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The suppression head impulse test paradigm (SHIMP) is a newly described indicator of vestibular function which yields two measures: vestibulo-ocular reflex (VOR) gain and a saccadic response. It is an alternative and complementary test to the head impulse test paradigm (HIMP). Parkinson's disease (PD) has known saccadic and central vestibular pathway dysfunction. This paper is the first description of SHIMP VOR gain and saccade characteristic in this population. This prospective observational study measured the SHIMP VOR gain and saccade characteristics in 39 participants with idiopathic PD and compared this to 40 healthy controls (HC). The effect of group, demographic variables and SHIMP characteristics were evaluated. SHIMP VOR gains were not significantly different between groups (p = 0.10). Compared to HC, the PD group mean SHIMP peak saccade velocity was significantly reduced by an average of 77.07°/sec (p < 0.001), and SHIMP saccade response latency was longer, with an average delay of 23.5 ms (p = 0.003). SHIMP saccade peak velocity was also associated with both head impulse velocity (p = 0.002) and SHIMP VOR gain (p = 0.004) variables, but there was no significant influence of these variables when SHIMP saccade peak velocity was considered as a predictor of PD (p = 0.52-0.91). VOR gains were unaffected by PD. PD-specific saccadic dysfunction, namely reduced peak saccade velocities and prolonged response latencies, were observed in the SHIMP-induced saccade responses. VOR gain using slow phase eye velocity is preferred as the indicator of vestibular function in the SHIMPs paradigm as non-vestibular factors affected saccade peak velocity.
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Doença de Parkinson , Vestíbulo do Labirinto , Teste do Impulso da Cabeça , Humanos , Doença de Parkinson/complicações , Reflexo Vestíbulo-Ocular , Movimentos SacádicosRESUMO
OBJECTIVE: To evaluate the effect of artifacts on the impulse and response recordings with the video head impulse test (VHIT) and determine how many stimuli are necessary for obtaining acceptably efficient measurements. METHODS: One hundred fifty patients were examined using VHIT and their registries searched for artifacts. We compared several variations of the dataset. The first variation used only samples without artifacts, the second used all samples (with and without artifacts), and the rest used only samples with each type of artifact. We calculated the relative efficiency (RE) of evaluating an increasingly large number of samples (3 to 19 per side) when compared with the complete sample (20 impulses per side). RESULTS: Overshoot was associated with significantly higher speed (p = 0.005), higher duration (p < 0.001) and lower amplitude of the impulses (p = 0.002), and consequent higher saccades' latency (p = 0.035) and lower amplitude (p = 0.025). Loss of track was associated with lower gain (p = 0.035). Blink was associated with a higher number of saccades (p < 0.001), and wrong way was associated with lower saccade latency (p = 0.012). The coefficient of quartile deviation escalated as the number of artifacts of any type rose, indicating an increment of variability. Overshoot increased the probability of the impulse to lay on the outlier range for gain and peak speed. Blink did so for the number of saccades, and wrong way for the saccade amplitude and speed. RE reached a tolerable level of 1.1 at 7 to 10 impulses for all measurements except the PR score. CONCLUSIONS: Our results suggest the necessity of removing artifacts after collecting VHIT samples to improve the accuracy and precision of results. Ten impulses are sufficient for achieving acceptable RE for all measurements except the PR score.
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Artefatos , Teste do Impulso da Cabeça , Humanos , Reflexo Vestíbulo-Ocular , Movimentos SacádicosRESUMO
OBJECTIVES: Oscillopsia is a disabling condition for patients with bilateral vestibular hypofunction (BVH). When the vestibulo-ocular reflex is bilaterally impaired, its ability to compensate for rapid head movements must be supported by refixation saccades. The objective of this study is to assess the relationship between saccadic strategies and perceived oscillopsia. DESIGN: To avoid the possibility of bias due to remaining vestibular function, we classified patients into two groups according to their gain values in the video head impulse test. One group comprised patients with extremely low gain (0.2 or below) in both sides, and a control group contained BVH patients with gain between 0.2 and 0.6 bilaterally. Binary logistic regression (BLR) was used to determine the variables predicting oscillopsia. RESULTS: Twenty-nine patients were assigned to the extremely low gain group and 23 to the control group. The BLR model revealed the PR score (saccades synchrony measurement) to be the best predictor of oscillopsia. Receiver operating characteristic analysis determined that the most efficient cutoff point for the probabilities saved with the BLR was 0.518, yielding a sensitivity of 86.6% and specificity of 84.2%. CONCLUSIONS: BVH patients with higher PR values (nonsynchronized saccades) were more prone to oscillopsia independent of their gain values. We suggest that the PR score can be considered a useful measurement of compensation.
