Effects of middle ear pressure changes on clinical symptoms in patients with Ménière's disease--a clinical multicentre placebo-controlled study.

Different medical and surgical methods have been tried in attempting to reduce endolymphatic pressure in Ménière's disease. Pressure treatment has a role on the treatment staircase, after pharmacological treatment and before destructive methods. Pressure chamber treatment has shown that some patients respond well to the treatment with diminishing inner ear symptoms and also some hearing improvement. Earlier studies have shown that electrocochlear measurements improve after local pressure treatment in the ear. The present study was a prospective randomized placebo controlled, multicentre clinical trial. 56 patients with active Ménière's disease, age 20-65 years, with a hearing loss of 20-65 dB PTA participated. A total of 31 patients completed 2 weeks use with an active apparatus (Meniett) and 25 patients completed the 2 weeks with the placebo gadget. Both machines were produced by Pascal Medical, Halmstad, Sweden. Two weeks before the start of treatment a grommet was placed in the tympanic membrane. A significant improvement concerning frequency and intensity of vertigo, dizziness, aural pressure and tinnitus was reported by the active group on the visual analogue scales (VAS) questionnaire. In the placebo group no change was the most common finding, followed by worsening of the symptoms and a few improvements. The function in professional and family life improved during active treatment and did not during placebo treatment. Pure-tone audiometry did not improve after placebo treatment, but improved at the frequencies 500 Hz and 1,000 Hz after active treatment. The study showed an improvement in the inner ear symptoms after Meniett treatment. The mechanism may be explained by the influence on the round window membrane pressure receptors or an endolymphatic flow out through the pressure release points, such as the endolymphatic duct and sac, thus activating the longitudinal flow. Other mechanisms are also possible.

Postural stability using different neck positions in normal subjects and patients with neck trauma.

Subjects with neck problems, such as whiplash injuries, often complain of disturbed equilibrium and, in some instances, provocation of the neck position can elicit such problems. The importance of neck proprioceptors for maintaining balance is gaining increased interest, moreover the function or malfunction of the otoliths may disturb equilibrium in certain head positions. The aim of the study was to create a reference material for postural control and its dependence on head position in healthy subjects and to compare this with a set of patients with known neck problems and associated vertiginous problems. A total of 32 healthy subjects (16 men, 16 women, age range 21-58 years) as well as 10 patients age range 27-62 years (mean 44 years) with neck problems and associated balance problems since a whiplash injury were tested for postural control using the EquiTest dynamic posturographic model. The normal subjects were initially split into four age groups in order to estimate the effects of age on performance. The postural stability was evaluated for dependence of support surface conditions (stable or sway-referenced), visual input (eyes open or closed) and head position (neutral, left rotated, right rotated, extended backwards or flexed forward) using analysis of variance (ANOVA) with Tukey's post hoc test in case of a significant factor effect. As expected, visual cues as well as stable support surface improve postural stability (p < 0.001). Postural stability is statistically different in the head extended backwards condition compared with the other four head positions (p < 0.001 in all cases) in both patients and controls. Eliminating this test condition from the analysis, only a slight (p < 0.05) difference between head forwards and head turned left remained. This pattern of results remained if the normal subjects were only split into two age groups instead of four. Finally, the patient group exhibited significantly lower postural performance than all the groups of normal subjects (p <0.01), but none of the normal groups differed significantly from each other. It is concluded that the postural control system is significantly challenged in the head extended backwards condition in both normal subjects and patients with previous whiplash injury and persistent neck problems. The patient group differed statistically from all groups of normal subjects. This suggests that neck problems impair postural control, and that the head extended position is a more challenging task for the postural system to adapt to. Whether this is due to utricular malpositioning, central integrative functions or cervical proprioceptive afferents is not within the scope of this study to answer.

Postural control--a comparison between patients with chronic anterior cruciate ligament insufficiency and healthy individuals.

