A comparison of head movements tests in force plate and accelerometer based posturography in patients with balance problems due to vestibular dysfunction.

This study compares HS posturography on inertial sensors (MediPost) with force platform posturography in patients with unilateral vestibular dysfunction. The study group included 38 patients (age 50.6; SD 11.6) with unilateral vestibular weakness (UV) and 65 healthy volunteers (48.7; SD 11.5). HS tests were performed simultaneously on the force plate and with MediPost sensor attached at L4. Four conditions applied: eyes open/closed, firm/foam. The tests were performed twice, with the head moving at the frequency of 0.3 Hz (HS 0.3) and 0.6 Hz (HS 0.6). Mean sway velocity was significantly lower for MediPost than force plate in 4th condition both in UV and healthy group. For HS 0.3 the differences between devices were marginal; the highest sensitivity (87%) and specificity (95%) were in 4th condition. For HS 0.6 MediPost revealed lower sensitivity than force plate although the surface parameter improved results. MediPost IMU device and force platform posturography revealed a similar ability to differentiate between patients with balance problems in course of vestibular pathology and healthy participants, despite the differences observed between measuring methods. In some tests surface parameter may be more appropriate than sway velocity in improving MediPost sensitivity.

Development of a new method for assessing otolith function in mice using three-dimensional binocular analysis of the otolith-ocular reflex.

In the interaural direction, translational linear acceleration is loaded during lateral translational movement and gravitational acceleration is loaded during lateral tilting movement. These two types of acceleration induce eye movements via two kinds of otolith-ocular reflexes to compensate for movement and maintain clear vision: horizontal eye movement during translational movement, and torsional eye movement (torsion) during tilting movement. Although the two types of acceleration cannot be discriminated, the two otolith-ocular reflexes can distinguish them effectively. In the current study, we tested whether lateral-eyed mice exhibit both of these otolith-ocular reflexes. In addition, we propose a new index for assessing the otolith-ocular reflex in mice. During lateral translational movement, mice did not show appropriate horizontal eye movement, but exhibited unnecessary vertical torsion-like eye movement that compensated for the angle between the body axis and gravito-inertial acceleration (GIA; i.e., the sum of gravity and inertial force due to movement) by interpreting GIA as gravity. Using the new index (amplitude of vertical component of eye movement)/(angle between body axis and GIA), the mouse otolith-ocular reflex can be assessed without determining whether the otolith-ocular reflex is induced during translational movement or during tilting movement.

Clinical Techniques and Technology: Vestibular Telemetry.

When a patient presents to a clinician with dizziness, it can be difficult for the patient to describe their symptoms in a clear manner, and clinical examination often yields entirely normal results. Ideally, it would be favorable to measure key physiological parameters during their episodes of dizziness. From a clinical perspective, this would allow a more timely and more accurate diagnosis. From a research perspective, it would allow a greater understanding of how the vestibular system malfunctions as a consequence of vestibular disease. The authors of this report have been funded by the UK Medical Research Council to develop and test a novel technology to measure, record, and analyze key physiological parameters provided by the dizzy individual during an episode of dizziness while active in the community. We provide the context to evolving work in this field, the outcome of preliminary studies, and a consideration of future opportunities.

Nystagmus characteristics of healthy controls.

BACKGROUND: Healthy controls exhibit spontaneous and positional nystagmus which needs to be distinguished from pathological nystagmus. OBJECTIVE: Define nystagmus characteristics of healthy controls using portable video-oculography. METHODS: One-hundred and one asymptomatic community-dwelling adults were prospectively recruited. Participants answered questions regarding their audio-vestibular and headache history and were sub-categorized into migraine/non-migraine groups. Portable video-oculography was conducted in the upright, supine, left- and right-lateral positions, using miniature take-home video glasses. RESULTS: Upright position spontaneous nystagmus was found in 30.7% of subjects (slow-phase velocity (SPV)), mean 1.1±2.2 degrees per second (°/s) (range 0.0 - 9.3). Upright position spontaneous nystagmus was horizontal, up-beating or down-beating in 16.7, 7.9 and 5.9% of subjects. Nystagmus in at least one lying position was found in 70.3% of subjects with 56.4% showing nystagmus while supine, and 63.4% in at least one lateral position. While supine, 20.8% of subjects showed up-beating nystagmus, 8.9% showed down-beating, and 26.7% had horizontal nystagmus. In the lateral positions combined, 37.1% displayed horizontal nystagmus on at least one side, while 6.4% showed up-beating, 6.4% showed down-beating. Mean nystagmus SPVs in the supine, right and left lateral positions were 2.2±2.8, 2.7±3.4, and 2.1±3.2°/s. No significant difference was found between migraine and non-migraine groups for nystagmus SPVs, prevalence, vertical vs horizontal fast-phase, or low- vs high-velocity nystagmus (<5 vs > 5°/s). CONCLUSIONS: Healthy controls without a history of spontaneous vertigo show low velocity spontaneous and positional nystagmus, highlighting the importance of interictal nystagmus measures when assessing the acutely symptomatic patient.

