Journal of Vestibular Research - Volume 24, issue 5-6

Article Type: Editorial

DOI: 10.3233/VES-140539

Citation: Journal of Vestibular Research, vol. 24, no. 5-6, pp. 327-327, 2014

Authors: Schneider, Rosalyn | Liao, Ke | Walker, Mark F. | Bronstein, Adolfo | Leigh, R. John

Article Type: Research Article

Abstract: Background: During head translations, vestibular eye movements are ∼ 60% of those required to hold the line of sight on target but, during translation of the orbits due to head rotation about an eccentric axis, the eyes are held %eye on target. Objective: To resolve this paradoxical behavior of vestibulo-ocular reflexes. Methods: Subjects sat on a moving platform viewing a near target and were: (1) rotated en bloc in yaw about a vertical axis centered on the head at 1 Hz; (2) rotated with their head displaced ∼ 10 cm anterior (eccentric rotation) at …1 Hz; (3) translated along the inter-aural axis at 1.9 Hz; (4) rotated with the head centered at 1 Hz while they were translated along the inter-aural axis at 1.9 Hz. We calculated compensation ratio (CR): Eye velocity/eye velocity geometrically required to hold the eye on target. Results: During yaw, mean CR was 0.88 and during eccentric rotation CR was 0.93. During translation at 1.9 Hz, CR was 0.65. During combined rotation at 1.0 Hz and translation at 1.9 Hz, CR was 0.81 for head rotations and 0.74 for head translations. Conclusions: Translations of the orbits due to head rotation are better compensated for than translations of the orbits due to head translation. These different behaviors may be determined by context, the important difference being whether the subject is moving through the environment. Show more

Keywords: Vestibulo-ocular reflex, head rotation, head translation, motion parallax

DOI: 10.3233/VES-140522

Citation: Journal of Vestibular Research, vol. 24, no. 5-6, pp. 329-333, 2014

Authors: Faralli, Mario | Lapenna, Ruggero | Mandalà, Marco | Trabalzini, Franco | Ricci, Giampietro

Article Type: Research Article

Abstract: This is a study of Subjective Visual Vertical (SVV) perception during acute attacks of Ménière's disease (MD) with comparative evaluation of concurrent nystagmus. We studied 21 patients with unilateral MD during the acute phase and 7 days later. Of the nine patients with an initial attack of MD, seven had an alteration of SVV perception and of these, three indicated a match with canal functional signs, while four patients showed an opposite trend of SVV perception relative to the spontaneous nystagmus. Nine of the 12 patients with definite MD had a pathological SVV perception always in correspondence with the same …type of canal event. At 1-week control, no patient with an initial MD attack had alteration of SVV perception, whereas 5 patients with definite MD presented a pathological SVV perception toward the affected side. In the course of acute attacks of unilateral MD, clinical manifestations may include otolithic involvement and this may have an opposite trend compared to concomitant canal signs, especially during initial attacks. This behavior allows us to distinguish clinical signs of maculo-canal "correspondence" and "dissociation" with a significant prevalence of the second indication in those subjects with an initial MD attack. Show more

Keywords: Ménière's disease, otolithic function, subjective visual vertical, SVV, maculo-canal dissociation

DOI: 10.3233/VES-140533

Citation: Journal of Vestibular Research, vol. 24, no. 5-6, pp. 335-342, 2014

Authors: Asprella-Libonati, Giacinto

Article Type: Research Article

Abstract: Objective: To investigate the incidence of Lateral Semicircular Canal BPPV (LSC BPPV) with Pseudo-Spontaneous Nystagmus in patients preliminarily diagnosed for vestibular neuritis in the Emergency Department (ED). Methods: Retrospective study of 273 patients with acute vertigo and persistent horizontal nystagmus in upright position (male 110, female 163, 14–93 years old) observed over four years. All the patients were checked for any nystagmus modification by performing the Head Pitch Test (HPT) in the upright position. Results: The HPT modified the beating direction of the persistent horizontal nystagmus in 56 of the 273 examined patients. The …positioning tests subsequently confirmed the diagnosis of LSC BPPV in all those 56 patients. There were 37 geotropic variants and 19 apogeotropic variants and all of them were successfully treated by performing liberatory manoeuvres in the course of the same session. Conclusion: Performing the HPT in the upright position helps to differentiate a direction fixed nystagmus from a direction changing one, and in so doing, to make the differential diagnosis between vestibular neuritis and LSC BPPV, achieving the goal of successfully treating LSC BPPV in the first session. Show more

