: a retrospective study.
abstract: BACKGROUND
  Cranial nerve deficits during CEA are a known complication. The purpose of this study is to evaluate if significant changes in somatosensory evoked potentials and electroencephalography increase cranial nerve deficits during CEA.
  
  
  METHODS
  This is an observational retrospective case-control study analyzed with data collected from patients who underwent CEA at the University of Pittsburgh Medical Center. Five hundred and eighty-seven patients were included in the final analysis. Due to the small number of cranial nerve deficits and the comparatively large number of potential covariates, we used a regression analysis with Bayesian shrinkage.
  
  
  RESULTS
  Analysis was performed on 587 patients, of which a total of 11 (1.8%) cases of cranial nerve deficits were recorded. The marginal mandibular branch of the facial nerve was injured in nine (81%) patients and hypoglossal nerve was injured in two (19%) patients. Of the 11 patients, 9 cases resolved by the time of discharge, the 2 cases that persisted both were injuries to the facial nerve. Multivariate analysis using Bayesian shrinkage showed that after adjusting for all risk factors only IOM changes increased the risk of cranial nerve deficits (OR 38.47, 95% CI 7.73, 191.42).
  
  
  CONCLUSIONS
  Cranial nerve injury is 38 times more likely in patients who experienced a change in IOM during CEA shunt. Future studies examining the effect of stretch and the degree of retraction on the CN might be more helpful in reducing cranial nerve deficits.
authors.affiliation: Department of Neurological Surgery, University of Pittsburgh Medical Center, Pittsburgh, USA; Department of Neurology, University of Pittsburgh Medical Center, Pittsburgh, USA. Electronic address: thirumalapd@upmc.edu.
authors.forename: Parthasarathy D
authors.initials: PD
authors.lastname: Thirumala
authors.affiliation: Department of Neurological Surgery, University of Pittsburgh Medical Center, Pittsburgh, USA.
authors.forename: Harsha
authors.initials: H
authors.lastname: Kumar
authors.affiliation: School of Public Health, University of Pittsburgh, Pittsburgh, USA.
authors.forename: Marnie
authors.initials: M
authors.lastname: Bertolet
authors.affiliation: Department of Neurological Surgery, University of Pittsburgh Medical Center, Pittsburgh, USA.
authors.forename: Miguel E
authors.initials: ME
authors.lastname: Habeych
authors.affiliation: Department of Neurological Surgery, University of Pittsburgh Medical Center, Pittsburgh, USA.
authors.forename: Donald J
authors.initials: DJ
authors.lastname: Crammond
authors.affiliation: Department of Neurological Surgery, University of Pittsburgh Medical Center, Pittsburgh, USA; Department of Neuroscience, University of Pittsburgh, Pittsburgh, USA.
authors.forename: Jeffrey R
authors.initials: JR
authors.lastname: Balzer
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D016022:Case-Control Studies; D020209:Cranial Nerve Injuries / Q000209:etiology*; D004569:Electroencephalography / Q000379:methods; D016894:Endarterectomy, Carotid / Q000009:adverse effects*; D005260:Female; D006801:Humans; D007431:Intraoperative Complications / Q000209:etiology*; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D012307:Risk Factors
keywords: Carotid endartectomy; Cranial nerve injury; Electroencephalography; Intraoperative neurophysiological monitoring; Somatosensory evoked potentials