Evaluation of Vertical Semicircular Canal Function in Patients With Vestibular Schwannoma

2018 ◽  
Vol 128 (2) ◽  
pp. 113-120 ◽  
Author(s):  
Keishi Fujiwara ◽  
Hiroko Yanagi ◽  
Shinya Morita ◽  
Kimiko Hoshino ◽  
Atsushi Fukuda ◽  
...  

Objectives: The aim of this study was to investigate vertical semicircular canal function in patients with vestibular schwannoma (VS) by video head impulse test (vHIT). Methods: Fifteen patients with VS who had not received any treatment, including surgery or stereotactic radiotherapy, before vHIT examination were enrolled. Vestibulo-ocular reflex gain and catch-up saccade in vHIT were evaluated. Results: Dysfunction of anterior and posterior semicircular canals was detected by vHIT in 26.7% and 60.0%, respectively. Six patients (40.0%) demonstrated abnormalities referable to both vestibular nerve divisions. Abnormalities referable to the superior vestibular nerve were identified in 3 patients (20.0%), while 3 patients (20.0%) demonstrated a pattern indicative of inferior vestibular nerve involvement. Anterior semicircular canal vHIT produced fewer abnormalities than did either horizontal or posterior semicircular canal vHIT. Conclusions: Dysfunction of the semicircular canals, including the vertical canals, in patients with VS was detected by vHIT. The anterior semicircular canal was less frequently involved than the horizontal or posterior semicircular canal. The examination of the vertical canals by vHIT is useful in the evaluation of vestibular function in patients with VS.

2021 ◽  
Vol 12 ◽  
Author(s):  
Louise Wittmeyer Cedervall ◽  
Måns Magnusson ◽  
Mikael Karlberg ◽  
Per-Anders Fransson ◽  
Anastasia Nyström ◽  
...  

Objective: The use of goggles to assess vertical semicircular canal function has become a standard method in vestibular testing, both in clinic and in research, but there are different methods and apparatus in use. The aim of this study was to determine what the cause of the systematic differences is between gain values in testing of the vertical semicircular canals with two different video head impulse test (vHIT) equipment in subjects with normal vestibular function.Study Design: Retrospective analysis of gain values on patients with clinically deemed normal vestibular function (absence of a corrective eye saccade), tested with either Interacoustics or Otometrics system. Prospective testing of subjects with normal vestibular function with the camera records the eye movements of both eyes. Finally, 3D sensors were placed on different positions on the goggles measuring the actual vertical movement in the different semicircular planes.Results: In the clinical cohorts, the gain depended on which side and semicircular canal was tested (p < 0.001). In the prospective design, the combination between the stimulated side, semicircular canal, and position of the recording device (right/left eye) highly influenced the derived gain (p < 0.001). The different parts of the goggles also moved differently in a vertical direction during vertical semicircular canal testing.Conclusion: The gain values when testing the function of the vertical semicircular canals seem to depend upon which eye is recorded and which semicircular plane is tested and suggests caution when interpreting and comparing results when different systems are used both clinically as well as in research. The results also imply that further research and development are needed to obtain accurate vertical semicircular canal testing, in regard to both methodology and equipment design.


2021 ◽  
pp. 1-9
Author(s):  
Kim E. Hawkins ◽  
Elodie Chiarovano ◽  
Serene S. Paul ◽  
Ann M Burgess ◽  
Hamish G. MacDougall ◽  
...  

BACKGROUND: Parkinson’s disease (PD) is a common multi-system neurodegenerative disorder with possible vestibular system dysfunction, but prior vestibular function test findings are equivocal. OBJECTIVE: To report and compare vestibulo-ocular reflex (VOR) gain as measured by the video head impulse test (vHIT) in participants with PD, including tremor dominant and postural instability/gait dysfunction phenotypes, with healthy controls (HC). METHODS: Forty participants with PD and 40 age- and gender-matched HC had their vestibular function assessed. Lateral and vertical semicircular canal VOR gains were measured with vHIT. VOR canal gains between PD participants and HC were compared with independent samples t-tests. Two distinct PD phenotypes were compared to HC using Tukey’s ANOVA. The relationship of VOR gain with PD duration, phenotype, severity and age were investigated using logistic regression. RESULTS: There were no significant differences between groups in vHIT VOR gain for lateral or vertical canals. There was no evidence of an effect of PD severity, phenotype or age on VOR gains in the PD group. CONCLUSION: The impulsive angular VOR pathways are not significantly affected by the pathophysiological changes associated with mild to moderate PD.


