[Infarction of the olivary area of the medulla oblongata].

The two first cases of an infarct involving the arterial olivary territory of the medulla oblongata are reported. In the first one, an old infarct of the medial territory and a recent infarct involving the whole inferior olivary nucleus at its middle third level were associated. Rostrally this infarct was reduced to the medial reticular formation and internal half of the olive. Caudally it was reduced to its external half. In the second case the infarct involved only the external half of the right olive, but involved also the external half of the left olive with the lateral territory. From these two cases and from the anatomic, pathologic and clinical data reviewed in the literature, the authors propose as "total" olivary territory a triangular area including all the inferior olivary nucleus, the dorsal accessory olivary nucleus and partly the medial reticular formation, and as "minimum" olivary territory the external half of the olive. The many important medial, lateral and cranio-caudal arteries which supply the olivary territory account for these "total" and "minimum" territories, as well as for some cases in the literature. They account also for the pyramid-like cranio-caudal extension of the olivary territory infarction. The olivary territory is likely to be supplied by two short circumferential arterial groups, i.e. inferior bulbar and superior medullo-pontine. Nevertheless, the cause of the olivary territory infarction is an occlusion of the vertebral artery.