Impairment of Caloric Function After Cochlear Implantation

PURPOSE

This article seeks to review current literature on caloric function following cochlear implantation while analyzing any correlations of caloric function changes with vestibular symptoms.

METHOD

This article is a systematic review of evidence-based literature. English language articles published between 1980 and 2014 that presented some form of caloric data from cochlear implant (CI) patients and that did not solely analyze overlapping data from a previous study were reviewed. Twenty-five articles met these criteria.

RESULTS

Of the 439 individuals tested, 37% of patients demonstrated reduced maximum slow-phase velocity, and 34% had onset of caloric asymmetry post-CI.

CONCLUSIONS

This review article found that cochlear implantation can affect caloric responses but is variable. When counseling patients preoperatively, possible effects of CI on labyrinthine function should be discussed.

[Vestibular Dysfunction in Patients with Sudden Sensorineural Hearing Loss without Vertigo]

OBJECTIVE

To observe the vestibular dysfunction in sudden sensorineural hearing loss (SSHL) patients without vertigo.

METHODS

Forty-two cases of unilateral SSHL without vertigo were enrolled in the study from May 2012 to May 2014. All patients underwent air conducted sound elicited oVEMP and cVEMP respectively. Some of them also received caloric test. Sixty-two SSHL patients with vertigo and twenty-five age-and gender-matched normal subjects were recruited as controls to analyze the vestibular dysfunction in SSHL patients without. vertigo.

RESULTS

Abnormal oVEMP was observed in 54. 8% affected ears without vertigo (23/42), 64. 5% ears with vertigo (40/62), and 26. 0% normal ears (13/50). Abnormal cVEMP was observed in 52. 4% affected ears without vertigo (22/42), 48. 4% ears with vertigo (30/62), and 14. 0% normal ears (7/50). Caloric test was operated in 21 SSHL patients without vertigo and 29 patients with vertigo. Abnormal caloric test was observed in 52.4% (11/21) SSHL patients without vertigo and 75. 9% (22/29) SSHL patients with vertigo respectively. Statistical significance was found in oVEMP and cVEMP rates between SSHL without vertigo and normal group (P<0. 01). However, no significant statistical difference was found in oVEMP, cVEMP rates and caloric test between SSHL without vertigo and SSHL with vertigo group (P>0. 05).

CONCLUSION

Vestibular function could be damaged in SSHL patients without vertigo. The abnormal rates of oVEMP, cVEMP and caloric test in SSHL patients without vertigo were similar to that of SSHL patients with vertigo. The appearance of vertigo might be irrelevant to the range and extent of vestibular dysfunction.

[CHARACTERIZATION OF VESTIBULAR DISORDERS IN THE INJURED PERSONS WITH THE BRAIN CONCUSSION IN ACUTE PERIOD]

There were examined 32 injured persons, ageing (34.1 ± 1.3) yrs at average, for the brain commotion (BC). The adopted protocol SCAT-3 (Standardized Concussion Assessment Tool, 3rd ed.), DHI (Dizziness Handicap Inventory questionnaire), computer stabilography (KS) were applied for the vestibular disorders diagnosis. There was established, that in acute period of BC a dyssociation between regression of objective neurological symptoms and permanence of the BC indices occurs, what confirms a latent disorder of the balance function. Changes of basic indices of statokinesiography, including increase of the vibration amplitude enhancement in general centre of pressure in a saggital square and the BC square (235.3 ± 13.7) mm2 in a modified functional test of Romberg with the closed eyes is possible to apply as objective criteria for the BC diagnosis.

Vestibular impairment in older people frequently contributes to dizziness as part of a geriatric syndrome

Research to identify whether dizziness is a geriatric syndrome has largely overlooked often treatable vestibular causes. To ascertain the degree to which vestibular and other causes of dizziness interact in older people, an eight-month retrospective case-note review was undertaken in patients aged ≥: 65 years referred with dizziness or imbalance to an audiovestibular medicine clinic. Of 41 patients aged 65-93 years old, 15 (37%) had multiple symptom triggers, 23 (56%) had recent dizziness-related falls, 24 (59%) and 10 (24%) had peripheral and central vestibular causes for dizziness respectively, whereas 6 (15%) had both. Sixteen (39%) had benign paroxysmal positional vertigo, of which 13 (32%) had an additional peripheral vestibular impairment. Twenty-six (63%) had other (general medical/cardiac) causes; of these 13 (50%) also had vestibular causes. Polypharmacy, orthostatic hypotension, psychotropic drug use and anxiety were common contributory factors. Vestibular causes of dizziness contribute to a multifactorial geriatric syndrome. All patients with dizziness and falls should have a vestibular assessment (especially peripheral) to improve quality of life and reduce falls.

