Vestibular System Impairment Research Articles

Case Report: Pendular Nystagmus Presenting in Usher Syndrome Type I.

We describe a 42-year-old patient with reported "shaking" vision referred due to concerns of possible vestibular system dysfunction. The patient has known history of Usher syndrome type I, bilateral cochlear implants, and severe vision impairment. This case describes an unusual nystagmus previously only reported in individuals with central demyelinating disorders, significant light deprivation, or in congenital / early-onset visual pathway impairment. Case study. Retrospective chart review of vestibular function. Vestibular function was likely absent in this case. There was no evidence of vestibular (jerk) nystagmus for sinusoidal harmonic acceleration stimuli or repeatable responses for cervical vestibular evoked myogenic potentials. Significant pendular low amplitude high frequency oscillations of approximately 6 Hz were present for horizontal and vertical tracings throughout testing. Nystagmus may not always be associated with vestibular system impairment. In this case, the patient's reported "shaking" vision was attributed to pendular low amplitude high frequency nystagmus and hypothesized to relate to long-standing significant vision impairment. This presentation is unusual in adults and has historically been associated with individuals with significant central pathology or in those with long duration light deprivation.

Fully Automatic Fall Risk Assessment Based on a Fast Mobility Test.

This paper presents a fall risk assessment approach based on a fast mobility test, automatically evaluated using a low-cost, scalable system for the recording and analysis of body movement. This mobility test has never before been investigated as a sole source of data for fall risk assessment. It can be performed in a very limited space and needs only minimal additional equipment, yet provides large amounts of information, as the presented system can obtain much more data than traditional observation by capturing minute details regarding body movement. The readings are provided wirelessly by one to seven low-cost micro-electro-mechanical inertial measurement units attached to the subject’s body segments. Combined with a body model, these allow segment rotations and translations to be computed and for body movements to be recreated in software. The subject can then be automatically classified by an artificial neural network based on selected values in the test, and those with an elevated risk of falls can be identified. Results obtained from a group of 40 subjects of various ages, both healthy volunteers and patients with vestibular system impairment, are presented to demonstrate the combined capabilities of the test and system. Labelling of subjects as fallers and non-fallers was performed using an objective and precise sensory organization test; it is an important novelty as this approach to subject labelling has never before been used in the design and evaluation of fall risk assessment systems. The findings show a true-positive ratio of 85% and true-negative ratio of 63% for classifying subjects as fallers or non-fallers using the introduced fast mobility test, which are noticeably better than those obtained for the long-established Timed Up and Go test.

The Role of Vestibular Evoked Myogenic Potential and the Video Head Impulse Test in Patients with Multiple Sclerosis without Radiologic Findings

Objective: The aim is to evaluate the vestibular system using the video head impulse test (vHIT) and vestibular evoked myogenic potentials (VEMP) in patients with multiple sclerosis (MS) without central vestibular involvement in magnetic resonance imaging (MRI), and to determine whether there was subclinical vestibular system impairment. Materials and Methods: The study comprised 27 patients with MS and 26 healthy participants. The participants had no lesions in the central vestibular system in an MRI taken in the past 3 months. Detailed neuro-otologic and neuro-ophthalmologic examinations were performed on all participants. Then, the Dizziness Handicap Inventory (DHI) was completed for subjective vestibular system evaluation. In addition, vHIT and cervical VEMP (cVEMP) were performed for objective vestibular system evaluation. The results were analyzed statistically. Results: The mean age of the patients in the MS group was 39.3 ± 11.4 years and 42.7 ± 9.7 years in the control group. The median DHI score was 4 (range, 0–8) in the MS group and 2 (range, 0–6) in the control group. There were no statistically significant differences between the DHI score averages of the groups. The mean vestibulo ocular reflex (VOR) gain in vHIT was 0.76 ± 0.21 in the MS group and 0.99 ± 0.13 in the control group. VOR gain was statistically significantly lower in patients with MS. The VOR gain cut-off level was considered as 0.8. Gain level was below the cut-off level in 53.7% of patients with MS. There was no cVEMP response in 31.5% of patients with MS. In addition, patients with MS had prolonged P1 and N1 latencies and decreased P1-N1 peak-to-peak amplitudes. Conclusion: We found subclinical involvement in electrophysiologic tests (vHIT and cVEMP) in patients with MS without MRI lesions and without subjective vestibular system symptoms. We believe that vHIT and cVEMP can be used for subclinical evaluation in patients with MS without central vestibular system involvement in MRI.

