[The vestibular craniovertebral joints]. / Die vestibulären Kopfgelenke.

INTRODUCTION: The significance of cervical proprioception for human balance has thus far not been sufficiently elucidated. The aim of this study was to provoke selective cervico-vestibular stimulation using the trunk excursion test (TET) we ourselves constructed. This chair is designed to enable evaluation of cervico-ocular reactions during isolated trunk excursion and possible effects of aging. METHODS: The previously used head excursion test (HET) was statistically compared to the TET. In both methods, 100 healthy subjects of two age groups (group(26): median age = 26 years, n = 50; group(50): median age = 50 years, n = 50) were randomized for comparison of similar neck-to-trunk-positions. RESULTS: HET enabled detection of significant nystagmus modulation in horizontal and vertical dimensions; whereas in pure cervical stimulation using the new TET, this was only evident in the horizontal dimension and only during trunk torsion. Comparison of the two methods confirmed significantly stronger nystagmus modulation through head excursion. In terms of the HET, group(50) showed significantly more vertical nystagmus activity than group(26). However, no significant difference was found between the groups in terms of their reactions to trunk excursion in the TET. In a group-specific comparison of the methods, group(26) showed a significant increase in horizontal nystagmus in head compared to trunk excursion, whereas group(50) generally displayed a significantly greater response to provocation by head excursion in HET. Analysis of the significant vertical nystagmus modulation produced with the TET method showed predominance of upbeat- (UBN) over downbeat-nystagmus (DBN). Through head excursion with the HET, DBN was more frequently evoked in group(50) than in group(26). No significant age-dependent difference could be derived in UBN. CONCLUSION: The results of the pilot study indicate that head-to-trunk provocation is a suitable means of evaluating cervicotonic provocation nystagmus. Only by evaluation of adequate excursion limits and consistent analysis of patients with cervical deficiency can the effects of the method be further assessed.

Nistagmo vertical inferior: ¿es obligada la resonancia magnética? / Inferior vertical nystagmus: is magnetic resonance imaging mandatory?

Introducción. La aparición de un nistagmo vertical inferior clásicamente obliga a descartar una patología vascular o de la unión craneocervical mediante resonancia magnética (RM). Estudios recientes demuestran una baja rentabilidad de esta prueba, ya que sugieren que este signo oculomotor puede tener una causa vestibular periférica, sobre todo cuando el paciente presenta un vértigo posicional paroxístico benigno (VPPB) del canal semicircular superior. Objetivo. Comprobar la rentabilidad de la RM en una población de pacientes con nistagmo de posición vertical inferior. Pacientes y métodos. Estudio retrospectivo de 42 pacientes consecutivos a los que se les realizó una historia clínica, exploración física, y pruebas vestibulares calóricas y rotatorias. A todos ellos se les practicó una RM craneal y cervical. Resultados. El 52% de los pacientes con nistagmo de posición vertical inferior presentaba una clínica y exploración física compatibles con VPPB del canal semicircular superior. La RM fue normal en un 67%, un 26% mostraba datos de espondilopatía y un 5% de microangiopatía cerebral no relacionados con la clínica del paciente. La prevalencia de malformación de Arnold-Chiari de tipo I fue de un 9% en la población estudiada, sin que nadie tuviera un antecedente reciente de VPPB. Los resultados obtenidos en las pruebas complementarias vestibulares no aportaron información adicional para llegar a un diagnóstico etiológico. Conclusión. En los pacientes con un VPPB, la RM craneal y las pruebas vestibulares tienen una baja rentabilidad diagnóstica, y se debe evaluar la necesidad real de esta prueba con el contexto clínico (AU)

