We have found numerous case reports, but no systematic study of the megadolichovertebrobasilar anomaly (MDVBA). The purpose of this paper is to evaluate the relationships between arterial shifts of the vertebro-basilar system and neurological findings in the posterior fossa in our series of 132 cases. We found a high percentage (77.3%) of angiographic-clinical correlations having evaluated the arterial shifts, measured in mm, of the vertebro-basilar system in a frontal and a sagittal plane and concluded that the greater the degree of dislocation, the greater the number of positive cases. Nevertheless it is not possible to predetermine the presence of particular neurosymptomatology related to arterial dislocation degrees
