Numerous (3 - 6) short circumflex brainstem arteries depart from the basal artery to the right and left and supply the lateral parts of the brainstem .
There is also talk of "the long circumflex arteries of the brainstem". These include the posterior lower cerebellar artery (PICA), anterior lower cerebellar artery (AICA) and upper cerebellar artery. These supply the posterior/dorsal parts of the brainstem and the cerebellum.