Type, dose, and outcomes of physical therapy interventions for unilateral peripheral vestibular hypofunction: protocol for a systematic review.

BACKGROUND: Unilateral peripheral vestibular hypofunction can result in symptoms of dizziness, gaze and gait instability, and impaired navigation and spatial orientation. These impairments and activity limitations may negatively impact an individual's quality of life, ability to perform activities of daily living, drive, and work. There is strong evidence supporting vestibular physical therapy for reducing symptoms, improving gaze and postural stability, and improving function in individuals with vestibular hypofunction. However, there is great variability in clinical practice with regard to the type of interventions and only weak evidence to guide optimal exercise dosage. It is important to identify the most appropriate interventions and exercise dosage to optimize and accelerate recovery of function and to decrease distress. The objective of this systematic review is to determine which interventions and which doses are most effective in decreasing dizziness or vertigo, improving postural control, and improving quality of life in adults with unilateral peripheral vestibular hypofunction. METHODS: The literature will be systematically searched using the following online databases: PubMed/MEDLINE, EMBASE, Web of Science (Science and Social Science Citation Index), Cumulative Index for Nursing and Allied Health Literature (CINAHL), and The Cochrane Library (Cochrane Database of Systematic Reviews, Cochrane Central Register of Controlled Trials [CENTRAL], Cochrane Methodology Register). The review will include randomized controlled trials (RCTs), including cluster RCTs, to assess the beneficial effects of the interventions. Assessment of methodological quality and risk of bias will be performed by two independent, blinded reviewers using the PEDro scale and Cochrane Risk of Bias version 2, respectively. The primary outcome measure will be change in self-perceived handicap related to dizziness from baseline to the end of the study, measured using the Dizziness Handicap Inventory. Other relevant outcome measures will include self-reported change in symptoms (to include severity, frequency, and duration) such as verbal or visual analog scales for dizziness. Tertiary outcome measures will include questionnaires related to disability and/or quality of life. DISCUSSION: This systematic review will identify, evaluate, and integrate the evidence on the effectiveness of physical therapy interventions for unilateral peripheral vestibular hypofunction in an adult population. We anticipate our findings may inform individualized treatment and future research. Clinical recommendations generated from this systematic review may inform vestibular physical therapy treatment of individuals with unilateral peripheral vestibular hypofunction. TRIAL REGISTRATION: In accordance with the guidelines, our systematic review protocol was registered with the International Prospective Register of Systematic Reviews (PROSPERO) on 06 August 2021 (registration number CRD42021266163 ). In the event of protocol amendments, the date of each amendment will be accompanied by a description of the change and the rationale.

Differences between physical therapist ratings, self-ratings, and posturographic measures when assessing static balance exercise intensity.

Introduction: In order for balance therapy to be successful, the training must occur at the appropriate dosage. However, physical therapist (PT) visual evaluation, the current standard of care for intensity assessment, is not always effective during telerehabilitation. Alternative balance exercise intensity assessment methods have not previously been compared to expert PT evaluations. The aim of this study was therefore to assess the relationship between PT participant ratings of standing balance exercise intensity and balance participant self-ratings or quantitative posturographic measures. Methods: Ten balance participants with age or vestibular disorder-related balance concerns completed a total of 450 standing balance exercises (three trials each of 150 exercises) while wearing an inertial measurement unit on their lower back. They provided per-trial and per-exercise self-ratings of balance intensity on a scale from 1 (steady) to 5 (loss of balance). Eight PT participants reviewed video recordings and provided a total of 1,935 per-trial and 645 per-exercise balance intensity expert ratings. Results: PT ratings were of good inter-rater reliability and significantly correlated with exercise difficulty, supporting the use of this intensity scale. Per-trial and per-exercise PT ratings were significantly correlated with both self-ratings (r = 0.77-0.79) and kinematic data (r = 0.35-0.74). However, the self-ratings were significantly lower than the PT ratings (difference of 0.314-0.385). Resulting predictions from self-ratings or kinematic data agreed with PT ratings approximately 43.0-52.4% of the time, and agreement was highest for ratings of a 5. Discussion: These preliminary findings suggested that self-ratings best indicated two intensity levels (i.e., higher/lower) and sway kinematics were most reliable at intensity extremes.

