Sensory interaction platform posturography in patients with Ménière's syndrome

Menière's disease patients improve specific posturographic parameters following diagnostic intratympanic injection

PURPOSE

Evaluation of specific computerized posturographic parameters in patients with Menière's disease (MD) following the intratympanic injection of gadolinium, a contrast agent, used in radiological diagnosing.

MATERIALS AND METHODS

We have observed 12 adult patients with unilateral Menière's Disease subjected to inner ear magnetic resonance imaging (MRI) examination after intratympanic gadolinium injection (ITG). The diagnoses have been performed according to the guidelines of the American Academy of otolaryngology. Before and after 24 h the ITG, all patients were subjected to the clinical evaluation and computerized posturography (CP), in 4 conditions depending on open/closed eyes and with/without foam cushion under feet.

RESULTS

After ITG, in the affected ear the MRI confirmed the endolymphatic hydrops revealing a thin or even disappeared perilymphatic space. The statokinesigram showed improvement of stability only with closed eyes on a foam cushion. The CP performed 24 h after the contrast intratympanic injection showed a significant reduction of Path Length and Confidence Ellipse Area, due to an improvement of vestibular function on static balance. This improvement could be directly dependent to intratympanic pressure modification mediated by volume of contrast liquid, by "columella effect".

CONCLUSIONS

This study demonstrates the absence of vestibular damage in patients undergoing intratympanic gadolinium infiltration and confirms the relationship between intratympanic pressure and vestibular stability modifications providing positive evidences for an applicative use of CP as a functional assessment to better address diagnosis and follow-up in MD patients treated with intratympanic injections.

Disorders of the inner-ear balance organs and their pathways

Disorders of the inner-ear balance organs can be grouped by their manner of presentation into acute, episodic, or chronic vestibular syndromes. A sudden unilateral vestibular injury produces severe vertigo, nausea, and imbalance lasting days, known as the acute vestibular syndrome (AVS). A bedside head impulse and oculomotor examination helps separate vestibular neuritis, the more common and innocuous cause of AVS, from stroke. Benign positional vertigo, a common cause of episodic positional vertigo, occurs when otoconia overlying the otolith membrane falls into the semicircular canals, producing brief spells of spinning vertigo triggered by head movement. Benign positional vertigo is diagnosed by a positional test, which triggers paroxysmal positional nystagmus in the plane of the affected semicircular canal. Episodic spontaneous vertigo caused by vestibular migraine and Ménière's disease can sometimes prove hard to separate. Typically, Ménière's disease is associated with spinning vertigo lasting hours, aural fullness, tinnitus, and fluctuating hearing loss while VM can produce spinning, rocking, or tilting sensations and light-headedness lasting minutes to days, sometimes but not always associated with migraine headaches or photophobia. Injury to both vestibular end-organs results in ataxia and oscillopsia rather than vertigo. Head impulse testing, dynamic visual acuity, and matted Romberg tests are abnormal while conventional neurologic assessments are normal. A defect in the bony roof overlying the superior semicircular canal produces vertigo and oscillopsia provoked by loud sound and pressure (when coughing or sneezing). Three-dimensional temporal bone computed tomography scan and vestibular evoked myogenic potential testing help confirm the diagnosis of superior canal dehiscence. Collectively, these clinical syndromes account for a large proportion of dizzy and unbalanced patients.

Dynamic posturography for staging of patients with Ménière's disease

Objective:

In recent years, techniques such as computerised dynamic posturography have facilitated objective evaluation of patients with balance disorders. In this study, we used computerised dynamic posturography for clinical staging of Ménière's disease.

Material and methods:

We applied a computerised dynamic posturography sensory organisation test to 53 patients with American Academy of Otolaryngology criteria of Ménière's disease. The following parameters were considered in data analysis: computerised dynamic posturography scores for testing the patient's centre of gravity with a mobile surface, immobile visual surroundings and eyes closed, scores for testing with a mobile surface, mobile visual surroundings and eyes open, and vestibular ratio. We used four hearing threshold stages (although we had no patients at stage four).

