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At least 667 records · Page 37Linked to original sources
PubMedDate not supplied

Frequency following response evoked by vibratory stimuli in profoundly deaf subjects.

A vibratory stimulus at a frequency of about 100 Hz was transmitted through a bone conductor on the mastoid in 26 profoundly deaf subjects. In all of them, the function of the vestibular apparatus was tested by means of the Fitzgerald-Hallpike caloric test. In some of the deaf subjects, evoked potentials were recorded, which following the frequency of the stimulus and which according to amplitude and latency characteristics, corresponded to the frequency following response (FFR). A close correlation was found between the normal function of the vestibular apparatus and the appearance of FFR in deaf subjects. The possible receptors of the stimulus and the afferent pathways which generate the recorded response are discussed.

Acoustic Stimulation↗
PubMed2004

[Analysis of vascular vertigo due to cervical spondylosis and vertebro-basilar insufficiency based on sex and age in clinical materials].

According to examination of 97 patients with vascular vertigo the dependence on vertigo to vertebral spondylosis and insufficiency vertebro-basilar artery was showed. Vertebral degeneration was noticed in 70.1%, basilar artery insufficiency in 42.3% of the patients. In 75.6% of the patients there was noticed both of above symptoms. Rotary test showed labyrinth asymmetry in 41.2% and in caloric test 50.5% of the patients.

Adult↗
PubMed1983

Stapedius reflex test, brainstem audiometry and opto-vestibular tests in diagnosis of acoustic neurinomas. A comparison of test sensitivity in patients with moderate hearing loss.

The stapedius reflex test, brainstem audiometry and the opto-vestibular tests for identifying acoustic neurinomas (AN) were evaluated and compared in a study of 21 patients with radiologically or surgically verified AN and a pure tone average not exceeding 60 dB HL. The stapedius reflex test results were interpreted according to the criteria developed at this clinic. The stimuli for the auditory brainstem response (ABR) were 2 kHz haversine waves and 4 kHz square waves. The vestibular examination consisted of a caloric test and the recording of eye-tracking and gaze nystagmus. In the cases studied the stapedius reflex test gave 1 false-negative result and ABR none. The ENG gave 3 false-negatives whereas the results of speech discrimination tests were misleading in no fewer than 1/3 of the cases. The results of the different tests were directly correlated but correlation coefficients did not exceed 0.65. Tumours larger than 15-20 mm showed a different test pattern than those below that size: stapedius reflex response, ABR and caloric response were eliminated and all of these patients had abnormal optomotor function. It is suggested that an optimal routine test procedure should consist of a pure tone audiogram, supplemented by ABR or the stapedius reflex test. Opto-vestibular tests may be of value in a preliminary estimation of tumour size.

Audiometry↗
PubMed1981

[Comparative values of unilateral and bilateral caloric bithermal vestibular tests in the diagnosis of acoustic neurinoma (author's transl)].

Acoustic neurinomas must be diagnosed as early as possible for the tumour to be removed while it is still small and the facial and, sometimes, auditory functions to be preserved. Since 89% of neurinomas lie on the vestibular nerve, enhancing the sensitivity of test exploring this nerve is important. Bilateral bithermal caloric stimulation is more sensitive (85%) than unilateral stimulation (71%) in detecting functional impairment. By comparing the two examinations in a series of 28 patients the authors have demonstrated that the test is more sensitive and reliable when bilateral and unilateral stimulation are practised successively. A study of correlations between these tests and the volume of the neurinoma showed that while functional impairment generally increases with the size of the tumour, it may vary from nil to 100% in small neurinomas. However, the sensitivity of the caloric test remains inferior to that of more sophisticated audiometric techniques, such as BERA-recording of stapedial reflex.

Adolescent↗
PubMed1999

Current status of electronystagmography testing.

ENG testing, whether computerized or not, remains the most useful means of assessing the vestibular system. The caloric test provides invaluable site-of-lesion information that objectively documents a peripheral vestibular lesion. Double (bithermal) caloric irrigation of each ear provides a more thorough and wider range test of inner ear function than a single caloric irrigation because the vestibular system is both excited and inhibited, causing responses in opposite directions, which are important in evaluating patients with underlying spontaneous nystagmus. In an age in which economically efficient and clinically effective diagnostic methods are in high demand, ENG testing remains the gold standard of vestibular function tests.