Automatic ML-based vestibular gait classification: examining the effects of IMU placement and gait task selection.

BACKGROUND: Vestibular deficits can impair an individual's ability to maintain postural and/or gaze stability. Characterizing gait abnormalities among individuals affected by vestibular deficits could help identify patients at high risk of falling and inform rehabilitation programs. Commonly used gait assessment tools rely on simple measures such as timing and visual observations of path deviations by clinicians. These simple measures may not capture subtle changes in gait kinematics. Therefore, we investigated the use of wearable inertial measurement units (IMUs) and machine learning (ML) approaches to automatically discriminate between gait patterns of individuals with vestibular deficits and age-matched controls. The goal of this study was to examine the effects of IMU placement and gait task selection on the performance of automatic vestibular gait classifiers. METHODS: Thirty study participants (15 with vestibular deficits and 15 age-matched controls) participated in a single-session gait study during which they performed seven gait tasks while donning a full-body set of IMUs. Classification performance was reported in terms of area under the receiver operating characteristic curve (AUROC) scores for Random Forest models trained on data from each IMU placement for each gait task. RESULTS: Several models were able to classify vestibular gait better than random (AUROC > 0.5), but their performance varied according to IMU placement and gait task selection. Results indicated that a single IMU placed on the left arm when walking with eyes closed resulted in the highest AUROC score for a single IMU (AUROC = 0.88 [0.84, 0.89]). Feature permutation results indicated that participants with vestibular deficits reduced their arm swing compared to age-matched controls while they walked with eyes closed. CONCLUSIONS: These findings highlighted differences in upper extremity kinematics during walking with eyes closed that were characteristic of vestibular deficits and showed evidence of the discriminative ability of IMU-based automated screening for vestibular deficits. Further research should explore the mechanisms driving arm swing differences in the vestibular population.

Retention Effects of Long-Term Balance Training with Vibrotactile Sensory Augmentation in Healthy Older Adults.

Vibrotactile sensory augmentation (SA) decreases postural sway during real-time use; however, limited studies have investigated the long-term effects of training with SA. This study assessed the retention effects of long-term balance training with and without vibrotactile SA among community-dwelling healthy older adults, and explored brain-related changes due to training with SA. Sixteen participants were randomly assigned to the experimental group (EG) or control group (CG), and trained in their homes for eight weeks using smart-phone balance trainers. The EG received vibrotactile SA. Balance performance was assessed before, and one week, one month, and six months after training. Functional MRI (fMRI) was recorded before and one week after training for four participants who received vestibular stimulation. Both groups demonstrated significant improvement of SOT composite and MiniBESTest scores, and increased vestibular reliance. Only the EG maintained a minimal detectable change of 8 points in SOT scores six months post-training and greater improvements than the CG in MiniBESTest scores one month post-training. The fMRI results revealed a shift from activation in the vestibular cortex pre-training to increased activity in the brainstem and cerebellum post-training. These findings showed that additional balance improvements were maintained for up to six months post-training with vibrotactile SA for community-dwelling healthy older adults.

Patient Self-Management of Benign Paroxysmal Positional Vertigo: Instructional Video Development and Preliminary Evaluation of Behavioral Outcomes.

IMPORTANCE: Benign paroxysmal positional vertigo of the posterior canal (PC-BPPV) is a common disorder that is diagnosed using the Dix-Hallpike test (DHT) and treated with the canalith repositioning maneuver (CRM). Patients often seek out information about BPPV self-management, but studies to develop and evaluate patient-centered instructional resources are limited. OBJECTIVE: To develop and preliminarily evaluate a patient-oriented PC-BPPV self-management instructional video. METHODS: We assembled a multidisciplinary team and used an iterative process to develop a theory-based instructional video for self-performing the DHT and CRM. We recruited individuals searching online for information about dizziness to complete a survey and review the video. Patients rated the video by scoring seven questions that measure behavioral intent to perform the DHT or CRM (attitudes/acceptability, perceived self-efficacy, and social norms) using a 10-point scale (higher scores = more favorable ratings). A multilevel linear regression model was used to determine the association of age, sex, race, and education with video ratings. RESULTS: Of the 771 participants who completed the survey, 124 (16%) also reviewed and evaluated the PC-BPPV instructional video. The video review participants were typically more than or equal to 55 years old (70%; 93/124), women (70%; 87/124), and White (70%; 88/124). These participants also generally reported acute-subacute and moderate-to-severe dizziness, and 60% (75/124) reported typical BPPV triggers. The median scores for the seven questions about attitudes/acceptability, self-efficacy, and social norms on the PC-BPPV instructional video were all more than or equal to 9 out of 10 with interquartile ratios that ranged from 7 to 9 at the 25th percentile to 10 at the 75th percentile. Female sex was the only demographic variable associated with higher video ratings (coefficient, 1.21, 95% CI 0.60-1.83). CONCLUSION: This study found that participants rated the PC-BPPV self-management video favorably on measures that contribute to behavioral intent to perform the DHT or CRM. The findings provide support that the video is appropriate to use in future studies that evaluate patient self-performance accuracy and outcomes.

