title: Comparison of left and right vertebral artery intracranial diameters.
abstract: BACKGROUND
  The vertebral artery is vulnerable to mechanical injury, especially in the region of the first and second cervical vertebrae, with resultant thrombus and/or emboli formation, often found at the vertebro-basilar junction. Such vascular injuries and associated neurological insults have been documented repeatedly in the literature as following cervical spine manipulation, when movements of the head and neck can cause compression and/or stretching of the vertebral artery and alterations in its blood flow. This has particular clinical relevance if a patient has a hypoplastic vertebral artery. Such persons may be considered at risk as regards vascular accidents following manipulation of the cervical spine. The aim of this study was to measure and compare the intracranial diameters of the left and right vertebral arteries in groups of black and white male and female South African subjects.
  
  
  METHODS
  Cadaver material from 58 specimens was processed for light microscopy, and measurements of inner (lumen only) and outer (lumen, tunica intima, and tunica media) diameters taken and compared, using the t-test.
  
  
  RESULTS
  Data analysis revealed a significant difference between the left and right vertebral artery intracranial diameters in the white female group only (N = 8).
  
  
  CONCLUSIONS
  Such a statistically significant difference implies a difference of biological importance and it is suggested that this particular group of subjects may be a high-risk group as regards vascular accidents following cervical spine manipulation.
authors.affiliation: Department of Anatomy and Human Biology, Medical School, University of the Witwatersrand, Johannesburg, South Africa.
authors.forename: J
authors.initials: J
authors.lastname: Mitchell
authors.forename: A
authors.initials: A
authors.lastname: McKay
mesh_terms: D044383:Black People; D005260:Female; D006801:Humans; D008297:Male; D012727:Sex Characteristics; D014711:Vertebral Artery / Q000033:anatomy & histology*; D044465:White People