Vertical Canals Research Articles

Associations Between Vestibular Perception and Cognitive Performance in Healthy Adults.

A growing body of evidence has linked vestibular function to the higher-order cognitive ability in aging individuals. Past evidence has suggested unique links between vestibular function and cognition on the basis of end-organ involvement (i.e., otoliths versus canals). However, past studies have only assessed vestibular reflexes despite the diversity of vestibular pathways. Thus, this exploratory study aimed to assess associations between vestibular perception and cognition in aging adults to determine potential relationships. Fifty adults (21 to 84 years; mean = 52.9, SD = 19.8) were included in this cross-sectional study. All participants completed a vestibular perceptual threshold test battery designed to target perception predominantly mediated by each end-organ pair and intra-vestibular integration: 1 Hz y-translation (utricle), 1 Hz z-translation (saccule), 2 Hz yaw rotation (horizontal canals), 2 Hz right anterior, left posterior (RALP), and left anterior, right posterior (LARP) tilts (vertical canals), and 0.5 Hz roll tilt (canal-otolith integration). Participants also completed standard assessments of cognition and path integration: Digit Symbol Substitution Test (DSST), Trail Making Test (TMT), and the Gait Disorientation Test (GDT). Associations were assessed using Spearman rank correlation, and multivariable regression analyses. For correlation analyses, DSST correlated to RALP/LARP tilt, roll tilt, and z-translation. TMT-A only correlated to z-translation, and TMT-B correlated to roll tilt and z-translation after correcting for multiple comparisons. GDT correlated to RALP/LARP tilt and y-translation. In age-adjusted regression analyses, DSST and TMT-B were associated with z-translation thresholds and GDT was associated with y-translation thresholds. In this cross-sectional study, we identified associations between vestibular perceptual thresholds with otolith contributions and standard measures of cognition. These results are in line with past results suggesting unique associations between otolith function and cognitive performance.

Abnormal Vestibulo-Ocular Reflex Function Correlates with Balance and Gait Impairment in People with Multiple Sclerosis.

Multiple Sclerosis (MS) is the most prevalent autoimmune neurological condition in the world, leading to a wide variety of symptoms, including balance disorders. To evaluate the angular vestibulo-ocular reflex (aVOR) of all six semicircular canals (SCCs) through Head Impulse (HIMP) and Suppression HIMP (SHIMP) paradigms and any correlations with clinical balance scales. All participants were assessed using the Expanded Disability Status Scale (EDSS), Berg Balance Scale (BBS), and Mini-BESTest (MBT). Vestibular function was measured by video Head Impulse Test (vHIT), obtaining aVOR gain for each SSC. Twenty-seven PwMS (mean age 47.93 ± 8.51 years old, 18 females) were recruited. Most of the patients (81.48%) presented abnormal aVOR gains for at least one SSC. A moderate to strong correlation between aVOR gains of the left anterior SSC and, respectively, the MBT and the BBS was found. The subgroup analysis, based on the EDSS class, confirmed the correlation with the BBS in the patients with the most significant disability. People with MS may present impairments of the aVOR in one or more semicircular canals. The aVOR gain impairment of the vertical semicircular canals correlates with balance and gait disorders identified through clinical scales in PwMS.

Goggle Versus Remote-Camera Video Head Impulse Test Device Comparison.

This study compared remote versus goggle video head impulse testing (vHIT) outcomes to validate remote-camera vHIT, which is gaining popularity in difficult to test populations. Seventeen controls and 10 individuals with vestibular dysfunction participated. Each participant completed remote-camera and goggle vHIT. The main outcome parameters were canal gain, frequency of corrective saccades, and a normal versus abnormal rating. Horizontal and vertical canal vHIT gain was significantly lower in the vestibular compared with the control group; remote-camera gains were significantly lower compared with goggle gain for the vestibular group only. The devices categorized control versus vestibular canals identically except for one vertical canal. In the vestibular group, there was not a significant difference in the percentage of compensatory saccades between devices. These data provide validation that results obtained with a remote-camera device are similar to those obtained using a standard goggle device.

Evaluation of Semicircular Canal Function Using Video Head Impulse Test in Patients With Peripheral Vestibular Disorders Without Nystagmus.