Reliability and validity of the mCTSIB dynamic platform test to assess balance in a population of older women living in the community.

OBJECTIVES: Test the reliability and validity of the modified Clinical test of Sensory Interaction in Balance (mCTSIB) of the Balance Platform Biodex Balance System (BBS) in a female community dwelling population. METHOD: 100 women over 65 years community dwellers mean age 71.8 (SD±6, ranging from 65 to 91) years, were examined using the posturography modified Clinical test of Sensory Interaction on Balance (mCTSIB) protocol of the Biodex Balance system SD and the Greek Mini-Best Test (miniBESTest-GR) to assess concurrent validity, with 24 undergoing a second measurement after one week to test the reliability of the method. RESULTS: The m-CTSIB-"Composite Score" test was significantly and positively correlated with the mini-BESTest-GR (r= -0.652, p<0.001) indicating good validity properties. The test-retest reliability was measured using the intra-class correlation coefficient (ICC) using a two-way mixed-effects absolute-agreement single-measurement model, among the two measurements of mCTSIB test (test-retest). No statistical difference was found between the two samples (N1=100, N2=24, t= -1.755, df=122, p=0.08). ICC estimates as 0.628 with 95% confident interval=0.31-0.82. CONCLUSION: The mCTSIB test from the BBS has a moderate validity and reliability to evaluate balance in elderly women living in the community and can be used as a screening tool.

Coronavirus Disease 2019 Return to Work Guidance and Recommendations for Vestibular Clinicians.

As states begin issuing progressive deconfinement guidelines, hospitals and institutions are starting to reopen for elective procedures and consultations. Vestibular clinicians are opening their practices to evaluate, test, or treat patients with dizziness and balance problems. The following document, requested by the American Balance Society, collates the current information about the virus, including transmission from asymptomatic carriers, decontamination, and other safety protocols, and provides a return to work guidance for clinicians caring for this population of patients, promoting provider, patient, and staff safety.

An investigation into the diagnostic accuracy, reliability, acceptability and safety of a novel device for Continuous Ambulatory Vestibular Assessment (CAVA).

Dizziness is a common condition that is responsible for a significant degree of material morbidity and burden on health services. It is usually episodic and short-lived, so when a patient presents to their clinician, examination is normal. The CAVA (Continuous Ambulatory Vestibular Assessment) device has been developed to provide continuous monitoring of eye-movements, allowing insight into the physiological parameters present during a dizziness attack. This article describes the first clinical investigation into the medical and technical aspects of this new diagnostic system. Seventeen healthy subjects wore the device near continuously for up to thirty days, artificially inducing nystagmus on eight occasions. 405 days' worth of data was captured, comprising around four billion data points. A computer algorithm developed to detect nystagmus demonstrated a sensitivity of 99.1% (95% CI: 95.13% to 99.98%) and a specificity of 98.6% (95% CI: 96.54% to 99.63%). Eighty-two percent of participants wore the device for a minimum of eighty percent of each day. Adverse events were self-limiting and mostly the consequence of skin stripping from the daily replacement of the electrodes. The device was shown to operate effectively as an ambulatory monitor, allowing the reliable detection of artificially induced nystagmus.