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Movimentos Sacádicos , Vestíbulo do Labirinto , Teste do Impulso da Cabeça , Humanos , Reflexo Vestíbulo-Ocular , Transtornos da VisãoRESUMO
BACKGROUND: Classical posturography techniques have been recently enhanced by the use of different motion tracking devices, but for technical reasons they are not used to track directly the body spatial position of a subject. OBJECTIVE: To describe and clinically evaluate a wireless inertial measurement unit-based mobile system to track body position changes. METHODS: The developed system used a calculus transformation method using the acceleration data corrected by Kalman and Butterworth filters to output position data. A prospective non-randomized clinical study involving 15 healthy subjects was performed to evaluate the agreement between the confidence ellipse areas synchronously measured by the new developed system and a classical posturography system while performing a modified clinical test of sensory interaction in balance. RESULTS: The overall intra-class correlation index was 0.93 (CI 0.89, 0.96). Grouped by conditions, under conditions 1-4, Pearson's correlation was 0.604, 0.78, 0.882, and 0.81, respectively. CONCLUSION: The developed wireless inertial measurement unit-based posturography system was valid for tracking the sway variances in normal subjects under habitual clinical testing conditions. Further studies are needed to validate this system on patients and also under other posture conditions.
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Actigrafia , Movimento , Equilíbrio Postural , Postura , Aceleração , Acelerometria/instrumentação , Acelerometria/métodos , Actigrafia/instrumentação , Actigrafia/métodos , Adulto , Feminino , Humanos , Masculino , Teste de Materiais , Estudos Prospectivos , Tecnologia sem FioRESUMO
PURPOSE: Computerized posturography is the gold standard for balance assessment. Because of the great cost and dimensions of commercial equipments, low-cost and portable devices have been developed and validated, such as RombergLab, a software in open source term which works connected with a low-cost force platform. The objective of this study was to obtain normative posturography data using this software. METHODS: A multicentric prospective and descriptive study, with 350 healthy participants, was designed. Static postural stability (measured using the modified clinical test of sensory interaction on balance) was evaluated using the software connected to the force platform. Using the confidence ellipse area (CEA) in each condition, global equilibrium score (GES) was calculated and adjusted for significant variable factors using cluster analysis. RESULTS: Mean (SD) GES was 0.72 (0.22). Age (p < 0.01), height (p < 0.01) and recruitment center (p < 0.05) were found as influence factors for GES. Cluster analysis obtained 16 groups stratified by age and height. GES decreases with age and height (p < 0.005). No significant interaction of age nor height was found with GES in these clusters (p > 0.05). After correction for height and age, GES was no longer influenced by the recruitment center (p > 0.05). CONCLUSIONS: With the introduction of the global equilibrium score values of the present study into the software, we consider RombergLab v1.3 a reference posturography tool for healthy individuals. Further studies are needed for validating it as a suitable instrumented test for screening between healthy and pathologic subjects and its reliability over time for the follow-up of patients.