Objectives This study aims to evaluate semicircular canal function using video head impulse test (vHIT) in patients with peripheral vestibular disorders without nystagmus. Methods Patients who underwent vHIT were enrolled in this study, and the proportion of abnormal findings on vHIT in patients without nystagmus was investigated. In addition, the results of vestibular testing were investigated in cases in which both vHIT and caloric testing were performed in patients without nystagmus. Results Forty-six patients (23.4%) of 197 patients who had no abnormal findings on the nystagmus tests, including the gaze nystagmus test, positional nystagmus test, and positioning nystagmus test, showed dysfunction in at least one semicircular canal on vHIT. The most frequent diagnosis was vestibular schwannoma (14/46, 30.4%), and cases with bilateral vestibular dysfunction were also included (12/46, 26.1%). A disorganized pattern of catch-up saccade was observed more frequently in patients with subjective symptoms of dizziness/vertigo compared to those without subjective symptoms. Although the sensitivity of vHIT was low compared to caloric testing, vHIT could detect isolated vertical canal dysfunction not detected by caloric testing. Conclusions vHIT is considered to be a useful test for patients without nystagmus, as vHIT could detect abnormalities in approximately one-quarter of patients without nystagmus. vHIT is considered to be one of the first tests to be performed following nystagmus testing, including the gaze nystagmus test, the positional nystagmus test, and the positioning nystagmus test. On the other hand, there are some cases in which vHIT shows no abnormality while caloric testing shows canal paresis. It is necessary to perform vHIT, bearing in mind that there are abnormalities that cannot be detected by vHIT alone.

Comparing Video Head Impulse Testing in Patients With Acute Vestibular Dysfunction

Objective: The video head impulse test (v-HIT) can evaluate the function of all semicircular canals (SCCs) in a short period. In this work, we sought to compare v-HIT results among 2 commercially available devices, the ICS impulse (Otometrics, Denmark) (ICS) and Eye See Cam (Interacoustics, Denmark) (ESC), among individuals with unilateral vestibular disorders. Design: Retrospective study (n = 15). Setting: St. Marianna University School of Medicine Hospital. Patients: Fifteen patients with acute unilateral vestibular disorders. Intervention: Two v-HIT devices were conducted across patients to compare the results of the 2 models. Main Outcome Measures: Gain values and pathological saccades for each SCC were compared across the 2 models. Monothermal caloric testing was performed to compare alongside v-HIT gain values. Results: There was no difference between the 2 models for the evaluation of the horizontal SCCs. There was a significant negative correlation (ESC: r = −0.52, ICS: r = −0.53) between caloric testing and the gain values of the 2 models. In the vertical SCCs, the gain values of ESC were significantly higher than the gain values of ICS. Detection of catch-up saccades in vertical SCCs was similar across the 2 models. Conclusion: For the horizontal SCCs, there was no difference in test results between the 2 models. However, in the vertical SCCs, gain values were variable across the 2 devices. Larger scale studies are needed to develop normative ranges for the vertical canals.

Vestibular Disorders Limited to the Vertical Semicircular Canals.

Introduction The advent of the video head impulse test (vHIT) enables the study of each one of the six semicircular canals. In the present study, certain patients present disorders related only to the vertical semicircular canals, and they were carefully evaluated. Objective To investigate vestibular disorders limited to the vertical semicircular canals. Methods In total, 9,891 patients were submitted to the vHIT in our clinic; 26 (2.63%) of them, 11 men and 15 women, showed reduced vestibulo-ocular reflex (VOR) limited to the vertical canals. All of these patients had vestibular symptoms. Results These patients presented different disorders of the vestibular system, and ten of them presented vestibular neuritis. Conclusion Now, vestibular disorders limited the vertical canals can be evaluated through the vHIT. These disorders, however, may relate do different labyrinthine diseases.

Comparing Video Head Impulse Testing With Rotary Chair in Pediatric Patients: A Controlled Trial.

