Unilateral Peripheral Vestibular Loss Research Articles

People with multiple sclerosis and unilateral peripheral vestibular loss demonstrate similar alterations in head and trunk turning kinematics compared to healthy controls

BackgroundIndividuals with peripheral vestibulopathy are known to have difficulty with volitional head turns. This leads to differences in head and body turning kinematics, compared to those without vestibular dysfunction. Multiple sclerosis (MS), a neuro-inflammatory disease affecting the central nervous system, can cause vestibular dysfunction (dizziness, unsteadiness, gaze instability). However, head and trunk turning kinematics in people with MS (PwMS) have not been assessed. Research questionWill PwMS, demonstrate head and body kinematics alterations similar to individuals with a peripheral dysfunction compared to vestibular healthy individuals? MethodsEleven individuals with a recent vestibular schwannoma resection (VSR), fourteen PwMS, and 10 healthy control (HC) participants were fitted with head and trunk worn inertial measurement units (IMUs) and performed walking and turning tasks. Head and trunk peak turning speed and amplitude were extracted. Regression models controlling for gait speed were fit per outcome with post hoc corrections applied to significant models. ResultsYaw plane head turn speed and amplitude were significantly less in the VSR group compared to HC. Pitch plane head turn amplitude was significantly smaller in PwMS compared to HC (p = 0.04), however pitch plane speed did not differ between the groups. There was no difference between PwMS and the VSR group in yaw or pitch plane speed and amplitude. Both PwMS and the VSR group turned significantly slower than HC during the 180d body turn as measured at the head and trunk (head speed model p = 0.009 and <0.001; trunk speed model p < 0.001 for both groups) however the MS and VSR groups did not differ from each other. SignificanceTurning kinematics while walking in PwMS are altered compared to HC and are similar to individuals with unilateral vestibular hypofunction. Centrally mediated vestibular dysfunction in PwMS may alter movement kinematics and should be considered during examination and treatment.

Vertigoheel improves central vestibular compensation after unilateral peripheral vestibulopathy in rats.

The aim of this study was to assess the effect of Vertigoheel on central vestibular compensation and cognitive deficits in rats subjected to peripheral vestibular loss. Young adult male Long Evans rats were subjected to bilateral vestibular insults through irreversible sequential ototoxic destructions of the vestibular sensory organs. Vestibular syndrome characteristics were monitored at several time points over days and weeks following the sequential insults, using a combination of behavioral assessment paradigms allowing appreciation of patterns of change in static and dynamic deficits, together with spatial navigation, learning, and memory processes. Vertigoheel administered intraperitoneally significantly improved maximum body velocity and not moving time relative to its vehicle control on days 2 and 3 and on day 2, respectively, after unilateral vestibular lesion (UVL). It also significantly improved postural control relative to its vehicle 1 day after UVL. Conversely, Vertigoheel did not display any significant effect vs. vehicle on the severity of the syndrome, nor on the time course of other examined parameters, such as distance moved, mean body velocity, meander, and rearing. Spatial cognition testing using Y- and T-maze and eight-radial arm maze did not show any statistically significant difference between Vertigoheel and vehicle groups. However, Vertigoheel potentially enhanced the speed of learning in sham animals. Evaluating Vertigoheel's effect on thigmotaxis during the open-field video tracking test revealed no significant difference between Vertigoheel and its vehicle control groups suggesting that Vertigoheel does not seem to induce sedative or anxiolytic effects that could negatively affect vestibular and memory function. Present observations reveal that Vertigoheel improves central vestibular compensation following the unilateral peripheral vestibular loss as demonstrated by improvement of specific symptoms.

Head-shaking-induced nystagmus reflects dynamic vestibular compensation: A 2-year follow-up study.

