Validity and Responsiveness of the Visual Vertigo Analogue Scale

Optokinetic stimulation in the rehabilitation of visually induced dizziness in people with vestibular disorders: A systematic review

OBJECTIVE

This systematic review and meta-analysis investigates the effects optokinetic stimulation in people with vestibular disorders, with a specific focus on people with visually induced dizziness.

DATA SOURCES

A systematic review was conducted using three electronic databases, CINAHL, PubMed and Physiotherapy Evidence Database (PEDro), from 2000 up to February 2024.

REVIEW METHODS

Randomised controlled trials were included, which compared: (a) adults above 18 years old with vestibular disorders, (b) the study evaluated interventions using optokinetic stimulation, (c) the intervention was compared with usual care; placebo or to no intervention, (d) the study included at least one outcome measure evaluating vestibular symptoms and (e) published in English. The methodological quality of the included studies was assessed using the PEDro scale and PROSPERO's registration number ID: CRD42021273382).

RESULTS

Eleven randomised control trials, reported in 12 records, fulfilled the inclusion criteria. All of the studies were considered to have 'good' methodological quality according to the PEDro scale. All studies showed significant improvement in vestibular symptoms in both the intervention and control groups. A meta-analysis performed on six of the records found a preference towards the addition of OKS to conventional vestibular rehabilitation helped to further reduce dizziness symptoms for patients, but the results were not statistically significant.

CONCLUSION

No optimal duration or frequency for OKS has been determined. The addition of OKS to conventional vestibular rehabilitation may be beneficial in further improving vestibular symptoms in patients with dizziness. OKS could help to improve enjoyment and adherence to vestibular rehabilitation.

Compensatory strategies after an acute unilateral vestibulopathy: a prospective observational study

PURPOSE

In case of an acute unilateral vestibulopathy (UVP), compensatory strategies such as restoration and adaptation will lead to a decrease in intensity of the symptoms. Although measurements of compensatory strategies are available, currently, an overview taking the different strategies into account is lacking. The objectives of this study are to explore compensatory strategies and to investigate the association between compensatory strategies and patient characteristics.

METHODS

Restoration was objectified by the vestibulo-ocular reflex (VOR) gain on the video head impulse test, and adaptation-consisting of visual, multisensory, and behavioral substitution-was objectified by the Visual Vertigo Analog Scale (VVAS), Antwerp Vestibular Compensation Index (AVeCI), and Perez and Rey score (PR score), respectively. Adequate restoration and adaptation levels were interpreted as follows: VOR gain > 0.80, VVAS ≤ 40%, AVeCI > 0 and PR score ≤ 55.

RESULTS

Sixty-two UVP patients, 34 men and 28 women, were included with an average age of 52.1 ± 17.3 years. At 10.5 ± 1.4 weeks after onset, 41.9% of the UVP patients reached adequate restoration levels and 58.1-86.9% reached adequate adaptation levels. Furthermore, significant associations were found between (1) restoration status and UVP etiology [Odds Ratio (OR) with 95% CI: 4.167 {1.353;12.828}] and balance performance (OR: 4.400 {1.258;15.386}), (2) visual sensory substitution status and perceived handicap (OR: 8.144 {1.644;40.395}), anxiety (OR: 10.000 {1.579;63.316}) and depression (OR: 16.667 {2.726;101.896}), and (3) behavioral substitution status and balance performance (OR: 4.143 {1.341;12.798}).

CONCLUSION

UVP patients with adequate compensatory strategies presented with better balance performance, lower perceived handicap, and lower anxiety and depression scores.

The vestibular symptomatology of Machado-Joseph Disease

BACKGROUND

Machado Joseph Disease (MJD) is an autosomal dominant neurodegenerative disease. In previous studies, we described significant bilateral horizontal Vestibulo-Ocular Reflex (VOR) deficit within this population without any reference to the presence of vestibular symptomatology.