Self-report symptoms differ between younger and older dizzy patients.

To determine whether the responses of elders compared with younger patients differed significantly on a structured dizziness case history. Retrospective case reviews. Outpatient balance function testing center. Two-hundred thirty-three adults who underwent vestibular function testing and completed a structured case history. The mean age of the adult group (18-64 yr) was 46.4 years. The mean age of the old adult group (65 yr and older) was 76.2 years. Patient's self-reported symptoms on a structured case history questionnaire. Younger adults reported significantly more complaints of true vertigo and associated nausea and vomiting compared with older patients. Older patients tended to report symptoms of unsteadiness or falling. Despite the lack of vertiginous symptoms, BPPV was common in older adults. The clinician should be aware of differences in self-report dizziness symptoms in older patients. Older patients who do not have vertigo may be told that their symptoms are normal for their age, when, in fact, they may have an undiagnosed vestibular system impairment.

Concordance and discordance in patient and provider perceptions of dizziness

PurposeThe purpose of the present investigation was to determine whether there are significant differences in patient/healthcare provider perceptions of patient's dizziness severity, dizziness disability/handicap, anxiety, and signs of autonomic system activation. Materials and methodsThis was a prospective investigation of 30 patient–provider dyads drawn as a sample of convenience from an otology clinic in a large, tertiary care, medical center. Patients completed both the Dizziness Handicap Inventory (DHI) and the Vestibular Symptom Scale (VSS) prior to vestibular function testing. Providers were instructed to complete the same measures following the patient's clinic visit from what they estimated was the patient's point of view. The two measures were analyzed for concordance and discordance. ResultsPatient/provider differences in DHI and VSS vertigo subscale scores were not significantly different. However, difference scores on the VSS anxiety/autonomic subscale indicated that providers significantly under-estimated patient anxiety and symptoms of autonomic system activation. ConclusionsThe results suggest that providers may be missing information pertinent to the role anxiety and autonomic system activation may play in patient visits for complaints of dizziness. We suggest that this problem can be mitigated by administrating to patients prior to their clinic visit a standardized measure that quantifies patient self-report dizziness, vertigo, anxiety and autonomic system arousal. Patterns of response by patients on these measures can enable providers to diagnose correctly dizziness disorders that are rooted in clinically significant anxiety either related to, or unrelated to, a history of vestibular system impairment.

Wpływ zabiegów fizjoterapeutycznych na jakość życia pacjentów z zaburzeniami ośrodkowej części układu przedsionkowego

The aim of the study was to evaluate the impact of physiotherapy on balance stability and quality of life improvement in patients with central vestibular system dysfunction. Material and methodsThe study was conducted on 31 patients (23 females, 8 males) with vertigo/dizziness and unsteadiness diagnosed for central vestibular system impairment based on videonystagraphy examinations, in ENT Department Medical University of Lodz between 2010-2011 years. Patients’ history of diseases were collected. The physiotherapeutic programme was individually introduced during four weeks (five time a week). The intervention included balance training and habituation exercises. At baseline and after patients were evaluated therapy with WHO Quality of Life-BREF (WHOQOL-BREF) and Dizzeness Handicap Inventory (DHI) self-assessment scales. Clinical examination with Romberg and stand one leg tests (eyes opened and closed) was performed. ResultsAfter therapy statistically significant differences in total DHI score (p<0.005) and 3 subscales: physical, emotional, functional (p<0.05) and WHOQOL-BREF only physical subscale (p<0.05) compared baseline were found. There were no statistical differences between psychological, social relationships and environment subscales. In clinical evaluation significant reduction of unsteadiness in Romberg test (p<0.05) and in stand one leg tests eyes opened and closed tests (p<0.05) were found. ConclusionIn patients with central vestibular system impairment after physical therapy betterment in clinical examination and some subjective self-assessment scales were observed. Lack of significant improvement in psychological, social relationships and environment domain in WHOQOL-BREF subscale indicated that these patients may need more psychological support or extensions in physiotherapy.