Postural control in the sagittal plane was evaluated in 22 patients with chronic anterior cruciate ligament (ACL) deficiency and the result was compared to that of a control group of 20 uninjured subjects. Measurement of the body sway was done on a fixed and sway-referenced force plate in both single-limb and two-limb stance, with the eyes open and closed, respectively. Further, an analysis of the postural reactions to perturbations backwards and forwards, respectively, was made in single-limb stance. The results demonstrated statistically significant deficits of the postural control in the patient group compared to the control group, but also within the patient group. There was a significantly higher body sway within the patient group when standing on a stable support surface on the injured limb than standing on the uninjured limb with the eyes open, but no difference with the eyes closed. When standing on a stable support surface, there was a significantly higher body sway in the patient group standing on the injured leg than in the control group, both with eyes open and closed. The patient group also showed a significantly impaired postural control compared to the control group when standing on the uninjured leg with the eyes closed. There was no difference between the groups in the two-limb stance. When standing on the sway-referenced support surface, the patient group had a significantly larger body sway than the control group when the eyes were open, but there was no significant difference between the groups with the eyes closed. The measurement of the postural corrective responses to perturbations backwards and forwards showed that the reaction time measured from the initiation of the force plate translation, and the amplitude of the body sway was significantly greater in the patient group than in the control group. We conclude that patients with a continuing chronic ACL insufficiency several years after injury have an impaired postural control in the antero-posterior direction in single-limb stance on their injured leg. They also show a greater body sway and a prolonged reaction time when subjected to antero-posterior perturbations when standing on their injured leg.

Are deficits in the equilibrium system relevant to the clinical investigation of solvent-induced neurotoxicity?

OBJECTIVES: The diagnosis of solvent-induced chronic toxic encephalopathy is commonly based on case histories of exposure to solvents, symptoms, and deficits on psychometric tests. It has previously been demonstrated that long-term solvent-exposed workers have disturbances of the equilibrium system. The correlation between these disturbances and the diagnosis of chronic toxic encephalopathy has been analyzed in the present study. MATERIAL AND METHODS: Sixty men, consecutively admitted due to the suspicion of this syndrome, were investigated and classified into 3 groups--solvent-induced chronic toxic encephalopathy, incipient chronic toxic encephalopathy and nonchronic toxic encephalopathy. They were all examined using an otoneurological test battery, including analysis of saccades, smooth pursuit, visual suppression of the vestibular ocular reflex, and dynamic posturography. RESULTS: Compared with healthy referents several of the subjects, even in the nonchronic toxic encephalopathy group, showed a reduced visual suppression ability, a prolonged latency of saccades, and pathological posturographic results. Some otoneurological tests correlated with the duration of exposure and the results of psychometric tests representing memory and perceptual skills. Nevertheless, there was no significant group correlation between the otoneurological findings and the diagnosis of chronic toxic encephalopathy. CONCLUSION: Disturbances revealed by an otoneurological investigation have so far not been considered in the diagnosis of chronic toxic encephalopathy. Our results indicate that an otoneurological test battery adds worthwhile information about lesions within the brainstem-cerebellar complex not revealed by a psychometric investigation.

When and how to use gentamicin in the treatment of Menière's disease.

Gentamicin given as local therapy for severe Menière's disease is of considerable value in the control of vertigo. The ototoxic antibiotic is instilled through the tympanic membrane causing a peripheral vestibular loss and possibly also diminished endolymph production. In order to achieve the best results with gentamicin treatment it is of utmost importance that the diagnosis is correct. Given to a patient with vertigo of other than peripheral origin, the outcome would be worsening of the existing symptoms and addition of new ones. The method should be used only by physicians who are very familiar with vertigo and otology, and only in patients with such a disturbing degree of vertigo that they are well motivated to receive treatment. Thorough information regarding the disease, the treatment procedure and the symptoms caused by a unilateral peripheral vestibular loss should be given to the patient. Vestibular rehabilitation, including movement therapy, should be given by the physician or preferably, a well trained physiotherapist on an individual basis or in patient groups together with written practice programmes for use at home. Vertigo attacks are usually relieved in 95% of patients. Twenty percent of patients experience an added hearing loss in the treated ear, although this number is reduced if the treatment is given as a single installment on consecutive days with extra installments given one month later if the vertigo remains.