OBJECTIVE

To evaluate whether, beyond cerebellar ataxia complaints, MJD patients have typical vestibular symptomatology corresponding to the accepted diagnostic criteria of Bilateral Vestibulopathy (BVP) according to the definition of the International Barany Society of Neuro-Otology.

METHODS

Twenty-one MJD, 12 clinically stable chronic Unilateral Vestibulopathy (UVP), 15 clinically stable chronic BVP, and 22 healthy Controls underwent the video Head Impulse Test (vHIT) evaluating VOR gain and filled out the following questionnaires related to vestibular symptomatology: The Dizziness Handicap Inventory (DHI), the Activities-specific Balance Confidence Scale (ABC), the Vertigo Visual Scale (VVS) and the Beck Anxiety Inventory (BAI).

RESULTS

The MJD group demonstrated significant bilateral vestibular impairment with horizontal gain less than 0.6 in 71% of patients (0.54±0.17). Similar to UVP and BVP, MJD patients reported a significantly higher level of symptoms than Controls in the DHI, ABC, VVS, and BAI questionnaires.

CONCLUSIONS

MJD demonstrated significant VOR impairment and clinical symptoms typical of BVP. We suggest that in a future version of the International Classification of Vestibular Disorders (ICVD), MJD should be categorized under a separate section of central vestibulopathy with the heading of bilateral vestibulopathy. The present findings are of importance regarding the clinical diagnosis process and possible treatment based on vestibular rehabilitation.

Visual vertigo in children: Adaptation and validation of the visual vertigo analogue scale to European Portuguese

BACKGROUND

Visual vertigo occurs after vestibular and non-vestibular pathology and can be present in children and adolescents. It can be assessed by "the Visual Vertigo Analogue Scale" (VVAS), a questionnaire with a Portuguese version for adults.

OBJECTIVES

To perform the adaptation to pediatric age and validation of VVAS in European Portuguese.

METHODS

This prospective study involved the pediatric adaptation of the Portuguese VVAS, according to recognized guidelines. It was then completed by 30 healthy controls and 18 children with vestibulopathy. Patient caregivers also completed the Dizziness Handicap Inventory - Patient Caregivers (DHI-PC) to further explore the link between questionnaires. Groups were compared for severity of visual vertigo and VVAS test-retest reliability was tested.

RESULTS

The VVAS score was significantly higher in vestibular group (p < 0.001). No statistically significant differences were found between VVAS initial and re-test scores (p = 0.33). VVAS severity scores showed a positive correlation with DHI-PC (r = 0.598, p = 0.009).

CONCLUSION

The present Pediatric adaptation of VVAS in European Portuguese shows good psychometric properties for the assessment of visual vertigo. A positive correlation with the DHI-PC was showed, establishing the potential use of both questionnaires in the evaluation of vertigo children.

Cross-cultural adaptation and construct validity of the Chinese Version of Visual Vertigo Analogue Scale by using structural equation modeling

BACKGROUND

Visual vertigo (VV) is a disease characterized by various visual signal-induced discomforts, including dizziness, unsteady balance, activity avoiding, and so forth. Distinguishing it from other kinds of dizziness is important because it needs the combination of visual training and vestibular rehabilitation together. However, there is no appropriate tool to diagnose VV in China, thus we would like to introduce an effective tool to China.

OBJECTIVE

The aim of this study was to establish the reliability and validity of the Chinese version of visual vertigo analogue scale (VVAS-CH) and to achieve its cross-cultural adaptation in order to promote its further usage in China.

METHODS

A total of 1681 patients complaining of vertigo or dizziness were enrolled and they were asked to complete the VVAS-CH. The cross-cultural adaptation, reliability and construct validity of the VVAS-CH were determined.

RESULTS

Split-half reliability was 0.939, showing a good reliability. Factor analysis identified only one common factor for the nine items that explained 64.83% of the total variance. Most fit indices reached acceptable levels, proving the good fit of the VVAS-CH model.

