Dynamic vestibular compensation in vestibular peripheral diseases

Vestibular compensation, or neuronal plasticity in the central vestibular system, is quite an important process in patients with acute unilateral peripheral vestibular disease, allowing them to lead a comfortable daily life when medical treatments fail to cure the peripheral vestibular function. Is the residual unilateral vestibular input from damaged vestibular endo-organs a positive or negative factor for the development of dynamic vestibular compensation in the central nervous system? To elucidate the true mechanism of vestibular compensation, we examined the ENG findings and dizziness handicap inventory questionnaire in patients with vestibular neuronitis (VN), sudden deafness with vertigo (SDV), Meniere's disease (MD) and acoustic tumor (AT) during remission of the vertigo attacks. We obtained neuro-otological findings from caloric tests and head shaking after nystagmus using ENG and information on motion-evoked dizziness in daily life using the questionnaire. There were no significant differences in the sex, age or canal paresis % (CP%) among the four groups. The results of the present study showed that dynamic vestibular compensation processes developed progressively in the order of patients with SDV, VN, MD and AT (Kruskal-Wallis : p < 0.05). This finding suggests that processes of dynamic vestibular compensation could be accelerated in patients with fixed vestibular lesions caused by SDV and VN more than in those with fluctuating vestibular functions caused by MD and AT. In patients with fixed vestibular lesions caused by SDV and VN, patients with lower CP% showed dynamic vestibular compensation (i.e. disappearance of head shaking after nystagmus (chi-square: p < 0.05) and motion-evoked dizziness (Mann-Whitney: p < 0.0005)) more rapidly than those with higher CP%. In patients with fluctuating vestibular functions caused by MD and AT, patients with lower CP% did not always develop dynamic vestibular compensation more smoothly than those with higher CP%.     

Agreement between functional and electrophysiologic measures in patients with unilateral peripheral vestibular system impairment

This investigation was conducted to determine whether there was congruence between "physiology-based" definitions of compensated and uncompensated unilateral peripheral vestibular system impairment and "functional" measures of self-perceived dizziness disability/handicap. A retrospective analysis was performed on data obtained from 122 patients evaluated in the Balance Function Laboratory at Henry Ford Hospital over a 4-year period. Both electronystagmography and rotational test data were tabulated. Additionally, results of a self-report measure of dizziness disability/handicap were tabulated. Patients were placed into four groups, with one group representing normal vestibulometric test results, one group representing compensated unilateral peripheral vestibular system impairment, and two groups representing increasing magnitudes of uncompensated unilateral peripheral vestibular system impairment. The total and subscale scores on the self-report measure served as the dependent variable. Results showed a lack of congruence between the physiologic and functional measures. We interpret these findings as evidence that factors other than semiobjective evidence of vestibular system compensation probably impact functional recovery following unilateral peripheral vestibular system impairment.     

Role of central preprogramming in dynamic visual acuity with vestibular loss

OBJECTIVE: To determine the contribution of central preprogramming of eye movements to dynamic visual acuity (DVA) during head movement in patients with vestibular hypofunction. STUDY DESIGN: Prospective, clinical study. SETTING: Tertiary care, academic hospitals. PARTICIPANTS: Twenty-six healthy subjects and 20 patients with unilateral (UVL) and 7 with bilateral vestibular loss (BVL) (age range, 20-86 years). INTERVENTIONS: Diagnostic interventions, including caloric and rotational chair testing. MAIN OUTCOME MEASURE: Measurements of DVA during predictable (DVA-predictable) and unpredictable (DVA-unpredictable) head movements using a computerized test. RESULTS: There was a difference between DVA-predictable and DVA-unpredictable scores in all groups (P<.02). The difference between DVA-predictable and DVA-unpredictable scores for the BVL group was significantly greater than that for the other groups (P<.005). Age was a significant factor in DVA-unpredictable scores for the healthy subjects (P<.001) and UVL group (P<.02). Comparisons of DVA between groups were significant (P<.03), with the following exceptions: UVL group for head movements toward the unaffected side for DVA-predictable and DVA-unpredictable scores, compared with healthy subjects, and UVL group for head movements toward the affected side for DVA-predictable scores, compared with the BVL group. CONCLUSIONS: Unpredictable head movements cause a greater decrement in visual acuity than do predictable head movements. This suggests that central programming of eye movements and/or efference copy contributes to gaze stability during predictable head movements in healthy subjects and patients with vestibular hypofunction. Patients with BVL use central programming of eye movements to maintain gaze stability more than do healthy subjects or patients with UVL.     

