 |
 |

Adaptations and Deficits in the Vestibulo-Ocular Reflex After Third Nerve Palsy
Agnes M. F. Wong, MD, PhD;
James A. Sharpe, MD
Arch Ophthalmol. 2002;120:360-368.
Objective To analyze the vestibulo-ocular reflex (VOR) in patients with unilateral
peripheral third nerve palsy.
Participants and Methods Ten patients and 15 healthy subjects were studied using magnetic search
coils. Subjects made sinusoidal ±10° head-on-body rotations in
yaw, pitch, and roll in darkness and during monocular viewing in light.
Results Horizontal VOR and visually enhanced VOR (VVOR) gains of the paretic
eye were decreased during both abduction and adduction. Vertical VOR and VVOR
gains of the paretic eye were decreased during both elevation and depression.
Dynamic and static torsional VOR and VVOR gains of the paretic eye were reduced
during both excyclotorsion and incyclotorsion. Horizontal, vertical, and torsional
VOR and VVOR gains were normal in the nonparetic eye.
Conclusions Adducting VOR gains were reduced as anticipated from medial rectus palsy.
Abducting gains were also reduced; the reduction is attributed to an adaptive
decrease in innervation to the lateral rectus to achieve symmetry of the horizontal
VOR in the paretic eye. Torsional VOR gains were reduced during excyclotorsion
from palsy of the inferior oblique muscle. Gains were also reduced during
incyclotorsion, which can be explained by an adaptive decrease in innervation
to the superior oblique to restore symmetry of the torsional VOR in the paretic
eye.
Clinical Relevance Monocular adaptation in the VOR of the paretic eye reduces asymmetrical
movement of retinal images during head motion, prevents nystagmus, and reduces
retinal image disparity.
From the Division of Neurology, the Department of Ophthalmology, and
the University Health Network, University of Toronto, Ontario.
THIS ARTICLE HAS BEEN CITED BY OTHER ARTICLES
Saccade dynamics in peripheral vs central sixth nerve palsies
Wong et al.
Neurology 2006;66:1390-1398.
ABSTRACT
| FULL TEXT
Progressive ataxia and palatal tremor (PAPT): Clinical and MRI assessment with review of palatal tremors
Samuel et al.
Brain 2004;127:1252-1268.
ABSTRACT
| FULL TEXT
|