Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Caloric Tests”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 883 records · Page 49Linked to original sources

Dizziness from whiplash and head injury: differences between whiplash and head injury.

OBJECTIVE: Large discrepancies exist in the literature regarding incidence and types of symptomatology in whiplash. This is because of the evolution of whiplash injury over the years with the advent of head rests and seat belts. Previous authors have regarded symptoms of dizziness as a result of brainstem or cerebellar injury or both. It has been difficult in those studies to ascribe a mechanism of injury, as patients with whiplash injury only have been grouped with those who have incurred mild traumatic brain injury as a result of a significant blow to the head. The authors saw the need to delineate patients who had suffered whiplash injury from those who also had suffered mild head injury, as defined in the rehabilitation-neurosurgical literature, to attempt to define differences in symptoms, abnormalities, and mechanisms of recovery in these two groups. STUDY DESIGN: The study design was a retrospective case review. SETTING: The study was conducted at a tertiary-quaternary referral clinic. PATIENTS: The records of 36 patients were reviewed. Nineteen of these patients suffered a whiplash-associated disorder and 17 suffered a mild head injury as well. These patients were referred for assessment of symptoms persisting for at least 2 years after their injury. Patients were excluded if they had not completed clinical assessment, including electronystagmography (ENG) and computerized dynamic posturography (CDP). INTERVENTIONS: A full history, otolaryngologic examination, including assessment of eye movements, corneal reflexes and gait, as well as an investigation, including ENG and CDP, and history taking and detailed recording of related complaints immediately before diagnostic work-up were performed. MAIN OUTCOME MEASURES: Symptoms reported by patients who had received either whiplash alone or whiplash plus mild head trauma as defined in the literature were measured. Patients were classified according to type of accident, type of injury suffered, and degree and nature of posturographic abnormalities. RESULTS: Patients often have similar complaints regardless of whether or not they had suffered a head injury. Although CDP showed abnormalities in both groups, standard ENG assessment, including caloric testing, showed abnormalities only in the head-injured group. The posturographic abnormalities also were analyzed in both groups, and it was found that there was a correlation between the type of posturographic abnormality and the type of injury suffered. Although ENG testing is done routinely, posturography is shown to be more sensitive in picking up abnormalities. In addition, the authors have shown that posturography can delineate the type of injury suffered by exhibiting the compensation strategy used as well as the efficacy of that compensation strategy. CONCLUSIONS: Because ENG abnormalities are limited to patients who have suffered a head injury, the inference is that these two groups of patients have suffered damage at different sites along the balance system pathways, but both of these lesions can lead to similar symptoms. Although the mechanisms of whiplash injury and how they affect the vestibular system are poorly understood, posturography testing is essential in inferring how a patient is recovering by measuring how and how well the patient is overcoming his or her deficit. This has important medical legal implications regarding legitimizing a patient's problem, prognostic factors, as well as rehabilitation plans, measures, and outcomes.

Adolescent↗

Caloric and rotatory chair test results in patients with Ménière's disease.

OBJECTIVES: To determine whether an association exists between the parameters of the caloric and rotatory chair tests in patients with unilateral Ménière's disease. METHODS: Patients with unilateral Ménière's disease (n = 100) were subjected to the caloric and the rotatory chair test (sinusoidal harmonic acceleration and impulsive tests) on the same day. Canal paresis and directional preponderance were assessed in the caloric test, and different variables were measured in the rotatory chair test based on the existence of abnormal parameters in the vestibulo-ocular reflex at two or three consecutive frequencies of those tested and on the time constant of the vestibulo-ocular reflex. STUDY DESIGN AND SETTING: A prospective study was conducted at a University hospital. RESULTS: An abnormal result in the caloric test was obtained from 73% of the patients. In the rotatory chair test, the most frequent abnormal findings involved increases in the normal phase lead at 2 consecutive frequencies tested (23%). There was a stronger association between an abnormal result in phase, gain, and/or symmetry at three adjacent frequencies and a pathological result in the caloric test. CONCLUSION: Very few of the criteria used to define the caloric and rotatory chair tests seem to be associated. This confirms previous knowledge that both tests examine vestibulo-ocular reflex by different ways. Only when vestibular dysfunction is severe enough (manifested by the finding of an abnormal result in at least three consecutive frequencies in the rotatory chair test), the caloric test is also found to be abnormal.