Prediction of fall risk reduction as measured by dynamic gait index in individuals with unilateral vestibular hypofunction.

OBJECTIVE: To determine the effect of vestibular rehabilitation on reduction of fall risk in individuals with unilateral vestibular hypofunction and to identify those factors that predict fall risk reduction. STUDY DESIGN: Retrospective chart review. SETTING: Tertiary referral center. PATIENTS: Forty-seven patients with unilateral vestibular hypofunction, aged 28 to 86 years, who were at risk for falls on initial assessment. INTERVENTION: All patients underwent vestibular rehabilitation including adaptation exercises, designed to improve gaze stability, and gait and balance exercises. MAIN OUTCOME MEASURES: Fall risk (Dynamic Gait Index), visual acuity during head movements (Dynamic Visual Acuity), and subjective complaints were measured initially, at 2-week intervals, and at completion of physical therapy. RESULTS: As a group, the patients had significantly reduced risk for falls (p <0.001) after rehabilitation. Time from onset of symptoms did not affect the efficacy of vestibular rehabilitation. Both older (> or = 65 yr) and younger (< 65 yr) adults showed significant reductions in fall risk with vestibular rehabilitation (p <0.001). However, a significantly greater proportion (Chi2= 0.016) of older adults remained at risk for falls at discharge compared with young adults (45% versus 11%). Initial Dynamic Gait Index and Dynamic Visual Acuity scores predicted fall risk reduction in patients with unilateral vestibular hypofunction. A model was developed using initial Dynamic Gait Index and Dynamic Visual Acuity scores to predict fall risk reduction. CONCLUSIONS: Vestibular rehabilitation is effective in significantly reducing fall risk in individuals with unilateral vestibular deficit. The model predicts fall risk reduction with good sensitivity (77%) and specificity (90%).     

Objective measures of physical activity in patients with chronic unilateral vestibular hypofunction,and its relationship to handicap,anxiety and postural stability

Objective

Dizziness is one of the most common symptoms in the general population. Patients with dizziness experience balance problems and anxiety, which can lead to decreased physical activity levels and participation in their daily activities. Moreover, recovery of vestibular function from vestibular injury requires physical activity. Although there are reports that decreased physical activity is associated with handicap, anxiety, postural instability and reduced recovery of vestibular function in patients with chronic dizziness, these data were collected by self-report questionnaires. Therefore, the objective data of physical activity and the relationships between physical activity, handicap, anxiety and postural stability in patients with chronic dizziness are not clear. The purpose of this research was to objectively measure the physical activity of patients with chronic dizziness in daily living as well as handicap, anxiety and postural stability compared to healthy adults. Additionally, we aimed to investigate the relationships between physical activity, handicap, anxiety and postural stability in patients with chronic dizziness.

Change in tinnitus handicap after translabyrinthine vestibular schwannoma excision.

OBJECTIVE: To evaluate the change in tinnitus handicap after translabyrinthine vestibular schwannoma excision. STUDY DESIGN: Prospective administration of the Tinnitus Handicap Inventory (THI) preoperatively and at 3 and 12 months postoperatively. SETTING:: A tertiary referral neuro-otology clinic. PATIENTS: A total of 149 patients from a series of 170 consecutive patients who had vestibular schwannomas excised between May 1998 and July 2002 and who had completed THIs preoperatively and at 3 and 12 months postoperatively. INTERVENTIONS: Translabyrinthine excision of a unilateral sporadic vestibular schwannoma. MAIN OUTCOME MEASURES: THI scores. RESULTS: The number of patients with moderate or severe handicap was 21 (14%) in the preoperative group and 21 (14%) in the 12-month postoperative group. No significant differences in group data were found comparing (by Wilcoxon signed rank test) preoperative data with 3 months postoperative data (p = 0.09), preoperative data with 12 months postoperative data (p = 0.09), and 3 months postoperative data with 12 months postoperative data (p = 0.33). Considering group data, tinnitus handicap is neither alleviated nor exacerbated by translabyrinthine surgery. The application of the validated 20-point criteria for significant change in the status of an individual patient indicates that tinnitus handicap was worse in 10 (6.5%), unchanged in 129 (87%), and better in 10 (6.5%). CONCLUSIONS: The findings of the current study can be used during preoperative patient counseling. In particular, the clinician is now able to take an informed and positive stance about the tinnitus handicap to be expected postoperatively.     