Treatment of Vestibular Disorders (Inner Ear Balance Problems): How Does Your Physical Therapist Treat Dizziness Related to Inner Ear Balance Problems?

Dizziness is very common, but it is never normal. Dizziness can make performing daily activities, work, and walking difficult. Inner ear balance problems can make people dizzy when they turn their head, which can cause problems during walking and make people more likely to fall. Most of the time dizziness is not from a life-threatening disease. Often, dizziness is related to a problem of the vestibular (or inner ear balance) system. Vestibular disorders can be caused by infections in the ear, problems with the immune system, medications that harm the inner ear, and rarely from diabetes or stroke because of a lack of blood flow to the inner ear. Stress, poor sleep, migraine headaches, overdoing some activities, and feeling anxious or sad can increase symptoms of dizziness. Updated guidelines for the treatment of inner ear disorders are published in this issue of the Journal of Neurologic Physical Therapy. The guideline recommends which exercises are best to treat the dizziness and balance problems commonly seen with an inner ear problem.

Vestibular Rehabilitation for Peripheral Vestibular Hypofunction: An Updated Clinical Practice Guideline From the Academy of Neurologic Physical Therapy of the American Physical Therapy Association.

BACKGROUND: Uncompensated vestibular hypofunction can result in symptoms of dizziness, imbalance, and/or oscillopsia, gaze and gait instability, and impaired navigation and spatial orientation; thus, may negatively impact an individual's quality of life, ability to perform activities of daily living, drive, and work. It is estimated that one-third of adults in the United States have vestibular dysfunction and the incidence increases with age. There is strong evidence supporting vestibular physical therapy for reducing symptoms, improving gaze and postural stability, and improving function in individuals with vestibular hypofunction. The purpose of this revised clinical practice guideline is to improve quality of care and outcomes for individuals with acute, subacute, and chronic unilateral and bilateral vestibular hypofunction by providing evidence-based recommendations regarding appropriate exercises. METHODS: These guidelines are a revision of the 2016 guidelines and involved a systematic review of the literature published since 2015 through June 2020 across 6 databases. Article types included meta-analyses, systematic reviews, randomized controlled trials, cohort studies, case-control series, and case series for human subjects, published in English. Sixty-seven articles were identified as relevant to this clinical practice guideline and critically appraised for level of evidence. RESULTS: Based on strong evidence, clinicians should offer vestibular rehabilitation to adults with unilateral and bilateral vestibular hypofunction who present with impairments, activity limitations, and participation restrictions related to the vestibular deficit. Based on strong evidence and a preponderance of harm over benefit, clinicians should not include voluntary saccadic or smooth-pursuit eye movements in isolation (ie, without head movement) to promote gaze stability. Based on moderate to strong evidence, clinicians may offer specific exercise techniques to target identified activity limitations and participation restrictions, including virtual reality or augmented sensory feedback. Based on strong evidence and in consideration of patient preference, clinicians should offer supervised vestibular rehabilitation. Based on moderate to weak evidence, clinicians may prescribe weekly clinic visits plus a home exercise program of gaze stabilization exercises consisting of a minimum of: (1) 3 times per day for a total of at least 12 minutes daily for individuals with acute/subacute unilateral vestibular hypofunction; (2) 3 to 5 times per day for a total of at least 20 minutes daily for 4 to 6 weeks for individuals with chronic unilateral vestibular hypofunction; (3) 3 to 5 times per day for a total of 20 to 40 minutes daily for approximately 5 to 7 weeks for individuals with bilateral vestibular hypofunction. Based on moderate evidence, clinicians may prescribe static and dynamic balance exercises for a minimum of 20 minutes daily for at least 4 to 6 weeks for individuals with chronic unilateral vestibular hypofunction and, based on expert opinion, for a minimum of 6 to 9 weeks for individuals with bilateral vestibular hypofunction. Based on moderate evidence, clinicians may use achievement of primary goals, resolution of symptoms, normalized balance and vestibular function, or plateau in progress as reasons for stopping therapy. Based on moderate to strong evidence, clinicians may evaluate factors, including time from onset of symptoms, comorbidities, cognitive function, and use of medication that could modify rehabilitation outcomes. DISCUSSION: Recent evidence supports the original recommendations from the 2016 guidelines. There is strong evidence that vestibular physical therapy provides a clear and substantial benefit to individuals with unilateral and bilateral vestibular hypofunction. LIMITATIONS: The focus of the guideline was on peripheral vestibular hypofunction; thus, the recommendations of the guideline may not apply to individuals with central vestibular disorders. One criterion for study inclusion was that vestibular hypofunction was determined based on objective vestibular function tests. This guideline may not apply to individuals who report symptoms of dizziness, imbalance, and/or oscillopsia without a diagnosis of vestibular hypofunction. DISCLAIMER: These recommendations are intended as a guide to optimize rehabilitation outcomes for individuals undergoing vestibular physical therapy. The contents of this guideline were developed with support from the American Physical Therapy Association and the Academy of Neurologic Physical Therapy using a rigorous review process. The authors declared no conflict of interest and maintained editorial independence.Video Abstract available for more insights from the authors (see the Video, Supplemental Digital Content 1, available at: http://links.lww.com/JNPT/A369).