The subjective horizontal in eccentric rotation influenced by peripheral vestibular lesion.

Peripheral vestibular equilibrium disorders may originate in various parts of the labyrinth or the vestibular nerve. Traditionally, the function of the lateral semicircular canals has been assessed with caloric irrigation, and sometimes falsely been interpreted as a vestibular nerve lesion. The vertical semicircular canals are not easily assessed. Caloric testing with the head in different positions is not very helpful, but the canals may pairwise be tested using specific rotational techniques. Often the otolithic organs, capable of detecting linear acceleration forces, are forgotten as a source of vertigo and dizziness. We have implemented horizontal rotatory testing with the subject seated eccentrically facing the direction of rotation as a means of assessing otolithic function. The subject experiences a lateral tilt and is instructed in darkness to put a short light bar in the position he thinks a water surface would have, which is identical to his perceived tilt. In 39 normal subjects, a theoretical tilt of 24 degrees was estimated as approximately 19.5 degrees, and the standard deviation was 6 degrees. A side difference index was proposed to be normal if below 25%. The preliminary findings in a few patients with known labyrinthine lesions are presented. We propose that otolithic as well as lateral semicircular canal functions are useful to monitor in patients with suspected peripheral equilibrium disorders.

MR imaging in solvent-induced chronic toxic encephalopathy.

PURPOSE: To use MR to examine patients with CNS symptoms indicating +chronic intoxication. MATERIAL AND METHODS: Thirty-two subjects exposed to industrial solvents for 5 to 28 years and 40 age-matched, healthy controls were examined. RESULTS: All patients showed decreased signal in the basal ganglia on T2-weighted images. In 11 of the patients the white matter showed diffuse hyperintensity with loss of the grey-white matter discrimination and with distinct periventricular hyperintensities in 5 of the patients. The controls had no pathological changes in the brain. CONCLUSION: Although the relatively small number of patients may obscure the significance, findings observed on T2-weighted images were patchy periventricular hyperintensities and hypointensities in the basal ganglia. Fast spin-echo is a good technique with fast acquisition of images with true spin-echo contrast features.

Macrovascular causes underlying otoneurological disturbances.

In the diagnostic procedure for patients with symptoms and signs indicating VIIIth nerve or brain stem disturbances, the possible presence of tumors, infarcts, bleedings or microvascular loops are taken into account. Ten patients with vertigo, balance disorders, tinnitus or unilateral hearing loss proved to have a similar cause underlying the disturbances. They ranged in age from 51 to 80 years and had a duration of their symptoms of 1-10 years. In the test battery audiology, electronystagmography, broad-frequency rotatory testing and dynamic posturography were used. No uniform pattern was present. The results showed VIIIth nerve as well as CNS signs. Trigeminal neuralgia and hemifacial spasm were observed. CT, NMR or angiography were performed. The common finding for these patients were ectatic vertebral and/or basilar arteries. The size and position of the vessels indicated that compression of the VIIIth nerve or brainstem was the cause underlying their disturbances. To exclude that macrovessels appear in patients without neurotological symptoms and signs 300 consecutive NMR investigations in patients referred for other than neurotogic indications were scrutinized. In these patients no macrovessels were found. The findings indicate that ectatic vessels may cause disturbances mimicking a pontine angle tumor, Meniere's disease and other peripheral or central conditions with inner ear symptoms, vertigo and balance disorders. Arterial loops in the pontine angle may give indications for microvascular surgery, but the big ectatic vertebral and basilar arteries may offer surgical decompression possibilities, though with large risks.

Effects of loratadine on postural control.

The effects of classical sedating antihistamines on cognitive and perceptual functions are well known. Loratadine is a new antihistamine without sedative effects. In this study, loratadine 10 and 40 mg daily, clemastine 2 mg twice daily and placebo were evaluated in 8 healthy subjects in terms of effects on equilibrium as measured with dynamic posturography. Dynamic posturography comprises a sensory organization part in which the support surface and visual surround are either stable or referenced to the patient's sway, with eyes open or closed. In a movement coordination part, the platform makes active movements. Analysis of variance showed no effects on equilibrium attributable to loratadine. Comparing substances pairwise, however, a significant difference between loratadine and clemastine was displayed in 2 out of 6 sensory test conditions. In conclusion, loratadine can be considered safe regarding balance functions.