Caloric Tests↗

Influence of caloric and rotation testing upon blood pressure and pulse rate.

Vestibular stimulation is able to produce neurovegetative effects, which are disagreable and annoying. By an overflow of the vestibular stimulus to the neurovegetative centres changes in blood pressure and pulse rate are more frequently induced than are subjective neurovegetative symptoms as nausea, pallor etc. There is some correlation between both manifestations, but also some independency in occurrence.

Blood Pressure↗

Test-retest reliability of open-loop bithermal caloric irrigation responses from healthy young adults.

OBJECTIVE: To determine normal caloric responses and test-retest correlations of caloric responses in a group of otologically normal persons using an open-loop caloric irrigation system. STUDY DESIGN: An open-loop bithermal caloric irrigator was used to obtain maximum slow component speed caloric responses of healthy young persons with a repeat caloric test occurring- 1 week later. SETTING: The caloric examination took place in a university speech and hearing clinic. SUBJECTS: Twenty healthy young adults (10 men and 10 women, ranging in age from 18 to 33 years) who reported no history of dizziness or hearing loss were recruited at a university. They had thresholds of 25 dB HL or better for frequencies 250 of 8000 Hz and had passed an examination performed by an otologist. RESULTS: The mean unilateral weakness (UW) response was 1.73% with a standard deviation of 12.1%. Test retest correlations were 0.82 for UW and 0.80 to 0.90 for individual ear responses. CONCLUSIONS: The results indicate that a minimum of a 25% UW should be present when identifying a significant UW. Also the test-retest correlations were considerably higher using an open-loop irrigator than those obtained using a closed-loop irrigation system in a previously reported study.

Adolescent↗

Diagnosis of Gilbert's syndrome. Reliability of the caloric restriction and phenobarbital stimulation tests.

The diagnostic role of the reduced caloric intake test and phenobarbitone treatment in Gilbert's syndrome was evaluated. During fasting the increase in unconjugated serum bilirubin concentration was significantly higher in patients with Gilbert's syndrome than in normal subjects but not when compared with the increase observed in patients with acute hepatitis, which is the clinically most relevant differential diagnosis. Phenobarbital treatment significantly reduced the level of unconjugated serum bilirubin in patients with acute hepatitis or Gilbert's syndrome, but without any difference within these two groups of patients. The reduced caloric intake test and phenobarbital treatment seem to have low diagnostic specificity in Gilbert's syndrome when the differential diagnosis is that of hepatitis. The fraction of plasma unconjugated bilirubin of total bilirubin was significantly different in all three groups examined. The clinical diagnosis of Gilbert's syndrome can be established with relative certainty if the patients have a mild hyperbilirubinemia with a high fraction of unconjugated bilirubin, normal values of liver enzymes, and no overt signs of hemolysis. Liver biopsy is not mandatory.

Acute Disease↗

[Thermic investigations of the nystagmus induced in the Brunning's positions V-I in patients with unilateral, peripheral vestibular lesion].

There were examined 50 persons with unilateral peripheral lesion of vestibular system. Each patient was tested by method, in which inversion of nystagmus direction in respect of ampullopetal and ampullofugal stimulation followed cause of change of head's position--position Brünnings V-I--during irrigation 30 degrees C. Results obtained during these method were compared with effects of caloric Hallpike test. The method described in these paper could supply to classic caloric test.

Adolescent↗

[Early signs of occupational ototoxicity caused by inhalation of benzene derivative industrial solvents].

