Journal of Vestibular Research - Volume 5, issue 2

Authors: Curthoys, Ian S. | Halmagyi, G. Michael

Article Type: Review Article

Abstract: Vestibular sensory input is just one sensory input involved in the control of functions such as gaze and posture. The recovery of gaze and posture control after partial or complete unilateral loss of vestibular input is reviewed. The relatively rapid and apparently complete behavioral recovery after unilateral vestibular loss was once regarded as justifying vestibular compensation being used as a text-book example of plasticity in the CNS. This review emphasizes how false that impression is: Detailed examination shows that vestibular compensation is not a single process that recovers completely at a rapid rate but is made up of a number …of subprocesses that recover to different levels and at different rates. In some subprocesses there is very modest recovery; in other subprocesses there is probably substitution of other sensory input for the affected vestibular input. It also seems that in some instances new behavioral strategies appear to be learned to allow gaze and posture control to operate as if normal. Recent evidence concerning the physiological and pharmacological mechanisms underlying vestibular compensation is reviewed. Show more

Keywords: vestibular, otolith, semicircular canal, nystagmus, vestibular compensation, labyrinth, utricular saccular

DOI: 10.3233/VES-1995-5201

Citation: Journal of Vestibular Research, vol. 5, no. 2, pp. 67-107, 1995

Authors: Bles, Willem | Jelmorini, Monique | Bekkering, Harold | de Graaf, Bernd

Article Type: Research Article

Abstract: A sensation of linear self-motion can be induced in a blindfolded stationary sitting subject, who keeps contact with a linearly moving platform (acceleration 0.1 m/s2 ) in the frontoparallel plane by means of a hand-over-hand walking action. When discordant suprathreshold vestibular information from the otoliths is added by moving the subject laterally (acceleration 0.1 m/s2 ) in the same direction as the platform (acceleration of the platform 0.2 m/s2 , so the arthrokinetic stimulus is also an acceleration of 0.1 m/s2 , but into the opposite direction), the arthrokinetic information was found to have a predominant effect on the perceived …direction of self-motion. Show more

Keywords: otolith, vection, somatosensory, sled

DOI: 10.3233/VES-1995-5202

Citation: Journal of Vestibular Research, vol. 5, no. 2, pp. 109-116, 1995

Authors: Uimonen, Seija | Laitakari, Kyösti | Kiukaanniemi, Heikki | Sorri, Martti

Article Type: Research Article

Abstract: Voluntary, simulated vertigo and acute vertigo due to vestibular neuritis were examined by means of static posturography in 81 tests to evaluate the extent to which intentional malingering can be detected. Thirty healthy, normal subjects were first instructed to stand as still as possible on a static force platform and then to simulate dizziness. The true cases consisted of 21 patients with vestibular neuritis. The parameters analyzed included body sway velocity (BSV), body sway area of ellipse (BSE), and the Romberg quotient. Both the simulated and pathological posturographic BSV and BSE values differed from normal values under all test conditions, …but they did not differ from each other, whereas the simulated values could be differentiated from the pathological ones with the Romberg quotient based on BSV. Five staff members of our audiological department were able to differentiate between the simulations and pathological cases quite well, with a median sensitivity of 0.77 and a specificity of 0.71 in a blinded test. A posturographic measurement, even performed once, can be useful to some extent for detecting simulation, but more investigation and development of the analysis system is required to obtain more specific results. For the present, the results obtained by trained observation of the subject in the test situation are at least as reliable as those obtained through the analysis of statistical measurements. Show more

Keywords: posturography, vertigo, dizziness, malingering

DOI: 10.3233/VES-1995-5203

Citation: Journal of Vestibular Research, vol. 5, no. 2, pp. 117-124, 1995

Authors: Stivalet, Philippe | Marendaz, Christian | Barraclough, Lorna | Mourareau, Christian

Article Type: Research Article

Abstract: To see if the spatial reference frame used by pre-attentive vision is specified in a retino-centered frame or in a reference frame integrating visual and nonvisual information (vestibular and somatosensory), subjects were centrifuged in a nonpendular cabin and were asked to search for a target distinguishable from distractors by difference in orientation (Treisman’s “pop-out” paradigm [1]). In a control condition, in which subjects were sitting Immobilized but not centrifuged, this task gave an asymmetric search pattern: Search was rapid and pre-attentional except when the target was aligned with the horizontal retinal/head axis, in which case search was slow and attentional …(2). Results using a centrifuge showed that slow/serial search patterns were obtained when the target was aligned with the subjective horizontal axis (and not with the horizontal retinal/head axis). These data suggest that a multisensory reference frame is used in pre-attentive vision. The results are interpreted in terms of Riccio and Stoffregen’s “ecological theory” of orientation in which the vertical and horizontal axes constitute independent reference frames (3). Show more

Keywords: early vision, pre-attentive vision, spatial orientation, gravitational effects

DOI: 10.3233/VES-1995-5204

Citation: Journal of Vestibular Research, vol. 5, no. 2, pp. 125-135, 1995

Authors: Licata, Flora | Li Volsi, Guido | Maugeri, Giuseppe | Santangelo, Francesca

Article Type: Research Article

Abstract: The effects of dorsal raphe (DR) electrical stimulation on the neuronal activity of vestibular nuclei were studied in anaesthetized rats. The aim was to establish whether the central systems classically involved in nociceptive functions are able to influence vestibular secondary neurons. DR activation induced modifications of the firing in 70% of the tested neurons, the percentage being similar in the lateral (LVN), superior (SVN), and spinal (SpVN) vestibular nuclei. Three different types of responses were recorded: long-lasting modifications (generally enhancements) of the mean firing rate (43%), short-latency response patterns (14%), both (43%). Short-latency response patterns were more numerous in LVN …than in SVN. Iontophoretic applications of 5-HT antagonists Methysergide and Ketanserin blocked long-lasting effects but were scarcely effective on the short-latency response patterns evoked by DR stimulation. It is concluded that DR exerts a double control on secondary vestibular neurons: a generalised excitatory influence by serotoninergic fibers and a specific action mostly targeted on LVN, by nonserotoninergic pathways. Show more

Keywords: vestibular complex, 5-hydroxytryptamine, 5HT, electrical stimulation

DOI: 10.3233/VES-1995-5205

Citation: Journal of Vestibular Research, vol. 5, no. 2, pp. 137-145, 1995