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PubMed1973

Diagnosis of Gilbert's syndrome: role of reduced caloric intake test.

Reduction in caloric intake to 400 a day for 72 hours resulted in a significant increase in the plasma bilirubin concentration in patients with Gilbert's syndrome and in normal subjects. This was due to an increase in unconjugated pigment. There was no significant increase in the bilirubin concentration in patients with liver disease or haemolytic anaemia.The increase in unconjugated bilirubin was signficantly greater in Gilbert's syndrome than in normals but only when the initial bilirubin concentration was raised. It was usually seen within 24 hours of reducing the caloric intake. An increase of 100% or more suggests that unconjugated hyperbilirubinaemia is due to Gilbert's syndrome. In the normal subjects the unconjugated bilirubin level did not exceed 1.0 mg/100 ml.The increase in unconjugated bilirubin concentration on reducing the caloric intake may be due to decreased hepatic bilirubin uridine diphosphate glucuronyl transferase activity, which was shown to be present in seven rats starved for 72 hours. The effect of a 400 calorie diet for 24 hours on the unconjugated bilirubin level may distinguish Gilbert's syndrome from other causes of unconjugated hyperbilirubinaemia.

Anemia, Hemolytic↗
PubMed1981

[The diagnostic value of vertical nystagmus in the simultaneous bilateral calibrated caloric vestibular test (author's transl)].

Vertical nystagmus provoked by simultaneous bilateral caloric stimulation has been known since 1907 (Bàràny). However, if a controlled and calibrated injection os water at 44 degrees C or 30 degrees C for 30 seconds at a flow rate of 250 ml/minute is given in normal subjects, this stimulus is insufficient to provoke a response, whilst in subjects with a central vestibular disorder there appear upward vertical movements with hot stimulation and downward movements with cold stimulation. The degree of this response is proportional to the degree of horizontal nystagmic responses to classical unilateral caloric tests. The authors feel that vertical nystagmic responses to simultaneous bilateral caloric stimulation reflect a loss of control of the vestibular reflex activity of the superior semicircular canals.

Adult↗
PubMed2003

[Nystagmus and vibration test research of mechanisms, theoretical methods: on 52 cases of unilateral vestibular lesions].

OBJECTIVE: The aim of the present study was to examine the characteristics of the Vibratory Nystagmus (VN) optimise the topography and the frequency of the stimulus, determine the origin of the VN and analyse its clinical implications. MATERIAL AND METHOD: 52 severe unilateral vestibular lesions (SUVL) (post-surgical vestibular areflexy) were studied. The vibratory nystagmus was measured by 2D and 3D videonystagmography (Synapsis, France). The stimulus was applied with a 3S vibrator at the vertex, both mastoïds, and posterior cervical muscles at frequencies ranging from 20 to 150 Hz. For topographic optimisation, stimulation was given with S vibrator (Synapsis, France) at 100 Hz. The interferences between the vibratory test (VT) and the caloric test (CT) were studied on the normal ear (in 11 subjects). The same study was carried with the optokinetic test. RESULTS: The VT revealed a defective nystagmus at all frequencies of stimulation. Optimal response was obtained in a band frequency of 80-120 Hz. Stimulations at 100 Hz showed optimal responses for mastoïd topography (responses in 96% of the cases). Stimulation at the posterior cervical muscles and at the vertex indicated respectively a response in 90% and 60% of the cases. The efficiency of the mastoïd stimulation is not correlated with the side of stimulation (p = 0.9). The interference between the VT and caloric test (CT) at cold water (30 degrees et 20 degrees C) exhibited the inversion of the caloric nystagmus during the vibrator stimulation. The resulting nystagmus is respectively an algebric subtraction or addition between the pre-existing caloric nystagmus and the value of the vibratory nystagmus obtained before caloric test. Adaptation of the VN is moderate. The interference between the VT and the optokinetic test resulted in a subtraction or addition effect, according to the side of the lesion and the direction of the optokinetic stimulus. CONCLUSION: The VT is an efficient stimulation in mastoïd topography. The vestibular contribution is bilateral by bony conduction of the vibration, it explores frequencies ranging from 30 to 120 Hz, with a maximum of response at 100 Hz. The VT interacts with the caloric test and the optokinetic test. The stimulation is very strong, and is able to inverse the caloric nystagmus at cold water stimulation (20 degrees C). In labyrinthine-defective subjects, the VN is always defective at all frequencies, whatever is the topographic location of the stimulus, and the position of the head.

Caloric Tests↗
PubMed1999

Neurologic and otologic findings in Fisher's syndrome.