Vestibular rehabilitation for unilateral peripheral vestibular dysfunction

BACKGROUND

This is an update of a Cochrane review first published in The Cochrane Library in Issue 4, 2007 and previously updated in 2011.Unilateral peripheral vestibular dysfunction (UPVD) can occur as a result of disease, trauma or postoperatively. The dysfunction is characterised by complaints of dizziness, visual or gaze disturbances and balance impairment. Current management includes medication, physical manoeuvres and exercise regimes, the latter known collectively as vestibular rehabilitation.

OBJECTIVES

To assess the effectiveness of vestibular rehabilitation in the adult, community-dwelling population of people with symptomatic unilateral peripheral vestibular dysfunction.

SEARCH METHODS

We searched the Cochrane Ear, Nose and Throat Disorders Group Trials Register; the Cochrane Central Register of Controlled Trials (CENTRAL); PubMed; EMBASE; CINAHL; Web of Science; BIOSIS Previews; Cambridge Scientific Abstracts; ISRCTN and additional sources for published and unpublished trials. The most recent search was 18 January 2014.

SELECTION CRITERIA

Randomised controlled trials of adults living in the community, diagnosed with symptomatic unilateral peripheral vestibular dysfunction. We sought comparisons of vestibular rehabilitation versus control (e.g. placebo), other treatment (non-vestibular rehabilitation, e.g. pharmacological) or another form of vestibular rehabilitation. Our primary outcome measure was change in the specified symptomatology (for example, proportion with dizziness resolved, frequency or severity of dizziness). Secondary outcomes were measures of function, quality of life and/or measure(s) of physiological status, where reproducibility has been confirmed and shown to be relevant or related to health status (for example, posturography), and adverse effects

DATA COLLECTION AND ANALYSIS

We used the standard methodological procedures expected by The Cochrane Collaboration.

MAIN RESULTS

We included 39 studies involving 2441 participants with unilateral peripheral vestibular disorders in the review. Trials addressed the effectiveness of vestibular rehabilitation against control/sham interventions, medical interventions or other forms of vestibular rehabilitation. Non-blinding of outcome assessors and selective reporting were threats that may have biased the results in 25% of studies, but otherwise there was a low risk of selection or attrition bias.Individual and pooled analyses of the primary outcome, frequency of dizziness, showed a statistically significant effect in favour of vestibular rehabilitation over control or no intervention (odds ratio (OR) 2.67, 95% confidence interval (CI) 1.85 to 3.86; four studies, 565 participants). Secondary outcomes measures related to levels of activity or participation measured, for example, with the Dizziness Handicap Inventory, which also showed a strong trend towards significant differences between the groups (standardised mean difference (SMD) -0.83, 95% CI -1.02 to -0.64). The exception to this was when movement-based vestibular rehabilitation was compared to physical manoeuvres for benign paroxysmal positional vertigo (BPPV), where the latter was shown to be superior in cure rate in the short term (OR 0.19, 95% CI 0.07 to 0.49). There were no reported adverse effects.

AUTHORS' CONCLUSIONS

There is moderate to strong evidence that vestibular rehabilitation is a safe, effective management for unilateral peripheral vestibular dysfunction, based on a number of high-quality randomised controlled trials. There is moderate evidence that vestibular rehabilitation resolves symptoms and improves functioning in the medium term. However, there is evidence that for the specific diagnostic group of BPPV, physical (repositioning) manoeuvres are more effective in the short term than exercise-based vestibular rehabilitation; although a combination of the two is effective for longer-term functional recovery. There is insufficient evidence to discriminate between differing forms of vestibular rehabilitation.