Author(s):  
Ariana Paulina-Carabajal ◽  
Leonardo Filippi ◽  
Fabien Knoll

this taxon has uncertain phylogenetic relationships within the clade. An X-ray Computed Tomography (CT) scan of the holotypebraincase allowed the first reconstruction of the brain and inner ear of this taxon, making it possible to compare the neuroanatomy with thatof closely related forms. Except for the slightly sigmodal shape of the endocast in lateral view—considered a basal condition—, the brainshows derived titanosaurian traits such as a poorly developed dorsal expansion and a single exit for Cranial Nerve (CN) XII. In contrast, the innerear exhibits slender and long semicircular canals (the anterior semicircular canal is distinctly longer than the posterior semicircular canal), whichis a character present in more basal representatives of the group, such as Sarmientosaurus. We consider, however, the morphology of theinner ear as an unreliable indicator of phylogenetic position. Furthermore, there is a remarkable similarity between the morphology of theendocast of Narambuenatitanand the possible saltasaurid from (FAM 03.064), from the Upper Cretaceous of Fox-Amphoux-Métisson, France,suggesting saltasaurine affinities for the Argentinean taxon.


Author(s):  
Joost J. A. Stultiens ◽  
Nils Guinand ◽  
Vincent Van Rompaey ◽  
Angélica Pérez Fornos ◽  
Henricus P. M. Kunst ◽  
...  

Abstract Background Certain cases of superior semicircular canal dehiscence or benign paroxysmal positional vertigo can be treated by plugging of the affected semicircular canal. However, the extent of the impact on vestibular function and hearing during postoperative follow-up is not known. Objective To evaluate the evolution of vestibular function and hearing after plugging of a semicircular canal. Methods Six patients underwent testing before and 1 week, 2 months, and 6 months after plugging of the superior or posterior semicircular canal. Testing included caloric irrigation test, video Head Impulse Test (vHIT), cervical and ocular Vestibular Evoked Myogenic Potentials (VEMPs) and audiometry. Results Initially, ipsilateral caloric response decreased in all patients and vHIT vestibulo-ocular reflex (VOR) gain of each ipsilateral semicircular canal decreased in 4/6 patients. In 4/6 patients, postoperative caloric response recovered to > 60% of the preoperative value. In 5/6 patients, vHIT VOR gain was restored to > 85% of the preoperative value for both ipsilateral non-plugged semicircular canals. In the plugged semicircular canal, this gain decreased in 4/5 patients and recovered to > 50% of the preoperative value. Four patients preserved cervical and ocular VEMP responses. Bone conduction hearing deteriorated in 3/6 patients, but recovered within 6 months postoperatively, although one patient had a persistent loss of 15 dB at 8 kHz. Conclusion Plugging of a semicircular canal can affect both vestibular function and hearing. After initial deterioration, most patients show recovery during follow-up. However, a vestibular function loss or high-frequency hearing loss can persist. This stresses the importance of adequate counseling of patients considering plugging of a semicircular canal.


2021 ◽  
pp. 1-9
Author(s):  
Ruijie Wang ◽  
Xiuhua Chao ◽  
Jianfen Luo ◽  
Daogong Zhang ◽  
Jiliang Xu ◽  
...  

