Bilateral type 1 proatlantal arteries with absence of vertebral arteries

The persistent proatlantal artery is a well-described communication between the carotid and vertebrobasilar system, However, persistence of bilateral proatlantal arteries Is exceptionally rare, Although usually noted as an in cidental finding, the presence of a proatlantal artery, particularly when b ilateral, may result in unusual symptoms or may have implications for thera py. We report a case of bilateral proatlantal arteries, describe their embr yology, and consider potential clinical implications of this finding.