[Ocular and cervical vestibular evoked myogenic potentials in patients with peripheral vestibular disorders]

OBJECTIVE

To observe the ocular vestibular evoked myogenic potential (oVEMP) and the cervical vestibular evoked myogenic potential (cVEMP) in patients with vestibular diseases.

METHOD

From March, 2011 to March, 2012, 13 patients (14 ears) with peripheral vestibular diseases were recruited. Each patient underwent conventional oVEMP and cVEMP examinations elicited by intensive air conducted sound (short tone burst, 500 Hz) in bilateral ears.

RESULT

Thirteen cases (14 ears) were included in this study. They were 3 cases (3 ears) with Ramsay Hunt syndrome, 3 cases (4 ears) with acoustic neuroma, 1 case (1 ear) with VII and VIII cranial nerve trauma after head injury, 2 cases (2 ears) with vestibular neuritis, 3 cases (3 ears) with Meniere's disease, and Icase (1 ear) with unilateral hypoplasia of the internal auditory canal. Altogether, oVEMP could be elicited in only 2 ears (14. 3%) and cVEMP were found abnormal in 11 ears (78. 6%).

CONCLUSION

The otolithic vestibular end organs and their input pathways could be examined by cVEMP and oVEMP examinations in patients with peripheral vestibular disorders.

Chulalongkorn vestibular balance exercise for rehabilitation in persons with various types of vestibular disorders

OBJECTIVE

To study the efficiency of Chulalongkorn vestibular balance exercise for rehabilitation in persons with various types of vestibular disorders.

MATERIAL AND METHOD

Fifty-eight patients with various types of vestibular disorder were identified by a retrospective chart review. Thirty of the 58 patients met the inclusion criteria of having dizziness and unsteadiness post vestibular diseases with complete record of neuro-otologic examination; vestibular tests and had been followed-up for at least 3 month. These patients were treated with Chulalongkorn vestibular balance exercise and were evaluated for dizziness symptoms and balance bedside test at the beginning of treatment, one month and three months after the exercise.

RESULTS

The average age of the patients was 50.34 ± 14.04 years. The average of duration of exercise program was 5.6 months. There were 6 cases of vestibular neuronitis; 5 cases of post acoustic neuroma removal; 4 cases of acute cochleovestibular loss; 3 cases of motion sickness; 2 cases of cerebellar atrophy; 3 cases of multisensory dizziness; 4 cases of post meningitis with deafness; and 3 cases of ototoxicity. After the exercise, improvement of dizziness symptoms could be found in all groups of the diseases at one month and three months. The objective of balance bedside test was improved in most cases except motion sickness, multisensory dizziness and cerebellar atrophy. The overall percentage of improvement of dizziness was statistically significant at one month and three months (p = 0.0373 and p < 0.001). However the overall balance bedside test was statistically improved at three months after the exercise (p = 0.034).

CONCLUSION

Chulalongkorn vestibular balance exercise gave significantly effective results in the treatment of dizziness and unsteadiness from various types of vestibular disorder. This study demonstrated improvement of dizziness symptom post-exercise at one month and three months with statistical significance. The balance bedside test was also statistically significant improved at three months post-exercise.

The video head impulse test

CONCLUSION

Additional research is needed to validate the importance of the video head impulse tests (vHIT), but it provides an important contribution to the evaluation of anterior and posterior semicircular canal disorders.

OBJECTIVES

To share observations of the vHIT test in clinical neurotology and to discuss the significance of the study findings.

METHODS

This study comprised 200 patients with a clinical history of vestibular disturbances who were submitted to a vHIT including all six semicircular canals.

RESULTS

Abnormal responses of the anterior and posterior canals were found in several patients, either alone or combined with altered responses in the lateral canals. A unilateral hypoactive response of a posterior canal was found in a patient with a small vestibular schwannoma.