Results and discussion:

This study did not observe a statistically significant correlation between audiometric hearing thresholds and computerised dynamic posturography scores. Computerised dynamic posturography scores showed statistically significant variation with time elapsed since the last vertigo attack. Although our results showed an increasing trend in computerised dynamic posturography scores as Ménière's disease activity level decreased from recent post-attack (i.e. less than one week since last attack) through late post-attack (i.e. one week to 60 days since last attack) to inactive (i.e. more than 60 days since last attack), these differences were not statistically significant.

The usefulness of computerized dynamic posturography for the study of equilibrium in patients with Meniere’s disease: correlation with clinical and audiologic data

The use of computerized dynamic posturogaphy (CDP) in the evaluation of patients with balance alterations not only allows quantification of the subject's capacity to maintain a stable centre of gravity, but also analysis of the degree to which the subject is able to use different types of sensory information. The present study investigated the possible use of CDP for clinical staging of vestibular diseases, specifically Meniere's disease (MD). We applied CDP sensory organization tests to 75 patients with definitive MD (AAO-HNS 1995 criteria). A total of 98 CDP sessions were included in the analysis, which focused on four CDP parameters specifically related to vestibular function (condition-5 score, condition-6 score, overall balance score, and VEST, a measure of the relative importance of vestibular information for maintenance of balance). We found a statistically significant relationship between audiometric hearing threshold and CDP scores, especially in patients with audiometrically advanced disease. In addition, CDP scores showed statistically significant variation with time elapsed since the last typical vertigo attack, suggesting that patients can be usefully grouped into three MD activity-level categories: recent post-attack (less than 1 week since last vertigo attack), late post-attack (1 week - 60 days since last attack), and inactive MD (more than 60 days since last attack). On the basis of these results, we propose expected ranges for each of the four CDP parameters in each of the three MD activity-level categories, allowing staging in terms of balance and posture. This staging system complements existing staging systems (based on audiometric criteria, and on subjective assessment of the severity of vertigo attacks and their implications for quality of life).

The effect of foot position on the modified clinical test of sensory interaction and balance

OBJECTIVES

To determine whether there was a difference in the timed scores on a modified version of the Clinical Test of Sensory Interaction and Balance (CTSIB) with the feet apart versus feet together and to correlate modified CTSIB scores with Sensory Organization Test (SOT) scores.

DESIGN

Prospective correlational study.

SETTING

Outpatient clinic.

PARTICIPANTS

Thirty patients (mean age, 58+/-17 y) with vestibular dysfunction who were undergoing vestibular therapy.

INTERVENTIONS

Subjects completed the modified CTSIB with their feet together and feet apart at the end of a vestibular therapy session. Subjects also completed the SOT on the same day.

MAIN OUTCOME MEASURES

Modified CTSIB scores (feet together, feet apart) and SOT scores.

RESULTS

Modified CTSIB scores were slightly lower when performed with feet together as compared with feet apart. However, no statistically significant difference existed between scores on the modified CTSIB with feet together versus feet apart using the Wilcoxon signed-rank test (P<.05). The modified CTSIB correlated more strongly with SOT scores when performed with feet together than with feet apart using the Spearman rho.

CONCLUSIONS

Scores on the modified CTSIB performed with the feet together did not differ from scores on the modified CTSIB performed with the feet apart. In persons with vestibular disorders, the CTSIB done with the feet together correlated more closely with the SOT.

