Postural instability according to virtual reality program

Background: The popularity of virtual reality (VR) grew rapidly. Short guidelines with a lack of emphasis on safe use appears prior to usage. It is necessary for the user to realize how much potentially dangerous VR is.

Aims/objectives: The aim of this study is to investigate the effect of VR on balance in normal people.

Materials and methods: Mean equilibrium score (MES) of 15 adults who have normal sense of balance were obtained by using the sensory organization test (SOT). Conditions 1 and 2 were performed. Multiple VR programs were classified as three levels (Easy, Average, and Challenging) by the visual analog scale. Further SOT tests were performed during watching VR programs. MES of each test was used for statistical analysis.

Results: MES of condition 1 was significantly higher than condition 2. Although there was no statistical difference between Eye open and Easy program (p?=?.097), MES of average and Challenging programs showed significantly decreased scores compared to Eye open. In addition, MES of Average and Challenging programs were significantly decreased than that of Easy program.

Conclusions and significance: VR can cause postural imbalance to users. It is necessary to establish quantifiable and objective methods to measure imbalance caused by VR use.     

Prevalence of aphysiologic performance on dynamic posturography in work-related patients

Introduction and objectivesMedical-legal implications of dizziness and imbalance in work-related patients are important. In these cases, computerized dynamic posturography (CDP) adds information to standard vestibular tests and aphysiologic patterns have been described. The objective is to assess the prevalence of aphysiologic performance on CDP in work-related patients complaining of dizziness/imbalance.Material and MethodsRetrospective review of patients referred by the workers’ compensation board for assessment of dizziness, imbalance or both. Standard vestibular assessment including CDP was carried out in all patients. The sensory organization test (SOT) summaries were scored as normal, aphysiologic or vestibular using the scoring method published by Cevette et al. in 1995.ResultsAphysiologic performance in SOT, evaluated with the Cevette formula, was found in 31 out of 100 cases. Low composite score results and aphysiologic SOT results had a statistically-significant association (P=.01). Videonystagmography (VNG) was altered in 14 out of 31 cases with aphysiologic SOT.ConclusionThe 31% prevalence of aphysiologic results on CDP among work-related patients complaining of dizziness/imbalance is relatively high in comparison with the 25% published by Longridge and Mallinson in 2005. However, aphysiologic performance should not necessarily be related to malingering or exaggeration and altered vestibular tests are found in some of these cases.     

Sensory organization test principally reflects utricular function

Conclusion: Our study showed that sensory organization test (SOT) could principally reflect utricular function, and our cut-score of VEST ratio (the indicator of inputs from the vestibular system in balance performance) in SOT could help to screen patients with unilateral peripheral vestibular dysfunction in non-fallers.

Objectives: We aimed to know SOT reflects the function of which vestibular end organs and to assess the possibility of screening patients with peripheral vestibular dysfunction in non-fall population by means of SOT.

Methods: A total of 75 patients with unilateral peripheral vestibular dysfunction underwent SOT, ocular vestibular-evoked myogenic potential (oVEMP), cervical vestibular-evoked myogenic potential (cVEMP) and caloric tests.

Results: Regression model indicated that oVEMP, as an independent variable, exerted the greatest influence on VEST ratio, followed by age and cVEMP. There were no significant differences in VEST ratio among groups with different extents of peripheral vestibular involvement (p?>?.05). VEST ratio in the vestibular impairment groups was significantly lower than in the control group and significantly higher than in fall group (p?p?=?.013). The cut-score between populations with functional and dysfunctional vestibule was 0.649.     

Posturographic limits of stability can predict the increased risk of falls in elderly patients with instability?

Conclusions: There was a difference in average score of the sensory organization test (SOT) of the case group (elderly instability) compared to the control group (healthy subjects). Cases had worse scores on the limits of stability (LOS) than controls, but were only able to confirm statistically significant differences in the movement velocity.

Objective: To study the LOS of elderly patients with instability vs healthy subjects of the same age to try to explain the increased risk of falls in elderly patients with instability.