Patterns of Abnormality in cVEMP, oVEMP, and Caloric Tests May Provide Topological Information about Vestibular Impairment

The cervical vestibular evoked myogenic potential (cVEMP) is recorded from the sternocleidomastoid muscle (SCM) and represents a stimulus-evoked attenuation of electromyographic (EMG) activity following activation of the saccule and inferior vestibular nerve. In addition to the cVEMP, it is possible to record a biphasic response from the infraorbital region following stimulation that is identical to that used to record the cVEMP. This response is known as the ocular VEMP (oVEMP). The peripheral vestibular origins of the oVEMP elicited with air conduction remain controversial as some investigators argue the response originates from the saccule and others argue that the response emanates from the utricle. We review several lines of evidence and present several case studies supporting the contention that the oVEMP to air conduction stimulation derives its peripheral origins predominantly from the utricle and superior vestibular nerve. To review the current evidence regarding the peripheral origins of the oVEMP. Further, a purpose of this report is to present case studies illustrating that the cVEMP and oVEMP to air conduction stimulation may vary independently of one another in patients with peripheral vestibular system impairments. A collection of case studies illustrating three common patterns of abnormality observed in patients complaining of vertigo seen in a tertiary care referral center. Retrospective analysis of data from three patients complaining of dizziness and/or vertigo who have undergone vestibular function tests. Each case report illustrates a different pattern of abnormality of caloric, cVEMP, and oVEMP tests results from three patients with a vestibular nerve section, superior vestibular neuritis, and Ménière's disease, respectively. We have shown that the cVEMP and oVEMP can vary independent of one another, and in that way, provide topological information about the sites of impairment. We feel that, with caloric, oVEMP, and cVEMP tests, it is possible to augment the diagnostic information we are able to provide regarding the location, or locations, of vestibular system impairment. These findings suggest that air conduction oVEMPs measure a part of the peripheral vestibular system different from that measured by cVEMPs, perhaps the utricle, and similar to that measured by caloric testing, the superior portion of the vestibular nerve.

Ilościowa analiza testów wzrokowo-okoruchowych u pacjentów z SM

Abnormalities in the ocular-motor reflex recorded in electronystagmography may indicate central vestibular system impairment. Multiple sclerosis (MS) is the most common chronic, debilitating disease characterized by focal demyelinization that develops throughout the central nerves system at varying time. The aim of the study was to apply the quantitative analysis of ocular-motor tests to evaluation degree of the central system impairment in MS patients. The study was carried on 60 MS patients consulted in Balance Division, Otolaryngology Clinic, Medical University of Lodz, from 2002 to 2004, and 50 healthy persons as the control group. Clinical otoneurolaryngological examinations and electronystagmography tests (smooth pursuit, optokinetic, saccades) were performed in all patients. We apply the quantitative Z score analysis for gain in smooth pursuit test, slow phase velocity in optokinetic, maximal velocity of the saccades. Depending on Z score value the patients were qualified into one of three scale dysfunctions. Statistical correlation were found between results of all ocular-motor tests outcome in MS patients and control group. In smooth pursuit test most often second degree (35.0%), in OKN test first degree (28.3%) and in saccades the third degree (31.6%) of dysfunction was observed. The higher the values of Z score, the more abnormal results of ocular-motor reflex were observed. Application of the quantitative Z score analysis of the ocular-motor tests results demonstrating the degree of central ocular-motor system dysfunction in MS patients. This method may assist in monitoring the central vestibular system impairment and in evaluation course of the disease and degree of neurological disability.

Auditory and vestibular system findings in patients with vertebrobasilar dolichoectasia.

Impairment of the auditory-vestibular system has been reported in patients with vertebrobasilar dolichoectasia (VBD), but little is known about the underlying cause of the symptoms. Auditory testing (pure tone audiometry, auditory brain stem response and stapedius reflex) and vestibular tests (assessment of nystagmus, eye tracking tests, caloric test and rotational test) were performed in 23 patients with auditory-vestibular symptoms and/or cranial nerve impairment associated with VBD. Specific evidence of auditory and/or vestibular system impairment was observed in 19 cases (83%). Among patients with abnormal test findings, 47% had evidence suggesting peripheral impairment, 16% evidence suggesting central dysfunction, and 37% evidence suggesting both peripheral and central dysfunction. Although compression of the vestibulocochlear nerve plays an important role in the genesis of the auditory-vestibular dysfunction in patients with VBD, mechanism such as brain stem-cerebellar ischemia and impaired blood supply to the vestibular labyrinth may be just as important.