La colocación de los electrodos para el registro electronistagmográfico / The placement of the electrodes for the electronystagmography record

Fundamento: la calidad de un registro nistagmográfico durante los estudios del sistema vestibular, depende de la adecuada selección y colocación de los electrodos, los cuáles suelen ser ubicados en puntos específicos de la órbita ocular para permitir la recolección de la variación de potencial eléctrico generado entre la córnea y la retina causada por las sacudidas del nistagmo inducido o natural. Objetivo: presentar los resultados experimentales que demuestran esta influencia al cuantificar el efecto sobre los registros. Desarrollo:se empleó la técnica de estimulación visual con blanco móvil a diferentes frecuencias de movimiento, y los registros se realizaron en las condiciones de iluminación establecidas para electrooculografía, se utilizó un amplificador biomédico (electronistagmógrafo) de dos canales con frecuencia de muestreo de 1 kHz. Los Resultados obtenidos reflejan el cambio de las tensiones en los registros de acuerdo a la zona de colocación de los electrodos, al existir una zona óptima para el adecuado registro electronistagmográfico. Conclusiones: se demostró la afectación por zonas en los registros en el dominio temporal y de la frecuencia, y su influencia en la generación de errores en el diagnóstico topográfico de enfermedades que afectan el Sistema Vestibular(AU)

Background: quality of record of electronystagmography during the studies of the vestibular system depends on the proper selection and placement of the electrodes, which are usually located at specific points in the eye socket to allow the collection of the variation of electric potential generated between the cornea and the retina caused by the jerking of the induced or natural nystagmus. Objective: to present the experimental results that demonstrate this influence by quantifying the effect on the records. Development: it was used the technique of visual stimulation with moving target at different frequencies of movement, and the records were made under the lighting conditions established in the published standard for electrooculography, using a two-channel amplifier with a sampling frequency of 1 kHz. The results obtained reflect the change in the tensions in the records according to the electrode placement zone, there being an optimal zone for the adequate record of electronystagmography. Conclusions:the affectation by zones in the records in the temporal domain and the frequency was demonstrated, and its influence in the generation of errors in the topographic diagnosis of diseases that affect the Vestibular System(AU)

Assessment of Subjective Visual Vertical (SVV) Using the "Bucket Test" and the Virtual SVV System.

OBJECTIVE: The purpose of this study was to describe the variability and test-retest reliability of a commercially available subjective visual vertical (SVV) system known as Virtual SVV (Interacoustics). In addition, the study aimed to compare the reliability of the Virtual system with a previously established bucket test of SVV. STUDY DESIGN: Fifteen participants with normal hearing, normal middle ear function, and normal utricular function were included in the study. Each participant underwent static SVV testing using both the Virtual system and the bucket test. Subjects completed 2 testing sessions to determine test-retest reliability. For each test, data were collected with the head at 0°, tilted 45° to the right, and tilted 45° to the left. SETTING: This study was conducted in a balance function laboratory embedded in a large, tertiary care otology clinic. RESULTS: The mean SVV values obtained with the Virtual system were within 1°-2° from 0 with the head positioned at 0°, which is in agreement with many other studies of SVV with the head at 0° (Akin & Murnane, 2009; Halmagyi & Curthoys, 1999; Zwergal, Rettinger, Frenzel, Dieterich, & Strupp, 2009). Using the intraclass correlation coefficient, test-retest reliability of the Virtual system was excellent in the 45° left position and fair to good in the 45° right and 0° position. Test-retest reliability of the bucket test was poor in all head positions. CONCLUSIONS: The Virtual system is a more reliable measure of static SVV than the bucket test. Therefore, the Virtual system could be utilized as a screening device for utricular dysfunction in busy clinical settings.

Age-based normative data for a computerized dynamic posturography system that uses a virtual visual surround environment.

BACKGROUND: Computerized dynamic posturography (CDP) is the gold standard to differentiate between sensory, motor, and central adaptive impairments to postural control. OBJECTIVE: To obtain normative values in healthy adults age 20-69 for a CDP system that uses a full-field dynamic visual surround. This is in contrast to the mechanically movable visual surround used in traditional CDP systems. METHODS: Fifty healthy adults divided into five age groups were tested during the three test protocols for CDP: sensory organization test (SOT), motor control test (MCT), and adaptation test (ADT). Outcomes were compared across age groups and to published normative CDP values. Repeatability was assessed in five different subjects (23-30 years old) on 2 days, 1 week apart. RESULTS: Most outcomes were comparable to published norms with notable differences in SOT condition 4 and ADT. SOT composite and conditions 4-6, all MCT translations, and ADT toes up showed moderate to good repeatability (r = 0.60 to 0.99). Age group and gender differences were not substantial. CONCLUSIONS: Some but not all CDP outcomes with a virtual visual environment were comparable to published norms. The differences are likely related to the virtual surround having a more compelling effect on balance even in conditions with a stationary surround.