PurposeWe aimed to assess the ability of a head-shaking test (HST) to reflect vestibular compensation in patients after unilateral peripheral vestibular loss and to provide missing evidence and new insights into the features of head-shaking-induced nystagmus (HSN) over a 2-year follow-up.BackgroundHSN may occur after a prolonged sinusoidal oscillation of the head. HSN is frequently observed in subjects with vestibular function asymmetry; it usually beats toward the functionally intact or “stronger” ear and can be followed by a reversal of its direction.Study designA prospective observational case-control study.SettingsA tertiary academic referral center.MethodsA total of 38 patients after acute unilateral vestibular loss (22 patients with vestibular neuronitis and 16 patients after vestibular neurectomy) and 28 healthy controls were followed for four consecutive visits over a 2-year period. A complex vestibular assessment was performed on all participants, which included spontaneous nystagmus (SPN), the caloric test, the head-shaking test (HST), the video head impulse test (vHIT), the Timed Up and Go (TUG) test, and the Dizziness Handicap Inventory (DHI) questionnaire. We established the criteria for the poorly compensated group to assess different compensatory behaviors and results.ResultsWe found a time-related decrease in HSN (ρ < −0.84, p < 0.001) after unilateral vestibular loss. After 2 years of follow-up, HSN intensity in compensated patients reached the level of the control group; TUG and DHI also improved to normal; however, the caloric and vHIT tests remained abnormal throughout all follow-ups, indicating a chronic vestibular deficit. Besides, poorly compensated patients had a well-detectable HSN throughout all follow-ups; TUG remained abnormal, and DHI showed at least a moderate deficit.ConclusionsOur study showed that, after a unilateral peripheral vestibular loss, the intensity of HSN decreased exponentially over time, reflecting an improvement in dynamic ability and self-perceived deficit. HSN tended to decline to the value of the control group once vestibular compensation was satisfactory and sufficient for a patient's everyday life. In contrast, well-detectable HSN in poorly compensated patients with insufficient clinical recovery confirmed the potential of HSN to reflect and distinguish between adequate and insufficient dynamic compensation. HSN could serve as an objective indicator of stable unilateral vestibular loss.

Investigation of the Relationship between Vestibular Disorders and Sleep Disturbance.

Introduction Vestibular pathologies cause physical and psychological symptoms, as well as cognitive problems. Objective To evaluate the deterioration in sleep quality associated with vestibular pathologies. Methods The Dizziness Handicap Inventory (DHI), the Beck Depression Inventory (BDI), the Pittsburgh Sleep Quality Index (PSQI), and the Limits of Stability test (LOS) were applied to the participants. Results We included 25 patients with Meniere's disease (MD), 22 patients with benign paroxysmal positional vertigo (BPPV), 21 patients with unilateral peripheral vestibular loss (UPVL), 23 patients with vestibular migraine (VM), and 43 controls. The total PSQI scores of the controls were better than those of the MD ( p = 0.014), VM ( p < 0.001), BPPV ( p = 0.003), and UPVL ( p = 0.001) groups. The proportion of poor sleepers in the MD ( p = 0.005), BPPV ( p = 0.018), and UPVL ( p < 0.001) groups was significantly higher than that of the controls. The highest total DHI score (45.68 ± 25.76) was found among the MD group, and it was significantly higher than the scores of the BPPV ( p = 0.007) and control ( p < 0.001) groups. The highest BDI score was obtained in the VM group, and it was significantly higher than the scores of the BPPV ( p = 0.046) and control ( p < 0.001) groups. Moreover, the BDI scores of the MD ( p = 0.001) and UPVL groups were also significantly worse than the score of the controls ( p = 0.001). Conclusion The present study showed thatpatients with vestibular symptoms have physical and functional complaints, as well as increased psychosocial stress and decreased sleep quality. Evaluating multiple parameters of quality of life may contribute to a better understanding of vestibular physiology and symptoms, and may help establish a more effective therapeutic approach.

Is Skull-Vibration-Induced Nystagmus Modified with Aging?

Background: Despite clinical practice utilizing the Dumas test (SVINT), some questions remain unanswered, including the age-related changes in frequency (FN) and slow-phase angular velocity (SPAV). This study aims to retrospectively evaluate their variations in subjects affected by unilateral peripheral vestibular loss (UPVL). Methods: We evaluated the selected samples based on the results of the SVINT, the results of the vestibular-evoked potentials (C-VEMP and O-VEMP), and the results of the head impulse test (HIT) and we compared the results against the age of the patients. We calculated the timing between the onset of UPVL and clinical evaluation in days. The presence or absence of VEMP indicated the UPVL severity. UPVL and BPPV patients with spontaneous or pseudo-spontaneous nystagmus were compared. Results: Statistical analysis showed changes in the FN and SPAV depending on age and the side of the application of the stimulus. We also observed that, in the UPVL, the severity of the disease modifies the SPAV, but not the frequency. Conclusions: The SVINT is a simple, reliable, and straightforward test that, if evaluated instrumentally, can show significant differences with aging. Further studies need to be performed to refine the clinical significance of the test and clarify its physiological background.