Influence of cerebrospinal fluid tapping on dynamic equilibrium in suspected hydrocephalus.

Thirty-nine patients aged 21-82 years (mean 62 years) under investigation for suspected acquired hydrocephalus were investigated by dynamic posturography before and 6-8 h after a cerebrospinal fluid tap of 20-40 ml. Dynamic posturography comprises a sensory organization (SO) part in which the platform and visual surround are either stable or referenced to the patient's sway. The eyes are closed or open. In a movement coordination (MC) part the platform makes active movements, thus introducing external disturbances in the procedure. The patients improved their balancing ability in all tests on the sway referenced platform in SO, while MC remained unaffected. It is concluded that dynamic posturography is valuable for dysequilibrium assessment in clinical evaluation of suitable candidates for ventricular shunts in acquired hydrocephalus.

Recovery of equilibrium after intratympanal gentamicin in Menière's disease

A manutençäo do equilíbrio é baseada na visäo, impulsos vestibulares, na propriocepçäo e na sensaçäo de pressäo dos pés. Após uma lesäo vestibular unilateral, a compensaçäo vestibular depende das informaçöes de todos esses órgäos. É importante que os exercícios de reabilitaçäo vestibular comecem o mais rápido possível e tenham uma certa intensidade. Os efeitos do treino podem ser avaliados através da história clínica, da eletronistagmografia e posturografia dinâmica, mas mesmo a observaçäo com lentes de Frenzel e observaçöes clínicas do teste de Romberg e Unterberger säo de algum valor. Se há pertubaçäo na percepçäo ou na coordenaçäo central dos órgäos, como o cerebelo, a compensaçäo vestibular näo poderá ser totalmente perfeita. A compensaçäo vestibular observada em um caso e em um grupo de pacientes com doença de Menière incapacitante tratados com gentamicina intratimpânica será sinteticamente delineada

Randomized perturbed posturography: methodology and effects of midazolam sedation.

To study quiescent stance without applying external disturbances is not a theoretically appealing way to unveil the dynamic properties of human equilibrium. Methods to disturb equilibrium range from standing on foam surface, attaching vibrators to the calves to interfere with somatosensation, and exposure to body-position tracking environments, as in dynamic posturography (EquiTest). The EquiTest apparatus was modified by a menu-driven software to allow arbitrary movements of the support surface and visual surround, and force data were recorded for subsequent analysis. The support surface was randomly moved in the antero-posterior direction. First equilibrium was studied on the stable support surface, then low (RMS 1.3 cm) and high (RMS 2.6 cm) amplitude movements were used. Vision was either present or absent at all test amplitudes. Equilibrium was evaluated by the confidence (61%) ellipse sway area and average sway velocity during 45 s. Eleven healthy subjects aged 23-36 years (mean 29) were sedated with a short acting sedative, midazolam 0.1 mg/kg. Randomized perturbed posturography was conducted at baseline, and at about 60, 120 and 180 min after injection. Psychomotor tests were conducted at baseline, and at 30, 90, 150 and 210 min. Large interindividual variations were found. One subject could not be tested at all at 60 min due to sleepiness, whereas some subjects felt nearly full awake at 30 min. Sway areas were larger at 60 min, but not subsequently. At 60 min, sway velocities with open eyes were higher, just as when vision was absent and low amplitude movements were used. Later no effects could be shown.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of increased inertial load in dynamic and randomized perturbed posturography.