We performed neurologic and otologic examinations in 14 patients with Fisher's syndrome to determine whether its manifestations inducing acute ophthaloplegia, ataxia and areflexia may involve the auditory and vestibular systems. Tests included pure tone audiometry, auditory brainstem response, observations of nystagmus, smooth pursuit test, saccade test, optokinetic nystagmus test, and the caloric test. One patient showed downbeat nystagmus and lateral gaze nystagmus without restriction of eye movement, two patients showed dysmetria on saccades without restriction of eye movement, and three patients showed superimposed saccadic eye movement on smooth pursuit without lateral gaze nystagmus. The abnormalities in those six cases could not be explained by solely muscular weakness, but also appeared to involve the central oculomotor system. In the other patients, nystagmus could be explained by muscular weakness alone. Additionally, three patients, including two patients with dysmetria on saccades, showed a unilateral diminished response to caloric testing with no severe restriction of eye movements. In evaluating the auditory brainstem response of these three patients, one patient, who showed abnormality on the saccade and caloric tests, showed an elongation of wave I latencies and of wave I-III interpeak latencies at both ears, and one other patient showed an elongation of wave III-V interpeak latencies at both ears. This disorder may involve the peripheral and central auditory systems as well as the peripheral vestibular system.

Adolescent↗
PubMed1993

Clinical significance of the galvanic body sway test in cerebellopontine angle tumors.

Since 1984, we have been modifying a new method of recording fine body sway elicited by low current stimuli of less than 0.4 mA, and of quantitatively evaluating the responses by Fourier transform. In order to easily and early detect acoustic tumors, we have applied a test battery consisting ABR, caloric test and galvanic body sway test (GBST) to 31 cases with acoustic neurinoma, to 5 cases with other CPA-tumors, and to 24 cases suspected of having CPA tumors. Of 27 cases with acoustic neurinoma on whom the GBST was performed, 25 cases (92.6%) shows abnormal responses. On the other hand, the ABR was abnormal in all cases, except for one case in the early stage of an ear tumor. However, the ABR was positive in 12 cases out of 24 with suspected findings without tumor, but the GBST was positive in only 3 cases out of 17 tested. Moreover, 26 cases (83.9%) with acoustic tumors showed abnormal CP in their first caloric tests. Comparing these observations with the results of image diagnosis, we conclude that the GBST is as useful for detecting small acoustic neurinomas as the ABR and the carloric test. Therefore, we have routinely used a test battery consisting ABR, caloric test and GBST for evaluation of acoustic neurinomas. However, we could not differentiate between acoustic neurinoma and CPA-tumor by using the three-test battery.

Auditory Threshold↗
PubMed2003

[Nystagmus and vibratory test: evidence for mechanism. Material conditions and methods in the fast detection of unilateral vestibular lesions].

OBJECTIVE: The aim of the present study was to examine the characteristics of vibratory nystagmus (VN), optimise the topography and the frequency of the stimulus, determine the origin of the VN and analyze its clinical implications. MATERIAL AND METHOD: Fifty-two severe unilateral vestibular lesions (SUVL) (post-surgical vestibular areflexy) were studied. The vibratory nystagmus was measured by 2D and 3D videonystagmography (Synapsis, France). The stimulus was applied with a 3S vibrator at the vertex, both mastoïds, and posterior cervical muscles, at frequencies ranging from 20 to 150 Hz. For topographic optimization, stimulation was given with S vibrator (Synapsis, France) at 100 Hz. The interferences between the vibratory test (VT) and the caloric test (CT) were studied on the normal ear (in 11 subjects). The same study was carried out with the optokinetic test. RESULTS: The VT revealed a defective nystagmus at all frequencies of stimulation. Optimal response was obtained in a band frequency of 80-120 Hz. Stimulations at 100 Hz showed optimal responses for mastoid topography (responses in 96% of the cases). Stimulation at the posterior cervical muscles and at the vertex indicated respectively a response in 90% and 60% of the cases. The efficiency of the mastoid stimulation was not correlated with the side of stimulation (p=0.9). The interference between the VT and caloric test (CT) with cold water (30 degrees C and 20 degrees C) exhibited the inversion of the caloric nystagmus during the vibrator stimulation. The resulting nystagmus was respectively an algebraic subtraction or addition between the pre-existing caloric nystagmus and the value of the vibratory nystagmus obtained before the caloric test. Adaptation of the VN was moderate. The interference between the VT and the optokinetic test resulted in a subtraction or addition effect, according to the side of the lesion and the direction of the optokinetic stimulus. CONCLUSION: The VT is an efficient stimulation in mastoid topography. The vestibular contribution is bilateral by bony conduction of the vibration, it explores frequencies ranging from 30 to 120 Hz, with a maximum of response at 100 Hz. The VT interacts with the caloric test and the optokinetic test. The stimulation is very strong, and is able to inverse the caloric nystagmus at cold water stimulation (20 degrees C) In labyrinthine-defective subjects, the VN is always defective at all frequencies, whatever the topographic location of the stimulus, and the position of the head.

