Construct validity and reliability of the Bilateral Vestibulopathy Questionnaire (BVQ).

Background: The Bilateral Vestibulopathy Questionnaire (BVQ) is a recently developed 54-item Patient Reported Outcome Measure (PROM) that evaluates the clinically important symptoms of bilateral vestibulopathy (BVP) and its impact on daily life. This study aimed to assess the construct validity and reliability of the BVQ in a large BVP cohort. Methods: Patients diagnosed with BVP were asked to complete a set of questionnaires, including the BVQ, the EuroQol-5D-5L, the Health Utilities Index, the Dizziness Handicap Inventory, the Hospital Anxiety and Depression Scale, and the Oscillopsia Severity Questionnaire. The construct validity of the BVQ was evaluated by confirmatory and exploratory factor analyses (CFA and EFA), followed by hypotheses testing and known groups validity. Structural properties were explored for each individual item. Reliability was assessed by testing the internal consistency of the BVQ constructs (Cronbach's alpha) and test-retest reliability [intraclass correlation coefficients (ICCs)]. Results: A total of 148 patients with BVP (50% women, mean age 66 years) completed the set of questionnaires. The CFA did not show a satisfactory model in the original BVQ. However, the EFA showed a four-factor solution with 20 Likert-scale items related to oscillopsia, imbalance, emotion, and cognition. The succeeding CFA provided evidence for construct validity and an acceptable model of fit. Hypothesis testing confirmed that this shortened version validly measures the constructs to be measured. Statistically significant differences in scores between known groups were found, providing further support for good construct validity. The structural properties were acceptable. Cronbach's alpha confirmed good internal consistency for the four constructs, ranging from 0.80 to 0.89. The ICCs of the 20 Likert-scale items and four visual analog scale (VAS) items were interpreted as good (range 0.76-0.93). Conclusion: This study showed evidence of good construct validity of the new shortened version of the BVQ, consisting of four constructs with a total of 20 Likert-scale items and four VAS items. The final 24-item BVQ proved to be a reliable and valid multi-item PROM that captures the clinically important symptoms of BVP and evaluates its impact on daily life. Consequently, the BVQ enables the gathering of high-level evidence of treatment effectiveness in a systematic and quantitative manner.

Chronic symptoms in patients with unilateral vestibular hypofunction: systematic review and meta-analysis.

Objective: To systematically evaluate the full spectrum of self-reported chronic symptoms in patients with unilateral vestibular hypofunction (UVH) and to investigate the effect of interventions on these symptoms. Methods: A systematic review was conducted following the guidelines of the Preferred Reporting Items for Systematic Review and Meta-Analysis Statement (PRISMA). A literature search was performed in Pubmed, Web of Science, Embase, and Scopus to investigate self-reported symptoms and self-report questionnaires in patients with UVH. All original studies ranging from full-text clinical trials to case reports, written in English, German, and French, were included. The frequency of self-reported symptoms was presented. For self-report questionnaires, a meta-analysis was carried out to synthesize scale means by the pre- and post-intervention means and mean changes for studies that investigated interventions. Results: A total of 2,110 studies were retrieved. Forty-seven studies were included after title-abstract selection and full-text selection by two independent reviewers. The symptoms of UVH patients included chronic dizziness (98%), imbalance (81%), symptoms worsened by head movements (75%), visually induced dizziness (61%), symptoms worsened in darkness (51%), and oscillopsia (22%). Additionally, UVH could be accompanied by recurrent vertigo (77%), tiredness (68%), cognitive symptoms (58%), and autonomic symptoms (46%). Regarding self-report questionnaires, UVH resulted on average in a moderate handicap, with an estimated mean total score on the Dizziness Handicap Inventory (DHI) and the Vertigo Symptom Scale (VSS) of 46.31 (95% CI: 41.17-51.44) and 15.50 (95% CI: 12.59-18.41), respectively. In studies that investigated the effect of vestibular intervention, a significant decrease in the estimated mean total DHI scores from 51.79 (95% CI: 46.61-56.97) (pre-intervention) to 27.39 (95% CI: 23.16-31.62) (post intervention) was found (p < 0.0001). In three studies, the estimated mean total Visual Analog Scale (VAS) scores were 7.05 (95% CI, 5.64-8.46) (pre-intervention) and 2.56 (95% CI, 1.15-3.97) (post-intervention). Finally, a subgroup of patients (≥32%) persists with at least a moderate handicap, despite vestibular rehabilitation. Conclusion: A spectrum of symptoms is associated with UVH, of which chronic dizziness and imbalance are most frequently reported. However, semi-structured interviews should be conducted to define the whole spectrum of UVH symptoms more precisely, in order to establish a validated patient-reported outcome measure (PROM) for UVH patients. Furthermore, vestibular interventions can significantly decrease self-reported handicap, although this is insufficient for a subgroup of patients. It could therefore be considered for this subgroup of patients to explore new intervention strategies like vibrotactile feedback or the vestibular implant. Systematic review registration: [https://www.crd.york.ac.uk/prospero/], identifier [CRD42023389185].