Introduction. The presentation of a down-beating nystagmus force to discard vascular pathology of brain and cervical joint with magnetic resonance imagine (MRI). Recent studies support the low profitability of this study and is subjected that this oculomotor sign has a peripheral origin especially when the patient has a benign paroxysmal positional vertigo (BPPV) with affection of the superior semicircular canal. Aim. To evidence the profitability of MRI in a population of patients with positional down-beating nystagmus. Patients and methods. We present a retrospective study with 42 consecutive patients. A complete clinical history and physical examination was performed. All of them perform vestibular tests (caloric and rotatory), cranial and cervical MRI. Results. Fifty-two percent of patients present clinical manifestations and physical exploration compatible with BPPV. MRI was normal in 67%. We found spondylopathy in 26% and vascular cerebral pathology in 5%. Prevalence of type I ArnoldChiari malformation was 9% in our population. None of them was founded when the main symptom was suggestive of BPPV. Results obtained of vestibular tests didn’t contribute additional information to give an ethiologic diagnosis. Conclusion. The profitability of vestibular tests and MRI in our population with down beating nystagmus was very low. We must evaluate the real necessity of this test with the clinical context (AU)

[Optokinetic nystagmus associated with Parkinson's disease].

Optokinetic nystagmus is a complex many-level physiological reaction underlain by the mechanisms of oculomotor reaction and dependent on the correlated regulatory action of the upper parts of CNS. The objective of the present study was to estimate the quantitative parameters of optokinteic nystagmus in the patients presenting with clinically manifest Parkinson's disease (PD) with due regard for the character of optokinetic stimulation. It was shown that PD is associated with a decrease of velocity-related parameters of optokinetic nystagmus correlated with the severity of the disease. The decrease of velocity in the slow phase and the efficacy coefficient of vertical optokinetic nystagmus was more pronounced in comparison with horizontal nystagmus. It was totally absent in certain patients with stage IV of the disease which objectively reflects the overall motor deficiency associated with PD and manifest as the predominant involvement of mechanisms of the vertical oculomotor system.

Comparison of techniques for identification of peripheral vestibular nystagmus.

OBJECTIVE: To determine the best clinical method for identifying peripheral vestibular nystagmus, by comparing eye movement examination with optic fixation, and with fixation removed using Frenzel's glasses, infra-red video-Frenzel's goggles or an ophthalmoscope, with results of electronystagmography. METHOD: One hundred patients referred for electronystagmography from the audiovestibular medicine clinic at Queen Alexandra Hospital, Portsmouth, were examined immediately before undergoing electronystagmography. RESULTS: Video-Frenzel's goggles were highly effective at detecting peripheral vestibular nystagmus, with a sensitivity of 85 per cent (95 per cent confidence interval, 62.1-96.8 per cent) and a specificity of 65 per cent (53.5-75.3 per cent), compared with electronystagmography. Ophthalmoscopy had comparable sensitivity to Frenzel's glasses (used in the dark), i.e. 26.3 per cent (9.1-51.2 per cent) compared with 31.6 per cent (12.6-56.6 per cent), respectively. Frenzel's glasses as normally used in ENT clinics (i.e. in dim lighting) were ineffective, with a sensitivity of just 10 per cent (1.2-31.7 per cent). CONCLUSION: Video-Frenzel's goggles should be used in all clinics with substantial numbers of balance-impaired patients. Traditional Frenzel's glasses have no place in clinical practice unless formal black-out facilities are available.

[Infrared video-nystagmograph tracing].

As the infrared image gray distribution of nystagmus video is uneven, the accuracy of pupil edge detection could not be high enough. A pupil location method based on morphology and Canny algorithm was presented in this paper. Some meaningless regions were removed by morphology, and target was smoothed. The connected regions were separated, and the largest connected region-pupil was found. Then the pupil edges were extracted by the designed Canny edge detection algorithm. The coordinates of pupil for each frame images were calculated and the pupil movement tracking was fitted. Finally, desired clinical diagnostic information would be obtained from the tracking. Experimental results showed that the method could be adapted to different gray values for different objects, and could accurately detect the edge of the pupil. As the pupil was tracked well, the experimental results could reflect the eye movement. The method provides a practical way for the pupil location of existing domestic researches in video-nystagmograph.

Suppression of spontaneous nystagmus during different visual fixation conditions.