Perioperative vestibular assessment and testing

Vestibular disorders can be difficult to accurately diagnose and manage. A careful history and focused physical examination are typically adequate to establish a diagnosis and initiate medical treatment. Vestibular testing is an important component of the work-up, but it is particularly essential for patients being considered for surgical intervention for a vestibular disorder, where the testing can be used to more definitively confirm a suspected diagnosis and to determine baseline vestibular organ function. In this article, we will first briefly review key components of the history and physical examination of patients with vestibular complaints. We will then discuss the most commonly used vestibular tests and their role in the preoperative assessment of patients undergoing vestibular surgery, including nystagmography, caloric testing, rotary chair testing, video head impulse testing, and vestibular evoked myogenic potential testing.

The Effect of Peripheral Vestibular Recovery on Improvements in Vestibulo-ocular Reflexes and Balance Control After Acute Unilateral Peripheral Vestibular Loss.

Patients with an acute unilateral peripheral vestibular deficit (aUPVD), presumed to be caused by vestibular neuritis, show asymmetrical vestibular ocular reflexes (VORs) that improve over time. Questions arise regarding how much of the VOR improvement is due to peripheral recovery or central compensation, and whether differences in peripheral recovery influence balance control outcomes. Thirty patients were examined at aUPVD onset and 3, 6, and 13 weeks later with four different VOR tests: caloric tests; rotating (ROT) chair tests performed in yaw with angular accelerations of 5 and 20 degrees/s; and video head impulse tests (vHIT) in the yaw plane. ROT and vHIT responses and balance control of 11 patients who had a caloric canal paresis (CP) more than 90% at aUPVD onset and no CP recovery (no-CPR) at 13 weeks in caloric tests were compared with those of 19 patients with CP recovery (CPR) to less than 30%, on average. Balance control was measured with a gyroscope system (SwayStar) recording trunk sway during stance and gait tasks. ROT and vHIT asymmetries of no-CPR and CPR patients reduced over time. The reduction was less at 13 weeks (36.2% vs. 83.5% on average) for the no-CPR patients. The no-CPR group asymmetries at 13 weeks were greater than those of CPR patients who had normal asymmetries. The greater asymmetries were caused by weaker deficit side responses which remained deficient in no-CPR patients at 13 weeks. Contra-deficit side vHIT and ROT responses remained normal. For all balance tests, sway was slightly greater for no-CPR compared with CPR patients at aUPVD onset and 3 weeks later. At 13 weeks, only sway during walking eyes closed was greater for the no-CPR group. A combination of 5 degrees/s ROT and balance tests could predict at onset (90% accuracy) which patients would have no-CPR at 13 weeks. These results indicate that for ROT and vHIT tests, central compensation is observed in CPR and no-CPR patients. It acts primarily by increasing deficit side responses. Central compensation provides approximately 60% of the VOR improvement for CPR patients. The rest of the improvement is due to peripheral recovery which appears necessary to reduce VOR asymmetry to normal at 13 weeks on average. Balance control improvement is more rapid than that of the VOR and marginally affected by the lack of peripheral recovery. Both VOR and balance control measures at onset provide indicators of future peripheral recovery. For these reasons VOR and balance control needs to be tested at aUPVD onset and at 13 weeks.

Compensatory saccades in head impulse testing influence the dynamic visual acuity of patients with unilateral peripheral vestibulopathy1.