Comparison of virtual reality based therapy with customized vestibular physical therapy for the treatment of vestibular disorders

We examined outcomes in persons with vestibular disorders after receiving virtual reality based therapy (VRBT) or customized vestibular physical therapy (PT) as an intervention for habituation of dizziness symptoms. Twenty subjects with vestibular disorders received VRBT and 18 received PT. During the VRBT intervention, subjects walked on a treadmill within an immersive virtual grocery store environment, for six sessions approximately one week apart. The PT intervention consisted of gaze stabilization, standing balance and walking exercises individually tailored to each subject. Before, one week after, and at six months after the intervention, subjects completed self-report and balance performance measures. Before and after each VRBT session, subjects also reported symptoms of nausea, headache, dizziness, and visual blurring. In both groups, significant improvements were noted on the majority of self-report and performance measures one week after the intervention. Subjects maintained improvements on self report and performance measures at six months follow up. There were not between group differences. Nausea, headache, dizziness and visual blurring increased significantly during the VRBT sessions, but overall symptoms were reduced at the end of the six-week intervention. While this study did not find a difference in outcomes between PT and VRBT, the mechanism by which subjects with chronic dizziness demonstrated improvement in dizziness and balance function may be different.

On the biological plausibility of Wind Turbine Syndrome

An emerging environmental health issue relates to potential ill-effects of wind turbine noise. There have been numerous suggestions that the low-frequency acoustic components in wind turbine signals can cause symptoms associated with vestibular system disorders, namely vertigo, nausea, and nystagmus. This constellation of symptoms has been labeled as Wind Turbine Syndrome, and has been identified in case studies of individuals living close to wind farms. This review discusses whether it is biologically plausible for the turbine noise to stimulate the vestibular parts of the inner ear and, by extension, cause Wind Turbine Syndrome. We consider the sound levels that can activate the semicircular canals or otolith end organs in normal subjects, as well as in those with preexisting conditions known to lower vestibular threshold to sound stimulation.

Classification in postural style based on stochastic process modeling

We address the statistical challenge of classifying subjects as hemiplegic, vestibular or normal based on complex trajectories obtained through two experimental protocols designed to evaluate potential deficits in postural control. The classification procedure involves a dimension reduction step where the complex trajectories are summarized by finite-dimensional summary measures based on a stochastic process model for a real-valued trajectory. This allows us to retrieve from the trajectories information relative to their temporal dynamic. A leave-one-out evaluation yields a 79% performance of correct classification for a total of n=70 subjects, with 22 hemiplegic (31%), 16 vestibular (23%) and 32 normal (46%) subjects.

Vestibular impairment in Charcot-Marie-Tooth disease type 4C

Charcot-Marie-Tooth disease type 4C (CMT4C) is a hereditary neuropathy with prominent unsteadiness. The objective of the current study is to determine whether the imbalance in CMT4C is caused only by reduced proprioceptive input or if vestibular nerve involvement is an additional factor. We selected 10 CMT4C patients and 10 age-matched and sex-matched controls. We performed a comprehensive evaluation of the vestibular system, including video Head Impulse Test, bithermal caloric test, galvanic stimulation test and skull vibration-induced nystagmus test. None of the patients experienced dizziness, spontaneous or gaze-evoked nystagmus, but all had significant vestibular impairment when tested when compared to controls. Seven had completely unexcitable vestibular systems and abnormal vestibuloocular reflex. There was no correlation between the degree of vestibulopathy and age or clinical severity. Significant vestibular impairment is a consistent finding in CMT4C and is present early in disease evolution. The profound imbalance that is so disabling in these patients may result from a combination of proprioceptive loss and vestibular neuropathy, and this would modify the recommended rehabilitation strategies.

Clinical uses of cervical vestibular-evoked myogenic potential testing in pediatric patients

To demonstrate the feasibility and clinical significance of cervical vestibular-evoked myogenic potential (cVEMP) test in pediatric patients.Retrospective review study was conducted in a pediatric tertiary care facility. A total of 278 patients were identified with adequate data, including medical notes, results of cVEMP, and imaging studies.Among the total of 278 pediatric patients, only 3 children were not able to finish the cVEMP test successfully. In about 90% of the cases, the cVEMP test was requested to investigate a patient's hearing loss and/or vestibular complaints. Over 90% of the cVEMP tests were ordered by specialists such as pediatric otolaryngologists or otologists. Obtained cVEMP results provided useful information in clinical diagnosis and management in all cases.It is feasible to conduct cVEMP testing in children, including infants, and cVEMP testing can provide valuable information in the diagnosis and management of hearing loss and vestibular impairment. This simple and noninvasive test should be embraced by pediatric professionals.