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Diagnóstico por Computador/métodos , Técnicas de Diagnóstico Neurológico , Equilíbrio Postural/fisiologia , Software , Adolescente , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Valores de Referência , Reprodutibilidade dos Testes , Adulto JovemRESUMO
OBJECTIVES: To evaluate the ability of saccadic strategies developed during vestibular compensation to reduce the effect of an impaired vestibulo-ocular reflex (VOR) on a retinal smear and image motion sensation. DESIGN: Twenty patients with unilateral vestibular loss were examined with a video head impulse test before and after vestibular rehabilitation (VR) with the use of gaze stabilization and refixation saccades training. Head and eye velocity functions were processed to infer the retinal eccentricity, and through its correlation with visual acuity (VA), several measurements are proposed to evaluate the influence of VR on saccades behavior and visual performance. To isolate the effect of saccades on the findings and avoid bias because of gain differences, only patients whose VOR gain values remained unchanged after VR were included. RESULTS: Improved contribution of covert saccades and reduction of overt saccades latency were measured after VR. We found significant differences when assessing both the interval less than 70% VA (50.25 ms), which is considered the limit of a moderate low vision, and less than 50% VA (39.515 ms), which is the limit for severe low vision. Time to recover a VA of 75% (near normal) was reduced in all the patients (median: 56.472 ms). CONCLUSION: Despite the absence of VOR gain improvement, patients with unilateral vestibular loss are able to develop saccadic strategies that allow the shortening of the interval of retinal smear and image motion. The proposed measurements might be of use to evaluate VR outcomes and visually induced impairment.
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Movimentos Sacádicos , Doenças Vestibulares/reabilitação , Acuidade Visual , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Teste do Impulso da Cabeça , Humanos , Masculino , Pessoa de Meia-Idade , Movimento (Física) , Estudos Prospectivos , Acompanhamento Ocular Uniforme/fisiologia , Reflexo Vestíbulo-Ocular , Retina/fisiologia , Doenças Vestibulares/patologia , Doenças Vestibulares/fisiopatologiaRESUMO
To explore the applicability of discrete wavelet transforms in the analysis of vHIT responses. Discrete wavelet transform was applied to vHIT responses and a new method for calculating aVOR gain was developed. A prospective study was performed with two groups of normal (N = 10) and altered (N = 19) gain values; HIMP and SHIMP vHIT protocols were performed on both groups. To evaluate the gain values obtained, Intraclass Correlation Index, Pearson's correlation, linear regression, and t test were performed. Intraclass correlation indexes of 0.97 and 0.99 were determined for HIMP and SHIMP procedures performed on the proposed and standard gain calculation method. A significant difference of - 0.06 ± 0.07 (p < 0.001) was found between gain calculation methods for HIMP protocol. Significant differences were found (p < 0.001) between normal and altered groups for all gain calculation methods. Discrete wavelet transforms were successfully applied to measure head impulse test responses. Gain values obtained with this method appear to be valid and in concordance with gain values obtained with standard calculation method. However, a slight but significant difference was observed when this method was applied to tests obtained with HIMP.
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Teste do Impulso da Cabeça/métodos , Reflexo Vestíbulo-Ocular/fisiologia , Análise de Ondaletas , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Reprodutibilidade dos Testes , Movimentos Sacádicos/fisiologiaRESUMO
OBJECTIVE: To investigate the association between hearing function, as approached with the functional auditory capacity, and multimorbidity. STUDY DESIGN: Cross-sectional study. SETTING: The UK Biobank was established from 2006 to 2010 in the United Kingdom. This cross-sectional analysis included 165,524 participants who provided baseline information on hearing function. METHODS: Functional auditory capacity was measured with a digit triplet test. Three categories were defined according to the speech reception threshold in noise (SRTn): normal (SRTn < -5.5 dB signal-to-noise ratio [SNR]), insufficient (SRTn ≥ -5.5 to ≤ -3.5 dB SNR) and poor hearing function (SRTn > -3.5 dB SNR). To define multimorbidity, 9 chronic diseases were considered, including chronic obstructive pulmonary disease, dementia, Parkinson's disease, stroke, cancer, depression, osteoarthritis, coronary heart disease, and diabetes; multimorbidity was defined as the coexistence of 2 or more in the same individual. Analyses were conducted using logistic models adjusted for relevant confounders. RESULTS: Among the study participants, 54.5% were women, and the mean (range) age was 56.7 (39-72) years. The prevalence of insufficient and poor hearing function and multimorbidity was 13% and 13.2%, respectively. In comparison with having a normal SRTn, the odds ratio (95% confidence interval) of multimorbidity associated with insufficient SRTn was 1.13 (1.08-1.18), and with poor SRTn was 1.25 (1.14-1.37). CONCLUSION: Insufficient and poor hearing function was associated with multimorbidity. This association suggests common biological pathways for many of the considered morbidities.