Both the dynamic visual acuity (DVA) test and the video head-impulse test (vHIT) are fast and simple ways to assess peripheral vestibulopathy. After losing peripheral vestibular function, some patients show better DVA performance than others, suggesting good compensatory mechanisms. It seems possible that compensatory covert saccades could be responsible for improved DVA. To investigate VOR gain and compensatory saccades with vHIT and compare them to the DVA of patients with unilateral peripheral vestibulopathy. VOR gain deficit and compensatory saccades were measured with vHIT. VOR gain was calculated for each trial as mean eye velocity divided by mean head velocity during 4 samples between 24 ms - 40 ms after peak head acceleration. DVA was then assessed. VHIT was analyzed for percentage of covert saccades and for cumulative overt saccade amplitude. Twenty-four patients with unilateral vestibular deficit were included. A control group of 113 healthy subjects provided normal data. On the affected side, pathologic values for DVA (mean 0.83 logMAR±0.25 SD) and VOR gain (mean 0.16±0.13) were obtained, whereas the healthy side showed normal values (0.53 logMAR±0.15 for DVA and 0.89±0.18 for VOR gain). Yet, DVA performance on the affected side was significantly better in patients with higher covert saccade percentage (p = 0.012) and lower cumulative overt saccade amplitude (p < 0.001). Compensatory covert saccades seen in vHIT correlate with improved performance of DVA-testing in patients with unilateral peripheral vestibular loss. Hence, in addition to testing peripheral vestibulopathy, our results indicate a way for assessing rehabilitatory compensation in such patients by DVA in addition to vHIT.

The Effect of Age on Improvements in Vestibulo-Ocular Reflexes and Balance Control after Acute Unilateral Peripheral Vestibular Loss.

An acute unilateral peripheral vestibular loss (aUVL) initially causes severe gaze and balance control problems. However, vestibulo-ocular reflexes (VOR) and balance control are nearly normal 3 months later as a result of peripheral recovery and/or central compensation. As pre-existing vestibular sensory loss is assumed to be greater in the healthy elderly, this study investigated whether improvements in VOR and balance function over time after aUVL are different for the elderly than for the young. Thirty aUVL patients divided into three age-groups were studied (8 age range 23-35, 10 with range 43-58, and 12 with range 60-74 years). To measure VOR function eye movements were recorded during caloric irrigation, rotating chair (ROT), and head impulse tests. Balance control during stance and gait was recorded as lower trunk angular velocity in the pitch and roll planes. Measurements were taken at deficit onset, and 3, 6, and 13 weeks later. There was one difference in VOR improvements over time between the age-groups: Low acceleration ROT responses were less at onset in the elderly group. Deficit side VOR responses and asymmetries in each group improved to within ranges of healthy controls at 13 weeks. Trunk sway of the elderly was greater for stance and gait at onset when compared to healthy age-matched controls and the young and greater than that of the young and controls during gait tasks at 13 weeks. The sway of the young was not different from controls at either time point. Balance control for the elderly improved slower than for the young. These results indicate that VOR improvement after an aUVL does not differ with age, except for low accelerations. Recovery rates are different between age-groups for balance control tests. Balance control in the elderly is more abnormal at aUVL onset for stance and gait tasks with the gait abnormalities remaining after 13 weeks. Thus, we conclude that balance control in the elderly is more affected by the UVL than for the young, and the young overcome balance deficits more rapidly. These differences with age should be taken into account when planning rehabilitation.

P32. Prevalence of parkinson symptoms among patients with peripheral vestibular disorders

