Eric Anson

Purpose: Balance and vestibular disorders have a profound impact on quality of life. Anxiety (ANX) and depression (DEP) are common with dizziness, vertigo, or imbalance. It is unclear whether self-reported anxiety or depression depends on perceived physical function for individuals participating in vestibular rehabilitation (VPT). We hypothesized that individuals with worse physical function would be more likely to report abnormally high anxiety and/or depression levels. Participants: 170 individuals referred for vestibular rehabilitation (113 female, 57 males, and age 63.7 (21)). Methods: A retrospective chart review extracted age, Patient-Reported Outcome Measurement Information System (PROMIS) scores (ANX, DEP, physical function) and primary diagnoses [benign paroxysmal positional vertigo ( n = 42), unilateral vestibular hypofunction ( n = 39), bilateral vestibular hypofunction ( n = 14), concussion/head injury ( n = 7), dizziness/vertigo ( n = 37), and imbalance ( n = 31)]. Average PROMIS scores and percentage of abnormal scores were calculated for physical function, ANX, and DEP scores and reported using descriptive statistics. Logistic regression was performed to separately examine the odds of abnormal ANX and DEP based on abnormal physical function while controlling for age and sex, on the entire dataset and on diagnosis subgroups. Results: Individuals referred to vestibular physical therapy with self-reported abnormal physical function were more likely to have abnormal ANX (OR 5.1, p < 0.001) or DEP (OR 3.10, p = 0.002). Older adults were less likely to have abnormal ANX (OR = 0.96, p = 0.002). For individuals experiencing BPPV ( n = 42), those with abnormal physical function are more likely to report ANX (OR 9.9, p = 0.009). For individuals with UVH ( n = 39), those with abnormal physical function were more likely to report ANX (OR 10.1, p = 0.008) or DEP (OR 9.9, p = 0.010). Conclusion: Self-reported abnormal physical function corresponds to a higher incidence of abnormal ANX and DEP for individuals referred to VPT. Individuals with benign proximal positional vertigo and unilateral vestibular hypofunction were approximately 10 times more likely to experience abnormally high ANX or DEP compared to all other primary diagnosis. Clinicians seeing patients in VPT should be screening for anxiety and depression especially for those with self-reports of impaired physical function.

Motion of the visual field can alter postural sway and cause illusions of self-motion. The relative perceptual sensitivity of self-motion versus visual field motion induced by virtual reality (VR) stimulation and whether observable sway differs based on perceptual task is unknown. Methods to quantify sway perception while concurrently measuring sway do not exist. We measured head sway and motion perception (self or world) in healthy adults who stood with feet together wearing a VR headset while experiencing adaptive staircases of virtual sinusoidal pitch rotation about the ankle axis. In separate conditions of randomly ordered blocks, subjects were asked to indicate (yes/no) if the room moved (regardless of perceived postural sway) or if their postural sway increased (regardless of perceived room motion). Head sway area was measured by tracking movement of the VR headset. Yes/No responses were fit with psychometric curves to determine points of subjective equality (PSEs) for room motion and postural sway. PSEs were compared between conditions. Effects of motion perception (binary responses) on head sway area before, during, and after visual stimulation were examined. The mean PSE for room motion (0.42 degrees) was significantly lower than for postural sway (2.02 degrees) [t(1,18) = 4.4714, p = 0.00029]. Head sway area was significantly larger during (z = 11.53, p < 0.001) and after (z = 5.09, p < 0.001) visual stimulation only when participants perceived increased postural sway. Nearly 5-fold greater amplitudes of oscillating VR visual stimuli were required to induce perceptions of altered self-versus visual field motion. Observed head sway during visual motion was only linked to perceptual responses when participants focused internally on self-motion, not externally on room motion.

Suffering an acute asymmetry in vestibular function (i.e., vestibular neuritis) causes increased sway. Non-causal studies report associations between lateral semicircular canal function and balance ability, but direct links remain controversial. We investigate the immediate effect on body sway after unilateral vestibulo-ocular reflex (VOR) gain down adaptation simulating acute peripheral vestibular hypofunction. Eighteen healthy adults, mean age 27.4 (± 12.4), stood wearing an inertial measurement device with their eyes closed on foam before and after incremental VOR gain down adaptation to simulate mild unilateral vestibular neuritis. Active head impulse VOR gain was measured before and after the adaptation to ensure VOR gain adaptation. Percentage change for VOR gain was determined. Sway area was compared before and after VOR adaptation. VOR gain decreased unilaterally exceeding meaningful change values. Sway area was significantly greater immediately after VOR gain down adaptation, but quickly returned to baseline. In a subset of subjects VOR gain was re-assessed and found to remain adapted despite sway normalization. These results indicate that oculomotor adaptation targeting the lateral semicircular canal VOR pathway has an immediate, albeit transient increase in body sway. Rapid return of body sway to baseline levels suggests dynamic sensory reweighting between vestibular and somatosensory inputs to resolve the undesirable increased body sway.