Methods: Fifty individuals ≥65 years, 30 cases (at least one of the next inclusion criteria: ≥1 fall in the last 12 months, >15?s or some support in the timed up and go test, composite <68 in SOT, ≥1 fall during production of the SOT) compared to 20 controls. Postural study: SOT and LOS, Smart Equitest Neurocom^® platform. Statistical analysis: t-Student test (p?Result: Mean value of overall balance: patients with instability =56% vs controls =77.1% (p p?=?0.029). The reaction time (cases =1217?s vs controls =1.077?s), excursion (56.95% vs 59.35%) and directional control (56.95% vs 59.35%) differences were not statistically significant.     

Evaluation of balance in fallers and nonfallers elderly

Falls present a substantial health problem among the elderly population. Approximately one-third of community-dwelling people over 65 years of age will experience one or more each year.ObjectiveThe purpose of this study was to evaluate balance between fallers and non-fallers elderly. Study Design: Clinical study.MethodsWe studied 30 subjects older than 65 years of age. 15 subjects had a history of falls within a year (Group I) and 15 subjects had no history of falls (Group II). The scores of Computerized Dynamic Posturography (CDP); Sensory Organization Test (SOT), Limits of Stability (LOS), Rhytmic Weight Shift (RWS) and Berg Balance Scale (BBS) findings gathered from the individuals from Group I and Group II, were compared.ResultsThe SOT 3, 6, composite, BBS scores and left-right on-axis velocity score of RWS test of the Group I were found to be significantly lower the Group II (p < 0.05). A positive correlation between the SOT 3, 5, composite and BBS scores of Group I and the SOT 4, 5, 6, composite and BBS scores of Group II is determined (p < 0.05).ConclusionThe CDP and BBS scores in fallers were found to be significiantly lower as compared to the non-fallers elderly.     

Control of sway using vibrotactile feedback of body tilt in patients with moderate and severe postural control deficits

We evaluated the effect of the vibrotactile display of body tilt upon the postural stability of vestibulopathic subjects during standing. Two groups were studied: those with moderate and with severe deficits as defined by postural stability test scores. They were studied under conditions of distorted sensory input, and during anterior-posterior perturbations. Seventeen subjects, with uni- or bilateral vestibular deficits, as determined by electronystagmography and vertical axis rotation, were tested using Equitest computerized dynamic posturography (CDP). Based on their performance on the CDP they were divided into two groups having either moderate (nine subjects) or severe (eight subjects) postural control deficits. Their anterior-posterior (A/P) body motion at the waist was measured with a micromechanical rate gyroscope and a linear accelerometer. The resulting tilt estimate was displayed by a vibrotactile array attached to the torso. The vibration served as a tilt feedback to the subject. The subject's performance was evaluated using the root-mean-square (RMS) of both the A/P body motion and center-of-pressure (CoP) estimates. Sensory distortions were introduced using the Equitest Sensory Organization Tests (SOT). These tests are designed to distort A/P sensory inputs while standing. The SOT 5 distorts proprioceptive information about ankle joint movement, while the subject stands eyes-closed on a moving support platform that measures foot pressure. The SOT 6 adds distorted visual information about body movement instead of testing with eyes closed. Perturbations were introduced using the Equitest Motor Control Tests (MCT). These move the support platform forward or backward with small, medium and large displacements in the horizontal plane while measuring subjects' foot pressure responses. We used the medium and large backward tests. Vibrotactile display of body tilt reduced the subjects' A/P sway and improved their balance. The finding was more evident for those subjects with severe deficits than those moderate ones. This trend was found for both SOT 5 and 6, as well as the medium and large MCT. Additionally, during the MCT, the peak deflection and mean recovery time also decreased significantly.     

Postural responses without versus with acute external cervical spine fixation: a comparative study in healthy subjects and patients with acute unilateral vestibular loss