Introduction In a recent epidemiologic study 5.3% of patients with parkinson disease (PD; mean age 70.5years) and up to 11% of PD patients with self-reported vertigo and dizziness had a benign paroxysmal positional vertigo (BPPV) (VanWensen et al., 2013). The prevalence of PD in industrialized countries is generally estimated at 0.1– 0.3% of the entire population (mean age German population ∼44years). It is more common in the elderly, where prevalences rise from 1.8% in those over 65years of age to 2–3% in the population over 80years (Official guidelines of the German Neurological Society, 2012; De Lau and Breteler, 2006). Thus, two questions arise: first, whether the prevalence of PD is increased in patients with diagnosed BPPV, and secondly, whether the prevalence of parkinson symptoms differs in patients with BPPV compared to those with other peripheral vestibular syndromes such as an unilateral peripheral vestibular loss (vestibular neuritis, VN) or Meniere‘s disease (MD). Methods All patients with diagnosed BPPV ( n =2347), MD ( n =1481) and VN ( n =713) seen in an interdisciplinary dizziness unit as well as in the German Center for Vertigo and Balance disorders of the Munich University between 2004 and 2013 were retrospectively analysed concerning their signs and symptoms of PD. All patients routinely underwent a detailed neurological examination and detailed vestibular testing. The parkinson symptoms were retrospectively classified according to the modified Hoehn and Jahr scale (Goetz, 2004). Results The prevalence for parkinson symptoms in the total BPPV group (mean age 59years) was 1.1%. In the subgroups of BPPV patients >65years of age it raised to 2.6% ( n =25), >70years to 3.5% ( n =23; mean age 77years), and >80years to 4.5% ( n =8). The parkinson symptoms were only mild (Hoehn and Jahr stages ⩽ 2 in the great majority of patients; only 4 patients at stage 3). In VN (mean age 55years) and MD (mean age 59years) the prevalences lay within the range of the normal population: 0.1% in all VN patients, respectively 0.5% in those >65years ( n =1); 0.3% in MD patients, respectively 0.7% in those >65years ( n =4). Conclusions Among patients with peripheral vestibular disorders only the BPPV patients showed a slightly increased prevalence of parkinson symptoms compared to the general population (2.6% vs. 1.8% in patients >65years). However, the prevalence for PD in BPPV patients (3.5% >70years, mean age 77years) seems to be lower than the prevalence for BPPV in PD (5.3% at a mean age of 70.5years) at least in less severely affected patients that can visit an outpatient clinic.

Effectiveness of Conventional Versus Virtual Reality–Based Balance Exercises in Vestibular Rehabilitation for Unilateral Peripheral Vestibular Loss: Results of a Randomized Controlled Trial

ObjectiveTo compare the effectiveness of virtual reality–based balance exercises to conventional balance exercises during vestibular rehabilitation in patients with unilateral peripheral vestibular loss (UVL). DesignAssessor-blind, randomized controlled trial. SettingTwo acute care university teaching hospitals. ParticipantsPatients with UVL (N=71) who had dizziness/vertigo, and gait and balance impairment. InterventionsPatients with UVL were randomly assigned to receive 6 weeks of either conventional (n=36) or virtual reality–based (n=35) balance exercises during vestibular rehabilitation. The virtual reality-based group received an off-the-shelf virtual reality gaming system for home exercise, and the conventional group received a foam balance mat. Treatment comprised weekly visits to a physiotherapist and a daily home exercise program. Main Outcome MeasuresThe primary outcome was self-preferred gait speed. Secondary outcomes included other gait parameters and tasks, Sensory Organization Test (SOT), dynamic visual acuity, Hospital Anxiety and Depression Scale, Vestibular Rehabilitation Benefits Questionnaire, and Activities Balance Confidence Questionnaire. The subjective experience of vestibular rehabilitation was measured with a questionnaire. ResultsBoth groups improved, but there were no significant differences in gait speed between the groups postintervention (mean difference, −.03m/s; 95% confidence interval [CI], −.09 to .02m/s). There were also no significant differences between the groups in SOT scores (mean difference, .82%; 95% CI, −5.00% to 6.63%) or on any of the other secondary outcomes (P>.05). In both groups, adherence to exercise was high (∼77%), but the virtual reality–based group reported significantly more enjoyment (P=.001), less difficulty with (P=.009) and less tiredness after (P=.03) balance exercises. At 6 months, there were no significant between-group differences in physical outcomes. ConclusionsVirtual reality–based balance exercises performed during vestibular rehabilitation were not superior to conventional balance exercises during vestibular rehabilitation but may provide a more enjoyable method of retraining balance after unilateral peripheral vestibular loss.