头-眼运动训练视频在前庭康复中的应用

目的　探讨头-眼运动训练视频在前庭功能减退患者前庭康复中的作用及效果。方法　对2015年8月～2016年8月在耳鼻咽喉科就诊并确诊为前庭功能障碍37例行前庭康复训练,内容包括：采用视频软件进行头动训练和头-眼运动协调性训练;同时进行静态平衡功能练习和动态平衡功能练习,分别于训练前和训练2周后进行眩晕残障量表（dizziness handicap inventory,DHI）、眩晕的视觉模拟评分（visual analogue scale,VAS）和Romberg试验计时,并进行分析比较。结果　训练后DHI评分和眩晕VAS评分较训练前均显著降低（P＜0.01）;训练后Romberg试验计时较训练前显著延长（P＜0.01）。结论　头-眼运动训练视频可用于前庭康复训练,效果良好,值得临床推广。     

Effect of head orientation on human postural stability following unilateral vestibular ablation.

Effective interpretation of vestibular inputs to postural control requires that orientation of head on body is known. Postural stability might deteriorate when vestibular information and neck information are not properly coupled, as might occur with vestibular pathology. Postural sway was assessed in unilateral vestibulopathic patients before and acutely, 1, 4, and 18+ months after unilateral vestibular ablation (UVA) as well as in normal subjects. Postural equilibrium with eyes closed was quantified as scaled pk-pk sway during 20 s trials in which the support surface was modulated proportionally with sway. Subjects were tested with the head upright and facing forward, turned 45 degrees right, and 45 degrees left. Equilibrium was uninfluenced by head orientation in normal subjects. In contrast, patients after UVA showed both a general reduction in stability and a right/left head orientation-dependent asymmetry. These abnormalities adaptively recovered with time. It is concluded that vestibular inputs to postural control are interpreted within a sensory-motor context of head-on-body orientation.     

Effects of vestibular rehabilitation and social reinforcement on recovery following ablative vestibular surgery

This study investigated the relative effects of vestibular rehabilitation (VR) and social reinforcement (SR) on recovery following ablative vestibular surgery. Twenty-four subjects were randomly assigned to three treatment groups of either VR with SR, VR without SR, or general range of motion (ROM) exercises with SR. Outcome measures included equilibrium scores in dynamic posturography, asymmetry index in rotation testing, motion sensitivity quotient (MSQ), and dizziness handicap inventory (DHI). A multiple comparison of the overall outcome measures showed no significant differences in group performance over an 8-week period. When individual outcome measures were compared, MSQ and DHI results at the end of the 8-week treatment period revealed less motion sensitivity and dizziness handicap in groups who received VR, with or without SR, as compared with the group who received ROM exercises. These results suggest that after a vestibular injury most patients can effectively utilize central compensation mechanisms to recover from such an injury, regardless of the type of therapeutic intervention used. On the other hand, the reduction in motion sensitivity and dizziness handicap for patients who received VR could indicate a more rapid and complete recovery for these patients. This investigation is continuing as a long-term follow-up study to determine whether there are any long-term benefits in participating in a VR program.     

Effects of steroid therapy on long-term canal prognosis and activity in the daily life of vestibular neuronitis patients

We studied 28 patients with vestibular neuronitis treated at our hospital between 1997 and 1999. To determine the effects of steroid therapy on long-term canal prognosis and daily activity, we examined caloric tests and gave questionnaires to 12 steroid-treated and 16 nonsteroid-treated patients 2 years after onset. We found that canal improvement was 50% in the nonsteroid-treated group and 75% in the steroid-treated one. In cases with severe canal paresis (CP > or = 60%), canal improvement was 33% in the nonsteroid-treated group and 67% in the steroid-treated one. Steroid therapy at the acute stage of this disease significantly reduced the duration of spontaneous nystagmus and handicap in daily life due to dizziness induced by head and body movement, decreasing mood disturbance.     