Calorimetry↗
PubMed2003

Neurotological findings in a patient with narrow internal auditory canal: a case report.

We report neurotological findings in a patient with unilateral narrow internal auditory canal, as confirmed by computed tomography. The patient presented no auditory brainstem response on the affected side. Vestibular tests including vestibular-evoked myogenic potentials (VEMP) and caloric test revealed normal function of both inferior and superior vestibular neural pathways.

Acoustic Stimulation↗
PubMed2002

Preoperative versus postoperative role of vestibular-evoked myogenic potentials in cerebellopontine angle tumor.

OBJECTIVE/HYPOTHESIS: Vestibular-evoked myogenic potential (VEMP) examination was performed on patients with a cerebellopontine angle (CPA) tumor to evaluate its clinical role. METHODS: Patients with a CPA tumor were subjected to caloric test and VEMP examination. Follow-up study was performed 1 year after the surgery. RESULTS: Six (69%) of the 9 tumors did not exhibit either caloric response or VEMP on the lesioned side. Three patients received tumor excision and all tumors involved both the superior and inferior vestibular nerves. Two (22%) of the 9 tumors had normal caloric responses but no VEMP. One underwent surgical excision, and the tumor originated from the inferior vestibular nerve. In the follow-up study, only 1 patient with epidermoid cyst presented complete recovery of caloric response and VEMP, whereas in the other 3 patients with vestibular schwannoma, the responses were all absent persistently. CONCLUSION: Before surgery, VEMP test can be used to predict the nerve of origin and to formulate the best surgical approach. After surgery, VEMP test can be used to define the nature of the tumor (compressing or infiltrating the nerve) and disclose the residual function of the inferior vestibular nerve.

Adult↗
PubMedDate not supplied

New approach to caloric stimulation of the vestibular receptor.

A new caloric testing method is described. During continuous aural irrigation, fluid is switched between hot and cold values at times computed according to a mathematical model of heat conduction in the labyrinth area. As a result, the induced temperature difference across the lateral semicircular canal describes an approximately sinusoidal time course, reaching peak values of equal magnitude but opposite sign. The magnitude of the caloric stimulus may be selected by choosing appropriate irrigation durations from a graph or table. Application of the test to clinical subjects demonstrated that the heat conduction model and analysis used in timing the sequence of thermal pulses was accurate. The new procedure causes less patient discomfort and requires less time to complete than does the conventional Fitzgerald-Hallpike test.

Animals↗
PubMed1989

Quantitative vestibular function testing in elderly patients with dizziness.

Electronystagmography was used to examine 103 elderly patients complaining of dizziness. This series of tests included tests for pathologic nystagmus, saccades, smooth pursuit, and optokinetic nystagmus, as well as bithermal caloric testing and rotational testing. One or more specific diagnoses were identified in 100 patients (86.2%), with the two most common diagnoses being benign positional vertigo (30 patients, or 25.9%) and cerebrovascular disorders (25 patients, or 21.6%). An abnormality was found on ENG in 75 (65%) of the patients tested, the most common of these being a unilateral hypoexcitability to caloric stimulation. In most cases, the ENG data was used to support a presumptive diagnosis that was based on the patient's history and examination, although in 4 cases ENG provided the critical diagnostic information by identifying decreased caloric and rotational responses in patients with nonspecific dizziness and dysequilibrium.

Aged↗
PubMed1997

[Evaluating otolith function with subjective visual vertical discrimination].

This report summarizes our experiences with the subjective visual vertical (SVV) as a clinical neuro-otological tool. In the SVV test, patients have to orient a dim light bar in an otherwise dark surrounding earth-vertical, using a remote-control. Normal subjects in an upright position did not deviate more than 2 degrees from true vertical. After vestibular neurectomy, the SVV was consistently tilted by some 12 degrees toward the affected ear. Smaller tilts (approximately 7 degrees) of the SVV occurred in patients with spontaneous peripheral vestibular diseases. This shift in SVV disappeared within weeks to months, similar to the spontaneous nystagmus. After stapes surgery slight deviations of the SVV towards the unoperated ear were seen in about 20% of the patients, indicating a slight irritation of the otolith organs. Assessed in an upright position, the SVV thus may be regarded as reflecting tonic otolithic input differences between the two ears. Asymmetries in the shifts of the SVV induced by roll tilts of the gravito-inertial vector by eccentric rotations of the subject have been proposed as a test for otolithic sensitivity. In our studies such asymmetries in the shifts of the SVV could not be induced by 26 degrees or 90 degrees roll tilts of subjects towards the affected or healthy ears. A simple clinical test to reveal unilateral otolithic sensitivity (comparable to an otolithic "caloric test") thus still has to be found.