Using a diagnostic prospective cohort single center study design, the influence of a cervical collar on standing balance during dynamic postural perturbations in healthy adults and patients with acute unilateral vestibular dysfunction was measured in 31 healthy subjects and 27 patients with acute unilateral vestibular loss. The main outcome measures were completed standard protocols on the Sensory Organization Test (SOT) and Motor Control Test (MCT) of the NeuroCom Equitest^® computerized posturography platform measured without and with acute cervical fixation, respectively. Paired t test showed no significant difference during the six conditions of neither the SOT scores nor analyzing the SOT strategies or during the MCT between the non-fixed and fixed neck in healthy subjects and in the patients (all p > 0.05). Older healthy subjects showed decreased SOT scores but equal MCT results. The age effect was more dominant in the patients when wearing the collar. Gender had no influence whether in healthy individuals nor in patients. In almost all conditions of the SOT but only in some MCT subtests patients had significantly lower scores than healthy subjects without collar and with collar (all p < 0.05). In conclusion, the SOT but only some subtest of the MCT could clearly distinguish between healthy adults and patient with acute unilateral vestibular loss. Equilibrium scores did not change significantly when the cervical spine was fixed with a collar. Acute fixation of the neck with a collar seems not to affect standing balance, even not when vestibular, visual and/or somatosensory input are also reduced.     

Maturational effects of the vestibular system: a study of rotary chair, computerized dynamic posturography, and vestibular evoked myogenic potentials with children

Maturational effects were investigated in two age groups (N = 30 per group) of children with normal hearing sensitivity, using rotary chair (RC), computerized dynamic posturography (CDP), and vestibular evoked myogenic potential (VEMP) measures. Children recruited within the younger group were three through six years of age, and children within the older group were nine through eleven years of age. Data obtained for each pediatric group were compared with clinic and/or published adult normative data for each measure. Significant age effects were seen on many CDP subtests (sensory organization test and motor control test); VEMP latencies; and RC gain, phase, and step velocity measures. The results of this study demonstrate significant maturational effects from preschool age through adulthood and suggest that adult normative data may not be appropriate when interpreting pediatric test results. Since adult techniques should oftentimes not be utilized, a proposed test battery is described that may be efficiently utilized with pediatric patients.     

The development and evaluation of the Finnish digit triplet test

Objectives: The aim of the study was to develop a reliable and easily accessible screening test for primary detection of hearing impairment.

Methods: Digits 0–9 were used to form quasirandom digit triplets. First, digit specific intelligibility functions and speech recognition thresholds (SRTs) were determined. To homogenize the test material digits with steep intelligibility function slopes were chosen and level correction up to ±2?dB were applied to the digits as needed. Evaluation measurements were performed to check for systematic differences in intelligibility between the test lists and to obtain normative reference function for normal-hearing listeners.

Results: The mean SRT and the final slope of the test lists were ?10.8?±?0.1?dB signal-to-noise ratio (SNR) and 21.7?±?1.8%/dB, respectively (measurements at constant level; inter-list variability). The mean SRT and slope of the test subjects were ?10.8?±?0.5?dB SNR and 23.4?±?5.2%/dB (measurements at constant level; inter-subject variability). The mean SRT for normal-hearing young adults for a single adaptive measurement is ?9.8?±?0.9?dB SNR.

Conclusion: The Finnish digit triplet test is the first self-screening hearing test in the Finnish language. It was developed according to current standards, and it provides reliable and internationally comparable speech intelligibility measurements.     

Typical sensory organization test findings and clinical implication in acute vestibular neuritis

Objective

Sensory organization test (SOT) is used to evaluate postural instability. We wanted to characterize the SOT findings in patients with acute vestibular neuritis (VN).

Postural stability in a population of dancers,healthy non-dancers,and vestibular neuritis patients

Introduction: Several studies have indicated better balance control in dancers than in control participants, but some controversy remains. The aim of our study is to evaluate the postural stability in a cohort of dancers, non-dancers, compensated, and non-compensated unilateral vestibular neuritis (VN).

Methods: This is a prospective study of control subjects, dancers, and VN patients between June 2009 and December 2015. Dancers from the Dance Conservatory of Madrid and VN patients were referred to our department for analysis. After the clinical history, neuro-otological examination, audiogram, and caloric tests, the diagnosis was done. Results from clinical examination were used for the categorization of compensation situation. A computerized dynamic posturography was performed to every subject.

Results: Forty dancers and 38 women formed both ‘dancer’ and ‘normal’ cohorts. Forty-two compensated and 39 uncompensated patients formed both ‘compensated’ and ‘uncompensated’ cohorts. Dancers had significantly greater antero-posterior (AP) body sway than controls during condition 5 and 6 in the Sensory Organization Test (SOT) (p?p?Conclusions: Dancers demonstrated greater sways than non-dancers when they relied their postural control on vestibular input alone. Compensated patients had a similar posturographic pattern that the dancers cohort, suggesting a similar shift from visual to somatosensory information.     

