Physiology - Vestibular Ocular Reflex

Phylogenetically, the vestibula-ocular reflex is the oldest and simplest of all ocular motor subsystems. There are two central pathways between the primary vestibular afferents and the ocular motor neurons. The direct pathway is the well known three neuron arc consisting of the VIII nerve nucleus, the vestibular nucleus and the ocular motor nucleus. Although the direct pathway has been well studied and its physiology understood, it is the indirect reticular pathways which are required for proper operation of the vestibulo-ocular reflex. Lesions in these pathways are far more detrimental to a patient's eye movement control than lesions in the direct pathway.