iPod-based in-home system for monitoring gaze-stabilization exercise compliance of individuals with vestibular hypofunction

BACKGROUND

In the physical therapy setting, physical therapists (PTs) often prescribe exercises for their clients to perform at home. However, it is difficult for PTs to obtain information about their clients' compliance with the prescribed exercises, the quality of performance and symptom magnitude. We present an iPod-based system for capturing this information from individuals with vestibular hypofunction while they perform gaze stabilization exercises at home.

METHOD

The system's accuracy for measurement of rotational velocity against an independent motion tracker was validated. Then a seven day in-home trial was conducted with 10 individuals to assess the feasibility of implementing the system. Compliance was measured by comparing the recorded frequency and duration of the exercises with the exercise prescription. The velocity and range of motion of head movements was recorded in the pitch and yaw planes. The system also recorded dizziness severity before and after each exercise was performed. Each patient was interviewed briefly after the trial to ascertain ease of use. In addition, an interview was performed with PTs in order to assess how the information would be utilized.

RESULTS

The correlation of the velocity measurements between the iPod-based system and the motion tracker was 0.99. Half of the subjects were under-compliant with the prescribed exercises. The average head velocity during performance was 140 deg/s in the yaw plane and 101 deg/s in the pitch plane.

CONCLUSIONS

The iPod-based system was able to be used in-home. Interviews with PTs suggest that the quantitative data from the system will be valuable for assisting PTs in understanding exercise performance of patients, documenting progress, making treatment decisions, and communicating patient status to other PTs.

Evaluation of a bedside test of utricular function - the bucket test - in older individuals

CONCLUSION

As a bedside test of subjective visual vertical (SVV), the 'bucket test' has a role as a viable and cost-effective clinical test of unilateral utricular dysfunction in older individuals.

OBJECTIVE

To investigate whether the bucket test as a test of the SVV is a valid bedside test of utricular function in older individuals.

METHODS

This was a diagnostic validation study at a tertiary academic medical center. Vestibular function was evaluated using sound-evoked cervical and tap-evoked ocular vestibular evoked myogenic potential (cVEMP and oVEMP, respectively) asymmetry ratios, the bucket test of SVV, and the Dizziness Handicap Index (DHI), in 51 older individuals aged 70-95 years.

RESULTS

Bucket test scores are correlated in both magnitude and direction with utricle-selective tap-evoked oVEMP asymmetry ratios, but not with sound-evoked cVEMP asymmetry ratios, which are saccule-selective, or with the DHI. Receiver operating characteristics analysis suggests that the bucket test is more specific than sensitive for utricular dysfunction, and a bucket test SVV score of 2° may maximize diagnostic yield relative to the currently accepted score of 3.

[Galvanic vestibular stimulation in physiological and clinical studies in recent years]

Galvanic vestibular stimulation is a simple, harmless, noninvasive and low-cost research technique. In spite on a long history, it has been recently found popularity as a research tool. At present occurs of its revival as a research and diagnostic tool. Considerable effects of such stimulation for motor, visual, somatosensory, vestibular and cognitive/emotional function as well as for a range of neurological and psychiatric disorders have been reported. Obviously, any process that is able to extract an information due to head acceleration signals is a candidate on galvanic vestibular stimulation. In this review, we describe the basic physiological mechanisms of action of galvanic vestibular stimulation. We also consider a modern data of its influence on human, obtained in physiological and clinical studies.