Causes and characteristics of horizontal positional nystagmus

Direction changing horizontal positional nystagmus can be observed in a variety of central and peripheral vestibular disorders. We tested sixty subjects with horizontal positional nystagmus and vertigo on the Epley Omniax(®) rotator. Monocular video recordings were performed with the right or left ear down, in the supine and prone positions. Nystagmus slow-phase velocity (SPV) was plotted as a function of time. Thirty-one subjects diagnosed with horizontal canalolithiasis had paroxysmal horizontal geotropic nystagmus with the affected ear down (onset 0.8 ± 1 s, range 0-4.9 s, duration 11.7-47.9 s, peak SPV 79 ± 67°/s). The SPV peaked at 5-20 s and declined to 0 by 60 s; at 40 s from onset, the average SPV was 1.8 % of the peak. Nine subjects diagnosed with cupulolithiasis had persistent apogeotropic horizontal nystagmus (onset 0.7 ± 1.4 s, range 0-4.3 s). Peak SPV was 54.2 ± 31.8°/s and 26.6 ± 12.2°/s with unaffected and affected ears down, respectively. At 40 s, the average SPV had decayed to only 81 % (unaffected ear down) and 65 % (affected ear down) of the peak. Twenty subjects were diagnosed with disorders other than benign positional vertigo (BPV) [vestibular migraine (VM), Ménière's Disease, vestibular schwannoma, unilateral or bilateral peripheral vestibular loss]. Subjects with VM (n = 13) had persistent geotropic or apogeotropic horizontal nystagmus. On average, at 40 s from nystagmus onset, the SPV was 61 % of the peak. Two patients with Ménière's Disease had persistent apogeotropic horizontal nystagmus; the peak SPV at 40 s ranged between 28.6 and 49.5 % of the peak. Symptomatic horizontal positional nystagmus can be observed in canalolithiasis, cupulolithiasis and diverse central and peripheral vestibulopathies; its temporal and intensity profile could be helpful in the separation of these entities.

Effectiveness of conventional versus virtual reality based vestibular rehabilitation in the treatment of dizziness, gait and balance impairment in adults with unilateral peripheral vestibular loss: a randomised controlled trial

BackgroundUnilateral peripheral vestibular loss results in gait and balance impairment, dizziness and oscillopsia. Vestibular rehabilitation benefits patients but optimal treatment remains unkown. Virtual reality is an emerging tool in rehabilitation and provides opportunities to improve both outcomes and patient satisfaction with treatment. The Nintendo Wii Fit Plus® (NWFP) is a low cost virtual reality system that challenges balance and provides visual and auditory feedback. It may augment the motor learning that is required to improve balance and gait, but no trials to date have investigated efficacy.Methods/DesignIn a single (assessor) blind, two centre randomised controlled superiority trial, 80 patients with unilateral peripheral vestibular loss will be randomised to either conventional or virtual reality based (NWFP) vestibular rehabilitation for 6 weeks. The primary outcome measure is gait speed (measured with three dimensional gait analysis). Secondary outcomes include computerised posturography, dynamic visual acuity, and validated questionnaires on dizziness, confidence and anxiety/depression. Outcome will be assessed post treatment (8 weeks) and at 6 months.DiscussionAdvances in the gaming industry have allowed mass production of highly sophisticated low cost virtual reality systems that incorporate technology previously not accessible to most therapists and patients. Importantly, they are not confined to rehabilitation departments, can be used at home and provide an accurate record of adherence to exercise. The benefits of providing augmented feedback, increasing intensity of exercise and accurately measuring adherence may improve conventional vestibular rehabilitation but efficacy must first be demonstrated.Trial registrationClinical trials.gov identifier: NCT01442623

Recovery of the horizontal vestibulo-ocular reflex in motorized head impulse test is common after vestibular loss

Conclusion: Decreased horizontal vestibulo-ocular reflex (VOR) gain measured with the motorized head impulse rotator usually recovers at least partially within a few months after sudden unilateral vestibular loss. In addition to traditional evaluation of nystagmus, head impulse test responses provide valuable information on the severity and recovery of vestibular loss. Objectives: To quantify recovery of vestibular function with the motorized head impulse test in patients with acute unilateral peripheral vestibular loss, and to compare these results with other signs and symptoms. Methods: We recorded prospectively the horizontal VOR with the motorized head impulse rotator in 30 patients with sudden unilateral vestibular deficit on average 3 days after the onset (early). Twenty patients were measured sequentially on average 3 months later (late). We calculated VOR gain and asymmetry (mean ± standard deviation). Results: The early ipsilesional gain of 0.49 ± 0.21 improved highly significantly to the late gain of 0.79 ± 0.23 (p = 0.0000). The respective asymmetry improved highly significantly from 32 ± 18% to 12 ± 14% (p = 0.0002). Gain or asymmetry recovered at least partially in 80% of the patients. The late high symptom score correlated with low gain (p = 0.043) and high asymmetry (p = 0.018).