What is the most effective vestibular rehabilitation technique in patients with unilateral peripheral vestibular disorders?

Vestibular rehabilitation has been found to be effective and safe in patients with instability. There is insufficient evidence, however, for distinguishing between the efficacies of different rehabilitation techniques. The objective of this study is to verify whether there are differences between two instrumental vestibular rehabilitation techniques, computerised dynamic posturography (CDP) and optokinetic stimulation (OKN), in order to establish the optimal strategy for each patient. We conducted a prospective, comparative study of the two techniques (CDP and OKN) in patients with instability due to chronic unilateral peripheral vestibular disorder. We randomly included 12 patients in each group, performing the evaluation with the Dizziness Handicap Inventory and the CDP with the sensorial organisation test (SOT), rhythmic weight shift and limits of stability (LOS). We found a statistically significant improvement in both groups in average balance score according to the SOT. In the OKN group, however, improvement was greater in visual preference. The CDP group showed greater benefits in the visual and vestibular input and LOS. Patients with poor vestibular and visual input or with reduced LOS will benefit more from an exercise protocol with CDP. Patients with poor visual preference, however, are ideal candidates for rehabilitation with OKN.     

Chances of reversibility in early sensory deprivation of the Homo vulnerabilis: A 5-year (and ongoing) prospective study

Background: This prospective study evaluated the effectiveness of a rehabilitation program in vulnerable children with language deficits.

Aims/Objectives: Evaluating reversibility of a sensory understimulation.

Material/Methods: Two groups of five students, each, (sensory and not sensory deprived) were evaluated at ages 5 and 11. Both groups were taught the compulsory national educational program. The sensory deprived group also had a 5-year rehabilitation program. After that time, their language and vocabulary were reevaluated.

Results: Both groups became able to read, write and perform mathematical operations. Both groups took the compulsory elementary school national performance test and all of them performed above the national average. Despite these good performances the differences between both groups regarding language persisted.

Conclusions: Deficits in children with early sensory deprivation are improved with rehabilitation programs. In order to achieve better restoration, intervention should be done earlier than at 5 years of age. Even if some deficits are not fully reversible, the improvement is significant and allows social inclusion and the possibility of breaking their circle of vulnerability.

Significance: Documenting the importance of early rehabilitation in sensory deficits.     

The potential use of virtual reality in vestibular rehabilitation of motion sickness

ObjectiveMotion sickness (MS) can be triggered by direct or indirect stimuli due to mismatches in the visual-vestibular autonomic pathways. Various studies in the literature have shown that virtual reality technologies can generate provocative stimuli for MS. Therefore, our primary aim is to investigate the usability of virtual reality systems in MS rehabilitationMethods20 normal and 19 MS patients were included. A total of six virtual reality rehabilitation sessions (VRrs) with a game called “Roller Coaster Dreams” playable via PlayStation VR Head Mounted Display were applied thrice a week for 2 weeks, or twice a week for 3 weeks. Participants were evaluated at the pre-rehabilitation phase twice and after third and sixth rehabilitation sessions with the sensory organization test (SOT). The effectiveness of the rehabilitation program was statistically analyzed by comparing the results of SOTs.ResultsAll SOT results of the patient group were compared each other to evaluate the effectiveness of rehabilitation. According to the post-hoc comparisons, a statistically significant difference was found between the 1st, 2nd, 3rd, and 4th SOT- Equilibrium Scores; Condition 2 (p = 0.043), Condition 3 (p = 0.006), Condition 4 (p = 0.031), Condition 5 (p = 0.002) and Condition 6 (p = 0.040). There is no difference obtained in Condition 1 (p > 0.05). The Equilibrium Scores of SOT 3rd and SOT 4th were similar and 4th SOT-Equilibrium Scores were the highest among all SOT measurements. The results show that while the first three sessions were accepted as an orientation and adaptation sessions, 4^th, 5^thand 6^th sessions are habilitation sessions.ConclusionsVR proved to be significantly effective and useful for MS rehabilitation. Additionally, observations indicated that using VR makes rehabilitation fun, increases the efficiency of the process, and reduces the risk of inadaptability to exercise.     

