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At least 559 records · Page 31Linked to original sources
PubMed2006

Cochlear implant and vestibular function.

OBJECTIVES: To document incidences of vestibular dysfunction after cochlear implantation and investigate why it occurs. This work was also motivated by a desire to provide the basis for better preoperative counseling and postoperative vestibular therapy to cochlear implant patients. SETTING: Melbourne Cochlear Implant Clinic at a tertiary referral hospital. STUDY DESIGN: Prospective observational study. PATIENTS: One hundred forty-six adult implant recipients, mean age, 60 years (range, 20-90 yr). MAIN OUTCOME MEASURES: Postoperative vestibular disturbance was defined as symptoms lasting for 1 week or longer after surgery. The differences in preoperative and postoperative vestibular function were measured from subjective assessments (Dizziness Handicap Inventory and Activity Balance Confidence questionnaires) and objective assessments (bithermal caloric tests). The position of the postoperative electrode was classified as "loose", "regular", or "tight" fitting. RESULTS: Thirty-two percent of patients reported vestibular disturbance and had poorer Dizziness Handicap Inventory, Activity Balance Confidence, and caloric results in the implanted ear after surgery. Patient age, cause, and preoperative caloric result did not predict postoperative vestibular symptoms. Recipients aged 70 years or older had significantly poorer caloric results on the implanted side after surgery that was not related to the intracochlear electrode position or surgical team. CONCLUSION: One-third of recipients can expect to experience a significant vestibular disturbance after surgery, regardless of age, cause, or preoperative caloric result. "Older" ears seem more prone to permanent injury after cochlear implantation.

Adult↗
PubMed1987

Clinical features of cisplatin vestibulotoxicity and hearing loss.

Patients treated with cisplatin were observed in an otoneurological study with special reference to cochlear and vestibular toxicity. Toxicity-related symptoms appeared to be almost all transient. As with leukopenia, hearing loss and dizziness often occurred after several weeks of administration. In the equilibrium examinations, some abnormal findings such as spontaneous nystagmus and positional nystagmus were seen. Caloric tests and body sway tests detected abnormal findings in the early stages of cisplatin-related vestibulotoxicity.

Adolescent↗
PubMed1979

Central vestibular involvement in peroneal muscle atrophy: a preliminary report.

A family is presented in which 6 out of 8 members were found to have peroneal muscle atrophy. Neurophysiological and histopathological evidence for the hypertrophic form of this disease was obtained in 3 patients. Three patients with peroneal muscle atrophy and 1 unaffected family member had abnormal differential caloric tests. This is the first report of an apparently hereditary dysfunction of the central vestibular system associated with a hereditary neuropathy.

Caloric Tests↗
PubMed2000

What inner ear diseases cause benign paroxysmal positional vertigo?

Benign paroxysmal positional vertigo (BPPV) originating from the posterior semicircular canal (pSCC) is a common vestibular disorder that is easy to diagnose and usually easy to treat. The majority of patients with BPPV have no known inner ear disease; they have "primary" or "idiopathic" BPPV. However, a minority does have objective evidence of an inner ear disease on the same side as the BPPV and this group has "secondary" or "symptomatic" BPPV. Previous publications differ on the prevalence of secondary BPPV and about the types of inner ear diseases capable of causing it. In order to determine what proportion of patients have secondary as opposed to primary BPPV and which inner ear diseases are capable of causing secondary BPPV, we searched our database for the 10-year period from 1988 to 1997 and found a total of 2847 patients with BPPV. Of these, 81 (3%) had definite pSCC-BPPV secondary to an ipsilateral inner ear disease. Sixteen had Menière's disease, 24 had an acute unilateral peripheral vestibulopathy, 12 had a chronic unilateral peripheral vestibulopathy, 21 had chronic bilateral peripheral vestibulopathy and 8 had unilateral sensorineural hearing loss. It seems that any inner ear disease that detaches otoconia and yet does not totally destroy pSCC function can cause BPPV and that a case can be made for audiometry and caloric testing in all patients with BPPV.