Simultaneous recording of cervical and ocular vestibular-evoked myogenic potentials.

OBJECTIVE: To increase clinical application of vestibular-evoked myogenic potentials (VEMPs) by reducing the testing time by evaluating whether a simultaneous recording of ocular and cervical VEMPs can be achieved without a loss in diagnostic sensitivity and specificity. METHODS: Simultaneous recording of ocular and cervical VEMPs on each side during monaural stimulation, bilateral simultaneous recording of ocular VEMPs and cervical VEMPs during binaural stimulation, and conventional sequential recording of ocular and cervical VEMPs on each side using air-conducted sound (500 Hz, 5-millisecond tone burst) were compared in 40 healthy participants (HPs) and 20 patients with acute vestibular neuritis. RESULTS: Either simultaneous recording during monaural and binaural stimulation effectively reduced the recording time by ≈55% of that for conventional sequential recordings in both the HP and patient groups. The simultaneous recording with monaural stimulation resulted in latencies and thresholds of both VEMPs and the amplitude of cervical VEMPs similar to those found during the conventional recordings but larger ocular VEMP amplitudes (156%) in both groups. In contrast, compared to the conventional recording, simultaneous recording of each VEMP during binaural stimulation showed reduced amplitudes (31%) and increased thresholds for cervical VEMPs in both groups. CONCLUSIONS: The results of simultaneous recording of cervical and ocular VEMPs during monaural stimulation were comparable to those obtained from the conventional recording while reducing the time to record both VEMPs on each side. CLINICALTRIALSGOV IDENTIFIER: NCT03049683.

[The vestibular craniovertebral joints]. / Die vestibulären Kopfgelenke.

INTRODUCTION: The significance of cervical proprioception for human balance has thus far not been sufficiently elucidated. The aim of this study was to provoke selective cervico-vestibular stimulation using the trunk excursion test (TET) we ourselves constructed. This chair is designed to enable evaluation of cervico-ocular reactions during isolated trunk excursion and possible effects of aging. METHODS: The previously used head excursion test (HET) was statistically compared to the TET. In both methods, 100 healthy subjects of two age groups (group(26): median age = 26 years, n = 50; group(50): median age = 50 years, n = 50) were randomized for comparison of similar neck-to-trunk-positions. RESULTS: HET enabled detection of significant nystagmus modulation in horizontal and vertical dimensions; whereas in pure cervical stimulation using the new TET, this was only evident in the horizontal dimension and only during trunk torsion. Comparison of the two methods confirmed significantly stronger nystagmus modulation through head excursion. In terms of the HET, group(50) showed significantly more vertical nystagmus activity than group(26). However, no significant difference was found between the groups in terms of their reactions to trunk excursion in the TET. In a group-specific comparison of the methods, group(26) showed a significant increase in horizontal nystagmus in head compared to trunk excursion, whereas group(50) generally displayed a significantly greater response to provocation by head excursion in HET. Analysis of the significant vertical nystagmus modulation produced with the TET method showed predominance of upbeat- (UBN) over downbeat-nystagmus (DBN). Through head excursion with the HET, DBN was more frequently evoked in group(50) than in group(26). No significant age-dependent difference could be derived in UBN. CONCLUSION: The results of the pilot study indicate that head-to-trunk provocation is a suitable means of evaluating cervicotonic provocation nystagmus. Only by evaluation of adequate excursion limits and consistent analysis of patients with cervical deficiency can the effects of the method be further assessed.

Nistagmo vertical inferior: ¿es obligada la resonancia magnética? / Inferior vertical nystagmus: is magnetic resonance imaging mandatory?