Computerized dynamic posturography and seasickness susceptibility

OBJECTIVE/HYPOTHESIS: The neural mismatch theory emphasizes the role of conflicting multimodal sensory interactions in producing both motion sickness and the rearrangement process that finally leads to habituation to the adverse motion conditions. If this theory is, indeed, correct, the patterns of the response to the integrated signal from simultaneous multisensory stimulation, characterized by unusual relationships between the senses responsible for spatial orientation, should differ according to motion sickness susceptibility. Computerized dynamic posturography (CDP) provides the opportunity to simultaneously change the interactions between visual, somatosensory, and vestibular inputs, thus giving an indication of the relative importance of these senses in maintaining balance. The objective was to investigate balance strategies in naval crew members with differing susceptibility to sea conditions using CDP. STUDY DESIGN: Cross-sectional, parallel-group design. METHODS: Twenty subjects susceptible to seasickness (SS) and 20 nonsusceptible subjects (NSS), healthy male volunteers aged 18 to 25, were tested using the EquiTest system (NeuroCom, Inc., Clackamas, OR). RESULTS: The SS group exhibited significantly less stability than the NSS group in condition 5 of the sensory organization test (SOT). The ratio of the SOT scores of conditions 5 to 1 (the vestibular organization pattern) was also found to be significantly lower in the SS group. CONCLUSIONS: The results suggest that SS might be more dependent on somatosensory and visual inputs and less on vestibular inputs for maintenance of balance compared with NSS. Higher susceptibility to seasickness might reflect abnormal weighting of sensory modalities during the integration process. This would result in disruption of the integration process required to maintain balance and a sense of orientation in space in conditions producing conflicting sensory inputs.     

Influence of sensory information on static balance in older patients with vestibular disorder

IntroductionWith aging, the sensory systems suffer an accumulation of degenerative, infectious and/or traumatic processes that may hinder the body balance maintenance.ObjectiveTo assess the influence of sensory information on static body balance of elderly individuals with vestibular disorders.MethodsCross-sectional study of elderly individuals with vestibular disorders. The Clinical Test of Sensory Interaction and Balance and posturography integrated with virtual reality (Balance Rehabilitation Unit™) were used. Posturography parameters analyzed included center of pressure and velocity of body sway.Results123 individuals with mean age of 73.11 were assessed. Worst performance was observed in the Clinical Test of Sensory Interaction and Balance condition of visual dome-unstable surface. Differences between conditions were: firm surface-open eyes/firm surface-closed eyes, unstable surface-open eyes/unstable surface-closed eyes (p < 0.001), and unstable surface-closed eyes/unstable surface-visual dome. Considering center of pressure and velocity of body sway, significant differences were observed between the following conditions: firm surface-open eyes/firm surface-closed eyes: firm surface-saccadic stimulus/firm surface-vertical optokinetic stimulus; firm surface-optokinetic stimuli/firm surface-visual–vestibular interaction; and firm surface-visual–vestibular interaction/unstable surface. Worse performances were observed in conditions firm surface-closed eyes, firm surface-vertical optokinetic stimulus, F-visual–vestibular interaction, and unstable surface-closed eyes. There was a difference in the center of pressure between firm surface-closed eyes/firm surface-saccadic stimulus, with a worse performance in the condition of firm surface-closed eyes, and of velocity of body sway, between firm surface-saccadic stimulus/firm surface-horizontal optokinetic stimulus (p < 0.001).ConclusionStatic body balance in elderly individuals with vestibular disorders is worse when the sensory conditions are more challenging, i.e. stable and unstable surfaces, visual stimuli, such as optokinetic and visual–vestibular interaction, and with the eyes closed.     

Development of vestibular ocular reflex and gross motor function in infants with common cavity deformity as a type of inner ear malformation

Background： The function of common cavity deformity demonstrated by temporal bone CT and MRI has been unknown.

Aim/Objective: To investigate the developmental changes of vestibular ocular reflex and acquisition of postural control in infants with common cavity deformity.

Material and methods: Eight infants who were congenitally deaf complicated by common cavity deformity were studied. The damped rotational chair test was carried out to evaluate vestibular ocular reflex. Acquisition of head control and independent walking in these infants was compared with that in normal infant’s milestones of gross motor development.