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Bancos de Espécimes Biológicos , Percepção da Fala , Humanos , Feminino , Pessoa de Meia-Idade , Idoso , Masculino , Estudos Transversais , Multimorbidade , Fala , Biobanco do Reino Unido , Audição , Limiar AuditivoRESUMO
OBJECTIVE: To examine the association between hearing function, assessed with pure-tone average (PTA) of air conduction thresholds, and 24-hour ambulatory blood pressure (BP) in older adults. STUDY DESIGN: Cross-sectional study. SETTING: A total of 1404 community-dwelling individuals aged ≥65 years from the Seniors-ENRICA cohort were examined. METHODS: Hearing loss was defined as PTA > 40-AudCal hearing loss decibels (dB-aHL) in the better ear for standard frequency (0.5, 1, and 2 kHz), speech frequency (0.5, 1, 2, and 4 kHz), and high frequency (3, 4, and 8 kHz). Circadian BP patterns were calculated as the percentage decline in systolic BP during the night, and participants were classified as dipper, nondipper, and riser. Ambulatory hypertension was defined as BP ≥ 130/80 mm Hg (24 hour), ≥135/85 (daytime), and ≥120/70 (nighttime) or on antihypertensive treatment. Analyses were performed with linear- and logistic-regression models adjusted for the main confounders. RESULTS: In multivariable analyses, the PTA was associated with higher nighttime systolic BP [ß coefficient per 20 dB-aHL increment standard frequency (95% confidence interval, CI): 2.41 mm Hg (0.87, 3.95); ß (95% CI) per 20 dB-aHL increment speech frequency 2.17 mm Hg (0.70, 3.64)]. Among hypertensive patients, hearing loss at standard and high-frequency PTA was associated with the riser BP pattern [odds ratio: 2.01 (95% CI, 1.03-3.93) and 1.45 (1.00-2.09), respectively]; also, hearing loss at standard PTA was linked to uncontrolled nighttime BP [1.81 (1.01-3.24)]. CONCLUSION: PTA was associated with higher nighttime BP, and hearing loss with a riser BP pattern and uncontrolled BP in older hypertensives.
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Monitorização Ambulatorial da Pressão Arterial , Perda Auditiva , Hipertensão , Humanos , Idoso , Masculino , Feminino , Estudos Transversais , Hipertensão/fisiopatologia , Perda Auditiva/fisiopatologia , Audiometria de Tons Puros , Ritmo Circadiano/fisiologia , Pressão Sanguínea/fisiologia , Idoso de 80 Anos ou maisRESUMO
INTRODUCTION: Vestibular schwannoma (VS) is the most common tumour of the cerebellopontine angle. The greater accessibility to radiological tests has increased its diagnosis. Taking into account the characteristics of the tumour, the symptoms and the age of the patient, three therapeutic strategies have been proposed: observation, surgery or radiotherapy. Choosing the most appropriate for each patient is a frequent source of controversy. MATERIAL AND METHODS: This paper includes an exhaustive literature review of issues related to VS that can serve as a clinical guide in the management of patients with these lesions. The presentation has been oriented in the form of questions that the clinician usually asks himself and the answers have been written and/or reviewed by a panel of national and international experts consulted by the Otology Commission of the SEORL-CCC. RESULTS: A list has been compiled containing the 13 most controversial thematic blocks on the management of VS in the form of 50 questions, and answers to all of them have been sought through a systematic literature review (articles published on PubMed and Cochrane Library between 1992 and 2023 related to each thematic area). Thirty-three experts, led by the Otology Committee of SEORL-CCC, have analyzed and discussed all the answers. In Annex 1, 14 additional questions divided into 4 thematic areas can be found. CONCLUSIONS: This clinical practice guideline on the management of VS offers agreed answers to the most common questions that are asked about this tumour. The absence of sufficient prospective studies means that the levels of evidence on the subject are generally medium or low. This fact increases the interest of this type of clinical practice guidelines prepared by experts.
