Vestibular Evoked Potentials in Response to Direct Unilateral Mechanical Stimulation

1989 ◽  
Vol 100 (3) ◽  
pp. 177-186 ◽  
Author(s):  
Franklin S. Coale ◽  
Edward J. Walsh ◽  
JoAnn McGee ◽  
Horst R. Konrad
Keyword(s):  
Evoked Potentials ◽  
Semicircular Canal ◽  
Auditory Evoked Potentials ◽  
Temporal Structure ◽  
Fluid Pressure ◽  
Presentation Rate ◽  
Electrode Placement ◽  
Horizontal Semicircular Canal ◽  
Horizontal Canal ◽  
Vestibular Evoked Potentials

Evoked potentials produced by direct unilateral mechanical stimuiation of the cannulated horizontal semicircular canal were investigated parametrically in anesthetized adult cats (40 mg/kg pentobarbital). Stimuli were fluid pressure pulses in a closed hydraulic system (no net flow), which was coupled to the lateral semicircular canal near the ampulla. Hydraulic waveform output and fluid pressure was monitored In situ via a parallel hydraulic circuit during experiments. Maximum fluid displacement at the level of the horizontal canal was 0.025 microliters. The intensity, duration, and presentation rate of the stimulus were varied during experiments. Field potentials were recorded differentially using subdermal electrodes, with the active lead in the region of the mastoid referenced to a distant nasal site. A total of 256 trials was accumulated for each run using an averaging computer. Evoked responses were physiologically vulnerable and reproducible, with little variance among animals. Response amplitude Increased monotonically until saturation was noted and responses followed the temporal structure of the pressure wave. Polarity reversal with differir electrode placement suggests that the generator site lies within the mastoid. Buhner, intense broadband acoustic stimuli and eighth nerve sectioning did not affect the vestibular evoked potentials, but could be shown to abolish the auditory evoked potentials. Results of these experiments support the notion that vestibular evoked potentials are related to the first derivative of the pressure pulse waveforms. Future experiments will be directed toward the assessment of vestibular physiology and pharmacology with this evoked response method.

Evoked Potentials

2016 ◽  
Author(s):  
Marc R. Nuwer
Keyword(s):  
Evoked Potentials ◽  
Auditory Evoked Potentials ◽  
Motor Evoked Potentials ◽  
Clinical Care ◽  
Event Related Potentials ◽  
Clinical Tests ◽  
Therapeutic Trials ◽  
Complementary Role ◽  
Related Potentials ◽  
Vestibular Evoked Potentials

Visual evoked potentials, brainstem auditory evoked potentials, and somatosensory evoked potentials are established clinical tests that are useful for the diagnosis of multiple sclerosis. Motor evoked potentials, cognitive event-related potentials, and vestibular evoked potentials also are used clinically to test additional pathways and functions. These objective, reproducible tools can identify clinically silent lesions, predict clinical deterioration risk, and localize levels of impairment. They differ from magnetic resonance imaging in that they assess function rather than anatomy and thereby fill a complementary role in clinical care. They also are useful in therapeutic trials because they can predict outcomes in parallel with, or earlier than, clinical examinations.

scholarly journals Parameters for Applying the Brainstem Auditory Evoked Potential with Speech Stimulus: Systematic Review

2017 ◽  
Vol 22 (04) ◽  
pp. 460-468 ◽  
Author(s):  
Luísa Gabriel ◽  
Luíza Vernier ◽  
Maria Ferreira ◽  
Adriana Silveira ◽  
Márcia Machado
Keyword(s):  
Systematic Review ◽  
Evoked Potentials ◽  
Brain Stem ◽  
Auditory Evoked Potentials ◽  
Evoked Potential ◽  
Sampling Rate ◽  
Presentation Rate ◽  
Auditory Evoked Potential ◽  
Speech Stimulus ◽  
Brainstem Auditory Evoked Potential