Dark Adaptation↗
PubMed2004

Using Swaystar to measure sway amplitude in an office setting.

OBJECTIVE: The study was conducted to determine if Swaystar (University Hospital, Basel), a device that measures trunk sway, could be used in the office to detect abnormalities in patients who had vestibular abnormalities. DESIGN: Prospective study design. SETTING: Patients were referred to our tertiary and quaternary care dizziness clinic. METHODS: We measured total sway amplitudes using Swaystar during tandem walking of 18 patients referred sequentially who were identified as abnormal by caloric testing. These patients were compared with age- and sex-matched subjects from our normative Swaystar databank. MAIN OUTCOME MEASURES: We measured total sway amplitude in pitch and roll planes with Swaystar during tandem walking testing with eyes open and eyes closed. RESULTS: Patients with caloric abnormalities had significantly higher total sway than the age- and sex-matched normals from our normative databank. CONCLUSIONS: Swaystar is sensitive to measuring increased sway amplitude in patients with balance system deficits (as documented by caloric abnormalities) whether the patient is unstable in the pitch plane, roll plane, or both.

Adult↗
PubMed1993

A study into the phenomenon of head-shaking nystagmus: its presence in a dizzy population.

In this paper we have prospectively analyzed results from approximately 1,500 patients who underwent a head-shaking test during routine electronystagmography (ENG). The incidence of head-shaking nystagmus (HSN) in a dizzy population was relatively high (31.7%) when compared to other so-called abnormalities in the routine ENG test battery. Its presence was also similar in both active vs. passive head-shake tests. When present, different types of HSN were identified (monophasic (76.8%), biphasic (22.7%) and triphasic (0.5%)). In some cases, reversals of the expected "normal" pattern occurred. A high correlation was found to exist between a positive head-shake test and the presence of spontaneous nystagmus, positional nystagmus and caloric test abnormalities.

Adolescent↗
PubMed2004

Function of semicircular canals, utricles and saccules in deaf children.

OBJECTIVE: To study vestibular function in deaf children. MATERIAL AND METHODS: In 36 deaf children the function of the semicircular canals, saccules and utricles was measured by means of caloric testing, recordings of vestibular-evoked myogenic potentials (VEMPs) and measurements of the subjective visual horizontal (SVH) at different body tilts, respectively. RESULTS: In total, 30% of subjects had caloric hypo- or areflexia and 24% had a caloric asymmetry. VEMPs were weak or absent bilaterally in 22% of cases, and asymmetric in 19%. Regarding the utricle, 17% of subjects had a pathologically reduced perception of roll tilt to both sides and 25% had an asymmetry. In total, 30% of subjects were pathologic in all 3 tests and 30% were completely normal. Semicircular canal function correlated best with the function of the saccule. If hearing was better than 90 dB (pure-tone average of 0.5, 1.0 and 2.0 kHz) vestibular function was often normal. For hearing levels of 100-120 dB, otolith function declined significantly. CONCLUSIONS: Vestibular function tends to be preserved up to a point where hearing is nearly extinct. Hearing level correlates more closely with otolith function, especially that of the utricle, than with semicircular canal function.

Adolescent↗
PubMedDate not supplied

Preservation of vestibular nerves in surgery of the cerebellopontine angle: effect on hearing and balance function.