Acute Disease↗
PubMed1997

Argon laser irradiation to the semicircular canal.

In order to elucidate the effects of argon laser irradiation on the lateral semicircular canal of the guinea pig, the vestibular labyrinth was histologically studied after irradiation, using the conventional celloidin method. Irrigation of the external meatus with ice water was used to evaluate the function of the semicircular canal by recording caloric nystagmus. When irradiation was performed, a laser probe was approximated to the lateral canal, 0.5 to 1 mm away from the surface of the canal. Each time, power applied was 1.0 W on the dial of the laser machine. The duration of irradiation was 0.5 s. The lateral canal was irradiated one to 15 times. Twenty-five to 87 days after irradiation, the temporal bones were fixed in Heidenhein-Susa solution, removed, and subjected to celloidin processing. The irradiated bony wall of the lateral canal demonstrated charring. Lucent areas were observed around and under the charred area. The semicircular duct showed shrinkage with disappearance of the trabecular mesh. New bone formation was observed along the endosteum of the irradiated area. The lateral canal was completely occluded by ossification with or without fibrosis when sufficient energy was applied. The anterior and posterior canals were normal. Caloric tests using 5 mL of ice water for 5 s failed to elicit nystagmus on the irradiated side.

Animals↗
PubMed1989

[Vestibular suppression].

Evaluation of the function was carried out by using unilateral caloric test in different arousal status. The goal of this investigation is to further investigate the normal parameters of vestibular function. Maximum speed, latency, frequency, medium speed and number of beats of the slow component of nystagmus were calculated, as well as, the morphological pattern of the standard outline. Voluntary suppression of vestibular response was tested. A test request method was proposed as the best way to fix attention of subjects.

Adult↗
PubMed1981

Acoustic neuromas. Diagnostic efficiency of various test combinations.

In the majority of diagnostic tests usually used in the search for acoustic tumors, there is a large difference in the outcome between patients with and without tumors. Because of a possible coherence between the tests applied, a statistical analysis of this connection was performed with the aid of a logistic model. The best single investigation used to differentiate between patients with and without tumors was tomography of the internal acoustic meatus. This examination was used in combination with the differential caloric test and the alternate binaural loudness balance recruitment test to differentiate completely between patients with and without tumors. Results of other examinations did not contribute significantly to the differentiation between patients with and without tumors. This factor did not render the other examinations superfluous because the analysis was valuable only in patients with a hearing level better or equal to 80 dB. By applying the other tests, information was obtained on pressure conditions in the internal acoustic meatus and possible difficulties at surgery, as well as information about the size of the tumor.

Audiometry, Pure-Tone↗
PubMed2003

[Near infrared stimulation of the equilibrium organ--first clinical experiences].

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.

Caloric Tests↗
PubMed1995

[Computer system of the electronystagmographic examination. Part III. Comparative results obtained by computer and traditional technology in the examination of the vestibular organ].

The study presents a comparison of the research into results of vestibular organ stimulated with caloric tests which had been simultaneously registered with the help of a computer system of electronystagmographic examination, as well as the traditional electronystagmographic technic. In the case of 32 healthy persons there had been counted by hand average angular velocity of the slow phase caloric nystagmus average level of reduced excitability of labyrinth and direction predominance. It had been defined that those values are comparable to the ones given by the computer. That points to the right chose of the space of time in the climax of nystagmus reaction and a good identification of the phase both slow and fast by the computer system.

Adult↗
PubMed2002

Validity and limitation of detection of peripheral vestibular imbalance from analysis of manually rotated vestibulo-ocular reflex recorded in the routine vestibular clinic.