Analysis of spontaneous nystagmus is important in the evaluation of dizzy patients. The aim was to measure how different visual conditions affect the properties of nystagmus using three-dimensional video-oculography (VOG). We compared prevalence, frequency and slow phase velocity (SPV) of the spontaneous nystagmus with gaze fixation allowed, with Frenzel's glasses, and in total darkness. Twenty-five patients (35 measurements) with the peripheral vestibular pathologies were included. The prevalence of nystagmus with the gaze fixation was 40%, and it increased significantly to 66% with Frenzel's glasses and regular room lights on (p < 0.01). The prevalence increased significantly to 83% when the regular room lights were switched off (p = 0.014), and further to 100% in total darkness (p = 0.025). The mean SPV of nystagmus with visual fixation allowed was 1.0°/s. It increased to 2.4°/s with Frenzel's glasses and room lights on, and additionally to 3.1°/s, when the regular room lights were switched off. The mean SPV in total darkness was 6.9°/s. The difference was highly significant between all test conditions (p < 0.01). The frequency of nystagmus was 0.7 beats/s with gaze fixation, 0.8 beats/s in both the test conditions with Frenzel's glasses on, and 1.2 beats/s in total darkness. The frequency in total darkness was significantly higher (p < 0.05) than with Frenzel's glasses, and more so than with visual fixation (p = 0.003). The VOG in total darkness is superior in detecting nystagmus, since Frenzel's glasses allow visual suppression to happen, and this effect is reinforced with gaze fixation allowed. Strict control of visual surroundings is essential in interpreting peripheral nystagmus.

Electronystagmography versus videonystagmography.

UNLABELLED: Electronystagmography (ENG) and videonystagmography (VNG) are eye movement recording methods used for the evaluation of balance disorders. AIM: To compare literature information on the similarities, differences, advantages e disadvantages between ENG and VNG. MATERIALS AND METHODS: review of the scientific literature. RESULTS: ENG and VNG are very helpful methods for evaluating balance disorders, due to their capacity to recognize signs of peripheral or central vestibular dysfunction and to pinpoint the side of the lesion. Major advantages of VNG are related to calibration, temporospatial resolution, and recording of horizontal, vertical and torsional eye movements. CONCLUSION: VNG is a new technology that presents advantages in the evaluation of eye movements; however, despite its disadvantages, ENG is still considered a valuable test in the clinical setting.

Eletronistagmografia versus videonistagmografia: [revisão] / Electronystagmography versus videonystagmography: [review]

Electronystagmography (ENG) and videonystagmography (VNG) are eye movement recording methods used for the evaluation of balance disorders. AIM: To compare literature information on the similarities, differences, advantages e disadvantages between ENG and VNG. MATERIALS AND METHODS: review of the scientific literature. RESULTS: ENG and VNG are very helpful methods for evaluating balance disorders, due to their capacity to recognize signs of peripheral or central vestibular dysfunction and to pinpoint the side of the lesion. Major advantages of VNG are related to calibration, temporospatial resolution, and recording of horizontal, vertical and torsional eye movements. CONCLUSION: VNG is a new technology that presents advantages in the evaluation of eye movements; however, despite its disadvantages, ENG is still considered a valuable test in the clinical setting

A eletronistagmografia (ENG) e a videonistagmografia (VNG) são métodos de registro dos movimentos oculares, empregados na avaliação dos distúrbios do equilíbrio corporal. OBJETIVO: Comparar as informações da literatura sobre as semelhanças, diferenças, vantagens e desvantagens da ENG e da VNG. MATERIAL E MÉTODO: Estudo de revisão da literatura científica pertinente. RESULTADOS: A ENG e a VNG são sistemas muito úteis no diagnóstico dos distúrbios do equilíbrio corporal, diante da sua capacidade de identificar sinais de disfunção vestibular periférica ou central e determinar o lado da lesão. As principais vantagens da VNG estão relacionadas com calibração, resolução têmporo-espacial e gravação dos movimentos oculares horizontais, verticais e torsionais. CONCLUSÃO: A VNG é uma nova tecnologia que apresenta vantagens na avaliação dos movimentos oculares, mas a ENG, apesar de suas desvantagens, é ainda considerada um procedimento de valor na rotina clínica

Vestibular function testing.