Introducción. La aparición de un nistagmo vertical inferior clásicamente obliga a descartar una patología vascular o de la unión craneocervical mediante resonancia magnética (RM). Estudios recientes demuestran una baja rentabilidad de esta prueba, ya que sugieren que este signo oculomotor puede tener una causa vestibular periférica, sobre todo cuando el paciente presenta un vértigo posicional paroxístico benigno (VPPB) del canal semicircular superior. Objetivo. Comprobar la rentabilidad de la RM en una población de pacientes con nistagmo de posición vertical inferior. Pacientes y métodos. Estudio retrospectivo de 42 pacientes consecutivos a los que se les realizó una historia clínica, exploración física, y pruebas vestibulares calóricas y rotatorias. A todos ellos se les practicó una RM craneal y cervical. Resultados. El 52% de los pacientes con nistagmo de posición vertical inferior presentaba una clínica y exploración física compatibles con VPPB del canal semicircular superior. La RM fue normal en un 67%, un 26% mostraba datos de espondilopatía y un 5% de microangiopatía cerebral no relacionados con la clínica del paciente. La prevalencia de malformación de Arnold-Chiari de tipo I fue de un 9% en la población estudiada, sin que nadie tuviera un antecedente reciente de VPPB. Los resultados obtenidos en las pruebas complementarias vestibulares no aportaron información adicional para llegar a un diagnóstico etiológico. Conclusión. En los pacientes con un VPPB, la RM craneal y las pruebas vestibulares tienen una baja rentabilidad diagnóstica, y se debe evaluar la necesidad real de esta prueba con el contexto clínico (AU)

Introduction. The presentation of a down-beating nystagmus force to discard vascular pathology of brain and cervical joint with magnetic resonance imagine (MRI). Recent studies support the low profitability of this study and is subjected that this oculomotor sign has a peripheral origin especially when the patient has a benign paroxysmal positional vertigo (BPPV) with affection of the superior semicircular canal. Aim. To evidence the profitability of MRI in a population of patients with positional down-beating nystagmus. Patients and methods. We present a retrospective study with 42 consecutive patients. A complete clinical history and physical examination was performed. All of them perform vestibular tests (caloric and rotatory), cranial and cervical MRI. Results. Fifty-two percent of patients present clinical manifestations and physical exploration compatible with BPPV. MRI was normal in 67%. We found spondylopathy in 26% and vascular cerebral pathology in 5%. Prevalence of type I ArnoldChiari malformation was 9% in our population. None of them was founded when the main symptom was suggestive of BPPV. Results obtained of vestibular tests didn’t contribute additional information to give an ethiologic diagnosis. Conclusion. The profitability of vestibular tests and MRI in our population with down beating nystagmus was very low. We must evaluate the real necessity of this test with the clinical context (AU)

The horizontal computerized rotational impulse test.

Whole-body impulsive rotations were used to overcome several limitations associated with manual head impulse testing. A computer-controlled rotational chair delivered brief, whole-body, earth-vertical axis yaw impulsive rotations while eye movements were measured using video-oculography. Results from an unselected group of 20 patients with dizziness and a group of 22 control subjects indicated that the horizontal computerized rotational head impulse test (crHIT) is well-tolerated and provides an estimate of unidirectional vestibulo-ocular reflex gain comparable to results from caloric testing. This study demonstrates that the horizontal crHIT is a new assessment tool that overcomes many of the limitations of manual head impulse testing and provides a reliable laboratory-based measure of unilateral horizontal semicircular canal function.

Effects of vibrotactile vestibular substitution on vestibular rehabilitation - preliminary study, / Efeitos do biofeedback vibrotátil na reabilitação do equilíbrio corporal − estudo preliminar

ABSTRACT INTRODUCTION: Some patients with severe impairment of body balance do not obtain adequate improvement from vestibular rehabilitation (VR). OBJECTIVE: To evaluate the effectiveness of Vertiguard(tm) biofeedback equipment as a sensory substitution (SS) of the vestibular system in patients who did not obtain sufficient improvement from VR. METHODS: This was a randomized prospective clinical study. Thirteen patients without satisfactory response to conventional VR were randomized into a study group (SG), which received the vibrotactile stimulus from Vertiguard(tm) for ten days, and a control group (CG), which used equipment without the stimulus. For pre- and post-treatment assessment, the Sensory Organization Test (SOT) protocol of the Computerized Dynamic Posturography (CDP) and two scales of balance self-perception, Activities-specific Balance Confidence (ABC) and Dizziness Handicap Inventory (DHI), were used. RESULTS: After treatment, only the SG showed statistically significant improvement in C5 (p = 0.007) and C6 (p = 0.01). On the ABC scale, there was a significant difference in the SG (p= 0.04). The DHI showed a significant difference in CG and SG with regard to the physical aspect, and only in the SG for the functional aspect (p = 0.04). CONCLUSION: The present findings show that sensory substitution using the vibrotactile stimulus of the Vertiguard(tm) system helped with the integration of neural networks involved in maintaining posture, improving the strategies used in the recovery of body balance.