BACKGROUND: To date, systematically objective evaluations of vestibular function in children with cochlear implantation (CI) have been conducted sparsely, especiallyin children with large vestibular aqueduct syndrome (LVAS). OBJECTIVE: Our goal was to investigate the function of all five vestibular end-organs pre- and post-cochlear implantation in children with LVAS and normal CT. METHODS: In this retrospective cohort study, 34 children (age 4–17 years) with bilateral profound sensorineural hearing loss (SNHL) undergoing unilateral CI were included. Participants included 18 (52.9%) children with LVAS. Objective modalities to evaluate vestibular function included the caloric test, cervical vestibular-evoked myogenic potentials (cVEMP), ocular vestibular-evoked myogenic potentials (oVEMP), and video head impulse test (vHIT). All measurements were performed before surgery and 9 months after surgery. RESULTS: Mean age at CI was 8.1±3.7 years. Caloric testing showed hypofunction in 38.2%of cases before implantation and in 50%after (p >  0.05). We found a significant increase of overall abnormality rate in cVEMP and oVEMP from pre- to post-CI (p <  0.05). In all three semicircular canals tested by vHIT, there were no statistically significant mean gain changes (p >  0.05). Higher deterioration rates in cVEMP (53.3%) and oVEMP (52.0%) after surgery were observed (p <  0.05). In children with LVAS, cVEMP revealed a higher deterioration rate than superior semicircular canal (SSC) and posterior semicircular canal (PSC) (p <  0.05). In children with normal CT, the deterioration rates in VEMPs were both higher than those in vHIT (p <  0.05). CONCLUSIONS: In general, the otolith organs were the most affected peripheral vestibular sensors in children after cochlear implantation. The variations in otolith function influenced by CI were different between children with LVAS and normal CT. We recommend the use of this vestibular function test battery for children with cochlear implantation.


Author(s):  
Yijin Jereme Gan ◽  
Yih Meei Heng ◽  
Shailesh Khode ◽  
Aruni Seneviratna ◽  
Annabelle Leong

<p class="abstract"><strong>Backgrounds:</strong> The Video Head Impulse Test (vHIT) is used to test the function of each of the six semicircular canals. Each semicircular canal is tested by measuring eye rotation in response to head movements in the plane of the canal and is calculated as the Vestibulo-ocular reflex (VOR) gain. The aims of the study were firstly, to determine age-dependent normative values of VOR gain for the vHIT of semicircular canal function in healthy Asian subjects in each decade year of life. Secondly, to investigate if vHIT measured VOR gain decreases with age.</p><p class="abstract"><strong>Methods: </strong>A prospective cohort study of 60 healthy voluntary community-dwelling subjects, between 21 to 80 years of age. Subjects with prior history of vertigo were excluded. vHIT was conducted on each subject and analysed with the Interacoustics (EyeSeeCam) video goggles by the senior audiologist. The VOR gain for all six semicircular canals were calculated for each subject.</p><p class="abstract"><strong>Results: </strong>The mean (SD) vHIT (VOR) gain of all the 6 semicircular canals for the entire population were 1.18 (0.19). The mean of the VOR gain for each of the six semicircular canals were analysed to develop a normative guide. The mean VOR gain per decade year did not vary significantly with age (p=0.417). The correlation between age and mean VOR values was negligible (pearson’s r=0.121).</p><p class="abstract"><strong>Conclusions: </strong>We propose that our normative age-dependent data guide be used to improve the differentiation between normal and abnormal values of VOR gain in an Asian population. Our study shows that VOR gain is not associated with aging.</p>


2021 ◽  
Vol 12 ◽  
Author(s):  
Antonio Denia-Lafuente ◽  
Belén Lombardero

In patients with congenital nystagmus (CN), the study of vestibular function is complicated by many factors related to the measurement of the vestibulo-ocular reflex (VOR) by means of caloric testing and the video head impulse test (vHIT), and to date no such studies have successfully employed the vHIT to evaluate vestibular function in these patients. We present a case with CN and vertigo in which peripheral vestibular function was evaluated using the vHIT system, including head impulse testing and the suppression head impulse protocol. We show that it is possible (a) to identify lateral VOR changes such as abnormalities resembling those produced by bilateral vestibular lesions, though not necessarily related to the same mechanism; (b) to identify peripheral VOR lesions of the vertical semicircular canals (SCC); and (c) to document compensation and recovery subsequent to these peripheral lesions during follow-up of patients with CN. vHIT is a useful tool that should be used to study vestibular function in patients with CN and vertigo, which could constitute a new clinical application of this technique.