Recovery of dynamic visual acuity in unilateral vestibular hypofunction

OBJECTIVE: To determine the effect of vestibular exercises on the recovery of visual acuity during head movement in patients with unilateral vestibular hypofunction.Study DESIGN: Prospective, randomized, double-blind study. SETTING: Ambulatory referral center. PATIENTS: Twenty-one patients with unilateral vestibular hypofunction, aged 20 to 86 years. INTERVENTION: One group (13 patients) performed vestibular exercises designed to enhance the vestibulo-ocular reflex, and the other group (8 patients) performed placebo exercises. The placebo group was switched to vestibular exercises after 4 weeks. OUTCOME MEASURES: Measurements of dynamic visual acuity (DVA) during predictable (DVA-predictable) and unpredictable (DVA-unpredictable) head movements by means of a computerized test and measurement of intensity of oscillopsia by means of a visual analog scale. RESULTS: As a group, patients who performed vestibular exercises showed a significant improvement in DVA-predictable (P<.001) and DVA-unpredictable (P<.001), while those performing placebo exercises did not (P =.07). On the basis of stepwise regression analysis, the leading factor contributing to improvement was vestibular exercises. This reached significance for DVA-predictable (P =.009) but not DVA-unpredictable (P =.11). Other factors examined included age, time from onset, initial DVA, oscillopsia, and duration of treatment. Changes in oscillopsia did not correlate with DVA-predictable or DVA-unpredictable. CONCLUSIONS: Use of vestibular exercises is the main factor involved in recovery of DVA-predictable and DVA-unpredictable in patients with unilateral vestibular hypofunction. Exercises may foster the use of centrally programmed eye movements that could substitute for the vestibulo-ocular reflex. The DVA-predictable would benefit more from this than would DVA-unpredictable.     

Vestibular rehabilitation therapy in combination with transcranial direct current stimulation (tDCS) for treatment of chronic vestibular dysfunction in the elderly: a double-blind randomized controlled trial

IntroductionDizziness and imbalance are common dysfunctions in the elderly. Vestibular rehabilitation therapy is an effective method to alleviate chronic dizziness in patients with vestibular dysfunction. Transcranial direct current stimulation has reportedly improved balance function in patients with vestibular dysfunction.ObjectiveThis study was conducted to investigate the therapeutic efficacy of vestibular rehabilitation combined with transcranial direct current stimulation in elderly patients with vestibular dysfunction.MethodsIn a double-blinded randomized controlled trial, 36 elderly patients with chronic vestibular dysfunction were randomly assigned to either vestibular rehabilitation and transcranial direct current stimulation (n = 18) or vestibular rehabilitation alone (n = 18) group. The transcranial stimulation protocol consisted of multisession bifrontal electrical stimulation of the dorsolateral prefrontal cortex (2 mA intensity and 20 min duration), followed by rehabilitation exercises. The vestibular rehabilitation protocol consisted of habituation and adaptation exercises combined with gait exercises during a three week period. The primary outcome of this study was the dizziness handicap inventory score, and the secondary outcomes were activities-specific balance confidence and Beck anxiety inventory scores.ResultsFor the dizziness handicap score, the repeated-measures analysis of variance showed a significant main effect of “time”, “stimulation” and stimulation × time interaction effect. There was a significant reduction in the overall dizziness handicap score with “time” for both the groups, which was more pronounced in the vestibular rehabilitation and electrical stimulation group. In terms of activities-specific balance confidence change scores, we found a significant main effect of “time” and “stimulation” main factors, but this effect for stimulation × time interaction was not significant. For the Beck anxiety score, we observed a significant main effect of “time”, but no evidence for the main effect of the “stimulation” factor.ConclusionBifrontal transcranial direct current stimulation in combination with vestibular rehabilitation therapy is a promising approach to improve chronic vestibular symptoms in the elderly.     