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Neuroma Acústico , Neuroma Acústico/terapia , Neuroma Acústico/diagnóstico , Neuroma Acústico/diagnóstico por imagem , Humanos , Conduta ExpectanteRESUMO
OBJECTIVE: To develop a new method to quantify visually-enhanced vestibulo-ocular reflex (VVOR) gain, in patients with vestibular function loss, that is mathematically suitable given the nature of the test, and determine the reliability of the method by comparing results with those of the gold standard, the video head impulse test (vHIT). MATERIALS AND METHODS: We developed a new method for VVOR gain quantification and conducted a cross-sectional study in patients diagnosed with vestibular function loss and controls, all participants undergoing both a VVOR test and a vHIT. We measured VVOR gain with three different methods: area under the curve (AUC), slope regression, and a Fourier method (VVORAUC , VVORSP , and VVORFR , respectively); and compared these gain values with vHIT gain calculated using the AUC method. RESULTS: Overall, 111 patients were included: 29 healthy subjects and 82 patients with vestibular function loss. Intraclass correlation coefficients (ICC(1,1)) between gain from the gold standard and each of the VVOR gain methods were: 0.68 (CI: 0.61-0.75) for VVORAUC , 0.66 (CI: 0.58-0.73) for VVORSP and 0.71 (CI: 0.64-0.77) for VVORFR . No interference was found between VVOR gain calculation methods and potentially influential variables considered (p ≥ 0.98). CONCLUSION: The new method for quantifying VVOR gain showed good concordance with the vHIT method. LEVEL OF EVIDENCE: 2: Individual cross-sectional studies with consistently applied reference standard and blinding (Diagnosis) Laryngoscope, 133:3554-3563, 2023.
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Reflexo Vestíbulo-Ocular , Vestíbulo do Labirinto , Humanos , Estudos Transversais , Reprodutibilidade dos Testes , Teste do Impulso da Cabeça/métodosRESUMO
OBJECTIVE: The objectives of this study were to translate into Spanish, cross-culturally adapt and validate the TFI. MATERIALS AND METHODS: The TFI questionnaire translated into Spanish (Sp-TFI) and cross-culturally adapted following the published guidelines on cross-cultural adaptation of health questionnaires was evaluated using two indicators. Its internal consistency was assessed with Cronbach's α considering the Tinnitus Handicap Inventory (THI) as the gold standard. Further, its test-retest reliability was assessed with intraclass correlation coefficients (ICCs). ICCs were also calculated for the THI and visual analogue scales (VAS) for tinnitus tested and retested in all participants. RESULTS: The mean age of the 18 participants was 45.77 (SD: 11.87) years; 12 were female (66.67 %) and 6 were male (33.33%). Half of the participants experienced tinnitus in their left ear and half in their right. The mean pure-tone average (PTA) in the affected ear was 29.34 (SD: 8.08) dB-HL. Regarding internal consistency and reliability of the Sp-TFI respectively, Cronbach's α was 0.83 and the ICC type (2,1) was 1 (CI: 0.99-1). Among the variables studied, we found the following independent predictors had statistically significant effects on THI score: sex (pâ¯<â¯0.01), PTA (p = 0.03), overall Sp-TFI score (p = 0.02) and Sp-TFI SL, R and A subscale scores (p = 0.03, pâ¯=â¯0.03, and pâ¯<â¯0.01, respectively). CONCLUSION: Based on the internal consistency and reliability results obtained in this study, the cross-culturally adapted Spanish version of the TFI (Sp-TFI) has been validated for use in Spain. LEVEL OF EVIDENCE: 2B: Individual cohort study/low-quality randomized control studies.
