Localization of olivo-cerebellar fibers in inferior cerebellar peduncle in man.

The localization of the olivo-cerebellar fibers in the inferior cerebellar peduncle was examined in a patient who showed severe degeneration of the left olivary nucleus due to an old hemorrhagic infarct in the contralateral cerebellum. Other precerebellar nuclei which send their cerebellipetal axons to the inferior cerebellar peduncle, such as the external cuneate nucleus, the lateral reticular nucleus and the arcuate nucleus, were normally preserved. The dorsal spino-cerebellar tract and the vestibular nuclei, together with the juxtarestiform body were also intact. Degeneration of the inferior cerebellar peduncle was noted only in its ventromedial portion contralateral to the olivary lesion. As a result, it is concluded that the olivo-cerebellar fibers seem to be located in this portion of the inferior cerebellar peduncle.