Introduction Studies using the Brainstem Auditory Evoked Potential with speech stimulus are increasing in Brazil, and there are divergences between the methodologies used for testing. Objectives To analyze the parameters used in the study of the Brainstem Auditory Evoked Potentials with speech stimulus. Data Synthesis The survey was performed using electronic databases. The search strategy was as follows: “Evoked potentials, auditory” OR “Brain stem” OR “Evoked potentials, auditory, brain stem” AND “Speech.” The survey was performed from June to July of 2016. The criteria used for including articles in this study were: being written in Portuguese, English or Spanish; presenting the description of the testing parameters and the description of the sample. In the databases selected, 2,384 articles were found, and 43 articles met all of the inclusion criteria. The predominance of the following parameters was observed to achieve the potential during study: stimulation with the syllable /da/; monaural presentation with greater use of the right ear; intensity of 80 dB SPL; vertical placement of electrodes; use of in-ear headphones; patient seated, distracted in awake state; alternating polarity; use of speech synthesizer software for the elaboration of stimuli; presentation rate of 10.9/s; and sampling rate of 20 kHz. Conclusions The theme addressed in this systematic review is relatively recent. However, the results are significant enough to encourage the use of the procedure in clinical practice and advise clinicians about the most used procedures in each parameter.

scholarly journals New treatment strategy for apogeotropic horizontal canal benign paroxysmal positional vertigo

2016 ◽  
Vol 6 (2) ◽  
Author(s):  
Francisco Zuma e Maia
Keyword(s):  
Semicircular Canal ◽  
Treatment Strategy ◽  
Benign Paroxysmal Positional Vertigo ◽  
Biomechanical Model ◽  
Horizontal Semicircular Canal ◽  
Horizontal Canal ◽  
Positional Vertigo ◽  
New Treatment ◽  
Paroxysmal Positional Vertigo

The apogeotropic variant of horizontal semicircular canal benign paroxysmal positional vertigo (HC-BPPV) is attributed to canalithiasis of the anterior arm or cupulolithiasis. Despite some therapeutic maneuvers, I propose a new treatment strategy for apogeotropic HCBPPV that is designed to detach both the otoconial debris from the anterior arm of the semicircular canal and the debris that is attached to the utricular side of the cupula using inertia and gravity and based on simulations with a 3D biomechanical model.

Responses of pigeon horizontal semicircular canal afferent fibers. I. Step, trapezoid, and low-frequency sinusoid mechanical and rotational stimulation

1989 ◽  
Vol 62 (5) ◽  
pp. 1090-1101 ◽  
Author(s):  
J. D. Dickman ◽  
M. J. Correia
Keyword(s):  
Mechanical Stimulation ◽  
Semicircular Canal ◽  
Action Potentials ◽  
Transfer Functions ◽  
Semicircular Canals ◽  
Primary Afferent ◽  
Horizontal Semicircular Canal ◽  
Horizontal Canal ◽  
Best Fit ◽  
Rotational Stimulation

1. The horizontal semicircular canals of anesthetized (barbiturate/ketamine) pigeons were stimulated by rotational and by mechanical stimulation. 2. The mechanical stimulation consisted of making a small (less than 1 mm) fistula in the lateral part of the bony horizontal semicircular canal and, after inserting a probe coupled to a piezoelectric micropusher through the fistula, providing controlled indentation of the exposed membranous horizontal semicircular duct. 3. Extracellular action potentials from single horizontal semicircular canal primary afferent (HCA) fibers were recorded during sinusoidal rotational and during step, ramp, and sinusoidal mechanical stimulation. 4. The mean spontaneous discharge rate of 160 horizontal canal afferents was 86 +/- 4 (SE) spikes/s. This rate was not significantly different from that reported previously for pigeon HCA fibers recorded with the horizontal canal intact (i.e., no fistula introduced). 5. Sinusoidal mechanical indentation of the horizontal semicircular duct produced clearly entrained action potentials on 36 HCA fibers for a range of peak displacements from +/- 0.5 to +/- 30 microns. Action potentials were never modulated on afferents (n greater than 100) identified as innervating the anterior and posterior semicircular canals or the otolith organs during mechanical stimulation of the horizontal semicircular canal, even for displacements as large as 30 microns. 6. Intensity functions relating peak firing frequency (spikes per second) and peak probe displacement (micrometers) for 1.0-Hz sinusoidal mechanical stimulation were linear over the range 1.0-5.0 microns. The most sensitive units (6/36, 17%) showed response saturation as the stimulus magnitude was extended to 7 microns and beyond. 7. In 15 of 36 units, both mechanical and rotational sinusoidal stimulation (1.0 Hz) were applied to the same unit. The duct indentation magnitudes were 1.0, 2.5, 5.0, and 7.0 microns and the rotational velocities were 5, 10, and 20 deg/s. The constant of proportionality found to equate the peak response produced by rotational to that elicited by mechanical stimulation was 7.0 deg.sec-1/1.0 microns. 8. Bode plots and best-fit transfer functions of the frequency response (0.05-10.0 Hz) of 14 HCAs exposed to both mechanical and rotational stimulation were nearly identical. 9. Parameters for best-fit transfer functions, responses to step, and trapezoidal duct displacements were in excellent agreement with previous rotational studies carried out using the pigeon. 10. Although the mechanisms by which focal identation of the horizontal membranous duct produce responses have not yet been determined, primary afferent responses using this method of stimulation are directly comparable with rotatory stimulation.(ABSTRACT TRUNCATED AT 400 WORDS)