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Zumbido , Humanos , Masculino , Feminino , Pessoa de Meia-Idade , Zumbido/diagnóstico , Reprodutibilidade dos Testes , Estudos de Coortes , Índice de Gravidade de Doença , Inquéritos e QuestionáriosRESUMO
Benign paroxysmal positional vertigo (BPPV) and bilateral vestibulopathy (BVL) are two completely different forms of vestibular disorder that occasionally occur in the same patient. We conducted a retrospective review searching for that coincidence in our database of the patients seen over a 15-year period and found this disorder in 23 patients, that is 0.4%. More frequently they occurred sequentially (10/23) and BPPV was diagnosed first. Simultaneous presentation occurred in 9/23 patients. It was subsequently studied, but in a prospective manner, in patients with BPPV on all of whom a video head impulse test was performed to search for bilateral vestibular loss; we found it was slightly more frequent (6/405). Both disorders were treated accordingly, and it was found that the results follow the general trend in patients with only one of those disorders.
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This paper is concerned mainly with the assumptions underpinning the actual testing procedure, measurement, and interpretation of the video head impulse test-vHIT. Other papers have reported in detail the artifacts which can interfere with obtaining accurate eye movement results, but here we focus not on artifacts, but on the basic questions about the assumptions and geometrical considerations by which vHIT works. These matters are crucial in understanding and appropriately interpreting the results obtained, especially as vHIT is now being applied to central disorders. The interpretation of the eye velocity responses relies on thorough knowledge of the factors which can affect the response-for example the orientation of the goggles on the head, the head pitch, and the contribution of vertical canals to the horizontal canal response. We highlight some of these issues and point to future developments and improvements. The paper assumes knowledge of how vHIT testing is conducted.
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OBJECTIVE: Main objectives for this study were to develop a quantification method to obtain a Perez-Rey (PR) score adapted to the VVOR test and to evaluate the correlation of the PR score obtained with quantified VVOR with the PR score of the vHIT test. METHODS: A new PR score calculation method for quantified VVOR test was developed using the MATLAB computational software based on saccadic response time latency variability between each head oscillation cycle of the VVOR test. Retrospective correlation between PR scores in VVOR and vHIT tests, performed in the same vHIT testing session for patients with vestibular neuritis and vestibular neurectomy, was performed to correlate new PR (VVOR) score with the classic PR (vHIT) score. RESULTS: Thirty patients were included: 11 post-neurectomy and 19 subacute vestibular neuritis. Pearson's correlation coefficient (R2) for the overall sample was 0.92 (pâ<â0.001) and 95% confidence interval was 0.85 -0.96. In the linear mixed-effects statistical model developed, only PRVHIT and PRVVOR scores showed statistical association in Wald X2 test (pâ=â0.008). CONCLUSION: The new developed PR score for synchronization measurement of saccadic responses in VVOR testing is a valid method that outputs synchronization values and highly correlates with PR score in vHIT test.
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Teste do Impulso da Cabeça , Neuronite Vestibular , Humanos , Teste do Impulso da Cabeça/métodos , Movimentos Sacádicos , Reflexo Vestíbulo-Ocular/fisiologia , Canais Semicirculares , Estudos RetrospectivosRESUMO
Reduced eye velocity and overt or covert compensatory saccades during horizontal head impulse testing are the signs of reduced vestibular function. However, here we report the unusual case of a patient who had enhanced eye velocity during horizontal head impulses followed by a corrective saccade. We term this saccade a "backup saccade" because it acts to compensate for the gaze position error caused by the enhanced velocity (and enhanced VOR gain) and acts to return gaze directly to the fixation target as shown by eye position records. We distinguish backup saccades from overt or covert compensatory saccades or the anticompensatory quick eye movement (ACQEM) of Heuberger et al. (1) ACQEMs are anticompensatory in that they are in the same direction as head velocity and so, act to take gaze off the target and thus require later compensatory (overt) saccades to return gaze to the target. Neither of these responses were found in this patient. The patient here was diagnosed with unilateral definite Meniere's disease (MD) on the right and had enhanced VOR (gain of 1.17) for rightward head impulses followed by backup saccades. For leftwards head impulses eye velocity and VOR gain were in the normal range (VOR gain of 0.89). As further confirmation, testing with 1.84 Hz horizontal sinusoidal head movements in the visual-vestibular (VVOR) paradigm also showed these backup saccades for rightwards head turns but normal slow phase eye velocity responses without backup saccades for leftwards had turns. This evidence shows that backup saccades can be observed in some MD patients who show enhanced eye velocity responses during vHIT and that these backup saccades act to correct for gaze position error caused by the enhanced eye velocity during the head impulse and so have a compensatory effect on gaze stabilization.