Automatically evaluating balance using machine learning and data from a single inertial measurement unit.

BACKGROUND: Recently, machine learning techniques have been applied to data collected from inertial measurement units to automatically assess balance, but rely on hand-engineered features. We explore the utility of machine learning to automatically extract important features from inertial measurement unit data for balance assessment. FINDINGS: Ten participants with balance concerns performed multiple balance exercises in a laboratory setting while wearing an inertial measurement unit on their lower back. Physical therapists watched video recordings of participants performing the exercises and rated balance on a 5-point scale. We trained machine learning models using different representations of the unprocessed inertial measurement unit data to estimate physical therapist ratings. On a held-out test set, we compared these learned models to one another, to participants' self-assessments of balance, and to models trained using hand-engineered features. Utilizing the unprocessed kinematic data from the inertial measurement unit provided significant improvements over both self-assessments and models using hand-engineered features (AUROC of 0.806 vs. 0.768, 0.665). CONCLUSIONS: Unprocessed data from an inertial measurement unit used as input to a machine learning model produced accurate estimates of balance performance. The ability to learn from unprocessed data presents a potentially generalizable approach for assessing balance without the need for labor-intensive feature engineering, while maintaining comparable model performance.

Vestibular Physical Therapy and Fall Risk Assessment.

Vestibular physical therapy (VPT) is a specialized form of evidence-based therapy designed to alleviate primary (vertigo, dizziness, imbalance, gait instability, falls) and secondary (deconditioning, cervical muscle tension, anxiety, poor quality of life, fear of falling/fear avoidance behavior) symptoms related to vestibular disorders. This article provides an overview of VPT, highlighting various exercise modalities used to treat a variety of vestibular disorders. Patient safety and fall prevention are paramount; therefore, fall risk assessment and treatment are also addressed.

Posttraumatic Dizziness: Navigating the Maze Towards Accurate Vestibular Diagnosis and Treatment.

