VERTICAL VESTIBULO-OCULAR REFLEX, SMOOTH PURSUIT AND EYE-HEAD TRACKING DYSFUNCTION IN INTERNUCLEAR OPHTHALMOPLEGIA

Brain ◽  
1988 ◽  
Vol 111 (6) ◽  
pp. 1299-1317 ◽  
Author(s):  
PAUL J. RANALLI ◽  
JAMES A. SHARPE
Keyword(s):  
Smooth Pursuit ◽  
Head Tracking ◽  
Internuclear Ophthalmoplegia ◽  
Ocular Reflex ◽  
Vestibulo Ocular Reflex

The vertical vestibulo-ocular reflex, and its interaction with vision during active head motion: Effects of aging

2001 ◽  
Vol 11 (1) ◽  
pp. 3-12
Author(s):  
Ji Soo Kim ◽  
James A. Sharpe
Keyword(s):  
Smooth Pursuit ◽  
Low Frequency ◽  
The Elderly ◽  
Head Motion ◽  
Head Tracking ◽  
Elderly Age ◽  
Ocular Reflex ◽  
Visual Enhancement ◽  
Vestibulo Ocular Reflex ◽  
Effects Of Aging

The effects of aging on the vertical vestibulo-ocular reflex (VOR), and its interactions with vision during active head motion had not been investigated. We measured smooth pursuit, combined eye-head tracking, the VOR, and its visual enhancement and cancellation during active head motion in pitch using a magnetic search coil technique in 21 younger (age < 65) and 10 elderly (age ⩾ 65) subjects. With the head immobile, subjects pursued a target moving sinusoidally with a frequency range of 0.125 to 2.0 Hz, and with peak target accelerations (PTAs) ranging from 12 to 789Âř/s 2 . Combined eye-head tracking, the VOR in darkness, and its visual enhancement during fixation of an earth-fixed target (VVOR) were measured during active sinusoidal head motion with a peak-to-peak amplitude of 20Âř at frequencies of 0.25, 0.5, 1.0 and 2.0 Hz. The efficacy of VOR cancellation was determined from VOR gains during combined eye-head tracking. VOR and VVOR gains were symmetrical in both directions and did not change with aging, except for reduced gains of the downward VOR and VVOR at low frequency (0.25 Hz). However, in the elderly, smooth pursuit, and combined eye-head tracking gains and the efficacy of cancellation of the VOR were significantly lower than in younger subjects. In both the young and elderly groups, VOR gain in darkness did not vary with the frequency of active head motion while the gains of smooth pursuit, combined eye-head tracking, and VVOR declined with increasing target frequency. VOR and VVOR performance in the elderly implicates relative preservation of neural structures subserving vertical vestibular smooth eye motion in senescence.

Dissociation of smooth pursuit and vestibulo-ocular reflex cancellation in SCA-6

Neurology ◽  
2000 ◽  
Vol 54 (4) ◽  
pp. 860-866 ◽  
Author(s):  
N. Takeichi ◽  
K. Fukushima ◽  
H. Sasaki ◽  
I. Yabe ◽  
K. Tashiro ◽  
...  
Keyword(s):  
Smooth Pursuit ◽  
Ocular Reflex ◽  
Vestibulo Ocular Reflex

scholarly journals Enhancement of the Vestibulo-Ocular Reflex by Prior Eye Movements

1999 ◽  
Vol 81 (6) ◽  
pp. 2884-2892 ◽  
Author(s):  
Vallabh E. Das ◽  
Louis F. Dell’Osso ◽  
R. John Leigh
Keyword(s):  
Eye Movements ◽  
Smooth Pursuit ◽  
Initial Perturbation ◽  
Head Rotation ◽  
Gaze Shift ◽  
Stationary Target ◽  
Ocular Reflex ◽  
Vestibulo Ocular Reflex ◽  
Head Rotations ◽  
Horizontal Head