INTRODUCTION: Vestibular symptoms of vertigo, dizziness and dysequilibrium are common complaints which can be disabling both physically and psychologically. Routine examination of the ear nose and throat and neurological system are often normal in these patients. An accurate history and thorough clinical examination can provide a diagnosis in the majority of patients. However, in a subgroup of patients, vestibular function testing may be invaluable in arriving at a correct diagnosis and ultimately in the optimal treatment of these patients. METHOD: Literature review. CONCLUSION: In this review we aim to highlight the new understanding and insight into the underlying pathophysiology of vestibular disorders which in conjunction with technological advancements have led to significant improvements in the clinical and laboratory evaluation of vestibular disease. The vestibular and balance assessment modalities which are available to help optimise the management of vestibular disease are also discussed.

[Influence of different head-trunk positions to the upbeat-nystagmus]. / Einfluss der Kopf-Rumpf-Positionsänderung auf den Upbeat-Nystagmus.

The neck torsion test (NTT) can be used to evaluate the cervico-ocular reflex (COR). We think there are two main reasons why NRT has failed to gain general acceptance in clinical practice: the test does not fully exploit the somatosensory examination potential, and electronystagmography has been most commonly used but is inferior to videonystagmography for a very low-amplitude nystagmus. These considerations have led us to develop a modified neck torsion test (mNTT) with three-dimensional video-oculographic (3D-VOG) recording. Sensors on the video glasses enable three-dimensional and continuous registration of the head position. Horizontal, vertical and rotatory eye movements are determined in six different head-body positions (right/left head tilt, ante/retroflexion of the head, and right/left body rotation). The basis for assessing the mNTT is described in detail. We used the mNTT to examine prospectively compensated, vestibularly deficient (n = 52), and cervically deficient (n = 93) patients with vertigo against a control group (n = 22). Our results show that upbeat-nystagmus (UBN) significantly differentiated the groups. This occurs most frequently in the tonic analysis phase of head inclination and reclination. UBN is differential-diagnostically discussed on the basis of these examination findings, and its cervical origin is elucidated with the aid of model conceptions. We conclude that our modified NRT is an improved instrument for COR determination. A suspected cervical somatosensory reduction warrants testing particularly for UBN.

[Effects of electromagnetic fields emitted by cellular phone on auditory and vestibular labyrinth]. / Wirkung elektromagnetischer Felder des GSM-Mobilfunksystems auf auditives und vestibuläres Labyrinth und Hirnstamm.

BACKGROUND: It is the subject of this study to investigate the biological effect of the HF radiation produced by the Global System for Mobile Communications-( GSM)-mobile phone on the inner ear with its sensors of the vestibular and auditive systems. METHODS/PATIENTS: Thermographic investigations made on various model materials and on the human temporal bone should show whether mobile phone does induce any increases of temperature which would lead to a relevant stimulus for the auditive and vestibular system or not. We carried out video-nystagmographic recordings of 13 subjects, brainstem electric response audiometry of 24 ears, and recordings of distorsion products of otoacoustic emissions of 20 ears. All tests were made with and without a mobile phone in use. The data was then analyzed for variation patterns in the functional parameters of the hearing and balance system that are subject to the (non)existence of electromagnetic radiation from the mobile phone. RESULTS: The thermographic investigations suggest that the mobile phone does not induce any increases of temperature which would lead to a relevant stimulus for the auditive and vestibular system. Video-nystagmographic recordings under field effect do not furnish any indication of vestibular reactions generated by field effects. Compared with the recording without field, the brainstem electric response audiometry under field effect did not reveal any changes of the parameters investigated, i. e. absolute latency of the peaks I, III, V and the interpeak latency between the peaks I and V. The distorsion products of otoacoustic emissions do not indicate, comparing the three measuring situations, i. e. before field effect, pulsed field and continuous field, any possible impacts of the HF field on the spectrum or levels of emissions for none of the probands. CONCLUSION: The investigations made show that the electromagnetic fields generated in using the mobile phone do not have an effect on the inner ear and auditive system to the colliculus inferior in the brainstem and on the vestibular receptors in the inner ear and the vestibular system.

Abnormal computerized dynamic posturography findings in dizzy patients with normal ENG results.