Vestibular effects of a 7 Tesla MRI examination compared to 1.5 T and 0 T in healthy volunteers

Ultra-high-field MRI (7 Tesla (T) and above) elicits more temporary side-effects compared to 1.5 T and 3 T, e.g. dizziness or “postural instability” even after exiting the scanner. The current study aims to assess quantitatively vestibular performance before and after exposure to different MRI scenarios at 7 T, 1.5 T and 0 T. Sway path and body axis rotation (Unterberger's stepping test) were quantitatively recorded in a total of 46 volunteers before, 2 minutes after, and 15 minutes after different exposure scenarios: 7 T head MRI (n = 27), 7 T no RF (n = 22), 7 T only B₀ (n = 20), 7 T in & out B₀ (n = 20), 1.5 T no RF (n = 20), 0 T (n = 15). All exposure scenarios lasted 30 minutes except for brief one minute exposure in 7 T in & out B₀. Both measures were documented utilizing a 3D ultrasound system. During sway path evaluation, the experiment was repeated with eyes both open and closed. Sway paths for all long-lasting 7 T scenarios (normal, no RF, only B₀) with eyes closed were significantly prolonged 2 minutes after exiting the scanner, normalizing after 15 minutes. Brief exposure to 7 T B₀ or 30 minutes exposure to 1.5 T or 0 T did not show significant changes. End positions after Unterberger's stepping test were significantly changed counter-clockwise after all 7 T scenarios, including the brief in & out B₀ exposure. Shorter exposure resulted in a smaller alteration angle. In contrast to sway path, reversal of changes in body axis rotation was incomplete after 15 minutes. 1.5 T caused no rotational changes. The results show that exposure to the 7 Tesla static magnetic field causes only a temporary dysfunction or “over-compensation” of the vestibular system not measurable at 1.5 or 0 Tesla. Radiofrequency fields, gradient switching, and orthostatic dysregulation do not seem to play a role.

Nonlinear analysis of sensory organization test for subjects with unilateral vestibular dysfunction

Vestibular disorder is the cause of approximately 50% of dizziness in older people. The vestibular system is a critical postural control mechanism, and posturography analysis is helpful for diagnosing vestibular disorder. In clinical practice, the sensory organization test (SOT) is used to quantify postural control in an upright stance under different test conditions. However, both aging and vestibular disorder cause declines of postural control mechanisms. The aim of this study was to enhance the performance of the SOT using a nonlinear algorithm of empirical mode decomposition (EMD) and to verify the differences of effects caused by aging and/or illnesses benefits to clinical diagnosis. A total of 51 subjects belonging to 3 groups--healthy-young, healthy-elderly and dizzy--were recruited for this study. New dynamic parameters of the SOT were derived from the center of pressure (COP) signals. EMD served as an adaptive filter bank to derive the low- and high-frequency components of the COP. The effects on four ratios of sensory analysis caused by aging and vestibular disorder can be investigated for the specific frequency bands. According to our findings, new SOT parameters derived from the component with the specific frequency band more sensitively reflect the functional condition of vestibular dysfunction. Furthermore, both aging and vestibular dysfunction caused an increase in magnitude for the low-frequency component of the AP-direction COP time series. In summary, the low-frequency fluctuation reflects the stability of postural control, while the high-frequency fluctuation is sensitive to the functional condition of the sensory system. EMD successfully improved the accuracy of SOT measurements in this investigation.

Genetics of peripheral vestibular dysfunction: lessons from mutant mouse strains

BACKGROUND

A considerable amount of research has been published about genetic hearing impairment. Fifty to sixty percent of hearing loss is thought to have a genetic cause. Genes may also play a significant role in acquired hearing loss due to aging, noise exposure, or ototoxic medications. Between 1995 and 2012, over 100 causative genes have been identified for syndromic and nonsyndromic forms of hereditary hearing loss. Mouse models have been extremely valuable in facilitating the discovery of hearing loss genes and in understanding inner ear pathology due to genetic mutations or elucidating fundamental mechanisms of inner ear development.

PURPOSE

Whereas much is being learned about hereditary hearing loss and the genetics of cochlear disorders, relatively little is known about the role genes may play in peripheral vestibular impairment. Here we review the literature with regard to genetics of vestibular dysfunction and discuss what we have learned from studies using mutant mouse models and direct measures of peripheral vestibular neural function.

RESULTS

Several genes are considered that when mutated lead to varying degrees of inner ear vestibular dysfunction due to deficits in otoconia, stereocilia, hair cells, or neurons. Behavior often does not reveal the inner ear deficit. Many of the examples presented are also known to cause human disorders.