OBJECTIVE: Highlight the importance of establishing a differential diagnosis to identify and treat multiple origins of dizziness in a patient following traumatic brain injury (TBI). PATIENT: 73-year-old man with TBI and temporal bone fracture developed posttraumatic bilateral multiple canal benign paroxysmal positional vertigo (BPPV). INTERVENTION: Multi-disciplinary diagnostic evaluation and vestibular rehabilitation (VR) treatment focused on canalith repositioning maneuvers (CRMs) and central adaptation. MAIN OUTCOME MEASURES: Diagnostic imaging, audiometric testing, clinical evaluation including video recordings of patterns of nystagmus, Dizziness Handicap Inventory (DHI). RESULTS: Systematic clinical examination identified multiple semicircular canal BPPV in addition to a suspected underlying unilateral hypofunction. Treatment focused on the appropriate CRMs and adaptation exercises. DHI scores improved significantly and patient returned to work and recreational activities. CONCLUSION: This Clinical Capsule Report highlights the importance of a comprehensive clinical evaluation of the TBI patient with dizziness when making an accurate diagnosis and treatment plan. Due to the complexity of differentiating between multiple canal BPPV in addition to other central and vestibular disorders, it is imperative for the clinician to have a clear understanding of nystagmus patterns for multicanal BPPV as well as other vestibular pathology.

Changes in Vestibular/Ocular-Motor Screen Scores in Adolescents Treated With Vestibular Therapy After Concussion.

PURPOSE: To examine interrelationships among Vestibular/Ocular-Motor Screen (VOMS) items and to characterize the recovery of VOMS performance in a sample of adolescents treated with vestibular physical therapy (VPT) after concussion. METHODS: Seventy-seven patients with concussion and 77 participants without concussion completed the study. Adolescents with concussion received an individualized VPT intervention consisting of targeted exercises for gaze stability, postural stability, ocular-motor control, habituation, and aerobic activities. The exercises were performed during a weekly clinic visit and via a home exercise program. RESULTS: Except for near-point convergence distance, all VOMS items were significantly interrelated. Over the course of VPT, significant improvements in VOMS performance were observed, and discharge scores were similar to scores observed in adolescents without concussion. CONCLUSIONS: The VOMS measured moderately related functions and captured changes over the course of VPT. Clinicians should consider the contextual risk of "false positive" in their interpretation of VOMS.

Effects of long-term vestibular rehabilitation therapy with vibrotactile sensory augmentation for people with unilateral vestibular disorders - A randomized preliminary study.

BACKGROUND AND OBJECTIVE: This pilot study aimed to investigate the effects of incorporating vibrotactile sensory augmentation (SA) on balance performance among people with unilateral vestibular disorders (UVD). METHODS: Eight participants with UVD were recruited. Participants completed 18 balance training sessions across six weeks in a clinical setting. Four participants (68.1±7.5 yrs) were randomized to the experimental group (EG) and received trunk-based vibrotactile SA while performing the balance exercises, and four participants (63.1±11.3 yrs) were assigned to the control group (CG); CG participants completed the balance training without SA. Clinical and kinematic balance performance measures were collected before training; midway through training; and one week, one month, and six months after training. RESULTS: All participants, regardless of group, demonstrated improvements in a subset of the clinical or balance metrics immediately following completion of the balance training protocol. The EG showed significantly greater improvements than the CG for the Activities-specific Balance Confidence Scale and postural stability during the two standing balance exercises with head movements. The EG also had larger improvements than the CG for the Sensory Organization Test (SOT), Mini Balance Evaluations Systems Test, Gait Speed Test, Dynamic Gait Index, Functional Gait Assessment, and vestibular reliance metric calculated based on the SOT. CONCLUSIONS: Incorporating vibrotactile SA into vestibular rehabilitation programs may lead to additional benefits that may be retained up to six months after training compared to training without vibrotactile SA. A larger study is warranted to demonstrate statistical significance between the groups.

Potential Mechanisms of Sensory Augmentation Systems on Human Balance Control.