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Introduction: On video head impulse testing (vHIT) of semicircular canal function, some patients reliably show enhanced eye velocity and so VOR gains >1.0. Modeling and imaging indicate this could be due to endolymphatic hydrops. Oral glycerol reduces membranous labyrinth volume and reduces cochlear symptoms of hydrops, so we tested whether oral glycerol reduced the enhanced vHIT eye velocity. Study Design: Prospective clinical study and retrospective analysis of patient data. Methods: Patients with enhanced eye velocity during horizontal vHIT were enrolled (n = 9, 17 ears) and given orally 86% glycerol, 1.5 mL/kg of body weight, dissolved 1:1 in physiological saline. Horizontal vHIT testing was performed before glycerol intake (time 0), then at intervals of 1, 2, and 3 h after the oral glycerol intake. Control patients with enhanced eye velocity (n = 4, 6 ears) received water and were tested at the same intervals. To provide an objective index of enhanced eye velocity we used a measure of VOR gain which captures the enhanced eye velocity which is so clear on inspecting the eye velocity records. We call this measure the initial VOR gain and it is defined as: (the ratio of peak eye velocity to the value of head velocity at the time of peak eye velocity). The responses of other patients who showed enhanced eye velocity during routine clinical testing were analyzed to try to identify how the enhancement occurred. Results: We found that oral glycerol caused, on average, a significant reduction in the enhanced eye velocity response, whereas water caused no systematic change. The enhanced eye velocity during the head impulses is due in some patients to a compensatory saccade-like response during the increasing head velocity. Conclusion: The significant reduction in enhanced eye velocity during head impulse testing following oral glycerol is consistent with the hypothesis that the enhanced eye velocity in vHIT may be caused by endolymphatic hydrops.
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OBJECTIVE: To measure and analyze the clinical and epidemiological characteristics of patients and healthy controls with enhanced eye velocity responses as well as evaluate their relationship with endolymphatic hydrops related diseases. STUDY DESIGN: Cross-sectional clinical study. SETTING: Tertiary hospital. PARTICIPANTS: Three hundred sixty three participants allocated to patients (310) and healthy control (53) groups were collected on first time visit to neurotology unit. INTERVENTION: Diagnostic. MAIN OUTCOME MEASURES: Video head impulse test records, clinical diagnose, and variables and demographic data were used to get cross tables, a general linear model, diagnostic epidemiological parameters, and machine learning variable importance evaluation methods. RESULTS: All the statistical tests revealed a significant association between enhanced vestibulo-ocular reflex (VOR) and diagnostic categories (pâ<â0.001). Chi-squared residual and machine learning analyses showed Menière's disease as the main associated diagnostic category, whereas the lowest residuals and gain values were found in the control group. Enhanced VOR as a diagnostic sign of Menière's disease had a sensitivity of 42.59% and a specificity of 86.32%, with an odds ratio of 4.68 (pâ<â0.001). CONCLUSION: There is a significantly higher prevalence of enhanced VOR responses in patients with Menière's disease, central origin vertigo, otosclerosis, and vestibular migraine than in those with other neurotologic diseases and controls. Our study found that enhanced VOR are not pathognomonic of hydrops-related diseases and the diagnosis should not solely be based on these and instead take into context other clinical and examination findings.