The complexities of the balance system create difficulties for professionals interested in testing equilibrium function objectively. Traditionally, electronystagmography (ENG) has been used for this purpose, but it provides information on only a limited portion of the equilibrium system. Computerized dynamic posturography (CDP) is less specific than ENG, but it provides more global insight into a patient's ability to maintain equilibrium under more challenging environmental circumstances. CD Palso appears to be valuable in obtaining objective confirmation of an abnormality in some dizzy patients whose ENG findings are normal. Our review of 33 patients with normal ENG results and abnormal CDP findings suggests that posturography is useful for confirming or quantifying a balance abnormality in some patients whose complaints cannot be confirmed by other tests frequently used by otologists.

[The value of dynamic posturography (Equitest) in preparing an expert's report]. / Der Stellenwert der dynamischen Posturographie (Equitest) bei gutachterlichen Beurteilungen.

BACKGROUND: Expert appraisals of vestibular disorders and their effects on daily life are essentially based on an evaluation of the patient's subjectively described symptoms. The aim of the present study was to ascertain the extent to which dynamic posturography is able to assist in the preparation of expert's reports. MATERIAL AND METHODS: 60 patients underwent a survey of their balance impairment. Both a nystagmus analysis, with its objective criteria, and dynamic posturography were carried out. The investigation into reduction of fitness for work (MdE) made reference to the criteria specified in the table by STOLL. The data obtained were subjected to both correlation and variance analysis. RESULTS: Although the results of this analysis revealed no direct statistical dependency, they indicated a tendency for the composite values to be correlated with the nystagmus scores and/or the MdE values (when the nystagmus score and/or the MdE increases, the composite value decreases). CONCLUSIONS: The Equitest is, according to the available data, not able to replace the currently valid MdE scores. Nevertheless, it represents a means of providing objective data about the vestibulo-spinal reflex. The test also reveals any tendencies towards simulation and aggravation. In the context of a specific nystagmus analysis, the Equitest offers an additional means of providing an objective background to back up the more subjective assessment of MdE.

A comparative study on the observation of spontaneous nystagmus with Frenzel glasses and an infrared CCD camera.

OBJECTIVES: To compare the usefulness of a CCD camera with infrared illumination (IR-CCD camera) over Frenzel glasses (F Glasses) for the observation of spontaneous nystagmus, the incidence and direction of nystagmus, and the frequency, amplitude and slow phase of spontaneous nystagmus. METHODS: One hundred vertiginous patients, fifty-three females and forty-seven males participated in this study. Before undergoing routine neurotological examination, their eye movements were recorded by electronystagmogram (ENG) in conjunction with observations of eye movements under F glasses and through an IR-CCD camera. The data was collected from patients who exhibited spontaneous nystagmus either under F glasses or the IR-CCD camera. RESULTS: Thirty-three patients showed spontaneous nystagmus under F glasses. On the other hand, under the IR-CCD camera, all patients examined exhibited spontaneous nystagmus. The frequency of nystagmus was not significantly different between these two systems. However, the amplitude and slow phase velocity exhibited significantly larger values under the IR-CCD camera in patients with spontaneous nystagmus both under the IR-CCD camera and F glasses. CONCLUSION: From these observations and evidence, the IR-CCD camera can be recommended as a more useful system and powerful tool for neurotological examination than F glasses.

[Near infrared stimulation of the equilibrium organ--first clinical experiences]. / Nahinfrarotreizung des Gleichgewichtsorgans--erste klinische Erfahrungen.

BACKGROUND: A new method for the stimulation of the organ of equilibrium by means of a broad-scale and monochromatic near infrared emission was developed. This method should be examined within the framework of a pilot study, evaluated and its clinical possible applications examined. PATIENTS AND METHODS: Healthy probands (n = 15), patients with a radical cave of the ear (n = 5), patients with a defect of the tympanic membrane (n = 5) and spontaneous nystagmus (n = 5) were examined. In healthy probands an irritation with broad-scale as well as monochromatic near infrared (NIR) was performed and compared with a water irrigation (44 degrees, 50 ml in 30 seconds). The subjective, local feelings during the application and the appearance of giddiness according to irritation were recorded and the nystagmus was registered by means of videonystagmography. In patients with radical cave of the ear and tympanic membrane defects, a broad-scale NIR-irritation before a comparative irritation with warm air (44 degrees) was performed exclusively. RESULTS: In all healthy probands, a nystagmus reaction could be seen with broad-scale and monochromatic NIR. Compared to the hot water irritation slow phase velocity (SPV) was decreased however registrable by means of Frenzel glasses and electronystagmography during the culmination stage. In patients with radical cave (n = 4) and tympanic membrane defects (n = 3) showing paradoxical nystagmus reaction during hot air irritation, a nystagmus to the site of stimulation resulted by means of light calorisation. In patients with a spontaneous nystagmus an attenuation (n = 1) or inversion (n = 2) could be achieved by NIR-radiation. CONCLUSIONS: The method of the NIR-radiation is suitable in clinical practice for the caloric test proofing warm reaction. Vaporization cold does not occur. The application of heat charm is better proportionable and steerable than during air irritation. The procedure is sterile, noiseless and non-contact. Difficulties in interpretation of results of vestibular tests because of evaporation coldness do not occur.