Numerous studies have demonstrated the real-time use of visual, vibrotactile, auditory, and multimodal sensory augmentation technologies for reducing postural sway during static tasks and improving balance during dynamic tasks. The mechanism by which sensory augmentation information is processed and used by the CNS is not well understood. The dominant hypothesis, which has not been supported by rigorous experimental evidence, posits that observed reductions in postural sway are due to sensory reweighting: feedback of body motion provides the CNS with a correlate to the inputs from its intact sensory channels (e.g., vision, proprioception), so individuals receiving sensory augmentation learn to increasingly depend on these intact systems. Other possible mechanisms for observed postural sway reductions include: cognition (processing of sensory augmentation information is solely cognitive with no selective adjustment of sensory weights by the CNS), "sixth" sense (CNS interprets sensory augmentation information as a new and distinct sensory channel), context-specific adaptation (new sensorimotor program is developed through repeated interaction with the device and accessible only when the device is used), and combined volitional and non-volitional responses. This critical review summarizes the reported sensory augmentation findings spanning postural control models, clinical rehabilitation, laboratory-based real-time usage, and neuroimaging to critically evaluate each of the aforementioned mechanistic theories. Cognition and sensory re-weighting are identified as two mechanisms supported by the existing literature.

Effects of long-term balance training with vibrotactile sensory augmentation among community-dwelling healthy older adults: a randomized preliminary study.

BACKGROUND: Sensory augmentation has been shown to improve postural stability during real-time balance applications. Limited long-term controlled studies have examined retention of balance improvements in healthy older adults after training with sensory augmentation has ceased. This pilot study aimed to assess the efficacy of long-term balance training with and without sensory augmentation among community-dwelling healthy older adults. METHODS: Twelve participants (four males, eight females; 75.6 ± 4.9 yrs) were randomly assigned to the experimental group (n = 6) or control group (n = 6). Participants trained in their homes for eight weeks, completing three 45-min exercise sessions per week using smart phone balance trainers that provided written, graphic, and video guidance, and monitored trunk sway. During each session, participants performed six repetitions of six exercises selected from five categories (static standing, compliant surface standing, weight shifting, modified center of gravity, and gait). The experimental group received vibrotactile sensory augmentation for four of the six repetitions per exercise via the smart phone balance trainers, while the control group performed exercises without sensory augmentation. The smart phone balance trainers sent exercise performance data to a physical therapist, who recommended exercises on a weekly basis. Balance performance was assessed using a battery of clinical balance tests (Activity Balance Confidence Scale, Sensory Organization Test, Mini Balance Evaluation Systems Test, Five Times Sit to Stand Test, Four Square Step Test, Functional Reach Test, Gait Speed Test, Timed Up and Go, and Timed Up and Go with Cognitive Task) before training, after four weeks of training, and after eight weeks of training. RESULTS: Participants in the experimental group were able to use vibrotactile sensory augmentation independently in their homes. After training, the experimental group had significantly greater improvements in Sensory Organization Test and Mini Balance Evaluation Systems Test scores than the control group. Significant improvement was also observed for Five Times Sit to Stand Test duration within the experimental group, but not in the control group. No significant improvements between the two groups were observed in the remaining clinical outcome measures. CONCLUSION: The findings of this study support the use of sensory augmentation devices by community-dwelling healthy older adults as balance rehabilitation tools, and indicate feasibility of telerehabilitation therapy with reduced input from clinicians.

Vestibular rehabilitation following surgical repair for Superior Canal Dehiscence Syndrome: A complicated case report.

Superior Canal Dehiscence Syndrome (SCDS) causes auditory and vestibular symptoms. Following surgical repair of the dehiscence, patients often experience dizziness and imbalance. This case report describes a postoperative vestibular exercise program, focusing on the principles of central compensation and habituation, and how it was modified for a patient with delayed progress secondary to strabismus and visual vertigo. A 63-year-old male with history of strabismus eye surgery, right hearing loss, aural fullness, and sensitivity to loud sounds was referred for vestibular rehabilitation (VR). He was seen for one preoperative and six postoperative PT visits over eight months. Outcome measures two weeks postoperative were as follows: Dizziness Handicap Inventory (DHI) 38/100; Timed Up & Go (TUG) 9.92 seconds; Dynamic Gait Index (DGI) 16/24; and a 3-line difference in Dynamic Visual Acuity (DVA). Improved outcomes at discharge included: DHI 18/100; TUG 6.87 seconds; DGI 23/24; and 1-line difference in DVA. He was able to return to work and previously enjoyed recreational activities. Postoperative vestibular rehabilitation programs are functionally and symptomatically beneficial following surgical repair for SCDS. Deviations from expected recovery should be addressed to achieve optimal outcomes as demonstrated in this complicated case report.