To investigate the efficacy of video head impulse testing (VHIT) in detecting vestibular loss in pediatric patients with abnormal rotary chair testing, compared to a control group with normal rotary chair testing. Prospective, nonrandomized, controlled trial. Pediatric vestibular program at tertiary level children's hospital. Patients 3 to 18 years of age were recruited to undergo VHIT and rotary chair testing between September 2015 and November 2022. VHIT results were compared between an experimental group of 23 patients with vestibular symptoms and abnormal rotary chair testing results versus a control group of 14 patients without vestibular symptoms and with normal rotary chair testing results. The experimental group demonstrated reduced mean VHIT gain for the lateral semicircular canals (right = 0.83; left = 0.75) relative to the control group (right = 1.04, P = .005; left = 0.98, P < .001), but there was no significant difference between groups in superior and posterior canal responses. Among controls, there were no significant differences in mean gain values for each canal plane between age groups (3-7, 8-12, and 13-18 years) or between genders. A VHIT lateral canal gain value <0.85 and/or corrective saccades demonstrated 100% specificity and 100% positive predictive value for detecting vestibular loss on rotary chair, but only 69.6% sensitivity and 66.7% negative predictive value. VHIT is a useful test for detecting impairment of the lateral semicircular canals in children, though its sensitivity is limited relative to rotary chair. Its role in detecting vertical canal dysfunction in pediatric patients may be more limited and warrants further study.

Video head impulse test in subacute and chronic stroke survivors: new perspectives for implementation of assessment in rehabilitation.

The Video Head Impulse Test (vHIT) is a safe and reliable assessment of peripheral vestibular function. Many studies tested its accuracy in clinical settings for differential diagnosis and quantification of the vestibulo-oculomotor reflex (VOR) in various disorders. However, the results of its application after lesions of the CNS are discordant and have never been studied in rehabilitation. This study aims to assess the VOR performance in a sample of stroke survivors. This is a cross-sectional study on 36 subacute and chronic stroke survivors; only persons with first-ever stroke and able to walk independently, even with supervision, were included. We performed VOR assessments for each semicircular canal by vHIT and balance assessments by the Berg Balance Scale and the MiniBESTest scale. Two hundred and sixteen semicircular canals were assessed using the Head Impulse paradigm (in both the vertical and horizontal planes), while 72 semicircular canals were assessed using the Suppressed Head Impulse paradigm (horizontal plane). There was a high prevalence of participants with dysfunctional canals, particularly for the left anterior and right posterior canals, which were each prevalent in more than one-third of our sample. Furthermore, 16 persons showed an isolated canal dysfunction. The mean VOR gain for the vertical canals had confidence intervals out of the normal values (0.74-0.91 right anterior; 0.74-0.82 right posterior; 0.73-0.87 left anterior). Our findings suggest that peripheral vestibular function may be impaired in people with stroke; asystematic assessment in a rehabilitation setting could allow a more personalized and patient-centred approach.

Vertical saccades during horizontal head impulses: a sign of posterior semicircular canal hypofunction.

We describe an uncharacteristic vestibular-ocular reflex (VOR) pattern, studied by video head impulse tests (VHIT) in patients suffering from unilateral isolated posterior semicircular canal (PSC) hypofunction. In these patients, we found an upward sliding of the eyes, followed by an oblique downward catch-up saccade during horizontal head impulse to the healthy side. We present a retrospective study of all VHIT exams presenting isolated PSC hypofunction between May 2020 and November 2022. We found 37 patients, which led to the discovery of such incongruent eye movement in 19 cases; their gain data are shown and compared to the remaining 18 cases in which such an anomaly was absent. A control group of 31 healthy subjects was recruited to define the reference criteria for VHIT gain values. The correlation between the amplitude of the vertical saccade and the relative functional imbalance of the vertical semicircular canals was studied. We have observed that in approximately half of the subjects with isolated CSP deficiency, there is a VOR anomaly. A possible pathophysiological explanation of the unbalanced effect of vertical semicircular canal stimulation of a labyrinth during horizontal head thrust toward the opposite side is proposed. The planar incongruity of the response of the VOR described here appears more evident at the onset of the CSP deficit. Current VHIT systems do not detect this incongruent eye reflex. They can lead to an error in gain evaluation (pseudo-deficit) of the lateral semicircular canal of the healthy side and problems in performing the test (trace rejected). In the future, software for VHIT should take into account the possibility of non-coplanar ocular responses to cephalic stimuli.