Assessing balance in people with bilateral vestibulopathy using the Mini-Balance Evaluation Systems Test (Mini-BESTest): feasibility and comparison with healthy control data.

OBJECTIVES: Bilateral vestibulopathy (BVP) leads to unsteadiness when walking, which worsens in darkness or on uneven ground, as well as falls. Since simple balance tests struggle to distinguish between BVP and healthy participants, we aimed (1) to test if the Mini-BESTest is feasible in BVP, (2) how people with BVP perform on the Mini-BESTest and (3) to compare these scores with healthy reference data. METHODS: Fifty participants with BVP completed the Mini-BESTest. 12-month falls incidence was obtained by questionnaire. To compare the overall and sub-scores between our participants with BVP and those of healthy participants from the literature (n = 327; obtained via PubMed searches), Mann-Whitney U tests were used. Sub scores within the BVP group were also compared. Spearman correlations were used to investigate the relationships between Mini-BESTest score and age. RESULTS: No floor or ceiling effects were observed. Participants with BVP had significantly lower Mini-BESTest total scores than the healthy group. Anticipatory, reactive postural control and sensory orientation sub scores of the Mini-BESTest were significantly lower in BVP, while dynamic gait sub scores were not significantly different. A stronger negative correlation between age and Mini-BESTest total score was found in BVP than in the healthy group. Scores did not differ between patients with different falls history. CONCLUSION: The Mini-BESTest is feasible in BVP. Our results confirm the commonly reported balance deficits in BVP. The stronger negative association between age and balance in BVP might reflect the age-related decline in the remaining sensory systems with which people with BVP compensate.

Bilateral vestibulopathy: a clinical update and proposed diagnostic algorithm.

Bilateral vestibulopathy (BVP) is characterized by its heterogeneous and chronic nature with various clinical presentations and multiple etiologies. This current narrative review reflects on the main insights and developments regarding clinical presentation. In addition, it proposes a new diagnostic algorithm, and describes available and potential future therapeutic modalities.

Development and Content Validity of the Bilateral Vestibulopathy Questionnaire.

Background: To date, the burden and severity of the full spectrum of bilateral vestibulopathy (BVP) symptoms has not yet been measured in a standardized manner. Since therapeutic interventions aiming to improve BVP symptoms are emerging, the need for a new standardized assessment tool that encompasses the specific aspects of BVP arises. Therefore, the aim of this study was to develop a multi-item Patient Reported Outcome Measure (PROM) that captures the clinically important symptoms of BVP and assesses its impact on daily life. Methods: The development of the Bilateral Vestibulopathy Questionnaire (BVQ) consisted of two phases: (I) initial item generation and (II) face and content validity testing. Items were derived from a literature review and individual semi-structured interviews focusing on the full spectrum of reported BVP symptoms (I). Subsequently (IIa), individual patient interviews were conducted using "thinking aloud" and concurrent verbal probing techniques to assess the comprehensibility of the instructions, questions and response options, and the relevance, missing domains, or missing items. Interviews continued until saturation of input was reached. Finally, international experts with experience in the field of the physical, emotional, and cognitive symptoms of BVP participated in an online focus group to assess the relevance and comprehensiveness of the BVQ (IIb). Results: The BVQ consisted of two sections. The first section included 50 items scored on a six-point Likert scale arranged into seven constructs (i.e., imbalance, oscillopsia, other physical symptoms, cognitive symptoms, emotional symptoms, limitations and behavioral changes and social life). The second section consisted of four items, scored on a visual analog scale from 0 to 100, to inquire about limitations in daily life, perceived health and expectations regarding future recovery. Interviews with BVP patients [n = 8, 50% female, mean age 56 years (range 24-88 years)] and the expert meeting confirmed face and content validity of the developed BVQ. Conclusion: The BVQ, which was developed to assess the spectrum of BVP symptoms and its impact on daily life, proved to have good face and content validity. It can be used to characterize current self-reported symptoms and disability and to evaluate symptom burden before and after therapeutic interventions in future research and clinical practice.