Results: All of the eight infants with common cavity deformity did not show per-rotatory nystagmus in the damped rotational chair test around the first year of life. However, a normal number of beats and a longer duration of per-rotatory nystagmus for their age were recorded at around three or four years of age.

Conclusions and significance: In the eight infants with common cavity deformity, vestibular ocular reflex was not present around the first year of life, but appeared after three or four years probably because of some vestibular sensory cells. Head control and independent walking were delayed but eventually acquired by the central vestibular compensation.     

Implementation and evaluation of a Danish test battery for auditory processing disorder in children

Objective: This study presents a Danish test battery for auditory processing disorder (APD). The tests were evaluated as to normative cut-off values (pass-fail criteria) and their test–retest reliability. Design: The battery consists of four behavioural tests: the filtered words (FW) test, the dichotic digits (DD) test, the gap detection (GD) test and the binaural masking level difference (BMLD) test. The tests were evaluated through listening experiments on children with no known history of auditory problems. Study sample: The normative cut-off values were obtained from 158 children (75 boys and 83 girls, aged 6–16 years), whereas the test–retest reliability was obtained from 20 children (10 boys and 10 girls, aged 6–11 years). Results: For each of the four tests one to four different cut-off values were determined depending on whether the scores from the two ears and the different age groups could be pooled. For each of the four tests the test–retest reliability was found to be satisfactory. The test–retest reliability was highest for the FW and the DD test. Conclusions: A Danish APD test battery is now available for clinical use with normative data.     

Characteristics,behaviours and readiness of persons seeking hearing healthcare online

Objective: This study describes characteristics, behaviours and readiness of people who are interested in seeking hearing healthcare (HHC) online.

Design: A non-profit clinic was established from which services through a virtual clinic are offered. Most of the patient–audiologist interactions are conducted online. We used online means to invite individuals to take a free online digit-in-noise (DIN) test. Upon failing the test, individuals reported their readiness to seek HHC by using two tools: the line and the staging algorithm.

Study sample: Individuals ≥18?years of age, within the greater Durban area, South Africa, were eligible to participate in the study.

Results: A total of 462 individuals completed the online DIN test during the first 3?months. Of those, 58.66% (271/462) failed the test and 11.04% (51/462) submitted their details for further contact from the clinic audiologist. Five individuals proceeded to a comprehensive hearing evaluation and hearing aid trial: all those individuals showed readiness to seek further HHC on the measurement tools. These individuals have reported knowing of their hearing challenges prior to taking the test and have waited for a period of between 5 and 16 years before seeking HHC. A significant association between age and DIN test result was found.

Conclusion: This explorative study is the first clinic to utilise digital tools across the entire patient journey in combination with face-to-face interactions in providing HHC. Internet-connected devices provide an opportunity for individuals to seek HHC and for providers to offer initial services to detect, counsel and support persons through the initial engagement process of seeking HHC. This may open up new audiology patient pathways through online hearing screening, assessment of readiness to seek further HHC and enhancement of service delivery using hybrid services by combining online and face-to-face modes of synchronous and asynchronous communication.     

British children’s performance on the listening in spatialised noise-sentences test (LISN-S)

Abstract

Objective: To investigate whether British children’s performance is equivalent to North American norms on the listening in spatialised noise-sentences test (LiSN-S).

Design: Prospective study comparing the performance of a single British group of children to North-American norms on the LiSN-S (North American version).

Study sample: The British group was composed of 46 typically developing children, aged 6–11?years 11?months, from a mainstream primary school in London.

Results: No significant difference was observed between the British’s group performance and the North-American norms for Low-cue, High-cue, Spatial Advantage and Total Advantage measure. The British group presented a significantly lower performance only for Talker Advantage measure (z-score: 0.35, 95% confidence interval ?0.12 to ?0.59). Age was significantly correlated with all unstandardised measures.

Conclusion: Our results indicate that, when assessing British children, it would be appropriate to add a corrective factor of 0.35 to the z-score value obtained for the Talker Advantage in order to compare it to the North-American norms. This strategy would enable the use of LiSN-S in the UK to assess auditory stream segregation based on spatial cues.