CONCLUSIONS

The VVAS-CH validated in this study can be used as an effective tool for diagnosing and evaluating VV in patients whose native language is Chinese.

A Pilot Study to Assess Visual Vertigo in People with Persistent Postural-Perceptual Dizziness with a New Computer-Based Tool

BACKGROUND

Visual vertigo (VV) is a common symptom in people with persistent postural-perceptual dizziness (PPPD). Few subjective scales are validated for assessing the intensity of VV, yet these scales are limited by recall bias, as they require individuals to rate their symptoms from memory. The computer-Visual Vertigo Analogue Scale (c-VVAS) was developed by adapting five scenarios from the original paper-VVAS (p-VVAS) into 30 s video clips. The aim of this pilot study was to develop and test a computerized video-based tool for the assessment of visual vertigo in people with PPPD.

METHODS

PPPD participants (n = 8) and age- and sex-matched controls (n = 8) completed the traditional p-VVAS and the c-VVAS. A questionnaire about their experiences using the c-VVAS was completed by all participants.

RESULTS

There was a significant difference between the c-VVAS scores from the PPPD and the control group (Mann-Whitney, p < 0.05). The correlation between the total c-VVAS scores and the total c-VVAS scores was not significant (r = 0.668, p = 0.07). The study showed a high acceptance rate of the c-VVAS by participants (mean = 91.74%).

CONCLUSION

This pilot study found that the c-VVAS can distinguish PPPD subjects from healthy controls and that it was well-received by all participants.

Decrease in head sway as a measure of sensory integration following vestibular rehabilitation: A randomized controlled trial

OBJECTIVE

The purpose of this study was to determine the extent to which sensory integration strategies via head sway, derived from a Head-Mounted Display (HMD), change in people with vestibular disorders following vestibular rehabilitation.

DESIGN

Randomized Controlled TrialSetting:Vestibular Rehabilitation ClinicParticipants:Thirty participants with vestibular dysfunction and 21 age-matched controls.

MAIN OUTCOME MEASURES

Participants experienced two levels of visual surround (static or moving 'stars', front to back at 0.2 Hz, 32 mm) and white noise (none or rhythmic) while their head sway was recorded via the HTC Vive. We quantified head sway via Directional Path (DP) and Root Mean Square Velocity (RMSV) in 5 directions: anterior-posterior, medio-lateral, pitch, yaw, and roll and Power Spectral Density in low (PSD 1), medium (PSD 2) and high (PSD 3) frequencies in the anterior-posterior direction.

INTERVENTIONS

Participants performed the assessment prior to being randomized into 8-weeks of contextual sensory integration training in virtual reality or traditional vestibular rehabilitation and once again following completion of the intervention. Controls performed the assessment once. Twelve participants dropped out, half due to covid lock-down. We applied an intention to treat analysis.

RESULTS

We observed significant increases in AP DP, RMSV and all PSDs with change in visual level. Both intervention groups significantly decreased medio-lateral, pitch and roll DP and RMSV and anterior-posterior PSD 2 with no group differences. Vestibular participants were significantly higher than controls on all outcomes pre rehabilitation. Post rehabilitation they were only significantly higher on PSD 2. Sound was not a significant predictor of head sway in this protocol.

CONCLUSIONS

Head sway decreased following vestibular rehabilitation regardless of visual load or type of intervention applied. This change was measured via head kinematics derived from a portable HMD which can serve as a sensitive in-clinic assessment for tracking improvement over time.

Categorizing individuals based on the severity of Visual Vertigo Analogue Scale symptoms

BACKGROUND

The Visual Vertigo Analogue Scale (VVAS) assesses visual vertigo. Instead of the original scoring methods (positive VVAS > 1), we propose categorizing patients as having No (0), Mild (0.1-40), Moderate (40.01-70), or Severe (70.01-100) symptoms.