Enhancement of the vestibulo-ocular reflex by prior eye movements. We investigated the effect of visually mediated eye movements made before velocity-step horizontal head rotations in eleven normal human subjects. When subjects viewed a stationary target before and during head rotation, gaze velocity was initially perturbed by ∼20% of head velocity; gaze velocity subsequently declined to zero within ∼300 ms of the stimulus onset. We used a curve-fitting procedure to estimate the dynamic course of the gain throughout the compensatory response to head rotation. This analysis indicated that the median initial gain of compensatory eye movements (mainly because of the vestibulo-ocular reflex, VOR) was 0.8 and subsequently increased to 1.0 after a median interval of 320 ms. When subjects attempted to fixate the remembered location of the target in darkness, the initial perturbation of gaze was similar to during fixation of a visible target (median initial VOR gain 0.8); however, the period during which the gain increased toward 1.0 was >10 times longer than that during visual fixation. When subjects performed horizontal smooth-pursuit eye movements that ended (i.e., 0 gaze velocity) just before the head rotation, the gaze velocity perturbation at the onset of head rotation was absent or small. The initial gain of the VOR had been significantly increased by the prior pursuit movements for all subjects ( P < 0.05; mean increase of 11%). In four subjects, we determined that horizontal saccades and smooth tracking of a head-fixed target (VOR cancellation with eye stationary in the orbit) also increased the initial VOR gain (by a mean of 13%) during subsequent head rotations. However, after vertical saccades or smooth pursuit, the initial gaze perturbation caused by a horizontal head rotation was similar to that which occurred after fixation of a stationary target. We conclude that the initial gain of the VOR during a sudden horizontal head rotation is increased by prior horizontal, but not vertical, visually mediated gaze shifts. We postulate that this “priming” effect of a prior gaze shift on the gain of the VOR occurs at the level of the velocity inputs to the neural integrator subserving horizontal eye movements, where gaze-shifting commands and vestibular signals converge.

Impaired vestibular responses in internuclear ophthalmoplegia

Neurology ◽  
2017 ◽  
Vol 89 (24) ◽  
pp. 2476-2480 ◽  
Author(s):  
Seo-Young Choi ◽  
Hyo-Jung Kim ◽  
Ji-Soo Kim
Keyword(s):  
Vestibular Evoked Myogenic Potentials ◽  
Medial Longitudinal Fasciculus ◽  
Subjective Visual Vertical ◽  
Internuclear Ophthalmoplegia ◽  
Horizontal Canal ◽  
Head Impulse ◽  
Ocular Tilt Reaction ◽  
Ocular Reflex ◽  
Vestibulo Ocular Reflex ◽  
Visual Vertical

Objective:To determine the role of the medial longitudinal fasciculus (MLF) in conveying vestibular signals.Methods:In 10 patients with isolated acute unilateral internuclear ophthalmoplegia (INO) due to an acute stroke, we performed comprehensive vestibular evaluation using video-oculography, head impulse tests with a magnetic search coil technique, bithermal caloric tests, tests for the ocular tilt reaction, and measurements of subjective visual vertical and cervical and ocular vestibular evoked myogenic potentials (VEMPs).Results:The head impulse gain of the vestibulo-ocular reflex (VOR) was decreased invariably for the contralesional posterior canal (PC) (n = 9; 90%) and usually for the ipsilesional horizontal canal (n = 5; 50%). At least one component of contraversive ocular tilt reaction (n = 9) or contraversive tilt of the subjective visual vertical (n = 7) were common along with ipsitorsional nystagmus (n = 5). Cervical or ocular VEMPs were abnormal in 5 patients.Conclusions:The MLF serves as the main passage for the high-acceleration VOR from the contralateral PC. The associations and dissociations of the vestibular dysfunction in our patients indicate variable combinations of damage to the vestibular fibers ascending or descending in the MLF even in strokes causing isolated unilateral INO.

Cancellation of the vestibulo-ocular reflex during horizontal combined eye-head tracking

1992 ◽  
Vol 20 (1) ◽  
pp. 139-140
Author(s):  
Daniel J. Schneck ◽  
William Paul Huebner ◽  
R. John Leigh ◽  
Gecil W. Thomas
Keyword(s):  
Head Tracking ◽  
Ocular Reflex ◽  
Vestibulo Ocular Reflex
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