Increased Velocity Storage in Subjects with Meniere’s Disease

Abstract

OBJECTIVE:Velocity storage mechanism is a multisensory rotation estimator; it compensates for errors in the information provided by the peripheral vestibular organs by means of an adjustment in the duration of the vestibular signal. The aim of this study was to determine the activity of the velocity storage mechanism in the presence of a labyrinthine disorder, using galvanic vestibular stimulation to cause direct activation of the vestibular afferent neurons. MATERIALS and METHODS:Forty-one subjects with definite Meniere's disease (MD) and 36 healthy volunteers were evaluated using a 20-s galvanic vestibular stimulation. RESULTS:We found a post-stimulus nystagmus overshoot exclusively in subjects with MD (47% in subjects with unilateral disease and 82% in subjects with bilateral disease), but no overshoot in healthy subjects. CONCLUSION:Because post-stimulus nystagmus overshoot is caused by the velocity storage mechanism, this finding suggests an increase in the velocity storage in subjects with a labyrinthine disease.

In Vivo Localization of the Human Velocity Storage Mechanism and Its Core Cerebellar Networks by Means of Galvanic-Vestibular Afternystagmus and fMRI

“…To conduct a repeated measures analysis of variance (ANOVA) and be able to compare the responses of both stimulation sides regardless of their direction, responses in half the conditions were inverted. The repeated measure ANOVA revealed no statistically significant difference of the torsional slow-phase velocity or the duration of the afternystagmus with regard to the different intertrial intervals [6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24]. The slow-phase velocity of the nystagmus during and after stimulation did not significantly differ between left and right ear excitation.…”

“…Analogous to the ocular motor responses after sustained rotation and optokinetic stimulation, an afternystagmus has been observed after prolonged galvanic vestibular stimulation (GVS), which has been ascribed to the velocity storage mechanism [14,15]. Transmastoideal GVS is a robust vestibular stimulus recruiting both hair cells and vestibular afferent fibers by means of current and thereby modulates the tonic firing rate of the vestibular afferents [16][17][18].…”

Reduced Gain and Shortened Time Constant of Vestibular Velocity Storage as a Source of Balance and Movement Sensitivities in Gravitational Insecurity

“…For example, shortened VVS time constants have been found in fall-prone older individuals [ 13 ] and in adults self-identified with some combination of clumsiness, movement intolerance, gravitational insecurity, and “vestibular system dysfunction” [ 14 ]. Conversely, excessively prolonged time constants are associated with motion sickness [ 15 ], migrainous vertigo [ 16 ], and Meniere's disease [ 17 ]. Based on observations that nystagmus durations in children with GrI were sometimes shorter but often longer, Ayres and Robbins [ 8 ], p. 85] proposed that GrI might be associated with prolonged durations.…”