Muscular weakness is present in many diseases. The present study attempted to model a relative weakness of postural control muscles by loading the subjects with extra weight, and the effects on EquiTest dynamic posturography and randomized perturbed posturography were assessed. Ten healthy subjects aged 15-39 years (mean 26 years) were used. Their weights ranged 53-82 kg. Equilibrium was measured with and without an extra 20% of body weight attached to the upper part of the trunk by means of pieces of lead metal placed in a specially sewn shirt. Dynamic posturography (EquiTest) comprises a sensory organization test in which the support surface and visual surround are either stable or referenced to the patient's sway, his or her eyes open or closed. In a movement coordination part the platform makes active movements. Antero-posterior sway on a stable support surface with absent or distorted visual cues was marred, and the correction pattern was altered on a movable support surface when the vision was absent. Furthermore, the EquiTest apparatus was driven by special software to produce randomized antero-posterior movements during 45 s. In addition to stable conditions, small and large amplitude perturbations were used. The subject's ability to remain in equilibrium was estimated by the sway velocity and a confidence ellipse sway area during 45 s. During weightbearing, sway areas were larger on the stable support surface both with and without vision. Postural sway velocity was lower when vision was absent both using small and large amplitudes.(ABSTRACT TRUNCATED AT 250 WORDS)

Otoneurologic disturbances caused by solvent pollution.

Subjects exposed to industrial solvents may experience vertigo and nausea. Solvents are usually volatile hydrocarbon compounds, which are important parts of everyday life in a modern society. They may also cause neurastenia, personality changes, and reduced intellectual capacity. The syndrome that may develop was formerly named psycho-organic syndrome (POS), but in modern terminology it is called chronic toxic encephalopathy (CTE). The syndrome develops slowly, and during the first years no pathological findings will be found using various test batteries. Somewhat later, when the syndrome still might be reversible, psychometric, auditory, and otoneurologic testing may well unveil disturbances within the posterior fossa structures. Animal experiments suggest one site of effect for solvents to be within the cerebellum and brainstem regions with close relationship to the gamma-amino-butyric acid (GABA) transmission. In the otoneurologic test battery, visual suppression and smooth pursuit are of extreme value, as are some auditory tests such as discrimination of interrupted speech and cortical response audiometry using frequency glides as stimuli. Dynamic posturography and magnetic resonance imaging (MRI) have recently proved valuable in the diagnosis. Research is needed concerning the most efficient test battery for early detection of solvent-induced lesions. During further research it is important to unveil other toxic agents, like heavy metals and alcohol, and their damage to the central nervous system and to make comparisons between these substances and the lesions caused by hydrocarbon solvents.

Computerized dynamic posturography: a new method for the evaluation of postural stability following anaesthesia.

Dynamic posturography, a new method to study postural stability in humans, was performed in 11 healthy volunteers before administration of midazolam 0.1 mg/kg body weight i.v., and repeated subsequently at 45, 105 and 165 min. Results indicate that balance was affected significantly (P less than 0.008) up to 45 min after i.v. midazolam and did not return to control values until 105 min. The quantified version of the Romberg test performed with the eyes open or closed using the Equitest did not appear to be sensitive in detecting residual effects of midazolam on balance. We conclude that healthy, young persons should not be considered to have regained postural stability for up to 105 min after sedation with midazolam. Dynamic posturography appears to be a useful test in the objective assessment of balance disturbances.

Langerhans cells and subsets of lymphocytes in the nasal mucosa.

Langerhans cells and different lymphocytes were studied in the nasal mucosa of 39 woodwork teachers and a control group of 14 healthy subjects. Ten of the woodwork teachers were sensitized as determined by skin prick test. A panel of different monoclonal antibodies was applied on the frozen nasal mucosal specimens. Intraepithelial CD1-positive dendritic cells were found in all specimens. However, there was no difference between the number of these Langerhans cells found in the study group and the number found in the controls. In every specimen the intraepithelial lymphocyte population was dominated by T lymphocytes, and there were relatively few B cells. Similarly the ratio between CD4- and CD8-positive lymphocytes in the study group and the controls was the same. In all specimens there was a dominance of T suppressor/cytotoxic cells compared with T helper/inducer cells. The study confirms that Langerhans cells are present in normal nasal surface epithelium, and suggests that there is no basic difference in the number of Langerhans cells between healthy persons, persons with nasal complaints, and persons with nasal allergy. The dominance of T lymphocytes in the epithelium may indicate the existence of a local cell-mediated immunity other than that associated with the regulation of IgE.