Congenital aural atresia in a 4‐month‐old Dalmatian

AbstractA 4‐month‐old female entire Dalmatian was presented for persistently excessive ceruminous discharge, suspected left aural malformation and decreased hearing. Otoscopic examination of the left ear showed a normal external meatus with an abnormal ending of the ear canal in a cul‐de‐sac. Computed tomography (CT) study of the head showed a diffusely tortuous and convoluted external ear canal with saccular distension and a stenotic area with the presence of a septum. Based on the clinical presentation and imaging findings, total ear canal ablation and lateral bulla osteotomy were performed. Macroscopically, the ear canal appeared to be sigmoid, as in the CT study. Notably, in the stenotic area, there was a membrane separating the vertical and horizontal ear canals. The histopathology of the external ear canal was consistent with that of hyperplastic otitis externa. No growth was observed on bacterial culture. The dog recovered uneventfully and no abnormalities were detected on re‐examination 2 weeks post‐surgery.

Preliminary Evidence for the Effects of Gentamicin on Vertical Semicircular Canals

Introduction: Gentamicin is a vestibulotoxic antibiotic often used in patients with Ménière's disease for its vestibular ablative effects. Gentamicin’s effect on the horizontal semicircular canal does not always correlate with the degree of vertigo control achieved by patients; its effect on the vertical semicircular canals remains unknown. We sought to examine the effect of intratympanic gentamicin on vertical semicircular canal function in patients with Ménière's disease using video head impulse testing. Methods: A retrospective case series was carried out at a tertiary academic center. Patients with Ménière's disease who received ≥1 intratympanic gentamicin injection from 2019–2022 and had video head impulse testing performed were included. Outcomes of interest were vertical semicircular canal function following intratympanic gentamicin, correlations between vertical semicircular canal function and horizontal semicircular canal function, and residual symptoms following injection. Results: Ten patients met inclusion criteria. Twenty percent had abnormal V-SCC function prior to any injection and 40% following the first injection. There was an association between abnormal vertical and horizontal semicircular canal function following the first intratympanic gentamicin injection, though the relationship did not reach statistical significance (p = 0.058). While patients with abnormal vertical semicircular canal function following the first injection were less likely to report ongoing vertigo attacks, the relationship was not statistically significant (p = 0.260). Conclusions: Intratympanic gentamicin leads to changes in vertical semicircular canal function in at least a proportion of patients with Ménière's disease. Further study is required to better assess correlations between vertical semicircular canal function and symptom control following intratympanic gentamicin.

The vertical computerized rotational head impulse test.

The computerized rotational head impulse test (crHIT) uses a computer-controlled rotational chair to deliver whole-body rotational impulses to assess the semicircular canals. The crHIT has only been described for horizontal head plane rotations. The purpose of this study was to describe the crHIT for vertical head plane rotations. In this preliminary study, we assessed four patients with surgically confirmed unilateral peripheral vestibular abnormalities and two control subjects. Results indicated that the crHIT was well-tolerated for both horizontal head plane and vertical head plane stimuli. The crHIT successfully assessed each of the six semicircular canals. This study suggests that the crHIT has the potential to become a new laboratory-based vestibular test for both the horizontal and vertical semicircular canals.

Dynamic visual acuity screening test results analysis of 25 patients with peripheral vertigo

