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Vestibular and Related Oculomotor Disorders
Published in Anthony N. Nicholson, The Neurosciences and the Practice of Aviation Medicine, 2017
Nicholas J. Cutfield, Adolfo M. Bronstein
The vestibulo-ocular reflex stabilizes vision with head movement in all directions. If the head rotates left in ‘yaw’, the eyes respond to the right with the same angular magnitude as the head movement. If the head elevates, the eyes depress. If the head rolls, the eyes roll in the opposite direction, subject to mechanical restrictions. The reflex operates continuously, unnoticed as we move our heads, and guarantees clear vision during a large range of head movements. It is a fast reflex using only three neurons – the vestibular nerve, an interneuron from the vestibular nuclei to the oculomotor nuclei of the third, fourth or sixth cranial nerves, and the relevant efferent oculomotor nerve. A problem with the reflex is likely if fast head movements or riding in a car result in ‘wobbly’ vision (oscillopsia), or if, after turning the head quickly, the vision seems to ‘catch up’. When visually tracking a moving object while the head is moving, the reflex is suppressed (see below).
Impact of Retinal Stimulation on Neuromodulation
Published in Yu Chen, Babak Kateb, Neurophotonics and Brain Mapping, 2017
The Edinger–Westphal nucleus is an accessory nucleus of the oculomotor nerve and receives input for pupillary constriction from external light. This nucleus also receives internal information from the olivary pretectal nuclei, which also receive signals from a subtype of the intrinsically photosensitive retinal ganglion (ipRGC) cells. The olivary pretectal nuclei are involved in linking internal metabolism with external luminance—through the suprachiasmatic nuclei (SCN) of the hypothalamus and intergeniculate leaflet (IGL) of the thalamus (Ishikawa 2013).
Neuroimaging
Published in Sarah McWilliams, Practical Radiological Anatomy, 2011
o The oculomotor nerve passes through the superior orbital fissure. It arises from the anterior midbrain and runs through the lateral wall of the cavernous sinus. The nerve supplies the five orbital muscles not supplied by abducens and trochlea.
Deep brain stimulation programming strategies: segmented leads, independent current sources, and future technology
Published in Expert Review of Medical Devices, 2021
Bhavana Patel, Shannon Chiu, Joshua K. Wong, Addie Patterson, Wissam Deeb, Matthew Burns, Pamela Zeilman, Aparna Wagle-Shukla, Leonardo Almeida, Michael S. Okun, Adolfo Ramirez-Zamora
To optimally utilize directional programming, it is critical to understand the anatomical structural and functional connections of the STN region. The STN is a small lens-shaped structure located in the anterior-lateral part of the midbrain. It is bordered by the substantia nigra pars reticulata (SNr) ventrally; internal capsule anterolaterally; the medial lemniscus posteriorly; the red nucleus, the medial forebrain bundle, the oculomotor nerve fibers medially; rostral zona incerta and fields of Forel dorsally (Figure 4) [64,82,83]. In addition to these neighboring anatomical structures, the STN has been described to be divided into territories (i.e., motor, limbic, and associative) [84]. Majority of studies report using the contacts located in the dorsolateral aspect of the STN to be the most effective and efficient stimulation to reduce PD motor symptoms [74,75]. Some examples of stimulation induced side-effects in STN-DBS include contralateral muscle contractions (internal capsule), dysconjugate gaze or diplopia (oculomotor nerve fibers), autonomic dysfunction (medial zonal incerta, red nucleus, or hypothalamus), paresthesia (medial lemniscus), dysarthria (internal capsule or cerebello-thalamic tracts), and mood changes (substantia nigra, ventromedial limbic region of STN, medial forebrain bundle region).