Symptoms, disability and handicap in unilateral peripheral vestibular disorders. Effects of early presentation and initiation of balance exercises

The aim of this study was to obtain a profile of disability and handicap in patients with unilateral peripheral vestibular disorders presenting to a specialist tertiary care unit. Two validated questionnaires were sent to patients who had a unilateral peripheral vestibular disorder as defined by strict criteria. Some patients still suffered moderate handicap and disability 5 years after the initial symptoms related to a unilateral vestibular disorder, although the duration of symptoms (onset to questionnaire completion) did not correlate with severity of disability and handicap, as judged by questionnaire scores. However, patients presenting to the unit within 6 months of onset of vertigo commenced balance exercises significantly earlier and had significantly lower disability scores than patients presenting later. A high proportion of non-compliance with, and delay in initiation of, vestibular rehabilitation exercises was noted in the total patient sample, while compliance with, and early initiation of, Cooksey Cawthorne exercises were significantly correlated with low disability and questionnaire scores. These findings suggest that early referral to a specialist balance unit for patients with persistent dizziness is associated with better outcome.     

Aquatic physiotherapy: a vestibular rehabilitation option

IntroductionVestibular rehabilitation is a fundamental resource for vestibular symptom control. Its performance in the aquatic environment is considered safe for the physical activities of the elderly, because they act simultaneously on musculoskeletal disorders and balance improvement.ObjectiveTo evaluate the effects of an aquatic physiotherapy protocol in individuals with peripheral vestibular alterations.MethodsThis was an interventional case study with a paired intentional sample of four subjects, who were selected for convenience. The subjects, all of them diagnosed with peripheral vestibulopathy, were submitted to twelve sessions of aquatic physiotherapy for vestibular rehabilitation, being evaluated for dizziness in three moments: initial, after six sessions and at the end of the sessions. The tests applied were: unipodal support to measure static balance, the Fukuda stepping test, which estimates the dynamic balance and the dizziness handicap inventory protocol, aimed at verifying how dizziness influences daily life.ResultsWhen analyzing the static balance, initially the individuals were in the adaptive and abnormal dimensions, and all reached normality at the end of the protocol. Regarding the dynamic balance, the individuals initially showed marked impairment in the angular deviation, mainly to the side of pathology (75% to the left and 25% to the right), achieving improvement at the end of the study. However, it failed to reach statistical significance. The dizziness handicap inventory showed a statistically significant difference in its totality (p = 0.0414), which addresses the physical, functional and emotional factors.ConclusionIn conclusion, the aquatic physiotherapy protocol for vestibular rehabilitation of patients with peripheral impairment was positively assessed by the participants, considering the improvement in dizziness (static and dynamic) and its impact on daily activities.     

Vestibular rehabilitation for migraine-associated dizziness

The purpose of this study was to investigate the effects of a vestibular rehabilitation program on patients with the diagnosis of migraine-associated dizziness. Subjects were placed in four groups as follows: idiopathic migraine-associated dizziness; idiopathic migraine-associated dizziness and associated benign positional vertigo; posttraumatic migraine-associated dizziness; and posttraumatic migraine-associated dizziness and benign positional vertigo. Vestibular rehabilitation therapy was administered to all patients. Criterion measurements included the dizziness handicap inventory, activities-specific balance confidence scale, computerized dynamic posturography performance, and dynamic gait index. After vestibular physical therapy, all subjects showed significant improvement in the dizziness handicap, activities-specific balance confidence, dynamic gait, and computerized dynamic posturography measures. Patients with migraine-associated dizziness can benefit from physical therapy intervention. The results of this study are important in considering the approach to vertiginous migraine patients with and without head injury.     

Optimal parameters for the clinical test of dynamic visual acuity in patients with a unilateral vestibular deficit

OBJECTIVE: To determine the influence of frequency and direction of head movement and type of vision chart on the score of a clinical test of dynamic visual acuity (DVA). METHODS: The subjects were 31 healthy individuals (22 to 79 years old) and 10 patients (19 to 70 years old) with a unilateral vestibular deficit owing to surgical resection of an acoustic neuroma. They read a Snellen or an E-chart while their head was passively moved +/- 20 degrees back and forth in the horizontal or vertical direction at one of four frequencies (0.5, 1.0, 1.5, and 2.0 Hz). The DVA score was the difference in the number of lines on the vision chart that could be read with the head passively moved versus with the head immobile. RESULTS: Four healthy subjects had a low DVA score during horizontal head movements at the fastest frequency (2.0 Hz) with the Snellen chart. In patients, DVA scores significantly decreased as head movement frequency increased from 0.5 to 1.0 Hz and from 1.0 to 1.5 Hz, during horizontal and vertical movements, and with both vision charts (p < .001). The DVA scores of healthy subjects were more consistent across three trials with the E-chart than with the Snellen chart at 1.0 and 0.5 Hz (horizontal movements, p < .01) and at 1.5 and 1.0 Hz (vertical movements, p < .01). CONCLUSIONS: This study provides new indications on the optimal parameters for the clinical test of DVA. From the results, it is recommended that DVA be tested during horizontal and vertical head movements at a frequency of 1.5 Hz with the E-chart.     