Objective:To observe the results of dynamic visual acuity screening tests in patients with peripheral vertigo and explore its clinical significance. Methods:The number of 48 healthy volunteers were enrolled as control group and 25 peripheral vertigo patients as experimental group. In the experimental group, there are 12 patients with vestibular neuritis, 1 patient with Hunt syndrome, 5 patients with sudden deafness with vertigo and 7 patients with bilateral vestibular dysfunction. Horizontal and vertical dynamic visual acuity screening tests were performed on them. The number of lost rows of horizontal and vertical dynamic visual acuity was compared between the control group and the experimental group to figure out if there is a statistical difference. The number of lost rows of horizontal and vertical dynamic visual acuity was compared within the experimental group to figure out if there is a statistical difference. The two groups of 18 cases of unilateral vestibular function decline and 7 cases of bilateral vestibular function decline in the experimental group were compared with the control group, and figure out if there is a statistical difference. Results:The median number of lost rows of horizontal dynamic visual acuity in 48 healthy volunteers was 1.5 and median number of lost rows of vertical dynamic visual acuity was 1.0 in the control group. The median number of lost rows of horizontal dynamic visual acuity of 26 healthy volunteers was 6 and median number of lost rows of vertical dynamic visual acuity was 5 in the experimental group. Compared to the experimental group, the number of lost rows both have statistical significance in horizontal and vertical dynamic visual acuity（P<0.01）. The comparison of horizontal and vertical lost rows within the test group also have statistical significance（P<0.01）. Twenty five patients with exceptional vestibular disease in the experimental group were divided into unilateral vestibular function reduction group（n=18） and bilateral vestibular function reduction group（n=7）. Compared with the control group, there was significant differences in the number of horizontal and vertical lost rows（P<0.01） within the three groups. After pairwise comparison, the number of lost rows of horizontal and vertical in the control group was significantly lower than that in the unilateral vestibular function reduction group and the bilateral vestibular function reduction group（P<0.01）. There was a highly significant correlation between the number of horizontally lost rows of DVA and the mean vHIT values of bilateral horizontal semicircular canals in 25 patients（P<0.01）; and a highly significant correlation between the number of vertically lost rows of DVA and the mean vHIT values of vertical semicircular canals in 4 groups bilaterally（P<0.01）. Conclusion:The Dynamic Visual Acuity Screening Test is a useful addition to existing tests of peripheral vestibular function, particularly the vHIT test, and provides a rapid assessment of the extent of 2 Hz VOR impairment in patients with reduced vestibular function.

A Clinical Infrared Video-Oculoscopy Suppression Head Impulse (IR-cSHIMP) Test.

We propose a Suppression Head IMPulse (SHIMP) test method that provides for equipment only through the use of InfraRed Video-OculoScopy (IR-VOS) and allows horizontal and vertical semicircular canal function evaluation in bedside mode. We therefore named the test InfraRed clinical SHIMP (IR-cSHIMP). To check IR-cSHIMP diagnostic efficiency, we studied 22 normal subjects, 18 patients with unilateral, and 6 with bilateral deficient vestibulopathy. Each subject first underwent a vestibular examination and, only later, an IRc-SHIMP test. When the IR-cSHIMP test was performed in the horizontal plane, all normal subjects showed anti-compensatory saccades. When the vertical semicircular canal function was evaluated, the same result was obtained in all normal subjects except three, which were considered false positives. In patients with vestibular deficits, the test performed in the horizontal and vertical planes were always pathological, with 100% agreement between clinical and instrumental tests. Our bedside method proved to be fast, simple, and effective in discriminating between healthy and pathological subjects. It required only the same skill as the better-known cHIT. For these reasons, we believe that the IR-cSHIMP should be part of daily clinical practice as a useful tool in the selection of patients to undergo more sophisticated investigations.

A Case of Proliferative and Necrotizing Otitis Externa in a Scottish Fold Shorthair Cat

In this case report, the aim was to contribute to understanding PNOE's clinical presentation, histopathological features, and successful treatment approaches, emphasizing the significance of accurate diagnosis and appropriate management in affected felines. Proliferative necrotic otitis externa (PNOE) is a very rare skin disease of unknown etiology affecting the vertical ear canal and the concave surface of the auricle, which may be accompanied by secondary yeast or bacterial infections. In this case 8-month-old Scottish fold shorthair cat has fragile, papillomatous growths and caseous purulent exudate in the ear canal was presented. The differential diagnosis of this condition includes otoacariasis, plasma cell pododermatitis, papillomavirus and chronic bacterial or yeast otitis externa. Despite antimicrobial and antiparasitic based previous treatments, the lesions persisted. Histopathological examination revealed acanthotic epidermis, necrotic keratinocytes, and inflammatory cell infiltrates. Treatment involved methylprednisolone injection, topical pomades, and systemic antibiotics. The cat showed improvement after initial treatment week, with regression of lesions and cessation of ear discharge. Follow-up visits demonstrated continued improvement, and after two months, minimal sequelae remained. In conclusion, despite the unknown etiology of PNOE, the disease is quite responsive to immunosuppressive therapy, which is beneficial for both diagnosis and treatment.