People exposed to industrial solvents may suffer from disturbances of different psycho-physiological and vestibulo-oculomotor function. Therefore an investigation was performed testing vestibular and oculomotor reactions in workers exposed to solvents. It also seemed to be of interest to study if the auditory pathways were affected in these workers. 53 men aged 27-54 (Md = 37.7) were studied. They had been exposed to aromatic solvents in their work as colour mixers, painters, printers and petrol truck drives. Time of working was between 4-25 (Md = 15.2) years. At the time of this investigation none of the men had been exposed to solvents for at least the last four years. The clinical investigation included cerebellar tests and a general ENT investigation. Electronystagmography was performed and comprised the following functions: 1) spontaneous and caloric vestibular tests; 2) a sinusoidal swing test in darkness, the patient sitting in a rotatory chair; 3) visual suppression test; 4) a saccade test; a slow pursuit eye movement test. In addition all the patients were subjected to an audiological test battery including pure tone threshold, conventional vocal audiometry, speech discrimination used interrupted speech 10 interruptions per second, acoustic reflex thresholds and reflex decay. The clinical investigation showed in 19 patients balance problems in the balance test. The sinusoidal test was normal in all cases. The caloric test showed 8 cases of asymmetry in vestibular reactions. 10 of the patients had pathological spontaneous nystagmus. 17 of the patients had a pathologically decreased ability for visual suppression. The saccades were abnormal in 25 patients. The patients who were subjected to audiological testing all had pure tone thresholds and conventional vocal thresholds as expected with regard to age. 31 patients showed decreased discrimination scores at the interrupted speech. The acoustic reflex thresholds were normal and there was not pathological reflex decay. Results show the prevalently pathologic concern for C.N.S. Authors, last, give prominence to the significant relationship between the exposure time to solvents' vapour and changing of several parameters, connection conditioned by constitution and life habits in predisposing workers to a greater susceptibility at damages caused by organic solvents.

Adult↗

The caloric vestibular nystagmus during short lasting microgravity.

In human subjects the caloric vestibular test was conducted during parabolic flight. The ear irrigation was performed from 35 secs. till 5 secs. before the onset of microgravity. Nystagmography covered a 10-minutes period, including three parabolic manoeuvres of the aircraft. a. The slow phase velocity (SPV) of the caloric nystagmus increased proportionally with the value of the g-force. Introduction of microgravity induced an exponential decrease of the SPV decay. b. The nystagmus disappeared completely in microgravity, but SPV decay showed a specific time constant. c. The averaged time constant values of the caloric nystagmus SPV decay after sudden onset of microgravity and the averaged time constant of the SPV decay following a sudden stop after sustained rotation during 0-g appeared to be on the same level (10.2 s. and 10.6 s.). d. These two averaged time constant values obtained during short lasting microgravity proved to be on a lower level than those time constants (15.5 secs.; 15.9 secs.) found in ground-based conditions. e. Because of the similarities in the characteristics of both SPV decay's and their accompanying time constants, a common working mechanism of cupular stimulation is likely. Most probably a fluid movement (or pressure) provokes a cupula deflexion followed by a cupula reflexion, either caused by a sudden stop after a sustained rotation or by a sudden onset of microgravity after g-load calorization. The present results support the Barany convection theory with regard the endolymph stimulatory properties following the caloric test.

Adult↗

Posturographic findings in two common peripheral vestibular disorders.

Peripheral vestibular pathology disturbs the vestibulospinal reflex in a number of cases. The recording of postural sway furnishes an evaluation of this vestibulospinal influence. Two common peripheral vestibular syndromes were studied: Ménière's disease and peripheral unilateral vestibular hypofunction. It is evident that, by posturography, vestibulospinal disturbance is shown in these peripheral syndromes, whereas its occurrence cannot be predicted by other tests, e.g. caloric and rotation tests. Normalization of the vestibulospinal reflex depends on central adapting mechanisms, which were evidently still incomplete in a number of the cases examined. Whereas abnormal postural results were equally observed in both groups, rotation tests showed better vestibulo-ocular compensation in Ménière's disease, compared to the cases with unilateral vestibular hypofunction. It mattered not whether the Ménière patient was in an active or a stabilized phase. A striking difference was noted for those Ménière patients with atypical vertigo complaints, who showed a high frequency of posturographic disturbances.

Humans↗

MRI as a single screening procedure for acoustic neuroma: a cost effective protocol.

Magnetic resonance imaging (MRI) is accepted as the 'gold standard' in diagnosing acoustic neuromas. Limited availability and perceived high costs have prevented clinicians from using it as a first-line investigation. A prospective study was set up in a specially designated screening session to audit the cost effectiveness and accuracy of audiovestibular investigations compared to MRI. Ninety-nine patients with asymmetrical audiovestibular symptoms or signs were investigated. Of these 54 evoked response audiometry tests, and 39 calorics were either not performed or were inconclusive. One patient refused to enter the MRI machine. All others received an unequivocal report after MRI and four tumours (three intracanalicular) were detected. The total cost of the audiovestibular protocol was 12,545 pounds compared to 12,900 pounds for the MRI protocol, which is a diagnostic and well-tolerated procedure. This study shows that MRI can be cost effective, as well as accurate, when used as a single screening procedure for acoustic neuromas.

Adult↗