Suffering an acute asymmetry in vestibular function (i.e. vestibular neuritis) causes increased sway. Non-causal studies report associations between lateral semicircular canal function and balance ability, but direct links remains controversial. We investigate the immediate effect on body sway after unilateral vestibulo-ocular reflex (VOR) gain down adaptation simulating acute peripheral vestibular hypofunction. Eighteen healthy adults, mean age 27.4 (SD 12.4), stood wearing an inertial measurement device with their eyes closed on foam before and after incremental VOR gain down adaptation to simulate mild unilateral vestibular neuritis. Active head impulse VOR gain was measured before and after the adaptation to ensure VOR gain adaptation. Percentage change for VOR gain and sway area were determined. Sway area was compared before and after VOR adaptation. VOR gain decreased unilaterally exceeding meaningful change values. Sway area was significantly greater immediately after VOR gain down adaptation, but quickly returned to baseline. In a subset of subjects VOR gain was re-assessed and found to remain adapted despite sway normalization. These results indicate that oculomotor adaptation targeting the lateral semicircular canal VOR pathways have an immediate, albeit transient increase in body sway. Rapid return of body sway to baseline levels suggests dynamic sensory reweighting between vestibular and somatosensory inputs to resolve the undesirable increased body sway.

Not all dizziness presents as vertigo, suggesting other perceptual symptoms for individuals with vestibular disease. These non-specific perceptual complaints of dizziness have led to a recent resurgence in literature examining vestibular perceptual testing with the aim to enhance clinical diagnostics and therapeutics. Recent evidence supports incorporating rehabilitation methods to retrain vestibular perception. This review describes the current field of vestibular perceptual testing from scientific laboratory techniques that may not be clinic friendly to some low-tech options that may be more clinic friendly. Limitations are highlighted suggesting directions for additional research.

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 numberCRD42021266163). In the event of protocol amendments, the date of each amendment will be accompanied by a description of the change and the rationale.

Wearing a facemask (FM) reduces the spread of COVID-19, but it also blocks a person's lower visual field. Many new public safety rules were created in response to COVID-19, including mandated FM wearing in some youth sports like youth ice hockey. We hypothesized that FM wearing in youth hockey players obstructs the lower field of view and may impact safety. Youth hockey players (n = 33) aged 12.03 (1.6) years button press when they saw an LED on the floor turn on in two conditions (wearing FM or no FM) in random order. An interleaved one-up/one-down two-alternative-forced-choice adaptive staircase design was used. Visual thresholds were calculated for each condition and participant. The visual angle threshold (VAT) was determined using standing eye height and the linear distance from the tip of the skates to the visual threshold. Paired t-tests determined whether mask wearing changed the VAT. We modeled the probability a player could see the puck on their stick in four distinct scenarios to estimate the potential impact of FM wearing during hockey play. The average unmasked VAT (11.4 degrees) was significantly closer to the skates than the masked VAT (20.3 degrees) (p < 0.001). Our model indicated a significant reduction in ability to visualize the puck using peripheral vision when more upright while wearing a FM. FM wearing compromised their lower visual field, suggesting a downward head tilt may be necessary to see the puck. Playing ice hockey while wearing a FM may lead to unsafe on-ice playing conditions due to downward head tilt to see the puck.

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.

BACKGROUND: Spatial orientation is a complex process involving vestibular sensory input and possibly cognitive ability. Previous research demonstrated that rotational spatial orientation was worse for individuals with profound bilateral vestibular dysfunction. OBJECTIVE: Determine whether rotational and linear vestibular function were independently associated with large amplitude rotational spatial orientation perception in healthy aging. METHODS: Tests of rotational spatial orientation accuracy and vestibular function [vestibulo-ocular reflex (VOR), ocular and cervical vestibular evoked myogenic potentials (VEMP)] were administered to 272 healthy community-dwelling adults participating in the Baltimore Longitudinal Study of Aging. Using a mixed model multiple linear regression we regressed spatial orientation errors on lateral semicircular canal function, utricular function (ocular VEMP), and saccular function (cervical VEMP) in a single model controlling for rotation size, age, and sex. RESULTS: After adjusting for age, and sex, individuals with bilaterally low VOR gain (β= 20.9, p = 0.014) and those with bilaterally absent utricular function (β= 9.32, p = 0.017) made significantly larger spatial orientation errors relative to individuals with normal vestibular function. CONCLUSIONS: The current results demonstrate for the first time that either bilateral lateral semicircular canal dysfunction or bilateral utricular dysfunction are associated with worse rotational spatial orientation. We also demonstrated in a healthy aging cohort that increased age also contributes to spatial orientation ability.