Pool boiling on vertical and horizontal heated plates with a dielectric fluid: Influence of vertical canal width

A closed system testbench has been developed to study pool boiling with a dielectric fluid at atmospheric pressure. The experimental setup consists in immerged horizontal and vertical adjacent heated plates, representing the corner of a parallelepipedal heating element. Both plates are 64x40mm2. The plates can be heated separately or simultaneously, with surface heat flux ranging from 0 to 20 W/cm2. Additionally, the canal width in front of the vertical heated plate is varied from 0.5 to 15 mm to study the influence of confinement. The opposite wall of the canal is made of transparent glass to allow optical visualization of the boiling on the vertical plate. A condenser at the top of the system controls the fluid subcooling. The wall temperatures are measured in steady-state regime in the middle of the plates, heat transfer coefficients are also determined. This configuration leads to complex flows, from natural convection to film boiling, including nucleate boiling. For low heat flux, smaller vertical canal widths enhance natural convection mixed with phase change phenomena: this conveys significantly higher heat transfer coefficients than in the vertical free configuration case. At higher heat flux, confinement does not enhance heat exchange on the vertical plate. When the vertical plate is confined, bubble coalescence and critical heat flux occur for lower heat flux compared to the free configuration. Visual observations on boiling regimes on the vertical plate are given depending on confinement. Finally, simultaneous heating of both plates is compared to isolated plate heating: boiling on the vertical plate improves heat exchange on the horizontal one, whereas boiling on the horizontal plate has no effect on the vertical one.

Head and vestibular kinematics during vertical semicircular canal impulses.

The video head impulse test (vHIT) is a common assessment of semicircular canal function during high-speed impulses. Reliability of the vHIT for assessing vertical semicircular canals is uncertain. Vertical head impulses require a complex head movement, making it difficult to isolate a single semicircular canal and interpret resulting eye rotations. The purpose of this study was to provide descriptive head kinematics and vestibular stimuli during vertical plane impulses to ultimately improve impulse delivery and interpretation of vHIT results for vertical semicircular canals. Six participants received right anterior (RA) and left posterior (LP) semicircular canal impulses. Linear displacements, rotational displacements, and rotational velocities of the head were measured. Peak velocities in semicircular canal planes and peak-to-peak gravitoinertial accelerations at the otolith organs were derived from head kinematics. The largest rotational velocities occurred in the target semicircular canal plane, with non-negligible velocities occurring in non-target planes. Larger vertical displacements and accelerations occurred on the right side of the head compared to the left for RA and LP impulses. These results provide a foundation for designing protocols to optimize stimulation applied to a singular vertical semicircular canal and for interpreting results from the vHIT for vertical semicircular canals.

Three-dimensional characteristics of nystagmus induced by low frequency in semicircular canals of healthy young people.