INTRODUCTION: Small tumors of the cerebellopontine angle (CPA) can frequently be removed with preservation of the auditory and the vestibular portion of the eighth cranial nerve. This study was undertaken to estimate the effect of vestibular nerve preservation on both balance and hearing following surgery. MATERIALS AND METHODS: A retrospective study of all cases of CPA lesions between 1987 and 1991 was undertaken. This identified 11 patients in whom either the superior and/or inferior vestibular nerves were preserved. This included eight acoustic neuromas and three meningiomas. The retrosigmoid approach and total tumor extirpation was undertaken in all cases. Patients undertook a vestibular questionnaire, audiometric testing, and evaluation of vestibulo-ocular responses preoperatively and postoperatively. Additionally, static and dynamic platform posturography was performed postoperatively in 9 of 11 patients. RESULTS: Follow-up ranged from 6 to 44 months. Of the eight patients with acoustic neuroma, four had a preoperative balance disorder that resolved postoperatively. One patient died of unrelated causes. Of the remaining seven patients with caloric testings, one maintained normal caloric responses. A persistent postoperative phase shift was noted in 4 of the 7 cases with rotatory testing. Three patients were treated for a meningioma. All had a preoperative balance disorder that resolved postoperatively. Two patients showed vestibular response indicative of residual but compromised function on the involved side. The third patient showed absent responses indicating an anatomically intact nerve that does not necessarily predict functional activity. Preservation of the vestibular nerve was associated with preservation of preoperative hearing in five of the patients. This included four of the eight acoustic patients and one of the three meningioma patients. CONCLUSIONS: Preservation of the vestibular nerve did not result in a chronic balance disorder in this patient population. This study does not allow the authors to conclude if vestibular nerve preservation improves overall hearing after CPA surgery; however, these data suggest that preservation of the inferior vestibular nerve may result in less damage to the cochlear nerve in some patients. Accordingly, preservation of the vestibular nerve in CPA meningioma surgery can be recommended.

Adult↗
PubMed1992

Inner ear morphology of experimental perilymphatic fistula.

The inner ear pathology of experimental perilymphatic fistula (EPLF) is described. EPLF was produced by injecting artificial perilymph into the subarachnoid space, or by suctioning 4 microL of perilymph through one of the round window membranes of the guinea pig. The animals were either killed immediately, or were kept alive for 3 weeks to 3 months. The conventional celloidin embedding method was employed for morphologic study. Vestibular function of the animals was tested by observing spontaneous nystagmus and positional nystagmus after the experiment. The caloric test was also performed. Various pathologic changes of the membranous labyrinth were observed. In the cochlea these included rupture or collapse of Reissner's membrane, bulging of Reissner's membrane, loss of hair cells, and compression of the organ of Corti. Pathology of the otolithic organs and semicircular canals mainly consisted of collapse of the membranous labyrinth. Clinical symptoms in patients with perilymphatic fistula (PLF) are explained, based on our experimental findings. Electronystagmography (ENG) of EPLF animals showed either no caloric response or, with a longer duration, caloric irregularity. Prolonged unsteadiness in patients may be due to "floating" labyrinth.

Animals↗
PubMedDate not supplied

Electronystagmographic findings in central nervous system disease.

A helpful central sign on electronystagmography with eyes closed is hyper-excitability on a caloric test. Another sign is consistent nystagmus in the presence of normal calorics. With eyes open, calibration overshoot, gaze nystagmus, pendulum tracking, failure of tracking a pendulum were by far the most common central abnormality in the experience of the author.

Brain Neoplasms↗
PubMed2000

Vestibular impairment in peripheral sensory neuropathies.

OBJECTIVE: Patients with peripheral sensory neuropathies frequently complain of dizziness, mainly unsteadiness, which occasionally seems to be more severe than the neuropathy. This study is an attempt to determine whether in cases where dizziness is a prominent feature the underlying cause is, at times, a concomitant vestibular dysfunction. METHOD: The files of 50 patients suffering from peripheral sensory neuropathies were retrospectively reviewed. Patients with central nervous system disease capable of inducing vestibular dysfunction were excluded from this study. In 47 of 50 patients, bithermal caloric tests were performed as part of electronystagmographic recordings. According to the caloric responses, these patients were divided into three groups: group 1: bilaterally reduced responses, group 2: unilaterally reduced responses, and group 3: normal symmetric responses. RESULTS: In 17 of 47 patients, the caloric responses were reduced bilaterally (group 1). In 8 of 47 patients, the responses were reduced unilaterally (group 2). In 22 of 47 patients, the caloric responses were normal and symmetric (group 3). CONCLUSION: Vestibular dysfunction was encountered in 25 of 47 patients (53.2%) suffering from peripheral sensory neuropathy. One wonders whether the pathologic process affecting the peripheral sensory nerves may also affect the vestibular nerve. This seems possible in view of the fact that the vestibular nerve, a sensory nerve itself, has a histologic structure similar to the peripheral sensory nerves.

Female↗