Benign positional paroxysmal vertigo: videonystagmographic study using rotatory test.

Benign Peripheral Paroxysmal Vertigo is a disease of the posterior labyrinth caused by endolymphatic debris, provoking vertigo with some movements of the head. Diagnosis is usually made by finding the positional nystagmus with appropriate manoeuvres. Spontaneous resolution is frequent and in these cases diagnosis is only probable and suspected from anamnesis. Aim of the present investigation was to establish more evaluation parameters in the study of Benign Peripheral Paroxysmal Vertigo. A series of 97 selected patients presenting Benign Peripheral Paroxysmal Vertigo, have been submitted to sinusoidal kinetic test. Patients have been studied during the acute phase of the condition and after recovery. Vestibulo-oculomotor reflex has been sought by stimulating the horizontal and vertical canals. Kinetic stimulus consisted in sinusoidal rotation at 0.12 Hz and 0.05 Hz. Evaluation parameters comprised preponderance, gain and phase of provoked nystagmus, recorded by means of an Ulmer videonystagmograph. Using this same technique of stimulation, 20 normal volunteers were studied in order to establish normal values for reference. Values obtained in the patient population of patients have been compared, by Student t test, with values obtained in the same cured patients and with those in normal subjects. In the patients with Benign Peripheral Paroxysmal Vertigo of the lateral canal a nystagmus preponderance toward the healthy side was observed, as well as an increase in the phase lead, also in the canals not affected by the condition. In cured patients, disappearance of the preponderance and persistence of the phase abnormalities are observed. These results suggest a multicanal pathogenesis of Benign Peripheral Paroxysmal Vertigo.

Vibration-induced nystagmus in patients with vestibular disorders.

OBJECTIVE: Our goal was to clarify the clinical significance of vibration-induced nystagmus (VIN). METHODS: One hundred patients with unilateral vestibulocochlear disorders were enrolled into this study. However, patients with spontaneous nystagmus were excluded. Vibratory stimuli (approximately 100 Hz) were presented to the mastoids and the forehead. Patients also underwent caloric testing and vestibular evoked myogenic potential testing. RESULTS: Of the 100 patients, 60 (60%) showed VIN. The nystagmus was mainly horizontal. VIN was more frequently evoked on the mastoids than the forehead. In the majority of patients, the direction of VIN was toward the healthy side, whereas some patients, especially patients with Meniere's disease, showed nystagmus toward the affected side. VIN was frequently evoked in patients with severe unilateral vestibular damages (canal paresis >50%) (39 of 43, or 90%). CONCLUSION: VIN testing is a simple and sensitive clinical test that indicates unilateral vestibular dysfunction.

[Video-nystagmography findings in healthy elderly subjects]. / Resultados videonistagmográficos en un grupo de sujetos sanos de edad avanzada.

This study investigated 44 healthy elderly subjects aged between 64 and 87, who were analysed with videonystagmoscopy and quantitative videonystagmography, for establishing new standards for normal limits into this new diagnostic tool. 15.9% of the subjects were found to have spontaneous and provoked nystagmus at least in one position studied. Vertical nystagmus in head hanging position was the most frequent finding. In the Dix-Hallpike test we found one case of torsional nystagmus. No subject had seated position nystagmus. Nystagmus after head shaking and evoked nystagmus were not found.