Subjective head vertical test reveals subtle head tilt in unilateral peripheral vestibular loss

Utricular dysfunction has been indirectly measured with subjective visual horizontal or vertical testing. Video-oculography equipment with integrated head position sensor allows direct evaluation of head tilt. The aim was to assess head tilt after peripheral vestibular lesion by recording tilting of the head after excluding visual cues (static test condition), and after three lateral head tilts to both sides [subjective head vertical (SHV)]. Thirty patients with unilateral, peripheral vestibular loss were measured in the acute state, and 3months later. Twenty healthy, age- and sex-matched subjects served as controls. Mean static tilt of 2.6±1.1° in patients with acute vestibular loss differed significantly from that of 1.0±0.4° in healthy subjects (p=0.004), and from that of 1.1±0.5° during the follow-up visit (p=0.008). The mean SHV of 3.4±0.7° in patients with acute vestibular loss was significantly more than that of 1.2±0.5° in controls (p<0.001). The SHV towards the lesion was 4.9±1.0° while returning from the lesion side and 2.0±1.0° while returning from the healthy side. The SHV was definitely abnormal in 60%, moderately abnormal in 20% and normal in 20% of the patients in acute state. Abnormal SHV persisted in only 20% of the patients indicating that recovery of the peripheral utricular function is occurring within months. In summary, head tilts slightly towards acute peripheral lesion, and this tilting is reinforced, when the head is actively moved on the lesion side.

A New Dynamic Visual Acuity Test to Assess Peripheral Vestibular Function

To evaluate a novel test for dynamic visual acuity (DVA) that uses an adaptive algorithm for changing the size of Landolt rings presented during active or passive head impulses, and to compare the results with search-coil head impulse testing. Prospective study in healthy individuals and patients with peripheral vestibular deficits. Tertiary academic center. One hundred neuro-otologically healthy individuals (age range, 19-80 years) and 15 patients with bilateral (n = 5) or unilateral (n = 10) peripheral vestibular loss (age range, 27-72 years). Testing of static visual acuity (SVA), DVA during active and passive horizontal head rotations (optotype presentation at head velocities >100 degrees/s and >150 degrees/s), and quantitative horizontal head impulse testing with scleral search coils. Difference between SVA and DVA, that is, visual acuity loss (VA loss), gain of the high-acceleration vestibulo-ocular reflex. Passive head impulses and higher velocities were more effective than active impulses and lower velocities. Using passive head impulses and velocities higher than 150 degrees/s, the DVA test discriminated significantly (P < .001) among patients with bilateral vestibulopathy, those with unilateral vestibulopathy, and normal individuals. The DVA test sensitivity was 100%, specificity was 94%, and accuracy was 95%, with search-coil head impulse testing used as a reference. In healthy individuals, VA loss increased significantly with age (P < .001; R(2) = 0.04). Dynamic visual acuity testing with Landolt rings that are adaptively changed in size enables detection of peripheral vestibular dysfunction in a fast and simple way.

Case Report Vestibular Rehabilitation Decreases Fall Risk and Improves Gaze Stability for an Older Individual with Unilateral Vestibular Hypofunction

Partial or total unilateral vestibular loss is the third most common cause of peripheral vestibular dysfunction. Dysfunction of one or both of the vestibular mechanisms can manifest physically as abnormalities of posture, balance, and/or visual acuity. This case report describes physical therapy examination and individualized intervention with vestibular rehabilitation for a patient with unilateral vestibular hypofunction. The patient was an 80-year-old male with electronystamographically confirmed unilateral vestibular loss of 98.3%. He demonstrated altered balance and gaze stability classifying him as having an increased risk for falling. After 5 weeks of individualized vestibular rehabilitation, the patient significantly decreased his fall risk from 11 to 20 of 24 on the Dynamic Gait Index. His gaze stability also improved from a 4 to 1 line disparity with dynamic visual acuity testing. The patient also had a decrease in perceived disability on the Dizziness Handicap Inventory from 30/100 at evaluation to 12/100 at discharge. Individualized vestibular rehabilitation decreased fall risk and improved gaze stability for a patient with significant unilateral vestibular hypofunction.