CONCLUSIONS

Knowledge regarding the roles of particular genes in the operation of the vestibular sensory apparatus is growing, and it is clear that gene products co-expressed in the cochlea and vestibule may play different roles in the respective end organs. The discovery of new genes mediating critical inner ear vestibular function carries the promise of new strategies in diagnosing, treating, and managing patients as well as predicting the course and level of morbidity in human vestibular disease.

Is a pulling sensation in the anteroposterior direction associated with otolith dysfunction?

CONCLUSION

A pulling sensation in the anteroposterior direction is suggested to originate from a dysfunction of the otolith organs.

OBJECTIVES

Previous study with vestibular evoked myogenic potential (VEMP) confirmed that a falling sensation (in an up or down direction) and a lateral tilt sensation (in a right or left direction) were caused by otolith lesions. The purpose of this study was to clarify whether a pulling sensation in the anteroposterior (forward or backward) direction originates from otolith dysfunction.

METHODS

The otolith function was assessed by cervical and ocular VEMPs (cVEMPs and oVEMPs) in 12 patients who complained of a forward or backward pulling sensation. cVEMPs were evaluated by the asymmetry ratio (AR) of the amplitude of the p13-n23 wave and the peak latencies of the p13 and n23 waves. oVEMPs were evaluated by the AR of the amplitude of the n1-p1 wave and the peak latency of the n1 and p1 waves.

RESULTS

Abnormal ARs on cVEMP were observed in 7 of 12 patients. Nine of 12 patients had abnormal oVEMP results including 3 bilateral absent responses. Most (10 of 12) patients had abnormal cVEMP and/or oVEMP results. The latency of each detected wave was within the normal ranges.

Peripheral vestibular dysfunction is prevalent in older adults experiencing multiple non-syncopal falls versus age-matched non-fallers: a pilot study

BACKGROUND

vestibular disorders are common in the general population, increasing with age. However, it is unknown whether older adults who fall have a higher proportion of vestibular impairment compared with age-matched older adult non-fallers.

OBJECTIVE

to identify whether a greater proportion of older adult fallers have a peripheral vestibular impairment compared with age-matched healthy controls.

DESIGN

case-controlled study.

SETTING

tertiary falls and neuro-otology clinics and local community centres, London, UK.

PARTICIPANTS AND METHODS

community-dwelling older adults experiencing: (i) ≥2 unexplained falls within the previous 12-months (Group F, n = 25), (ii) a confirmed peripheral vestibular disorder (Group PV, n = 15) and (iii) healthy non-fallers (Group H, n = 16). All the participants completed quantitative vestibular function tests, the functional gait assessment (FGA), physiological profile assessment (PPA) and subjective measures for common vestibular symptoms (i.e. giddiness), balance confidence during daily activities and psychological state.

RESULTS

a clinically significant vestibular impairment was noted for 80% (20/25) of Group F compared with 18.75% (3/16) for Group H (P < 0.01). Group F performed less well in complex gait tasks (FGA), and reported a greater number of falls than both Groups H and PV (P < 0.05). Vestibular symptom scores showed no significant difference between Groups F and PV.

CONCLUSION

vestibular dysfunction is significantly more prevalent in older adult fallers versus non-fallers. Individuals referred to a falls clinic are older, more impaired and report more falls than those referred to a neuro-otology department. A greater awareness of vestibular impairments may lead to more effective management and treatment for older adult fallers.

Timing of surgical intervention with cochlear implant in patients with large vestibular aqueduct syndrome

Objectives

(1) To report the speech perception and intelligibility results of Mandarin-speaking patients with large vestibular aqueduct syndrome (LVAS) after cochlear implantation (CI); (2) to compare their performance with a group of CI users without LVAS; (3) to understand the effects of age at implantation and duration of implant use on the CI outcomes. The obtained data may be used to guide decisions about CI candidacy and surgical timing.

Methods

Forty-two patients with LVAS participating in this study were divided into two groups: the early group received CI before 5 years of age and the late group after 5. Open-set speech perception tests (on Mandarin tones, words and sentences) were administered one year after implantation and at the most recent follow-up visit. Categories of auditory perception (CAP) and Speech Intelligibility Rating (SIR) scale scores were also obtained.