Follow-Up Studies↗
PubMed1987

The caloric vestibular test in weightlessness.

Although the theoretical background for the caloric vestibular test was assumed to be known, recent studies in weightlessness have thrown doubts on the original theory of its mechanism. It is most likely that several mechanisms are involved in the generation of caloric nystagmus in addition to the convection current theory. Experiments with the caloric test in humans conducted during parabolic flight are described. These results are compared with the results of similar experiments performed in orbital missions.

Adult↗
PubMed1996

A comparison of test-retest variability of caloric induced nystagmus in a normal population using an air stimulus presented via a standard and modified irrigating probe.

The caloric test has traditionally been carried out using water. Air caloric techniques have been available for some time but one of the reported disadvantages is the high variability of response (Coats et al., 1976). The aim of this study was to compare the test-retest variability of the air caloric response using a normal irrigation probe and a modified probe. The modified probe allowed observation of the placement of the probe tip within the ear canal and could be used to observe the direction of air flow during the irrigation. It was found that the variability with the modified probe is smaller than with the normal probe.

Adolescent↗
PubMed1985

[Comparative studies of the results of caloric vestibular tests and classical torsion swing tests].

Vestibular Paresis (PL) and Directional Preponderance (PD) are the measurements found on caloric testing described by Fitzgerald and Hallpike (1942); frequency nystagmogram is the typical result of the torsion swing test of the French school. The differences between the two methods stimulated us to make a comparison of the results. Seventy-eight patients affected by unilateral peripheral vestibulopathy in various degree of compensation were submitted to both tests. Frequency nystagmogram was transformed, for calculation purposes, into normalized percentual difference (SSP). SSP and PD were found highly significantly correlated and were considered as equivalent from the statistical point of view. SSP and PL were completely independent at slow velocity stimulation. Using high velocities of stimulation a correlation was demonstrated between SSP and PL; unfortunately to the elevation of SSP corresponds a so minimal increasing of PL that the correlation is scarcely useful from the clinical point of view.

Caloric Tests↗
PubMed1999

Electronystagmographic changes in patients with unilateral vestibular schwannomas in relation to tumor progression and central compensation.

Vestibular function was studied in a group of 121 patients with unilateral vestibular schwannomas who were referred to University Hospital Utrecht between 1986 and 1996. Testing included the caloric test, torsion test, saccade test, smooth pursuit test and the registration of spontaneous nystagmus. Each patient's symptoms were taken from a chart review. The size of the tumor was expressed as the maximum extrameatal diameter in the axial plane parallel to the petrous ridge as seen in magnetic resonance imaging or computed tomography. Large tumors were significantly more often accompanied by a more severe paresis on caloric testing, a smaller gain on torsion testing, spontaneous nystagmus, an abnormal saccade test and an abnormal smooth pursuit test. The presence of spontaneous nystagmus was significantly more frequently combined with an abnormal smooth pursuit and saccade test. There was a significant correlation between the slow component's velocity of the spontaneous nystagmus and the size and progression of tumor. However, a specific relation between tumor size and central vestibular compensation could not be demonstrated.

Caloric Tests↗
PubMed1979

[A caloric vestibular test with increased positive evidence (author's transl)].

A decrease of the variance of a caloric test would increase the importance of the statement of this test. An important source of variance are the differences concerning the timecourse of the induced heat wave, determined by the different anatomic conditions in the petrous bone, particularly the pneumatisation. A constant temperature gradient is obtained by the irigation in a pessimum position with the head flexed 30 degrees to the front. This temperature gradient evokes immediately a constant maximum vestibular stimulus after having reflected the head 90 degrees to the back. Comparing this new method with the traditional irrigation, one can state an important reduction of variance. The dependence of the nystagumus response on caloric irrigation of the petrous bone demands a X-ray-examination according to the technique of Schüller before starting with the caloric examination. In case of differences between the right and left sides the described test would be necessary in our opinion.

Caloric Tests↗
PubMed1995

Reappraisal of the monothermal warm caloric screening test.