Keywords: Vestibular neuritis, BPPV, positional nystagmus, spontaneous nystagmus, pseudo-spontaneous nystagmus

DOI: 10.3233/VES-140532

Citation: Journal of Vestibular Research, vol. 24, no. 5-6, pp. 343-349, 2014

Authors: Gordon, Carlos R. | Zivotofsky, Ari Z. | Caspi, Avi

Article Type: Research Article

Abstract: Vestibulo-Ocular Reflex (VOR) abnormalities in cerebellar ataxias are a matter of renewed interest. We have previously reported vestibular areflexia in a group of Yemenite-Jews with Spinocerebellar Ataxia Type 3 (SCA3) who had clear bilateral pathological horizontal Head Impulse Test (HIT). The objective of this study was to evaluate the VOR of ten SCA3 patients who have variable bedside HIT responses by recording their eye movements using magnetic search coils and to correlate these results with their clinical and genetic data. Eight out of the ten patients have abnormal horizontal HIT detected by both clinical bedside examination and laboratory tests. Results …of bedside HIT testing were significantly correlated with the VOR gain recorded using magnetic search coils. No significant correlations were found between VOR gain and other clinical or genetic data. Our study confirms the presence of defective VOR in SCA3 patients and corroborates the useful of the HIT as a reliable bedside test for diagnosis of VOR deficits. Show more

Keywords: Vestibular, head impulse test, magnetic search coil, Machado-Joseph disease

DOI: 10.3233/VES-140527

Citation: Journal of Vestibular Research, vol. 24, no. 5-6, pp. 351-355, 2014

Authors: Schneider, Rosalyn | Walker, Mark F.

Article Type: Research Article

Abstract: The goal of this study was to assess the effect of amplitude and frequency predictability on the performance of the translational vestibulo-ocular reflex (tVOR). Eye movements were recorded in 5 subjects during continuous vertical translation that consisted of a series of segments with: 1) 3 amplitudes at constant frequency (2 Hz) or 2) 3 different frequencies (1.6, 2, 2.5 Hz). Stimulus changes were presented in a pseudo-random order. We found that there was little change in the tVOR immediately after an unexpected stimulus change, as if eye velocity were being driven more by an expectation based on previous steady-state motion …than by current head translation. For amplitude transitions, only about 30% of the eventual response change was seen in the first half cycle. Similarly, a sudden change in translation frequency did not appear in eye velocity for 70 ms, compared to a 8 ms lag during similar yaw rotation. Finally, after a sudden large decrease in frequency, the eyes continued to track at the original higher frequency, resulting initially in an anti-compensatory tVOR acceleration. Our results elucidate further the complexity of the tVOR and show that motion prediction based on prior experience plays an important role in its response. Show more

Keywords: Eye movements, vestibular, otolith, translation, visual-vestibular interaction

DOI: 10.3233/VES-140528

Citation: Journal of Vestibular Research, vol. 24, no. 5-6, pp. 357-364, 2014

Authors: Manzari, Leonardo | MacDougall, Hamish G. | Burgess, Ann M. | Curthoys, Ian S.

Article Type: Research Article

Abstract: Vertigo and vigorous horizontal spontaneous nystagmus in a presenting patient is usually taken to indicate unilaterally reduced horizontal canal function. However here we report results which question that presumption. In three such patients with an acute vestibular syndrome, complete testing of all peripheral vestibular sense organs using new tests of canal and otolith function (vHIT and VEMPs) showed that semicircular canal function was normal, but that there were unilateral otolithic deficits which probably caused their acute syndrome.

