Two Unusual Cases of the Posterior Cranial Fossa Blood Supply

Variations of the posterior fossa blood supply are relatively uncommon but should be borne in mind by the clinician. We present two unusual cases of posterior cranial fossa blood supply and review the literature regarding such abnormalities. Both cases demonstrated a lack of the vertebrobasilar system to varying degrees. Such arterial variations as present herein should be known to the clinician dealing with the treatment of patients with pathology of the posterior cranial fossa.