Significant Vestibular System Impairment Is Common in a Cohort of Elderly Patients Referred for Assessment of Falls Risk

Falls in elderly patients are associated with morbidity, mortality, and cost to the healthcare system. The development of falls risk assessment programs have represented a method of responding to what is known about injurious falls. The multidimensional assessments involve the comparison against normative data of a patient's performance on metrics known to influence the likelihood of future falls. The factors assessed usually include falls and medication history, measures of mentation, depression, orthostatic hypotension, simple or choice reaction time, gait stability, postural stability, and the integrity of the patient's vision, somesthetic, and vestibular senses. This investigation was conducted to measure the proportion of patients referred for falls risk assessment who have evidence of vestibular system impairment. Qualitative, retrospective review of data collected from 2003 to 2007. The cohort was 185 consecutive patients referred for multidimensional assessments of falls risk. Patients underwent quantitative assessments of peripheral and central vestibular system function consisting of electro- or videonystagmography (i.e., ENG/VNG), and sinusoidal harmonic acceleration testing. Results of these tests were compared to normative data. We found that 73% of the sample who underwent vestibular system assessment had quantitative evidence of either peripheral or central vestibular system impairment. Our results suggest that quantitative assessments of the vestibulo-ocular reflex should be conducted on patients who are evaluated for falls risk. These examinations should include at least caloric testing and, where available, rotational testing.

Alexander's Law Revisited

It is a common occurrence in the balance function laboratory to evaluate patients in the post-acute period following unilateral vestibular system impairment. It is important to be able to differentiate spontaneous nystagmus (SN) emanating from peripheral vestibular system impairments from asymmetric gaze-evoked nystagmus (GEN) that originates from central ocular motility impairment. To describe the three elements of Alexander's Law (AL) that have been used to define SN from unilateral peripheral impairment. Additionally, a fourth element is described (i.e., augmentation of spontaneous nystagmus from unilateral peripheral vestibular system impairment) that differentiates nystagmus of peripheral vestibular system origin from nystagmus that originates from a central eye movement disorder. Case reports. Case data were obtained from two patients both showing a nystagmus that followed AL. None Videonystagmography (VNG), rotational, vestibular evoked myogenic potential (VEMP), and neuro-imaging studies were presented for each patient. The nystagmus in Case 1 occurred as a result of a unilateral, peripheral, vestibular system impairment. The nystagmus was direction-fixed and intensified in the vision-denied condition. The nystagmus in Case 2, by appearance identical to that in Case 1, was an asymmetric gaze-evoked nystagmus originating from a space-occupying lesion in the cerebello-pontine angle. Unlike Case 1, the nystagmus did not augment in the vision-denied condition. Although nystagmus following AL usually occurs in acute peripheral vestibular system impairment, it can occur in cases of central eye movement impairment. The key element is whether the SN that follows AL is attenuated or augmented in the vision-denied condition. The SN from a unilateral peripheral vestibular system impairment should augment in the vision denied condition. An asymmetric GEN will either not augment, decrease in magnitude, or disappear entirely, in the vision-denied condition.

Psychological Comorbidities and Their Relationship to Self-Reported Handicap in Samples of Dizzy Patients

Factors such as anxiety, depression, somatic awareness, autonomic symptoms, and differences in coping strategies are known to affect dizziness handicap. We studied these factors in 63 consecutive "dizzy" patients. This sample was subgrouped into normals and patients with benign paroxysmal positional vertigo, compensated and uncompensated unilateral peripheral vestibular system impairment, or abnormal vestibular evoked myogenic potential as a single significant diagnostic finding. Results showed that (1) anxiety and depression occur with greater frequency in dizzy patients than in the normal population; (2) the magnitude of anxiety, depression, somatization, and autonomic symptoms does not differ significantly in subgroups of patients; (3) women tended to report greater handicap and somatic/autonomic symptoms; and (4) Dizziness Handicap Inventory total scores were correlated with patients' complaints of somatic/autonomic symptoms, anxiety, depression, and coping strategies. These findings suggest that self-reported measures represent unique pieces of information important for the management of dizzy patients.