OBJECTIVE

Our primary aim was to validate an alternative interpretation of the VVAS by exploring the relationship between categories of visual vertigo symptoms and measures of activity and participation, dizziness handicap, anxiety, and depression. We aimed to describe the severity of visual vertigo reported by patients in different vestibular diagnostic categories.

METHODS

Participants with vestibular disorders (n = 250) completed the VVAS, Vestibular Activities and Participation (VAP) Measure, Dizziness Handicap Inventory (DHI), and the Hospital Anxiety and Depression Scale (HADS).

RESULTS

Patients with central disorders were more symptomatic than those with peripheral vestibular disorders. As evaluated by one-way ANOVA, the scores on the VAP, HADS, and DHI significantly differed among mild, moderate, severe, and no visual vertigo categories (p < 0.001). As VVAS severity increased, activity and participation decreased (r = 0.582, p < 0.001); dizziness handicap increased (r = 0.597, p < 0.001, n = 199); anxiety increased (r = 0.405, p < 0.001); and depression increased (r = 0.521, p < 0.001).

CONCLUSIONS

The findings of this study support the use of an alternative VVAS interpretation method of categorizing symptoms as none, mild, moderate, and severe visual vertigo.

Protocol for a randomised controlled feasibility study of psychologically informed vestibular rehabilitation for people with persistent dizziness: INVEST trial

Background

Dizziness is a common complaint that often persists and leads to disability and distress. Several cognitive and behavioural responses may contribute to the neurobiological adaptations that maintain persistent vestibular symptoms. This paper will present the protocol of a two-arm parallel group feasibility randomised controlled trial designed to determine whether a fully powered efficacy trial is achievable by examining the feasibility of recruitment, acceptability and potential benefits of an integrated cognitive behavioural therapy and vestibular rehabilitation (CBT-VR) treatment for people with persistent dizziness.

Methods

Forty adult patients will be recruited from a tertiary vestibular clinic with persistent movement–triggered dizziness for 3 months or longer who have moderate–high levels of dizziness handicap. Participants will be 1:1 randomised, using a minimisation procedure, to six sessions of either CBT-VR (intervention arm) or VR only (control arm). Measures will be collected at baseline and 4 months post randomisation. The primary feasibility outcomes include descriptive data on numbers meeting eligibility criteria, rates of recruitment, numbers retained post randomisation, treatment adherence and an acceptability questionnaire. Treatment effects on self-report outcomes will be estimated to determine that 95% confidence intervals for the effects are consistent with anticipated effects and minimum clinically important differences, and to provide information needed for the power calculation of an efficacy trial. A nested qualitative study will be conducted post-intervention (intervention group only) to explore the acceptability of the intervention and identify any areas in need of improvement.

Discussion

If a trial of CBT-VR is feasible, acceptability data will be used to enhance the intervention if needed and refine the multicentre RCT protocol. Future studies will need to consider the training required for other physiotherapists to deliver the intervention.

Trial registration

ClinicalTrials.gov, ISRCTN 10420559

Supplementary Information

The online version contains supplementary material available at 10.1186/s40814-021-00896-y.

Instrumented Gait Analysis to Identify Persistent Deficits in Gait Stability in Adults With Chronic Vestibular Loss

Importance

Regaining the ability to walk safely is a high priority for adults with vestibular loss. Thus, practitioners need comprehensive knowledge of vestibulopathic gait to design, provide, and/or interpret outcomes of interventions. To date, few studies have characterized the effects of vestibular loss on gait.

Objectives

To investigate the use of an instrumented 2-minute walk test in adults with vestibular loss, to further characterize vestibulopathic gait, and to assess whether those with chronic vestibular loss have enduring gait deficits.