Results

The patients with LVAS with more than 5 years of implant use (18 cases) achieved a mean score higher than 80% on the most recent speech perception tests and reached the highest level on the CAP/SIR scales. The early group developed speech perception and intelligibility steadily over time, while the late group had a rapid improvement during the first year after implantation. The two groups, regardless of their age at implantation, reached a similar performance level at the most recent follow-up visit.

Conclusion

High levels of speech performance are reached after 5 years of implant use in patients with LVAS. These patients do not necessarily need to wait until their hearing thresholds are higher than 90 dB HL or PB word score lower than 40% to receive CI. They can do it “earlier” when their speech perception and/or speech intelligibility do not reach the performance level suggested in this study.

Differing response properties of cervical and ocular vestibular evoked myogenic potentials evoked by air-conducted stimulation

•

cVEMPs and oVEMPS were recorded simultaneously from 15 healthy volunteers and 1 patient with superior canal dehiscence (SCD) using air conducted (AC) sound over a 30 dB range.

•

The SCD patient had larger amplitude responses at all intensities except for the cVEMP at the loudest intensity.

•

Whilst the cVEMP p13/n23 response was well fitted by a power law relationship the oVEMP n10/p16 response showed a change in gradient for the louder intensities and this may relate to differences in the pathways responsible.

Objective

To determine the amplitude changes of vestibular evoked myogenic potentials (VEMPs) recorded simultaneously from the neck (cVEMPs) and eyes (oVEMPs) in response to 500 Hz, 2 ms air-conducted sound pips over a 30 dB range.

Methods

Fifteen healthy volunteers (mean age 29, range 18–57 years old) and one patient with unilateral superior canal dehiscence (SCD) were studied. The stimulus was reduced in increments to 105 dB pSPL for the normals (81 dB pSPL for the SCD patient). A statistical criterion was used to detect responses.

Results

Ipsilateral (i-p13/n23) and contralateral (c-n12/p24/n30) peaks for the cVEMP montage and contralateral (c-n10/p16/n21) and ipsilateral (i-n13) peaks for the oVEMP montage were present for the baseline intensity. For the lowest intensity, 6/15 subjects had responses for the i-p13 cVEMP potential and 4/15 had c-n10 oVEMP responses. The SCD patient showed larger responses for nearly all intensities. The cVEMP potentials were generally well fitted by a power law relationship, but the oVEMP c-n10, p16 and n21 potentials showed a significant increase in gradient for the higher intensities.

Conclusion

Most oVEMP and cVEMP responses follow a power law relationship but crossed oVEMP responses showed a change in gradient above a threshold.

Significance

The pattern of response to AC stimulation may be a property of the pathways underlying the potentials.

Standing balance tests for screening people with vestibular impairments

OBJECTIVES/HYPOTHESIS

To improve the test standards for a version of the Romberg test and to determine whether measuring kinematic variables improved its utility for screening.

STUDY DESIGN

Healthy controls and patients with benign paroxysmal positional vertigo, postoperative acoustic neuroma resection, and chronic peripheral unilateral weakness were compared.

METHODS

Subjects wore Bluetooth-enabled inertial motion units while standing on the floor or medium-density, compliant foam, with eyes open or closed, with head still or moving in pitch or yaw. Dependent measures were time to perform each test condition, number of head movements made, and kinematic variables.

RESULTS

Patients and controls did not differ significantly with eyes open or with eyes closed while on the floor. With eyes closed, on foam, some significant differences were found between patients and controls, especially for subjects older than 59 years. Head movement conditions were more challenging than with the head still. Significantly fewer patients than controls could make enough head movements to obtain kinematic measures. Kinematics indicated that lateral balance control is significantly reduced in these patients compared to controls. Receiver operator characteristics and sensitivity/specificity analyses showed moderately good differences with older subjects.

CONCLUSIONS

Tests on foam with eyes closed, with head still or moving, may be useful as part of a screening battery for vestibular impairments, especially for older people.

LEVEL OF EVIDENCE

3b.