Caspase Inhibitors Promote Vestibular Hair Cell Survival and Function after Aminoglycoside TreatmentIn Vivo

The sensory hair cells of the inner ear undergo apoptosis after acoustic trauma or aminoglycoside antibiotic treatment, causing permanent auditory and vestibular deficits in humans. Previous studies have demonstrated a role for caspase activation in hair cell death and ototoxic injury that can be reduced by concurrent treatment with caspase inhibitors in vitro. In this study, we examined the protective effects of caspase inhibition on hair cell death in vivo after systemic injections of aminoglycosides. In one series of experiments, chickens were implanted with osmotic pumps that administrated the pan-caspase inhibitor z-Val-Ala-Asp(Ome)-fluoromethylketone (zVAD) into inner ear fluids. One day after the surgery, the animals received a 5 d course of treatment with streptomycin, a vestibulotoxic aminoglycoside. Direct infusion of zVAD into the vestibule significantly increased hair cell survival after streptomycin treatment. A second series of experiments determined whether rescued hair cells could function as sensory receptors. Animals treated with streptomycin displayed vestibular system impairment as measured by a greatly reduced vestibulo-ocular response (VOR). In contrast, animals that received concurrent systemic administration of zVAD with streptomycin had both significantly greater hair cell survival and significantly increased VOR responses, as compared with animals treated with streptomycin alone. These findings suggest that inhibiting the activation of caspases promotes the survival of hair cells and protects against vestibular function deficits after aminoglycoside treatment.

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.

Acquired Bilateral Peripheral Vestibular System Impairment: Rehabilitative Options and Potential Outcomes

Acquired bilateral vestibular impairment can be a devastating disorder that is most frequently the result of aminoglycoside-induced toxicity. The presenting complaints are typically oscillopsia and gait and balance disturbances. These patients can be excellent candidates for vestibular rehabilitation therapy that focuses on facilitating maximal use of any remaining vestibular function, improving gaze and postural stability through the use of visual and somatosensory cues, and improving home and workplace safety. The prognosis for recovery is determined by the extent of the loss and the presence of other progressive disorders that may affect vision or somatosensation, coexisting illnesses, and the patient's compliance with the therapy program. Two cases are presented to illustrate the salient aspects of vestibular rehabilitation for patients with acquired bilateral vestibular system loss, including factors affecting patient progress and final outcome.

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).

VEP-flash mapping in clinical practice

Abnormalities in the ocular-motor reflex recorded in electronystagmography may indicate central vestibular system impairment. Multiple sclerosis (MS) is the most common chronic, debilitating disease characterized by focal demyelinization that develops throughout the central nerves system at varying time. The aim of the study was to apply the quantitative analysis of ocular-motor tests to evaluation degree of the central system impairment in MS patients.The study was carried on 60 MS patients consulted in Balance Division, Otolaryngology Clinic, Medical University of Lodz, from 2002 to 2004, and 50 healthy persons as the control group. Clinical otoneurolaryngological examinations and electronystagmography tests (smooth pursuit, optokinetic, saccades) were performed in all patients. We apply the quantitative Z score analysis for gain in smooth pursuit test, slow phase velocity in optokinetic, maximal velocity of the saccades. Depending on Z score value the patients were qualified into one of three scale dysfunctions.Statistical correlation were found between results of all ocular-motor tests outcome in MS patients and control group. In smooth pursuit test most often second degree (35.0%), in OKN test first degree (28.3%) and in saccades the third degree (31.6%) of dysfunction was observed. The higher the values of Z score, the more abnormal results of ocular-motor reflex were observed.Application of the quantitative Z score analysis of the ocular-motor tests results demonstrating the degree of central ocular-motor system dysfunction in MS patients. This method may assist in monitoring the central vestibular system impairment and in evaluation course of the disease and degree of neurological disability.