Development ◽  
1973 ◽  
Vol 29 (3) ◽  
pp. 721-743
Author(s):  
Howard C. Howland ◽  
Joseph Masci

1. The ontogenetic allometry of radii of curvature and the tube radii of the semicircular canals of approximately 85 juvenile (2–20 g) centrarchids of the species Lepomis gibbosus (L.) was investigated. The radii of curvature of the semicircular canals have different allometries; these arefor the anterior vertical, posterior vertical and horizontal canals respectively. The differences in growth exponents between the anterior and posterior vertical semicircular canals and between the anterior vertical and horizontal semicircular canals were statistically significant (P &lt; 0·02 and P &lt; 0·05 respectively). 2. Body mass and standard length were almost equally good predictors of the radii of curvature of the anterior vertical semicircular canals, but body mass was the better predictor of the radii of curvature of the posterior vertical and horizontal semicircular canals, as judged by the magnitude of the mean squares about the logarithmic regressions of radii on length and mass. 3. By measuring and estimating the area moments of the fins of the fish, the moments of inertia about various axes and the allometry of the characteristic swimming velocity of the fish, we attempted to account for the magnitude and direction of the differences in allometric growth exponents of the radii of curvature of the semicircular canals. Unexplained by our best estimate of growth exponents was the very high value observed for the posterior vertical semicircular canals. 4. No significant correlation could be found between the residuals of the major dimensions of the posterior vertical semicircular canals and those of body width or depth once the influence of body mass was removed. This finding suggests the rejection of the hypothesis that the allometry of this semicircular canal is simply correlated with overall body expansion in its plane. 5. The discrepancies between our predictions and observations of growth exponents could be explained by a gradual increase of the spring constant of the semicircular canals on the order ofthough they may also be due to other factors neglected in our model, e.g. the allometry of the added mass of the fish. 6. No evidence suggested that the shape of the semicircular canals was altered over the size range of the fish we studied. However, among the fins of the fish and the major body dimensions, only the width and the depth of the fish exhibited growth constants that did not differ significantly from each other. 7. We computed the effective toroidal radii of the non-toroidal-shaped vertical semicircular canals and found that the equivalent toroidal radius of the anterior vertical semicircular canal was consistently greater than that of the posterior vertical semicircular canal. This difference is explicable on the basis of the different moments of inertia of the animal about axes through the center of gravity and parallel to the axes of the semicircular canals. 8. We computed the allometry of the ratios R̄/r2 for all three semicircular canals and found in accordance with the prediction of Jones & Spells that they did not differ significantly from zero. 9. The allometry of the outer tube radii of the several semicircular canals was determined, and, while there was no significant difference in the growth exponents of the tube radii, it was noted that the tube radius of the horizontal semicircular canal was consistently and significantly smaller than that of the vertical semicircular canal. We suggested that this difference might be due to the broader range of frequencies that the fish experienced about its yaw axis. 10. Taken as a whole the data and calculations of this paper generally support the theory that the dimensions of the semicircular canals and the ontogenetic changes in them attune the semicircular canals to the angular frequency spectra that the fish experience about their axes.


2021 ◽  
Vol 1 (1) ◽  
Author(s):  
Stefan K. Plontke ◽  
Torsten Rahne ◽  
Ian S. Curthoys ◽  
Bo Håkansson ◽  
Laura Fröhlich

Abstract Background The receptors for hearing and balance are housed together in the labyrinth of the inner ear and share the same fluids. Surgical damage to either receptor system was widely believed to cause certain permanent loss of the receptor function of the other. That principle, however, has been called into question because there have been anecdotal reports in individual patients of at least partial preservation of cochlear function after major surgical damage to the vestibular division and vice versa. Methods We performed specific objective vestibular function tests before and after surgical trauma (partial or subtotal cochlear removal) for treatment of intracochlear tumors in 27 consecutive patients in a tertiary referral center. Vestibular function was assessed by calorics (low-frequency response of the lateral semicircular canal), vestibulo-ocular reflex by video head impulse test (vHIT) of the three semicircular canals, cervical and ocular vestibular evoked myogenic potentials (cVEMP, saccule and oVEMP, utricle). Preoperative and postoperative distributions were compared with paired t-tests. Results Here we show that there was no significant difference between pre- and post-operative measures for all tests of the five vestibular organs, and that after major surgical cochlear trauma, the vestibular receptors continue to function independently. Conclusions These surprising observations have important implications for our understanding of the function and the surgery of the peripheral auditory and vestibular system in general and open up new possibilities for the development, construction and evaluation of neural interfaces for electrical or optical stimulation of the peripheral auditory and vestibular nervous system.


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