RESUMO INTRODUÇÃO: Alguns pacientes com déficit severo do equilíbrio corporal submetidos à reabilitação vestibular (RV) podem não apresentar resultados satisfatórios. OBJETIVO: Verificar a eficácia do equipamento de biofeedback Vertiguard(tm) como substituto sensorial do sistema vestibular em pacientes sem bons resultados à RV. MÉTODO: Estudo prospectivo clínico randomizado. Treze pacientes sem resposta satisfatória à RV convencional foram randomizados entre grupo de estudo (GE), que utilizou o estímulo vibratório do Vertiguard(tm) por dez dias e grupo controle (GC) que usou o equipamento desligado. Para avaliação pré e pós-tratamento foi utilizado o protocolo Teste de Integração Sensorial (TIS) da Posturografia Dinâmica Computadorizada (PDC) e duas escalas de autopercepção do equilíbrio: ABC (Activities-specific Balance Confidence) e DHI (Dizziness Handicap Inventory). RESULTADOS: Apenas o GE apresentou melhora estatisticamente significante em C5 (p = 0,007) e C6 (p = 0,01) da PDC após treinamento. Na escala ABC houve diferença significante no GE (p = 0,04). No DHI ocorreu diferença significante no aspecto físico em ambos os grupos e no aspecto funcional (p= 0,04) apenas no GE. CONCLUSÃO: O estímulo de substituição sensorial do Vertiguard(tm) auxiliou a integração das redes neurais e na manutenção da postura, melhorando as estratégias utilizadas na recuperação do equilíbrio corporal.

Eye Movements as Indicators of Vestibular Dysfunction.

Virtual reality technologies are in wide use in sport psychology. An advantage of this kind of technology is the possibility to assess sportspeople's readiness to perform complex movements. This study is aimed at developing a method for the evaluation of vestibular function disturbances in young skaters. Such disturbances may occur while skaters are performing rotation movements. To achieve this goal, we induced a vection illusion, accompanied by virtual environment rotation in a CAVE virtual reality system. Vestibular disturbances were tested for two groups-professional skaters and people who had very little or no skating experience. The quantitative evaluation of vestibular dysfunction was based on eye movement characteristics, which were recorded in subjects experiencing a vection illusion.

Effects of vibrotactile vestibular substitution on vestibular rehabilitation - preliminary study.

INTRODUCTION: Some patients with severe impairment of body balance do not obtain adequate improvement from vestibular rehabilitation (VR). OBJECTIVE: To evaluate the effectiveness of Vertiguard™ biofeedback equipment as a sensory substitution (SS) of the vestibular system in patients who did not obtain sufficient improvement from VR. METHODS: This was a randomized prospective clinical study. Thirteen patients without satisfactory response to conventional VR were randomized into a study group (SG), which received the vibrotactile stimulus from Vertiguard™ for ten days, and a control group (CG), which used equipment without the stimulus. For pre- and post-treatment assessment, the Sensory Organization Test (SOT) protocol of the Computerized Dynamic Posturography (CDP) and two scales of balance self-perception, Activities-specific Balance Confidence (ABC) and Dizziness Handicap Inventory (DHI), were used. RESULTS: After treatment, only the SG showed statistically significant improvement in C5 (p=0.007) and C6 (p=0.01). On the ABC scale, there was a significant difference in the SG (p=0.04). The DHI showed a significant difference in CG and SG with regard to the physical aspect, and only in the SG for the functional aspect (p=0.04). CONCLUSION: The present findings show that sensory substitution using the vibrotactile stimulus of the Vertiguard™ system helped with the integration of neural networks involved in maintaining posture, improving the strategies used in the recovery of body balance.

Peripheral vestibular loss detected in pediatric patients using a smartphone-based test of the subjective visual vertical.