scholarly journals Skull Vibration-Induced Nystagmus Test in a Human Model of Horizontal Canal Plugging

2021 ◽  
Vol 11 (3) ◽  
pp. 301-312
Author(s):  
Georges Dumas ◽  
Christol Fabre ◽  
Anne Charpiot ◽  
Lea Fath ◽  
Hella Chaney-Vuong ◽  
...  
Keyword(s):  
Semicircular Canal ◽  
Vestibular Function ◽  
Human Model ◽  
Vestibular Evoked Myogenic Potentials ◽  
Head Impulse Test ◽  
Slow Phase ◽  
Caloric Test ◽  
Horizontal Semicircular Canal ◽  
Horizontal Canal ◽  
Tertiary Referral Center

Background/Aim: the aim of this study was to assess the skull vibration-induced nystagmus test (SVINT) results and vestibular residual function after horizontal semicircular canal (HSCC) plugging. Methods: In this retrospective chart review performed in a tertiary referral center, 11 patients who underwent unilateral horizontal semicircular canal plugging (uHSCCP) for disabling Menière’s disease (MD) were included. The skull vibration-induced nystagmus (SVIN) slow-phase velocity (SPV) was compared with the results of the caloric test (CaT), video head impulse test (VHIT), and cervical vestibular-evoked myogenic potentials (cVEMP) performed on the same day. Results: Overall, 10 patients had a strong SVIN beating toward the intact side (Horizontal SVIN-SPV: 8.8°/s ± 5.6°/s), 10 had a significant or severe ipsilateral CaT hypofunction, 10 had an ipsilateral horizontal VHIT gain impairment, and 3 had altered cVEMP on the operated side. Five had sensorineural hearing worsening. SVIN-positive results were correlated with CaT and horizontal VHIT (HVHIT) results (p < 0.05) but not with cVEMP. SVIN-SPV was correlated with CaT hypofunction in % (p < 0.05). Comparison of pre- and postoperative CaT % hypofunction showed a significant worsening (p = 0.028). Conclusion: SVINT results in a human model of horizontal canal plugging are well correlated with vestibular tests exploring horizontal canal function, but not with cVEMP. SVINT always showed a strong lesional nystagmus beating away from the lesion side. SVIN acts as a good marker of HSCC function. This surgical technique showed invasiveness regarding horizontal canal vestibular function.

Role of semicircular canals in positional alcohol nystagmus

1965 ◽  
Vol 208 (6) ◽  
pp. 1065-1070 ◽  
Author(s):  
K. E. Money ◽  
W. H. Johnson ◽  
B. M. A. Corlett
Keyword(s):  
Semicircular Canal ◽  
Semicircular Canals ◽  
The Other ◽  
Positional Nystagmus ◽  
Horizontal Semicircular Canal ◽  
Horizontal Canal ◽  
Unilateral Labyrinthectomy

Following unilateral labyrinthectomy or inactivation of one horizontal semicircular canal in cats, a horizontal positional nystagmus was observed when the cat, after ingesting alcohol, was held with the head up or with the head down. This nystagmus was toward the operated ear in the head-up position and away from the operated ear in the head-down position. It disappeared following inactivation of the horizontal canal of the other ear. In cats with both horizontal canals discretely inactivated, there was no horizontal alcohol nystagmus in any position, but the vertical and rotary components of positional alcohol nystagmus were still present. It was concluded that positional alcohol nystagmus is initiated by the action of gravity on receptors of the semicircular canals. No conclusion could be drawn concerning the site or mechanism of the action of alcohol.

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