Patterns of Vestibular Impairment in Bilateral Vestibulopathy and Its Relation to Etiology.

Objective: This study aimed to investigate (1) the patterns of vestibular impairment in bilateral vestibulopathy (BVP) and subsequently, the implications regarding patient eligibility for vestibular implantation, and (2) whether this pattern and severity of vestibular impairment is etiology dependent. Methods: A total of one hundred and seventy-three subjects from three tertiary referral centers in Europe were diagnosed with BVP according to the Bárány Society diagnostic criteria. The subjects underwent vestibular testing such as the caloric test, torsion swing test, video Head Impulse Test (vHIT) in horizontal and vertical planes, and cervical and/or ocular vestibular evoked myogenic potentials (c- and oVEMPs). The etiologies were split into idiopathic, genetic, ototoxicity, infectious, Menière's Disease, (head)trauma, auto-immune, neurodegenerative, congenital, and mixed etiology. Results: The caloric test and horizontal vHIT more often indicated horizontal semicircular canal impairment than the torsion swing test. The vHIT results showed significantly higher gains for both anterior canals compared with the horizontal and posterior canals (p < 0.001). The rates of bilaterally absent oVEMP responses were higher compared to the bilaterally absent cVEMP responses (p = 0.010). A total of fifty-four percent of the patients diagnosed with BVP without missing data met all three Bárány Society diagnostic test criteria, whereas 76% of the patients were eligible for implantation according to the vestibular implantation criteria. Regarding etiology, only horizontal vHIT results were significantly lower for trauma, neurodegenerative, and genetic disorders, whereas the horizontal vHIT results were significantly higher for Menière's Disease, infectious and idiopathic BVP. The exploration with hierarchical cluster analysis showed no significant association between etiology and patterns of vestibular impairment. Conclusion: This study showed that caloric testing and vHIT seem to be more sensitive for measuring vestibular impairment, whereas the torsion swing test is more suited for measuring residual vestibular function. In addition, no striking patterns of vestibular impairment in relation to etiology were found. Nevertheless, it was demonstrated that although the implantation criteria are stricter compared with the Bárány Society diagnostic criteria, still, 76% of patients with BVP were eligible for implantation based on the vestibular test criteria. It is advised to carefully examine every patient for their overall pattern of vestibular impairment in order to make well-informed and personalized therapeutic decisions.

Bilateral vestibulopathy decreases self-motion perception.

OBJECTIVE: Current diagnostic criteria for bilateral vestibulopathy (BV) primarily involve measurements of vestibular reflexes. Perceptual self-motion thresholds however, are not routinely measured and their clinical value in this specific population is not yet fully determined. Objectives of this study were (1) to compare perceptual self-motion thresholds between BV patients and control subjects, and (2) to explore patterns of self-motion perception performance and vestibular function in BV patients. METHODS: Thirty-seven BV patients and 34 control subjects were included in this study. Perceptual self-motion thresholds were measured in both groups using a CAREN platform (Motek Medical BV, Amsterdam, The Netherlands). Vestibular function was evaluated (only in BV patients) by the caloric test, torsion swing test, video head impulse test of all semicircular canals, and cervical- and ocular vestibular-evoked myogenic potentials. Differences in thresholds between both groups were analyzed. Hierarchical cluster analysis was performed to visualize patterns between self-motion perception and vestibular function within the group of BV patients. RESULTS: Perceptual self-motion thresholds were significantly higher in BV patients compared to control subjects, regarding nearly all rotations and translations (depending on the age group) (p ≤ 0.001). Cluster analysis showed that within the group of BV patients, higher perceptual self-motion thresholds were generally associated with lower vestibular test results (significant for yaw rotation, caloric test, torsion swing test, and video head impulse test (p ≤ 0.001)). CONCLUSION: Self-motion perception is significantly decreased in BV patients compared to control subjects regarding nearly all rotations and translations. Furthermore, decreased self-motion perception is generally associated with lower residual vestibular function in BV patients. TRIAL REGISTRATION: Trial registration number NL52768.068.15/METC.

Bilateral vestibulopathy patients' perspectives on vestibular implant treatment: a qualitative study.