INTRODUCTION: Detection of peripheral vestibular loss (PVL) in children with dizziness is an important and challenging task. The static subjective visual vertical (SVV) test can effectively detect PVL, but requires specialized equipment. OBJECTIVE: The goal of this study was to determine the efficacy of a smartphone-based SVV test at detecting PVL in pediatric patients. METHODS: Thirty-nine patients between 7 and 18 years old (mean=14.0±2.70) underwent conventional SVV (conv-SVV) and smartphone-based SVV (ip-SVV) testing. Subjects included 6 with PVL (based on clinical history and other vestibular tests), 6 with benign paroxysmal positioning vertigo (BPPV), 11 with central causes of vertigo (CV), 8 with non-vestibular dizziness (NVD), and 8 controls. RESULTS: Mean ip-SVV score in the PVL group (2.77±1.45) was significantly higher than in each of the other groups (BPPV=0.89±0.55; CV=1.08±0.68; NVD=1.45±1.19; Control=1.08±0.73; one-way analysis of variance, p=0.008), and remained significant after adjusting for age and gender by multiple linear regression analysis. Receiver operating characteristic analysis predicted an optimal ip-SVV cut-off score of >2.13° with a sensitivity of 66.7%, specificity of 97.0%, positive predictive value (PPV) of 80%, and negative predictive value of 94.1% for detecting PVL. Sensitivity and PPV improved to 75% and 100%, respectively, when subjects tested >1 month after symptom onset (n=24) were excluded. CONCLUSION: Smartphone-based SVV testing is a simple and useful office-based method for detecting PVL in children with dizziness.

The D+R Balance application: a novel method of assessing postural sway.

BACKGROUND: Postural sway can be assessed clinically using the Romberg test, or quantified using dynamic posturography. We assessed the potential use of a novel iPhone application as a method of quantifying sway. METHODS: Fifty healthy volunteers performed the Romberg and tandem Romberg tests on a hard floor and on foam in soundproofed and normal clinic rooms. Postural sway was recorded using the D+R Balance application and data were compared using paired t-tests. RESULTS: Significantly more postural sway was noted in participants when standing with their eyes closed and feet in the 'tandem' position vs feet together; standing with their eyes closed on foam vs on the floor; and standing with their eyes closed on foam with feet in the tandem position vs on the floor with feet together. CONCLUSION: This feasibility study suggests that the iPhone D+R Balance application deserves further investigation as a means of assessing postural sway and may provide an alternative to current dynamic posturography systems.

Automated Romberg testing in patients with benign paroxysmal positional vertigo and healthy subjects.

OBJECTIVE: Benign paroxysmal positional vertigo (BPPV) is the most common cause of dizziness. The underlying pathomechanism responsible for the recurrent vertigo attacks has been elucidated in detail and highly effective treatment strategies (liberation maneuvers) have been developed. However, many BPPV patients complain about problems of balance especially following liberation maneuvers. AIM: To objectively demonstrate differences in balance performance in BPPV patients compared to healthy subjects both prior and after BPPV liberation maneuvers. METHODS: Seven patients with BPPV of the posterior semicircular canal and nine healthy subjects participated. To assess balance while standing, we analyzed the location and temporal stability of the center of pressure recorded by pressure-sensitive electronic soles during Romberg testing (on stable ground and on foam) and tandem stand. To assess regularity of gait, we analyzed the step frequency during walking of 50 m. All tests were performed prior and after liberation maneuvers in both groups. RESULTS: Healthy subjects and patients differ significantly in their balance performance and use different stabilization strategies both prior and after liberation maneuvers. Both Romberg tests indicated poorer balance in BPPV patients (mean COP shifted towards toes), especially in posttreatment tests, while tandem stand appeared unaltered. We did not observe differences in escorted (by an experimenter) walking regularities between patients and healthy subjects and between pre- and post-maneuver testing. CONCLUSION AND SIGNIFICANCE: Our findings confirm the typical clinical observation of a further posttreatment deterioration of already impaired postural performance in BPPV patients. While the etiology and the time course of this peculiar problem warrants further studies, the treating physician should be familiar with this transient side effect of therapeutic maneuvers to provide adequate counseling of patients. Finally, we successully demonstrated the pressure-sensitive electronic soles as a new and potentially useful tool for both clinical and research purposes.