Relationship Between Dynamic Balance and Self-Reported Handicap in Patients Who Have Unilateral Peripheral Vestibular Loss

OBJECTIVE:: The purpose of this study was to investigate whether Dizziness Handicap Inventory (DHI) score is related to postural performance as assessed by dynamic posturography. STUDY DESIGN:: Retrospective study. SETTING:: Outpatient in a tertiary referral center. PATIENTS:: Ninety-two complete unilateral vestibular loss patients, categorized into 3 groups according to the postlesion stage: 1 to 2 months (n = 32; age, 47.6 +/- 10.7 yr), 4 to 7 months (n= 23; 47.1 +/- 8.37 yr), and 1 year and older (n = 37; 49.2 +/- 9.5 yr). MAIN OUTCOME MEASURES:: Dizziness Handicap Inventory and dynamic balance measured with a seesaw platform moving either in the anterior-posterior or in the mediolateral direction. RESULTS:: The mean DHI score was 25.8 +/- 18.7 and the range was 0 to 68. Dizziness Handicap Inventory scores did not differ significantly between the different unilateral vestibular loss groups studied. No difference was detected between the groups for the 3 subscores (emotional, functional, and physical), except that the older-than-1-year group had a significantly higher physical score than the 2 others. No correlation was found between DHI scores and postural indicators for either direction of the platform. However, patients unable to maintain balance when the seesaw platform moved in the mediolateral direction had significantly higher DHI scores than those who did not fall. CONCLUSION:: Even if they are not directly related, we suggest that DHI and dynamic posturography are complementary approaches for appreciating the vestibular compensation process and are thus useful for postoperative counseling for vestibular loss patients.

Cognitive Requirements for Vestibular and Ocular Motor Processing in Healthy Adults and Patients with Unilateral Vestibular Lesions

This study investigated the role of cognition in the vestibulo-ocular reflex (VOR) and ocular pursuit using a dual-task paradigm in patients with unilateral peripheral vestibular loss and healthy adults. We hypothesized that cognitive resources are involved in successful processing and integration of vestibular and ocular motor sensory information, and this requirement would be greater in patients with vestibular dysfunction. Sixteen well-compensated patients with surgically confirmed absent unilateral peripheral vestibular function and 16 healthy age- and sex-matched controls underwent seven combinations of vestibular-only, visual-only, and visual-vestibular stimuli while performing three different information processing tasks. Visual-vestibular stimuli included a semicircular canal and an otolith stimulus provided through seated chair rotations; fixation on a laser target and sinusoidal smooth pursuit while still; and fixation on a head-fixed laser target during chair rotations. The information processing tasks were three different auditory reaction time (RT) tasks: (1) simple RT, (2) disjunctive RT, and (3) choice RT. Our results showed increases in RTs in both patients and controls under all vestibular-only stimulation conditions and during ocular pursuit. Patients showed greater increases in RTs during vestibular stimulation and the more complex disjunctive and choice RT tasks. No differences between the groups were found during the visual-only or visual-vestibular interaction conditions. These results reveal interference between vestibulo-ocular processing and a concurrent RT task, suggesting that the VOR and the ocular motor system are dependent upon cognitive resources to some extent, and thus, are not fully automatic systems. We speculate that this interference with cognition occurs as a result of the sensory integration required for resolving inputs from multiple sensory streams. The particularly large decrement in information processing task performance of the patients compared with controls during vestibular stimulation suggests that compensation for unilateral vestibular loss requires continued cognitive resources.

9.11 Interference between postural control and cognitive processing in patients suffering from a unilateral peripheral vestibular loss

9.11 Interference between postural control and cognitive processing in patients suffering from a unilateral peripheral vestibular loss