Journal of Vestibular Research - Volume 10, issue 3

Authors: Wade, Nicholas J.

Article Type: Research Article

Abstract: Vestibular research before Flourens typically involved vertigo and eye movements. In 1820 Purkinje integrated these in studies of postrotary vertigo and he is linked with Flourens as a founder of vestibular research. In the late eighteenth century Erasmus Darwin described vertigo in detail, but he did not accept that it involved an oculomotor component. Darwin reached this conclusion despite detailed experiments by William Charles Wells (1757–1817), who described the pattern of postrotary nystagmus and its dependence on head orientation during rotation. Wells generated afterimages prior to rotation and subsequently compared their motions with those of real images. He was able …to distinguish between the slow and fast phases of nystagmus, its reducing amplitude following cessation of rotation, its suppression with fixation, and its torsional dimension. In many ways, Wells's experiments were more sophisticated than those of Purkinje, and he should be recognised as a founder of vestibular research. Possible reasons for the neglect of Wells's work are discussed. Show more

Keywords: vestibulo-ocular nystagmus, vertigo, afterimages, vestibular history

DOI: 10.3233/VES-2000-10301

Citation: Journal of Vestibular Research, vol. 10, no. 3, pp. 127-137, 2000

Authors: Peters, Kim | Darlington, Cynthia L. | Smith, Paul F.

Article Type: Research Article

Abstract: Numerous animal studies have suggested that the vestibular system modulates respiratory and cardiovascular function. However, relatively few studies have examined vestibular-autonomic interaction in humans. In this study we investigated the effects of repeated horizontal (clockwise or anticlockwise) optokinetic stimulation on systolic blood pressure (SBP), diastolic blood pressure (DBP), pulse and latency to circularvection (CV) in humans, and compared the effects with those of repeated exposure to a stationary visual stimulus. Although all subjects experienced CV, neither mean SBP, DBP or pulse differed significantly between the clockwise/anticlockwise optokinetic stimulation and no optokinetic stimulation conditions. However, SBP and DBP changed significantly over …the 20 trials in each test session, even when there was no optokinetic stimulation (P < 0.001 in each case). These results suggest that while horizontal optokinetic stimulation does not significantly affect SBP, DBP or pulse in humans, changes in these variables can be induced by trial repetition itself, even when no optokinetic stimulation occurs. Show more

Keywords: optokinetic stimulation, circularvection, autonomic function, vestibular-autonomic interaction

DOI: 10.3233/VES-2000-10302

Citation: Journal of Vestibular Research, vol. 10, no. 3, pp. 139-142, 2000

Authors: Furman, Joseph M. | Koizuka, Izumi | Schor, Robert H.

Article Type: Research Article

Abstract: The nystagmus following yaw earth-vertical axis rotation often reverses direction, a phenomenon known as the “secondary phase”. The purpose of this study was to examine the existence and the spatial and temporal properties of the secondary phase of post-rotatory nystagmus following off-vertical axis rotation (OVAR). Eleven normal human subjects were rotated at 120 or 180 ∘ /s about an off-vertical axis and stopped in the left ear down or right ear down lateral position. Horizontal and vertical eye positions were recorded with a scleral search coil, and horizontal and vertical slow component eye velocities were …computed. Our results indicate that (a) there is a robust secondary phase nystagmus following OVAR, and (b) the direction of the secondary phase nystagmus tends to align with earth-horizontal. These results can be explained by a minor modification of an existing VOR model that has been shown to produce secondary phase responses. Show more

Keywords: human otolith vestibulo-ocular reflex, velocity storage

DOI: 10.3233/VES-2000-10303

Citation: Journal of Vestibular Research, vol. 10, no. 3, pp. 143-150, 2000

Authors: Fushiki, Hiroaki | Takata, Satoru | Watanabe, Yukio

Article Type: Research Article

Abstract: The contribution of fixation to latency of circular vection (CV) was examined in twenty-five normal adults aged 18–30 years. For induction of self-motion a random dot pattern was projected onto a hemispherical dome. The pattern was rotated either about the subject’s vertical axis or about their interaural axis at a constant acceleration of 1 deg / s 2 . For the group tested, the perceived CV latencies were significantly shorter with fixation than without fixation in both horizontal and vertical CV. The effect of fixation was pronounced in subjects with longer latencies. The mean …CV latencies for two different fixation points between the subject’s eyes and the moving pattern did not differ significantly. Our results suggest that the potential influence of fixation must be carefully controlled in studies of visually induced self-motion. Possible explanations for the effect of fixation on the generation of CV will also be discussed. Show more

Keywords: self-motion, optokinetic, fovea, visual-vestibular interaction

DOI: 10.3233/VES-2000-10304

Citation: Journal of Vestibular Research, vol. 10, no. 3, pp. 151-155, 2000

Authors: Nishiwaki, Yuji | Takebayashi, Toru | Imai, Azusa | Yamamoto, Masahiko | Omae, Kazuyuki

Article Type: Research Article

Abstract: There is no standard for the awareness of standing posture in stabilometry, yet little research addressing the matter has been carried out. In the present study, we evaluated the influence of different instructional sets during a test on stabilometry. Stabilometry was performed on 349 male subjects. Two different instructions were prepared for the subjects regarding the awareness of their standing posture. These instructions were a) “Please relax when you stand” (R-standing), and b) “Please make an effort to minimize your body sway” (E-standing). Subjects were classified into four groups according to the combination of these instructions they received. For the …five body sway parameters, a comparison between R-standing and E-standing was performed, controlling for possible confounders such as age, height, body weight, educational history, alcohol consumption, and smoking status. The sway length in E-standing was larger than that in R-standing, even after the adjustment for possible confounders. Our results indicate that the difference in the instructional set caused a significant measurement bias. Thorough-going unification of instructions for the stabilometry should be recommended when stabilometry is performed in an epidemiological investigation. Show more

Keywords: stabilometry, measurement bias, body sway, epidemiological investigation

DOI: 10.3233/VES-2000-10305

Citation: Journal of Vestibular Research, vol. 10, no. 3, pp. 157-161, 2000