Visuo-vestibular biofeedback in patients with peripheral vestibular disorders

It is well known that diseases of the vestibular system can be compensated by increased spontaneous activity of other systems engaged in maintaining equilibrium, i.e. proprioceptive and visual systems. A complex approach using multisensory stimulation is the optimal way to achieve vestibular compensation. The aim of our study was to determine the effect of vestibular rehabilitation therapy as measured by posturography in a group of 72 patients suffering from vestibular disorders: Ménière's disease (n = 31), neuritis vestibularis (n = 21) and vertebrobasilar insufficiency (n = 20). Patients underwent the following examinations: electronystagmography; caloric, rotatory and optokinetic tests; computed posturography; craniocorpography; pure-tone audiometry; speech audiometry; and tinnitometry (tinnitus loudness, pitch). The instability in patients with Ménière's disease decreased 3 weeks after starting the therapy; nevertheless, the decrease in area (the surface formed by the movement of the patient's equilibrium point during a defined time) was transitory because of the increase in area values obtained between the 3rd and 6th weeks when measured with closed eyes. In the vestibular neuronitis patients, the measured values of area and the velocity of the patient's movement decreased continuously. The values measured in the patients suffering from vertebrobasilar insufficiency decreased continuously, the absolute values remaining pathological.

Postural control and glycerol test in Ménière's disease

Ménière's disease is a clinical disorder, characterized by fluctuating hearing loss, recurrent spontaneous episodic vertigo, tinnitus and aural fullness, which may be defined as the idiopathic syndrome of endolymphatic hydrops. The most important test for diagnosis of Ménière's disease is the glycerol test. This is a simple and rapid method and several authors have confirmed its efficiency for identifying endolymphatic hydrops. This test provides information on the cochlear response to the osmotic changes produced by glycerol in the inner ear, whereas modifications in the vestibular labyrinth are usually not evaluated. The aim of this study was to evaluate the effects of glycerol on postural control during attacks of Ménière's disease, and to correlate this data with data on cochlear function. After the glycerol test, an improvement in postural control was recorded in 70% of patients, with all patients reporting a recovery of vertigo. The impairment of postural control during endolymphatic hydrops could be related to a pressure increase in the labyrinth, which interferes with the normal dynamics of the endolymph, and a rapid functional recovery could occur during an osmotic depletion. Dynamic posturography improves the sensitivity of the glycerol test and may therefore be useful in the diagnosis and staging of Ménière's disease.

Short-lasting drop attacks in Meniere's disease

OBJECTIVES

To study the vertigo attacks known as Tumarkin attacks or drop attacks (DA). DA are characterized by sudden loss of balance with or without falls but with preserved consciousness, and they are supposedly triggered by changes in the otolith function of Meniere's disease (MD).

STUDY DESIGN AND SETTING

Data from 243 consecutive MD patients were collected into a database of an otoneurologic expert system.

RESULTS

DA was experienced by 72% (n = 173) of the patients with MD. It correlated with visually provoked vertigo. Gait difficulties, tinnitus, and anxiety were more common in the DA group. Long lasting vertigo attacks were more frequently provoked in the DA subjects by physical strain (58% vs 14%), head movements or changes in head position (71% vs 48%), pressure changes (54% vs 12%), or rapid movements in visual surroundings (65% vs 35%) than in the non-DA subjects.

CONCLUSION

DA are common in MD patients. The abrupt occurrence of DA make them poorly tolerated.

SIGNIFICANCE

DA are more common in advanced MD.

Balance control near the limit of stability in various sensory conditions in healthy subjects and patients suffering from vertigo or balance disorders: impact of sensory input on balance control