Design, Setting, and Participants

This cross-sectional study, conducted between April 3, 2018, and June 27, 2019, recruited adults 20 to 79 years of age from an academic, tertiary, hospital-based, ambulatory care setting who were healthy or had confirmed unilateral or bilateral vestibular hypofunction. Of the 43 adults who were screened from convenience and referred samples, 2 declined, and 7 were excluded because of health conditions.

Exposures

The main exposure was the instrumented 2-minute walk test, which was conducted with participants using wearable inertial measurement units while they walked a 10-m path at their self-selected speed and turned 180° in their self-selected direction at either end.

Main Outcomes and Measures

The primary measures were spatiotemporal gait metrics (eg, stride length [SL] and peak whole-body turning velocity). Multivariate analysis of variance was used to assess between-group differences. Validity was assessed using the area under the curve from receiver operator characteristic analyses.

Results

Data from 17 healthy adults (mean [SD] age, 39.27 [11.20] years; 13 [76%] female) and 13 adults with vestibular loss (mean [SD] age, 60.50 [10.81] years; 6 [46%] female) were analyzed. Very large between-group differences were found for SL (left) (estimated marginal mean [SE] for healthy vs vestibular groups, 1.47 [0.04] m vs 1.31 [0.04] m; Cohen d, 1.35; 95% CI, 0.18-2.52), SL (right) (estimated marginal mean [SE] for healthy vs vestibular groups, 1.46 [0.04] m vs 1.29 [0.04] m; Cohen d, 1.44; 95% CI, 0.25-2.62), and peak turn velocity (estimated marginal mean [SE] for healthy vs vestibular groups, 240.17 [12.78]°/s vs 189.74 [14.70]°/s; Cohen d, 1.23; 95% CI, 0.07-2.40). The area under the curve was 0.79 (95% CI, 0.62-0.95) for SL (left), 0.81 (95% CI, 0.64-0.97) for SL (right), and 0.86 (95% CI, 0.72-0.99) for peak turn velocity.

Conclusions and Relevance

In this cross-sectional study, instrumented gait analysis had good discriminative validity and revealed persistent deficits in gait stability in those with chronic vestibular loss. The findings of this study suggest that these clinically and functionally meaningful deficits could be targets for vestibular rehabilitation.

Validated argentine version of the visual vertigo analogue scale

BACKGROUND

Visual vertigo (VV), triggered by environmental or dynamic visual stimuli and repetitive visual patterns, can affect daily life activities. The Visual Vertigo Analogue Scale (VVAS) is a valid and reliable self-administered questionnaire to assess VV, which has been culturally adapted to the Argentine population but has not been validated.

OBJECTIVE

To validate the Argentine version of VVAS (VVAS-A) by confirming its psychometric properties in patients with vestibular disorders.

METHODS

Vestibular patients (n = 82) completed the VVAS-A and the Dizziness Handicap Inventory Argentine version (DHI-A) during their initial visit and one week later. The VVAS-A's internal consistency, test retest reliability, ceiling and floor effects, and construct validity were determined. Test-retest data (n = 71) was used to calculate reliability using the intraclass correlation coefficient (ICC 2.1).

RESULTS

A ceiling effect was observed in 12 patients (14.6%). Internal consistency was acceptable (Cronbach's alpha: 0.91). The reliability was r = 0.764 [CI 95%: 0.7 -0.86]). Correlations were observed between the VVAS-A and the total DHI-A score (rho = 0.571), the DHI-A physical subscale (rho: 0.578), and DHI-A functional and emotional subscales of the DHI-A (rho: 0.537 and 0.387, respectively).

CONCLUSION

VVAS-A is a valid, reliable tool to evaluate VV in patients with vestibular disorders.

Validity and reliability of Veloflex to measure active cervical range of motion in asymptomatic and symptomatic subjects

BACKGROUND

Neck pain has a high annual incidence and decreases the cervical active range of motion (ROM). Clinicians use various methods to evaluate cervical range of motion (CROM) that some of them have also been proposed to give instant feedback. Accordingly, this study aimed to examine the validity and reliability of Veloflex (VF) to measure the CROM by comparison with the cervical range of motion (CROM) device, and to examine their test-retest reliability.