The study aimed to analyze the three-dimensional characteristics of nystagmus induced by different semicircular canal combinations in healthy young people, and to determine the reference range of nystagmus slow phase velocity (SPV) and its asymmetry. Fifty-two healthy volunteers (26 males and 26 females, aged 17-42 years, average 23.52 ± 6.59), were recruited to perform the manual triaxial rotation testing with a 3D-Videonystagmography (3D-VNG) device (VertiGoggles (ZT-VNG-II), Shanghai ZEHNIT Medical Technology Co., Ltd., Shanghai, China) using a 0.3 Hz prompt beat and a 90° amplitude, respectively. The induced nystagmus around the Z-, X-, and Y-axes were recorded in the yaw, pitch, and roll planes. The directions and slow phase velocities of the horizontal, vertical, and torsional components of the induced nystagmus under different semicircular canal combinations (the left lateral and right lateral semicircular canal combination, bilateral anterior semicircular canals, bilateral posterior semicircular canals combination, and the anterior and posterior semicircular canals combination of each ear), as well as their asymmetry, were taken as the observation indexes to analyze the characteristics of the nystagmus vectors of different combinations. Fifty-two healthy volunteers had no spontaneous nystagmus. The characteristic nystagmus was induced by the same head movement direction in all three axial rotation tests. The SPVs of the left and right nystagmus were 44.45 ± 15.75°/s and 43.79 ± 5.42°/s, respectively, when the subjects' heads were turned left or right around the Z-axis (yaw). The SPVs of vertically upward and downward nystagmus were 31.67 ± 9.46°/s and 30.01 ± 9.20°/s, respectively, when the subjects' heads were pitched around the X-axis (pitch). The SPVs of torsional nystagmus, with the upper poles of the eyes twisting slowly to the right and left ears (from the participant's perspective), were 28.99 ± 9.20°/s and 28.35 ± 8.17°/s, respectively, when the subjects' heads were turned left or right around the Y-axis (roll). There was no significant difference in the SPVs of nystagmus induced by the same rotation axis in two opposite directions (p > 0.05). The reference ranges for the slow phase velocities (SPVs) of nystagmus induced by the triaxial rotation testing were as follows: For the Z-axis (yaw), the SPVs were 13.58-75.32°/s for leftward head rotation and 13.56-74.02°/s for rightward head rotation. For the X-axis (pitch), the SPVs were 13.13-50.21°/s for upward head nystagmus and 11.98-48.04°/s for downward head nystagmus. For the Y-axis (roll), the SPVs were 10.97-47.02°/s for the left-sided head rotation and 12.34-44.35°/s for the right-sided head rotation. This study clarified the three-dimensional characteristics of nystagmus induced by different semicircular canal combinations in healthy young people. It also established a preliminary reference range of SPVs and SPV asymmetry of nystagmus induced by the vertical semicircular canal. It can further provide a basis for the mechanism of semicircular canal-induced nystagmus and the traceability of nystagmus in patients with otogenic vertigo. It is shown that the portable 3D-VNG eye mask can be used for the manual triaxial rotation testing to achieve the evaluation of the low-frequency angular vestibulo-ocular reflex (aVOR) function of the vertical semicircular canal, which is convenient, efficient, and practical.

Vestibulo-Ocular Reflex in the Aging Population.

The aim of this study was to evaluate vestibulo-ocular reflex (VOR) of individuals over 60 years of age who have not been diagnosed with a specific vestibular pathology. Bilateral six-semicircular canal video head impulse test (vHIT), Dizziness Handicap Inventory and European Evaluation of Vertigo scales were applied to participants. In total, 103 participants were included in the study (75 male, 28 female), and the mean age was 69.35 ± 7.41 years. The mean age of 7th decade group was 64.32±3.12 (59 participants; 38 male, 21 female), and the mean age of 8th decade and older group was 76.11±5.93 (44 participants; 37 male, 7 female). No significant differences were found between the VOR gains of the lateral or vertical semicircular canals between the 7th decade and 8th decade and older groups (p>0.05). In the 8th decade and older group, the presence of right lateral semicircular canal corrective saccade and left posterior semicircular canal corrective saccade showed a positively moderate correlation with VOR gains of the same semicircular canals (r=0.455, p=0.002, and r=0.518, p=0.001, respectively). No significant correlation was found between age and VOR gain in the 7th decade group, however, there was a negatively weak correlation between age and left lateral semicircular canal VOR gain (r=-0.366, p=0.017) in the 8th decade and older group. While assessing the age-related changes in VOR using vHIT, it must be considered that the changes related to aging of the vestibular system begin to emerge in the population over 70 years of age, and corrective saccade findings may be more informative than VOR gains in revealing these changes.

Investigation of the impacts of the thickness of the composite material on the temperature regime of energy-saving fencing of the outer wall with closed vertical wind channels

The proposes of investigation are the energy-saving facade structures with closed vertical canals, which were analyzed in ANSYS medium with finite elemental technique. An analysis of temperature lag of designed structures with vertical closed canals evidenced that contraction in frost protection material volume from 0.08 m3 to 0.055 m3 per 1 m2 gives rise to significant contraction in the temperature lag of outer shells in case with a heat directing shield up to 24.55%, and in case without a heat directing shield up to 26.9%. An analysis was also made of the heat directing shield influence on the temperature lag of a new structure, which evidenced that in case of the heat directing shield in vertical closed canals, the structure’s efficiency in terms of temperature lag value increases up to 20%, depending on external climate conditions. Since energy saving is the main problem all over the world, the investigation data can be realized in buildings’ design, construction, reconstruction, with a view to save heat release rate. At the same time, the use of the developed structures with a heat-reflecting screen with closed vertical channels leads to an increase in the temperature lag indicator, depending on external climatic conditions, by 8.5-20%.