The usefulness of a monothermal warm caloric screening test (MWST) for predicting alternate binaural bithermal test abnormalities has been reexamined. Previously, researchers have reported false-negative rates for the MWST ranging from 0% to over 35%. Alternate binaural bithermal test data from 504 consecutive patients were evaluated with MWST failure criteria of 24.5% and 29%, with and without the addition of failure criteria from subtests of the electronystagmography examination. Sensitivity of the MWST alone was high, and improved with additional failure criteria. The specificity levels were correspondingly high. Results support the use of the MWST with adjunctive failure criteria when patients have otherwise normal electronystagmography findings.

Caloric Tests↗
PubMed1992

[The efficiency of vestibular organs in persons addicted to opioids, barbiturates and volatile organic substances examined during the period of abstinence].

Opioids, barbiturates and volatile organic substances are the most common drugs used in Poland by addicts. In the literature there are no data concerning efficiency of vestibular organs of addicted persons examined during abstinence period. 74 drug addicts and 50 healthy persons were subjected to ENG examinations (spontaneous nystagmus, positional ny gaze ny, eye-tracking test, optokinetic test, rotatory test and caloric test were evaluated). ENG showed abnormal records in all tests performed in the addicted persons. This study has revealed that addicts have insufficiency of vestibular organs, which is probably a result of central lesions.

Adolescent↗
PubMed2006

Analysis of the vestibulo-ocular reflex time constant in patients with benign recurrent vertigo associated with head-shaking nystagmus.

CONCLUSIONS: When considering benign recurrent vertigo and a similar peripheral vestibular deficiency, the asymmetry of the vestibulo-ocular reflex (VOR) time constant (Tc) is lower in those patients with paretic head-shaking nystagmus (HSN) than in those with reversed HSN or without HSN. OBJECTIVE: To determine whether the existence of HSN is related to the time constant of the VOR in patients with benign recurrent vertigo (BRV). PATIENTS AND METHODS: This was a prospective study conducted at a tertiary care center in which patients were subjected to the head-shaking test, the caloric test and rotatory chair impulsive test on the same day. The clinical features of the disease analyzed were the disease duration, frequency of vertigo spells, time since the last vertigo spell and the existence of migraine. The results of the head-shaking test were considered positive when nystagmus appeared after head-shaking had ended. Two groups of patients were established on the basis of these results and the group that displayed HSN was divided according to the direction of nystagmus. In the impulsive test, the time constant of the VOR after ipsilesional and contralesional acceleration was analyzed, as was the symmetry of the response. The differences in the means were calculated. RESULTS: BRV was diagnosed in 25% of patients suffering recurrent spells of vertigo, of which 33 patients were HSN- and 29 were HSN+. In the latter group, vestibular migraine was frequently observed (83% of the patients), the spells of vertigo were more frequent and the patients were seen closer to the previous spell of vertigo. No differences were observed in the Tc of the VOR between HSN+ and HSN- patients, although the asymmetry of this Tc was higher in HSN- patients than in HSN+ patients. Nevertheless, the differences observed were only significant between paretic and reversed HSN patients and paretic HSN patients and HSN- patients.

Caloric Tests↗
PubMed1989

[Ocular motor abnormalities in progressive supranuclear palsy].

Eleven patients, 7 males and 4 females, of progressive supranuclear palsy (PSP) were examined neuro-otologically for the purpose of elucidating the characteristics of ocular motor abnormalities. All cases were admitted to our hospital and age at onset was from 52 to 71 years old, duration of illness was 2 to 11 years. Range of voluntary eye movements and abnormal eye movements including nystagmus were examined on naked eyes and with electronystagmography (ENG). Smooth pursuit movements and saccadic eye movements were tested both horizontally and vertically by using visual tracking method with ENG recordings. Optokinetic nystagmus test and caloric test with visual suppression test were also performed. These neurotological examinations were made repetitively in 5 cases and their progressions were observed. Vertical gaze palsy and convergence palsy were observed in all cases as the initial symptom. In this study downward gaze was more severely disturbed than upward gaze. Using ENG, saccadic eye movements (saccades) were disturbed earlier than smooth pursuit movements. Hypometric saccades and decreased saccadic velocity were common abnormalities. In the later stage of the disease, horizontal eye movements were also disturbed. In four cases bilateral adduction palsy was added to vertical gaze paralysis so that the lesion of the MLF to oculomotor nucleus was suggested to exist. These voluntary eye movements were worsened gradually as the disease progressed. By using ENG we could find so called abnormal eye movements more frequently than the previous reports. Eight patients demonstrated horizontal gaze nystagmus, and rebound nystagmus were observed in four cases.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