[Vertical vergence pathways].

Two pathways for vertical vergence probably exist: the cortical one carrying a psycho-optical reflex, the other sub-cortical connected to the vestibular apparatus and more probably to the otolith system. The sub-cortical pathway is essentially a vestibulo-cerebellar oculomotor pathway; but in addition there certainly exist direct vestibulo-oculomotor connections and long tracts passing through the interstitial nucleus of Cajal and the reticular formation.