Keywords: Vestibular, otolith, ocular vestibular-evoked myogenic potential, utricular, cervical vestibular-evoked myogenic potential

DOI: 10.3233/VES-140537

Citation: Journal of Vestibular Research, vol. 24, no. 5-6, pp. 365-373, 2014

Authors: Conrad, Julian | Baier, Bernhard | Dieterich, Marianne

Article Type: Research Article

Abstract: Most of our knowledge concerning central vestibular pathways is derived from animal studies while evidence of the functional importance and localization of these pathways in humans is less well defined. The termination of these pathways at the thalamic level in humans is even less known. In this review we summarize the findings concerning the central subcortical vestibular pathways in humans and the role of these structures in the central vestibular system with regard to anatomical localization and function. Also, we review the role of the thalamus in the pathogenesis of higher order sensory deficits such as spatial neglect, pusher syndrome …or thalamic astasia and the correlation of these phenomena with findings of a vestibular tone imbalance at the thalamic level. By highlighting thalamic structures involved in vestibular signal processing and relating the different nomenclatures we hope to provide a base for future studies on thalamic sensory signal processing. Show more

Keywords: Medial longitudinal fascicle, ascending tract of Deiters, brachium conjunctivum, ipsilateral vestibulothalamic tract, crossed ventral tegmental tract, vestibular, thalamus, neglect, pusher, astasia

DOI: 10.3233/VES-140534

Citation: Journal of Vestibular Research, vol. 24, no. 5-6, pp. 375-385, 2014

Authors: Eggers, Scott D.Z. | Neff, Brian A. | Shepard, Neil T. | Staab, Jeffrey P.

Article Type: Research Article

Abstract: A growing body of clinical and epidemiological evidence supports a specific relationship between vestibular symptoms and migraine. Without a biomarker or complete understanding of pathophysiology, diagnosis of vestibular migraine (VM) currently depends upon symptoms in two dimensions: episodic vestibular symptoms temporally related to migraine symptoms. The Bárány Society and the International Headache Society have recently developed consensus diagnostic criteria. However, many issues remain unsettled, including the type, duration, and timing of vestibular symptoms related to headache that should be required for diagnosing VM. This paper focuses on the challenging third dimension of comorbidity, a frequent cause of diagnostic uncertainty that …may confound clinical application and research validation of VM criteria. Several other neurotologic conditions occur more frequently in migraineurs than controls, including benign paroxysmal positional vertigo, Ménière's disease, and motion sickness. Patients with VM also have high rates of chronic subjective dizziness, which may be associated with anxious, introverted temperaments that can affect clinical presentation and treatment response. Broadly inclusive studies of well-characterized patients with other neurotologic and psychiatric comorbidities are needed to fully understand how vestibular symptoms and migraine interact in order to truly validate vestibular migraine, distill its essential features, define its boundaries, and characterize overlapping comorbidities. Show more

Keywords: Vestibular migraine, comorbidity, epidemiology, validation, diagnostic criteria

DOI: 10.3233/VES-140525

Citation: Journal of Vestibular Research, vol. 24, no. 5-6, pp. 387-395, 2014

Authors: Schubert, Michael C. | Mantokoudis, Georgios | Xie, Li | Agrawal, Yuri

Article Type: Research Article

Abstract: Background: Vestibular rehabilitation is a sub-specialization within the practice of physical therapy that includes treatments designed to reduce gaze instability. Gaze stability exercises are commonly given for head rotations to the left and right, even in subjects with one healthy vestibular system (as in unilateral loss). Few studies have investigated the difference in the angular vestibular ocular reflex gain (aVOR) measured in the acute phase after deafferentation for ipsilesional head rotations that move the head away from center or towards center. Objective: The purpose of this study was to compare differences in acute aVOR gain when the …head was passively rotated outward from an initially centered position (neck neutral) versus the head being rotated inward. Methods: We recorded head and eye velocity using video head impulse test equipment in patients with unilateral vestibular pathology scheduled for tumor resection via retrosigmoid approach (n=5) or labyrinthectomy due to Meniere's disease (n=2). Results: We found 1) no difference in the ipsilesional aVOR gain for inward or outward directed head impulse rotations and 2) head velocity is inversely correlated with aVOR gain for ipsilesional but not contralesional rotations. Conclusions: Bedside testing of the ipsilesional aVOR following acute vestibular ablation can be done with head impulse rotations to either side. In the acute stages, physical therapists should prescribe ipsilesional and contralesional gaze stability exercises. Show more

Keywords: Head impulse test, VOR gain, vestibular rehabilitation

DOI: 10.3233/VES-140523

Citation: Journal of Vestibular Research, vol. 24, no. 5-6, pp. 397-402, 2014