We compared the results of analysis of vestibulo-ocular reflex (VOR) obtained by manual rotation in routine vestibular clinical practice with that of caloric testing, and examined the validity and limitations of VOR analysis as a test for the estimation of peripheral vestibular function and imbalance. VOR response was recorded in daily vestibular clinical examinations by manually rotating the standard clinical chair for approximately 30 s. VOR gain was slightly, but significantly, correlated with the peak slow phase velocity of caloric response (r = 0.50, p < 0.001). However, 8 out of 12 patients with no caloric response failed to exceed the range of two standard deviations of the mean value of age-matched normal subjects, indicating that it is clinically difficult to use VOR gain alone as a estimate of unilateral vestibular function. VOR directional preponderance (VOR DP%) correlated well with caloric canal paresis (CP) (CP%; r = 0.89, p < 0.001). VOR DP% was within the normal range in patients with caloric CP% < 40 and exceeded the normal range in most cases with caloric CP% > 80. VOR DP% varied widely when caloric CP% ranged between 40 and 80. The effect of vestibular compensation on VOR DP% was examined by plotting VOR DP% divided by caloric CP% (DP/CP) against the number of days since the onset of vertigo in patients with vestibular neuritis or sudden deafness with vertigo. DP/CP was large within 50 days of the onset of vestibular damage, especially when caloric CP% was < 80, and gradually decreased with time. These results indicate that determination of VOR DP% should contribute to the early diagnosis of fresh vestibular imbalance, especially in daily clinical practice, because this type of VOR recording can be performed in < 1 min in routine vestibular clinics. The decay time constant of DP/CP was larger when caloric CP% exceeded 80, indicating that vestibular compensation proceeds more slowly when the vestibular damage is severe.

Adult↗
PubMed2007

Effect of intratympanic application of aminoglycosides on click-evoked myogenic potentials in Guinea pigs.

OBJECTIVES: Although numerous studies have identified damage to the cochlear and vestibular end organs as the primary site of aminoglycoside-induced ototoxicity, the effect on the saccule remains poorly understood, possibly due to lack of monitoring saccular function in experimental animals. Therefore, this study applied three kinds of aminoglycosides into the tympanic space of guinea pigs to examine their toxic impact on the saccule by way of click-evoked myogenic potential test coupled with morphologic assessment. DESIGN: Albino guinea pigs were treated with saline, gentamicin, tobramycin, or amikacin, with 10 animals assigned to each group. Each compound was injected directly overlying but not through the round window membrane on the left ear, with the right ear serving as a control. One week after injection, each animal underwent auditory brain stem response, caloric test, and click-evoked myogenic potential test. Animals were then killed for morphologic assessment through the use of light and electron microscopic examinations. RESULTS: The animals treated with saline, gentamicin, tobramycin, or amikacin exhibited abnormal auditory brain stem response in 0%, 30%, 100%, and 30% of cases; abnormal caloric responses were found in 0%, 100%, 40%, and 40% of cases; absent click-evoked myogenic potentials were found in 0%, 100%, 30%, and 40% of cases, respectively. Gentamicin and other groups differed significantly in abnormal rates of caloric responses and click-evoked myogenic potentials. Morphologic study of the gentamicin-treated animals confirmed that the absence of click-evoked myogenic potential originated from the lesion in the saccular macula. CONCLUSIONS: Gentamicin represents the dominant susceptibility of aminoglycoside-induced vestibulotoxicity for eliminating both semicircular canal and saccular functions. This study further confirms the findings of human studies in which the caloric and vestibular evoked myogenic potentials responses were monitored to assess the abolition of vestibular function in patients treated with intratympanic gentamicin injection.

Acoustic Stimulation↗
PubMedDate not supplied

Controversies on the caloric response. From Bárány's theory to studies in microgravity.

Two objections against Robert Bárány's scientific contributions are reviewed. Firstly the Medical Faculty in Vienna raised the question as to whether Bárány really could be credited with the initial discovery of the caloric reaction in man and whether therefore it was justified to have awarded him the Nobel Prize in 1914. The second objection consists in strong doubt as to the correctness of Bárány's theory that changes in the temperature of the irrigation water result in density changes in the endolymph, permitting the fluid to be acted upon by gravity, yielding convection currents. Four arguments against Bárány's theory have been put forward: that (1) a caloric response can be elicited from "dead" ears, (2) the two points of reversal of the caloric response from right- to left-beating do not lie 180 degrees apart, (3) the duration of the caloric response, to both cold and warm stimuli, is greater in the face-up than in the face-down position, and (4) caloric nystagmus can also be evoked in a weightless environment. Conclusions based on results of caloric tests in microgravity have been criticised. It is not possible today to dismiss Bárány's theory as incorrect on scientific grounds. On the contrary, there is evidence for the occurrence of both thermal convective currents and a simultaneous non-convective thermal mechanism, acting together in the caloric response.