Configurable, wearable sensing and vibrotactile feedback system for real-time postural balance and gait training: proof-of-concept.

BACKGROUND: Postural balance and gait training is important for treating persons with functional impairments, however current systems are generally not portable and are unable to train different types of movements. METHODS: This paper describes a proof-of-concept design of a configurable, wearable sensing and feedback system for real-time postural balance and gait training targeted for home-based treatments and other portable usage. Sensing and vibrotactile feedback are performed via eight distributed, wireless nodes or "Dots" (size: 22.5 × 20.5 × 15.0 mm, weight: 12.0 g) that can each be configured for sensing and/or feedback according to movement training requirements. In the first experiment, four healthy older adults were trained to reduce medial-lateral (M/L) trunk tilt while performing balance exercises. When trunk tilt deviated too far from vertical (estimated via a sensing Dot on the lower spine), vibrotactile feedback (via feedback Dots placed on the left and right sides of the lower torso) cued participants to move away from the vibration and back toward the vertical no feedback zone to correct their posture. A second experiment was conducted with the same wearable system to train six healthy older adults to alter their foot progression angle in real-time by internally or externally rotating their feet while walking. Foot progression angle was estimated via a sensing Dot adhered to the dorsal side of the foot, and vibrotactile feedback was provided via feedback Dots placed on the medial and lateral sides of the mid-shank cued participants to internally or externally rotate their foot away from vibration. RESULTS: In the first experiment, the wearable system enabled participants to significantly reduce trunk tilt and increase the amount of time inside the no feedback zone. In the second experiment, all participants were able to adopt new gait patterns of internal and external foot rotation within two minutes of real-time training with the wearable system. CONCLUSION: These results suggest that the configurable, wearable sensing and feedback system is portable and effective for different types of real-time human movement training and thus may be suitable for home-based or clinic-based rehabilitation applications.

Dizziness Symptom Type Prevalence and Overlap: A US Nationally Representative Survey.

BACKGROUND: The traditional approach to dizziness encourages providers to emphasize the type of dizziness. However, symptom types might substantially overlap in individual patients, thus limiting the clinical value of this approach. We aimed to describe the overlap of types of dizziness using a US nationally representative sample. METHODS: The 2008 US National Health Interview Survey was examined for prevalence and overlap of types of dizziness. The data were also separately examined among people who otherwise had typical features of traditionally vertigo-based disorders (ie, benign paroxysmal positional vertigo and Meniere's disease). Data analysis also included exploratory factor analysis. RESULTS: Twelve-month prevalence of problems with dizziness or balance was 14.8%, representing 33.4 million individuals. The mean number of dizziness symptoms was 2.4 (95% confidence interval [CI], 2.3-2.4), with 61.1% reporting more than one type. Of subjects who otherwise had typical features of traditionally vertigo-based disorders, the mean number of dizziness types was 3.1 (95% CI, 3.0-3.3), and only 24.6% (95% CI, 21.0%-28.7%) reported vertigo as the primary type. Exploratory factor analysis found that symptom types loaded onto a single factor without other clinical or demographic variables. CONCLUSIONS: Substantial overlap of dizziness types exists among US adults with dizziness. People otherwise having features of traditionally vertigo-based disorders also typically report multiple dizziness types and do not typically report vertigo as the primary type. Symptom types correlate more strongly with each other than with other clinical or demographic variables. These findings suggest that the traditional emphasis on dizziness types is likely of limited clinical utility.

The effects of attractive vs. repulsive instructional cuing on balance performance.

BACKGROUND: Torso-based vibrotactile feedback has been shown to improve postural performance during quiet and perturbed stance in healthy young and older adults and individuals with balance impairments. These systems typically include tactors distributed around the torso that are activated when body motion exceeds a predefined threshold. Users are instructed to "move away from the vibration". However, recent studies have shown that in the absence of instructions, vibrotactile stimulation induces small (~1°) non-volitional responses in the direction of its application location. It was hypothesized that an attractive cuing strategy (i.e., "move toward the vibration") could improve postural performance by leveraging this natural tendency. FINDINGS: Eight healthy older adults participated in two non-consecutive days of computerized dynamic posturography testing while wearing a vibrotactile feedback system comprised of an inertial measurement unit and four tactors that were activated in pairs when body motion exceeded 1° anteriorly or posteriorly. A crossover design was used. On each day participants performed 24 repetitions of Sensory Organization Test condition 5 (SOT5), three repetitions each of SOT 1-6, three repetitions of the Motor Control Test, and five repetitions of the Adaptation Test. Performance metrics included A/P RMS, Time-in-zone and 95 % CI Ellipse. Performance improved with both cuing strategies but participants performed better when using repulsive cues. However, the rate of improvement was greater for attractive versus repulsive cuing. CONCLUSIONS: The results suggest that when the cutaneous signal is interpreted as an alarm, cognition overrides sensory information. Furthermore, although repulsive cues resulted in better performance, attractive cues may be as good, if not better, than repulsive cues following extended training.