METHODS

Thirty-eight healthy and 20 symptomatic participants were evaluated. Cervical flexion-extension, side bending, and rotations were tested in two sessions, first by the CROM and VF and in the second only with the VF. To evaluate the concurrent validity and agreement between CROM and VF, Pearson correlation coefficient (r) and Bland-Altmann plots were used. Reliability were evaluated using intra-class correlation (ICC), standard error of measurement (SEM) and minimal detectable change (MDC).

RESULTS

CROM and VF showed excellent correlation for all movements (r > 0.960). Both devices provided small mean 'bias' (≤1.29%) in all movements regarding CROM measures. The intra-rater and inter-rater reliability of the VF was excellent (ICC > 0.98). SEMs ranging from 0.72% to 2.38% and the MDC ranging from 1.22° to 2.60° in all participants. The results support the validity and reliability of VF to measure CROM. For its use, with a basic training is enough to get reliable measurements.

Validation of a next-generation sensory organization test in adults with and without vestibular dysfunction

BACKGROUND

The traditional Sensory Organization Test (T-SOT) is a gold standard balance test; however, the psychometric properties of assessing sensory organization with a virtual-reality-based posturography device have not been established.

OBJECTIVE

Our overall aims were to assess the criterion, concurrent, and convergent validity of a next-generation Sensory Organization Test (NG-SOT).

METHODS

Thirty-four adults (17 vestibular-impaired) participated. We compared the area under the curve (AUC) for receiver operator characteristic (ROC) analysis for the T-SOT and NG-SOT composite scores. Between-group and between-test differences for the composite and sensory analysis scores from each SOT were assessed using Wilcoxon Rank Sum tests. Additionally, we ran Spearman correlations between the NG-SOT composite score and outcomes of interest.

RESULTS

The AUCs for the NG-SOT and T-SOT were 0.950 (0.883, 1) and 0.990 (0.969, 1) respectively (p = 0.168). The median composite, vision, and visual preference scores were lower on the NG-SOT compared to the T-SOT; whereas, the median somatosensory score was higher on the NG-SOT compared to the T-SOT. Associations between the composite score and patient-reported or performance-based outcomes ranged from poor to strong.

CONCLUSIONS

The NG-SOT is a valid measure of balance in adults. However, the results of the NG-SOT and T-SOT should not be used interchangeably.

Impact of Treatment on Vestibular Schwannoma-Associated Symptoms: A Prospective Study Comparing Treatment Modalities

OBJECTIVE

The degree to which various treatment modalities modify vestibular schwannoma (VS)-associated symptoms has received limited attention. The purpose of this study was to determine how different treatment modalities affect subjective symptoms in those presenting with VS.

STUDY DESIGN

Prospective survey.

SETTING

Tertiary neurotology referral center.

METHODS

Patients with sporadic VS who received treatment at our institution were prospectively surveyed with a VS symptom questionnaire. Those who completed a baseline survey prior to treatment and at least 1 posttreatment survey were included. The prospective survey evaluated the severity of self-reported symptoms (Likert scale, 1-10), including tinnitus, dizziness or imbalance, headaches, and hearing loss.

RESULTS

A total of 244 patients were included (mean age, 57 years). The mean duration of follow-up was 2.1 years, and the median number of surveys completed was 2 (interquartile range, 1-3). Seventy-eight (32%) cases were managed with observation, 118 (48%) with microsurgery, and 48 (20%) with radiosurgery. Multivariable analyses revealed no statistically significant difference in the change in tinnitus (P = .15), dizziness or imbalance (P = 0.66), or headaches (P = .24) among treatment groups. Evaluation of clinically important differences demonstrated that microsurgery leads to significant bidirectional changes in headaches.