The large inter-individual variability within the normal population, the limited reproducibility due to habituation or fatigue, and the impact of instruction and the subject's motivation, all constitute a major problem in posturography. These aspects hinder reliable evaluation of the changes in balance control in the case of disease and complicate objectivation of the impact of therapy and sensory input on balance control. In this study, we examine whether measurement of balance control near individualized limits of stability and under very challenging sensory conditions might reduce inter- and intra-individual variability compared to the well-known Sensory Organization Test (SOT). To do so, subjects balance on a platform on which instability increases automatically until body orientation or body sway velocity surpasses a safety limit. The maximum tolerated platform instability is then used as a measure for balance control under 10 different sensory conditions. Ninety-seven healthy subjects and 107 patients suffering from chronic dizziness (whiplash syndrome (n = 25), Meniere's disease (n = 28), acute (n = 28) or gradual (n = 26) peripheral function loss) were tested. In both healthy subjects and patients this approach resulted in a low intra-individual variability (< 14.5(%). In healthy subjects and patients, balance control was maximally affected by closure of the eyes and by vibration of the Achilles' tendons. The other perturbation techniques applied (sway referenced vision or platform, cooling of the foot soles) were less effective. Combining perturbation techniques reduced balance control even more, but the effect was less than the linear summation of the effect induced by the techniques applied separately. The group averages of healthy subjects show that vision contributed maximum 37%, propriocepsis minimum 26%, and labyrinths maximum 44% to balance control in healthy subjects. However, a large inter-individual variability was observed. Balance control of each patient group was less than in healthy subjects in all sensory conditions. Similar to healthy subjects, patients also show a large inter-individual variability, which results in a low sensitivity of the test. With the exception of some minor differences between Whiplash and Meniere patients, balance control did not differ between the four patient groups. This points to a low specificity of the test. Balance control was not correlated with the outcome of the standard vestibular examination. This study strengthens our notion that the contribution of the sensory inputs to balance control differs considerably per individual and may simply be due to differences in the vestibular function related to the specific pathology, but also to differences in motor learning strategies in relation to daily life requirements. It is difficult to provide clinically relevant normative data. We conclude that, like the SOT, the current test is merely a functional test of balance with limited diagnostic value.

Relevance of function tests in the diagnosis of vestibular disorders

The diagnostic value or relevance of a vestibular function test is dependent on the whole clinical and functional context of each particular case. It is not the ability to show 'abnormality' in a high number of patients complaining of whatever kind of vertigo, that indicates the relevance of a function test. Neither is relevance of a test based upon the possibility that this test can re-categorize some patients in the same way as has been done by other tests. Each test evaluates some particular functional aspect and this is very different from one test to another. A test is more relevant, i.e. indicates more abnormality when the type of vertigo caused by the dysfunction is also considered. These statements are confirmed by experience in peripheral vestibular disorders, especially benign paroxysmal positional vertigo (BPPV). A paroxysmal positional nystagmus (ppn) (nystagmus and vertigo elicited by movements and manoeuvres) is linked to the problem of provoked vertigo and gives a confirmation of this vertigo by reproducing it in some manoeuvres. Some inconstancy in the reproduction of this ppn may cause difficulties in diagnosis. Caloric tests are the clue for diagnosis of sudden unilateral loss (so-called neuronitis), whereas they give only complementary information for patients with BPPV. Posturography adds information in all categories concerning the standing position and can be interesting in the scope of rehabilitation treatment. The findings of a retrospective study in patients with BPPV (n = 95), compared with patients with Ménière's disease (n = 89) and others with sudden unilateral loss syndrome (n = 48), illustrate these concepts.

Can posturography contribute to the diagnosis of vertigo in patients where other tests fail to do so?

In this study, patients showing abnormal posturographic results in a test-configuration upon examination of the visuo-proprioceptive-vestibular interaction (Static Posturography type III, SPGIII) are reviewed. Group I (n = 81) comprised patients for whom no clear diagnosis could be obtained (neither central nor peripheral) and with rather atypical complaints. Group II (n = 77) comprised patients in whom a well-defined peripheral disorder could be found (typical provoked vertigo as BPPV (n = 30) and Meniere's disease (n = 30)). Group I consisted of s subgroup Ia, including patients with a complete negative classical examination (n = 32), a subgroup Ib with patients showing minor central signs (n = 28), and subgroup Ic comprising patients with slight peripheral indications (n = 21). The findings in SPGIII were compared between these two groups and are discussed in the light of earlier experience with such data in typical peripheral vestibular disorders. Similar sensory interaction patterns were found in both groups, with only small differences between them, suggesting that in some of these cases, especially in subgroups Ia and Ic, vestibular disturbance might be present, which would not have been sufficiently and clearly revealed by the classical tests. Especially the negative effects, i.e. when the withdrawal of a sensory input improved stability instead of aggravating it, which is the opposite to what should be expected, suggest that the other sensory inputs, vision and proprioception, play a role in the definition of the posturographic results in typical vestibular disorders as well as in diagnosis.