The effect of severity of unilateral vestibular dysfunction on symptoms, disabilities and handicap in vertiginous patients.

This study compares the symptoms, disabilities and handicap, as assessed by means of a questionnaire, in two groups of patients with a unilateral peripheral vestibular disorder: those with a total canal paresis and those with a partial canal paresis, as judged by the duration parameter using the Fitzgerald Hallpike caloric test in the absence of optic fixation. The results of the study indicate that the severity of dizziness, the Dizziness Index (severity x frequency) and the overall level of disabilities related to visual vertigo are less severe in unilateral profound or total loss of vestibular function than in unilateral mild vestibular loss.     

Postural control after vestibular schwannoma resection measured with visual feedback posturography

BACKGROUND: Vestibular symptoms after surgery diminish rapidly, but the simultaneous progress in active postural control has not been fully addressed. OBJECTIVES: The aim was to evaluate the progress in postural control in operated vestibular schwannoma (VS) patients with visual feedback posturography (VFP). METHODS: 36 consecutive patients with unilateral VS were studied with the VFP pre-operatively, 1 month and 3 months after the surgery. The accuracy and velocity of active postural control movements to distant targets in VFP was measured and compared to that of healthy controls. RESULTS: The hold percentage within the targets was significantly reduced in the VS patients compared to the controls (pre-operatively p = 0.005; postoperatively at 1 month p = 0.002 and at 3 months p = 0.017). The sway velocity (SV) within the targets among patients with VS was significantly increased pre-operatively (p = 0.009), at the 1-month (p = 0.004) and at the 3-month follow-up visits (p = 0.016). All the postural control parameters except SV tended to improve slightly postoperatively. The consecutive VFP measurements in individual VS patients correlated statistically significantly (p < 0.001 for all parameters). The abnormality in the pre-operative VFP results correlated statistically significantly with that of postoperative VFP (p = 0.001). CONCLUSIONS: The VFP is an objective and repeatable method, which can be used to assess and follow up the active postural control in individual patients with VS. Persisting abnormality in the VFP seems to be an indication for more aggressive vestibular rehabilitation to normalize the disturbed postural control.     

Feasibility and effectiveness of providing vestibular rehabilitation for dizzy patients in the community

Since the majority of people with dizziness in the community are never referred for specialist testing and treatment, the purpose of this study was to investigate whether it was desirable and feasible to provide vestibular rehabilitation for this patient population. Demand for therapy was assessed by a survey of 9198 working age people randomly sampled from six general practices. One in 10 respondents reported current, handicapping dizziness, but fewer than 2% of those with dizziness severe enough to merit treatment proved suitable and willing to attend hospital for testing and rehabilitation. Nevertheless, vestibular rehabilitation was clearly beneficial for the 16 patients who completed the therapy programme, as their scores on measures of symptoms, disability, handicap and postural stability improved significantly post-therapy to near-normal levels. We conclude that there is a need for provision of vestibular rehabilitation in primary care for patients with dizziness in the community.     

Self-perceived balance disability/handicap in the presence of bilateral peripheral vestibular system impairment

The purpose of this report was to characterize the self-perceived balance disability/handicap of patients with bilateral reductions and bilateral complete losses of peripheral vestibular system function. Data from 72 patients whose electronystagmography and rotational examinations suggested normal, unilateral, or bilateral reductions in peripheral vestibular system function were used in the first investigation. Patients also completed a Dizziness Handicap Inventory (DHI). Results demonstrated significant group differences for DHI total and physical subscale scores. There were significant differences between normal and bilateral weakness groups for the total DHI score and between normal and unilateral and normal and bilateral weakness groups for the physical subscale score. In a second investigation, an item analysis of the DHI is presented for five patients with bilateral complete losses of peripheral vestibular system function. Results show that, predictably, these patients have difficulty engaging in activities requiring an intact vestibulocular reflex (e.g., physical activities such as sports, household chores).