CONCLUSIONS

Limited prospective data exist regarding the progression or resolution of subjective symptoms in those presenting with VS. This study suggests that tinnitus, dizziness or imbalance, and headaches are unlikely to be significantly modified by treatment modality and generally should not be used to direct treatment choice.

Contextual sensory integration training via head mounted display for individuals with vestibular disorders: a feasibility study

Purpose: Virtual reality (VR) interventions can simulate real-world sensory environments. The purpose of this study was to test the feasibility of a novel VR application (app) developed for a Head Mounted Display (HMD) to target dizziness, imbalance and sensory integration in a functional context for patients with vestibular disorders. Here we describe the design of the app as well as self-reported and functional outcomes in vestibular patients before and after participating in vestibular rehabilitation using the app.Material and methods: Our app includes a virtual street, airport, subway or a park. The clinician controls the visual and auditory load including several levels of direction, amount and speed of virtual pedestrians. Clinicians enrolled 28 patients with central (mild-traumatic brain injury [mTBI] or vestibular migraine) and peripheral vestibular disorders. We recorded the Simulator Sickness Questionnaire, Visual Vertigo Analogue Scale (VVAS), Dizziness Handicap Inventory (DHI), Activities-Specific Balance Confidence Scale (ABC), 8-foot up and go (8FUG) and Four-Step Square Test (FSST) before and after the intervention.Results: Within the 15 patients who completed the study, 12 with peripheral hypofunction showed significant improvements on the VVAS (p = 0.02), DHI (p = 0.008) and ABC (p = 0.02) and a small significant improvement on the FSST (p = 0.015). Within-session changes in symptoms were minimal. Two patients with mTBI showed important improvements, but one patient with vestibular migraine, did not.Conclusion: HMD training within increasingly complex immersive environments appears to be a promising adjunct modality for vestibular rehabilitation. Future controlled studies are needed to establish effectiveness.IMPLICATIONS FOR REHABILITATIONVirtual Reality allows for gradual introduction of complex semi-real visual environments.Within VR training patients can re-learn to maintain balance when presented with a sensory conflict in a safe environment.Head Mounted Display training appears to be a promising adjunct modality for vestibular rehabilitation.Portability and affordability of the hardware and software enhance the potential clinical outreach.

Changes in Cortical Activation During Dual-Task Walking in Individuals With and Without Visual Vertigo

BACKGROUND AND PURPOSE

Persons with vestibular disorders are known to have slower gait speed with greater imbalance and veering during dual-task walking than healthy individuals, but the cerebral mechanisms are unknown. The purpose of this study was to determine whether individuals with visual vertigo (VV) have different cerebral activation during dual-task walking compared with control subjects.

METHODS

Fourteen individuals with VV and 14 healthy controls (CON) were included (mean 39 years old, 85% women). A cross-sectional experimental study consisting of 4 combinations of 2 surfaces (even and uneven) and 2 task conditions (single- and dual-task) was performed. Participants walked over an even (level flooring) or uneven (wood prisms underneath carpeting) surface, either quietly or while reciting every other letter of the alphabet. Changes in cerebral activation over the bilateral prefrontal cortices were recorded using functional near-infrared spectroscopy during 4 task conditions relative to quiet standing. Gait speed and cognitive performance were recorded.

RESULTS

There were no between-group differences in cognitive performance. Both groups slowed when walking on an uneven surface or performing a dual-task; participants in the VV group walked more slowly than those in the CON group in all conditions. Participants with VV had decreased cerebral activation in the bilateral prefrontal regions in comparison to CON participants in all conditions.

DISCUSSION AND CONCLUSIONS

Participants with VV had lower prefrontal cortex activation than CON participants during dual-task walking. Lower cortical activity in those with VV may be due to shifted attention away from the cognitive task to prioritize maintenance of dynamic balance.Video Abstract available for more insights from the authors (see the Video, Supplemental Digital Content 1, available at: http://links.lww.com/JNPT/A303).