• Illustration by Rob Flewell, CMI.
    File Size: 673 KB
    Neuro-Ophthalmology/Orbit

    Pursuit system. A moving object creates signals in the striate cortex (V1), and from there to the extrastriate cortex (V2, V3). These signals are subsequently relayed to the middle temporal (MT) area and medial superior temporal (MST) areas, the posterior parietal cortex, and the frontal eye field (FEF). The descending cortical pathways of the temporal, parietal, and frontal lobes innervate the ipsilateral dorsal lateral pontine nucleus (DLPN). The neurons in the DLPN decussate and project to the vermis and flocculus in the contralateral cerebellar lobe, which innervates the medial vestibular nucleus (VN). VN neurons then decussate and project to the contralateral CN VI nucleus. The nucleus of CN VI initiates conjugate horizontal eye movements by innervating the ipsilateral lateral rectus muscle and, via internuclear neurons that travel in the medial longitudinal fasciculus, the contralateral medial rectus muscle.