Austria↗
PubMed1999

[Heat and vestibular stimulation].

In 1905 Barany analyzed the nystagmus that appears during the irrigation of the ear with cold and hot water, justifying the phenomenon due to convectives currents in the horizontal semicircular canal. This hypothesis has been widely accepted until doubt was casted on it by the experiences carried out in the Skylab. Of the various mechanisms that could be responsible for the vestibular stimulation in the caloric tests, those which entail convection currents or endolymph expansion would need--we think--thermal gradients very superior to those occurring during these tests, that according to our calculations--always pro such hypothesis--seem insufficient.

Caloric Tests↗
PubMed1978

Clinical and electronystagmographic findings in Friedreich's ataxia.

A thorough investigation of vestibular function has been carried out in 16 patients with typical Friedreich's ataxia. Electronystagmography and caloric tests revealed a number of inconstant abnormalities. Most abnormal findings were related to ocular dysmetria, disorganized pursuit and square waves.

Adolescent↗
PubMed2002

[Contribution and Cost-Effectiveness of ABR and MRI in Acoustic Neuroma screening. Retrospective Study of 151 Cases].

The aim of this study was to retrospectively assess during two periods (1991-1995 and 1996-2000) if MRI spreading had changed: (1) private ENT physicians screening habits; (2) the average tumor size at the time of diagnosis and the diagnostic delay of acoustic neuroma; and (3) the cost of acoustic neuroma diagnosis. In addition, the sensibility of each diagnostic test was calculated on 151 tumors. Our results show no significant change neither in the screening strategy (except a mild decrease in CT-scan utilization) nor in the tumor size, diagnostic delay or diagnostic cost between the two periods. Even if MRI is the gold standard for acoustic neuroma diagnosis, our 86%-sensibility of ABR, increased to 99% if combined with stapedial reflex and caloric test may still incline to use ABR in selected cases.

Adolescent↗
PubMed1994

Immunological approach to Ménière's disease: vestibular immune injury following immune reaction of the endolymphatic sac.

Following direct antigen challenge to the endolymphatic sac (sac), the relation of caloric test results and spontaneous nystagmus to the histological changes of the sensory epithelium of the vestibular organ and perilymph antibody levels was investigated in the guinea pig. In a secondary keyhole limpet hemocyanin (KLH) challenge to the sac, irritative nystagmus was followed by paralytic nystagmus and a suppression of caloric reaction. These findings correlated well with the degree of degeneration of the sensory epithelium of the vestibular organ and the levels of perilymph antibody. On the other hand, neither phosphate-buffered saline inoculation nor primary KLH challenge to the sac nor a secondary KLH challenge to the intradural space resulted in a disturbance of the vestibular function. These results suggest that the immune response of the sac may possibly be an important key to the pathogenesis of Ménière's disease.

Animals↗
PubMed2006

Three patients with migraine following caloric-induced vestibular stimulation.

The co-occurrence of migraine and dizziness is greater than would be expected by chance. We report 3 patients who developed migraine following acute vertigo precipitated during caloric testing. A small proportion of the epidemiological links between migraine and vertigo may be due to vertigo-triggered migraine.

Acute Disease↗
PubMedDate not supplied

Cervical vertebral problems as a cause of variations in the nystagmographic R-factor.

All patients who complained of dizziness during 1981 and in whom the nystagmograms indicated either central damage or were found normal, were investigated further regarding changes in their R-factor (an expression for amplitude). This was deduced from the nystagmographic readings produced by caloric testing in these patients. It was thus found that patients with pain or stiffness in the neck had a significantly raised R-factor in all age groups.

Adolescent↗