Refractory Positional Vertigo With Apogeotropic Horizontal Nystagmus After Labyrinthitis: Surgical Treatment and Identification of Dysmorphic Ampullae.

OBJECTIVES: To describe the rationale, intraoperative details, and histopathologic findings discovered when treating an unusual case of apogeotropic horizontal canal positional vertigo with a transmastoid labyrinthectomy. PATIENT: A single case report. INTERVENTION: Therapeutic. MAIN OUTCOME MEASURES: Resolution of apogeotropic nystagmus and improvement of positional vertigo. RESULTS: The apogeotropic variant of horizontal canal positional vertigo can be a difficult entity to treat. This report describes a patient who developed profound sensorineural hearing loss and vertigo after an acute left labyrinthitis. Ten months later, she developed vertigo with apogeotropic positional nystagmus involving the left horizontal semicircular canal. Particle repositioning maneuvers and vestibular physical therapy were unsuccessful. In addition, she developed intermittent positional vertigo affecting the ipsilateral vertical semicircular canals. Given the persistence of her vertigo, multiple canal involvement, and patient preference for definitive treatment, a transmastoid labyrinthectomy was performed. Intraoperatively, the ampulla of the horizontal canal as well as that of the other canals was grossly abnormal as later confirmed on histology. After surgery, her apogeotropic nystagmus and vertigo resolved, and her balance ability gradually improved to a highly functional level. CONCLUSION: This case illustrates a unique form of positional vertigo that developed and persisted after acute labyrinthitis. Conservative measures were unsuccessful and a transmastoid labyrinthectomy documented dense inflammatory tissue involving all three ampullae. We postulate that the post-labyrinthitic inflammatory changes resulted in mass loading of the membranous ampullae, causing abnormal nystagmus patterns and positional vertigo, which resolved after the labyrinthectomy.

Nystagmus discordance with 2-dimensional videonystagmography in posterior semicircular canal benign paroxysmal positional vertigo.

OBJECTIVE: The Dix-Hallpike test is a standard component of the videonystagmography test battery and can diagnose posterior semicircular canal benign paroxysmal positional vertigo. The purpose of this study is to determine the prevalence of discordant, equivocal, and concordant nystagmus tracings in active posterior semicircular canal benign paroxysmal positional vertigo when compared directly with the eye video. STUDY DESIGN: Case series with chart review of patients diagnosed with posterior semicircular canal benign paroxysmal positional vertigo by 2-dimensional videonystagmography from August 1, 2007, to August 1, 2012. SETTING: A tertiary vestibular test laboratory. SUBJECTS AND METHODS: Ninety-six adults (4 had bilateral involvement) with posterior semicircular canal benign paroxysmal positional vertigo were included. A total of 100 videos with accompanying videonystagmography tracings were reviewed to determine nystagmus trajectory as well as globe position. Descriptive statistics were used to describe prevalence. Fisher exact test was used to compare proportions. RESULTS: Sixty-two percent of cases involved benign paroxysmal positional vertigo of the right posterior semicircular canal, while 38% involved the left posterior semicircular canal. The prevalence of discordant, equivocal, and concordant tracings was 65% (65/100), 29% (29/100), and 6% (6/100). All tracing errors involved the horizontal channel. There was no association between tracing accuracy and the ear of involvement or globe position (P > .05). CONCLUSIONS: Two-dimensional videonystagmography tracings are not reliable for identifying nystagmus trajectory in posterior semicircular canal benign paroxysmal positional vertigo.