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Teste do Impulso da Cabeça , Doença de Meniere , Estudos Transversais , Humanos , Doença de Meniere/diagnóstico , Doença de Meniere/epidemiologia , Prevalência , Reflexo Vestíbulo-OcularRESUMO
Importance: Several studies have examined the association between hearing loss (HL) and physical function, with inconsistent results. Few used pure-tone thresholds and considered possible confounders in the association. Objective: To examine the association between hearing loss and impaired lower extremity function, frailty syndrome, and disability in older adults. Design, Setting, and Participants: The Seniors-ENRICA-2 is a cohort study that was established in 2015-2017 in Spain. The present study was conducted from December 2015 to June 2017. Data were analyzed from January 2, 2021, to March 10, 2021. This cross-sectional analysis included 1644 community-dwelling individuals aged 65 years or older (range, 66-91 years) of both sexes. Participants had hearing threshold measurements and data on impaired lower extremity function, frailty syndrome, and disability. Exposures: Hearing loss defined as pure-tone average greater than 40 dB HL in the better ear for standard frequency (0.5, 1, and 2 kHz), speech frequency (0.5, 1, 2, and 4 kHz), and high frequency (3, 4, and 8 kHz). Main Outcomes and Measures: Impaired lower extremity function was defined with the Short Physical Performance Battery; the frailty syndrome was defined as having at least 3 of the 5 criteria, including weakness, slow walking speed, low physical activity, exhaustion, and weight loss; and disability in instrumental activities of daily living (IADL) was evaluated with the Lawton and Brody scale. Results: Of the 1644 participants, 831 were men (50.5%); mean (SD) age was 73.8 (4.3) years. The prevalence of moderate HL was 13.6% at speech frequency. After adjustment for age, sex, lifestyle, comorbidities, impaired cognition, and social isolation, HL in standard frequency was associated with impaired lower extremity function, with an odds ratio (OR) of 2.20 (95% CI, 1.25-3.88); the corresponding estimate for the frailty syndrome was 1.85 (95% CI, 0.98-3.49) and for the IADL disability, was 2.25 (95% CI, 1.29-3.94). When considering speech frequency pure-tone average, HL was also associated with impaired function (OR, 2.59; 95% CI, 1.57-4.28), frailty syndrome (OR, 1.85; 95% CI, 1.06-3.22), and IADL disability (OR, 2.18; 95% CI, 1.32-3.60). Conclusions and Relevance: In this cross-sectional analysis of data from the Seniors-ENRICA-2 cohort study, hearing loss was associated with impaired lower extremity function, frailty syndrome, and IADL disability. It may be useful to examine this association with the mechanisms elucidated in further studies.
Assuntos
Atividades Cotidianas , Idoso Fragilizado , Fragilidade/complicações , Avaliação Geriátrica , Perda Auditiva/complicações , Extremidade Inferior/fisiopatologia , Idoso , Idoso de 80 Anos ou mais , Estudos Transversais , Avaliação da Deficiência , Feminino , Fragilidade/diagnóstico , Fragilidade/fisiopatologia , Perda Auditiva/diagnóstico , Perda Auditiva/fisiopatologia , Testes Auditivos , Humanos , Vida Independente , Modelos Logísticos , Masculino , SíndromeRESUMO
Hypothesis: Build a biologic geometry based computational model to test the hypothesis that, in some circumstances, endolymphatic hydrops can mechanically cause enhanced eye velocity responses during clinical conditions of the head impulse test. Background: Some recent clinical and experimental findings had suggested that enhanced eye velocity responses measured with the video head impulse test could not only be caused by recording artifacts or central disfunction but also could be directly caused by the mechanical effect of endolymphatic hydrops on horizontal semicircular canal receptor. Methods: Data from clinical video head impulse test was computed in three biologic-based geometry models governed by Navier-Stokes equations; six head impulses of incrementally increasing peak head velocity were computed in each one of the three different geometric models, depending on absence, canal or utricular hydrops. Results: For all computed head impulses an increased endolymphatic pressure was measured at the ampullar region of the horizontal semicircular canal on both canal and utricular hydrops models. The mean of aVOR gain was 1.01 ± 0.008 for the no-hydrops model, 1.14 ± 0.010 for the canal hydrops model was, and 1.10 ± 0.007 for the utricular hydrops model. Conclusion: The results of the physical computation models support-the hypothesis that in endolymphatic hydrops conditions, which are affecting horizontal semicircular canal and utricular region on moderate dilatations, the eye velocity responses output-by the aVOR will be enhanced by a 1.14 factor and aVOR gain values will be enhanced by over 1.1 for impulses to the right side.