OBJECTIVES: The aim of this study was to explore expectations of patients with bilateral vestibulopathy regarding vestibular implant treatment. This could advance the definition of recommendations for future core outcome sets of vestibular implantation and help to determine on which characteristics of bilateral vestibulopathy future vestibular implant research should focus. METHODS: Semi-structured interviews were conducted with 50 patients diagnosed with bilateral vestibulopathy at Maastricht UMC + . Interviews followed a semi-structured interview guide and were recorded and transcribed. Transcripts were analyzed thematically by two independent researchers. A consensus meeting took place to produce a joint interpretation for greater dimensionality and to confirm key themes. RESULTS: Overall, patient expectations centralized around three key themes: (physical) symptom reduction, functions and activities, and quality of life. These themes appeared to be interrelated. Patient expectations focused on the activity walking (in a straight line), reducing the symptom oscillopsia and being able to live the life they had before bilateral vestibulopathy developed. In general, patients indicated to be satisfied with small improvements. CONCLUSION: This study demonstrated that patient expectations regarding a vestibular implant focus on three key themes: symptom reduction, functions and activities, and quality of life. These themes closely match the functional improvements shown in recent vestibular implantation research. The results of this study provide a clear guideline from the patient perspective on which characteristics of bilateral vestibulopathy, future vestibular implant research should focus. TRIAL REGISTRATION: NL52768.068.15/METC.

DISCOHAT: An Acronym to Describe the Spectrum of Symptoms Related to Bilateral Vestibulopathy.

Objective: To assess the prevalence of each symptom listed in the acronym DISCOHAT (worsening of symptoms in Darkness and/or uneven ground, Imbalance, Supermarket effect, Cognitive complaints, Oscillopsia, Head movements worsen symptoms, Autonomic complaints, and Tiredness) in patients with bilateral vestibulopathy (BVP), compared to patients with unilateral vestibulopathy (UVP). Methods: A descriptive case-control study was performed on BVP and UVP patients who were evaluated for their vestibular symptoms by two of the authors (RvdB, MCG) at a tertiary referral center, between 2017 and 2020. During history taking, the presence of each DISCOHAT symptom was checked and included in the electronic health record. Presence of a symptom was categorized into: "present," "not present," and "missing." Results: Sixty-six BVP patients and 144 UVP patients were included in this study. Prevalence of single DISCOHAT symptoms varied from 52 to 92% in BVP patients and 18-75% in UVP patients. Patients with BVP reported "worsening of symptoms in darkness," "imbalance," "oscillopsia," and "worsening of symptoms with fast head movements" significantly more than UVP patients (p ≤ 0.004). Conclusion: The DISCOHAT acronym is able to capture a wide spectrum of symptoms related to vestibulopathy, while it is easy and quickly to use in clinic. Application of this acronym might facilitate a more thorough and uniform assessment of bilateral vestibulopathy, within and between vestibular clinics worldwide.

The Effect of Different Head Movement Paradigms on Vestibulo-Ocular Reflex Gain and Saccadic Eye Responses in the Suppression Head Impulse Test in Healthy Adult Volunteers.

Objective: This study aimed to identify differences in vestibulo-ocular reflex gain (VOR gain) and saccadic response in the suppression head impulse paradigm (SHIMP) between predictable and less predictable head movements, in a group of healthy subjects. It was hypothesized that higher prediction could lead to a lower VOR gain, a shorter saccadic latency, and higher grouping of saccades. Methods: Sixty-two healthy subjects were tested using the video head impulse test and SHIMPs in four conditions: active and passive head movements for both inward and outward directions. VOR gain, latency of the first saccade, and the level of saccade grouping (PR-score) were compared among conditions. Inward and active head movements were considered to be more predictable than outward and passive head movements. Results: After validation, results of 57 tested subjects were analyzed. Mean VOR gain was significantly lower for inward passive compared with outward passive head impulses (p < 0.001), and it was higher for active compared with passive head impulses (both inward and outward) (p ≤ 0.024). Mean latency of the first saccade was significantly shorter for inward active compared with inward passive (p ≤ 0.001) and for inward passive compared with outward passive head impulses (p = 0.012). Mean PR-score was only significantly higher in active outward than in active inward head impulses (p = 0.004). Conclusion: For SHIMP, a higher predictability in head movements lowered gain only in passive impulses and shortened latencies of compensatory saccades overall. For active impulses, gain calculation was affected by short-latency compensatory saccades, hindering reliable comparison with gains of passive impulses. Predictability did not substantially influence grouping of compensatory saccades.