[Causes of variations in the pathway of the basilar and vertebral arteries]

Artery loops at the root exit zones of cerebral nerves are regarded as causes of certain diseases, e.g. trigeminal neuralgia or hemifacial spasm. The factors, which may cause such loops and displacements of arteries, however, are still not known sufficiently. In order to find out more about such causes, 60 corpses were examined. We recorded the variations in the positions of vertebral and basilar arteries and correlated them with the respective age at the time of death. We found that those showing atypical artery positions and loops were generally of older age. We further examined possible influences of blood flow factors on variations of artery positions. Our sample indicated such influence of flow factors on displacements of basilar artery, but they seemed to be of lesser importance than the effect of ageing.