Chronic toxic encephalopathy investigated using dynamic posturography.

Seven male patients previously exposed to industrial solvents and diagnosed with chronic toxic encephalopathy (aged 38 to 69 years; mean age, 56 years) were investigated by dynamic posturography and compared with healthy, age-matched male control patients. Dynamic posturography comprises two phases: a sensory organization (SO) phase, in which the support surface and visual surround are either stable or referenced to the patient's sway, with eyes open or closed, and a movement coordination (MC) phase, in which the platform makes active movements. In SO testing, the patient group showed significantly impaired equilibrium performance compared with the control group in most test conditions. The MC test revealed no differences between groups. A relationship was found between the equilibrium score resulting from SO testing with stable support and visual surround and the sway area of the confidence ellipse elicited 3 years previously by static posturography with eyes open. We conclude that patients with chronic toxic encephalopathy have impaired equilibrium, as demonstrated by dynamic posturography testing.

Effect of alcohol measured by dynamic posturography.

Thirteen healthy male volunteers aged 21-42 years (mean 27 years) were assessed by dynamic posturography before and after ingestion of alcohol. Each subject was given 0.6 g alcohol per kg body weight in fruit juice to be drunk within 10 min. Alcohol levels in blood samples at 15, 45 and 75 min after ingestion were assessed by gas chromatography. Posturographic measurements were conducted at 30 and 60 min after alcohol administration. Dynamic posturography comprises a sensory organization part in which the support surface and visual surround are either stable or referenced to the patient's sway and the test conditions are eyes open or eyes closed. In a movement coordination part the platform makes active movements. Alcohol levels were 0.40% (SD 0.14) after 45 min and 0.51% (SD 0.14) at 75 min. All subjects presented positional alcohol nystagmus and gaze nystagmus after 45 min. In the sensory organization part of the dynamic posturography in test conditions with eyes closed and the head in neutral position, both with stable (p less than 0.039) and sway-referenced platform (p less than 0.017), alcohol effects were found. In the test condition with sway referenced platform and stable visual surround the effect of alcohol was close to significance (p less than 0.069). When the head was tilted to either side, no effect of alcohol was detected, nor in the movement coordination test. It is concluded that dynamic posturography can detect the effect of alcohol on static and dynamic equilibrium. Test conditions with absent vision appear to be the most sensitive. The results in static conditions are well in agreement with previous studies; the findings under dynamic conditions are new.

Abstinent chronic alcoholics investigated by dynamic posturography, ocular smooth pursuit and visual suppression.

Eleven male chronic alcoholic volunteers aged 44-65 years (mean 57 years) were investigated by dynamic posturography, ocular smooth pursuit and visual suppression of the vestibulo-ocular reflex (VOR). Their drinking time ranged from 8-30 years (mean 20 years) and they had been abstinent for the last 1-20 years (mean 7 years). Ocular smooth pursuit showed abnormalities in 8/11. Abnormalities were found in 5/11 in the visual suppression of the VOR. The results of dynamic posturography tests were compared to an age-matched reference material. Dynamic posturography (EquiTest) comprises a sensory organization (SO) part in which the support surface and visual surround are either stable or referenced to the patient's sway, with eyes open or closed. In the SO part the chronic alcoholics had lower equilibrium scores in all test conditions, and the differences were significant in 4 tests out of 6. In a movement coordination part the platform makes active movements, the latencies to which were significantly prolonged in the 2 larger of the 3 translational amplitudes. Adaptation to repeated tilting of the platform was estimated to be pathological in 4/10, compared to none of the controls. The abnormal pattern found in dynamic posturography correlates well with the pathology in ocular smooth pursuit and visual suppression tests, suggested to be due to alcohol induced cerebellar lesions. It is concluded that dynamic posturography is a valuable test for assessing dysequilibrium in chronic alcoholics, even abstinent.