Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0028738 (nystagmus)
 7,431 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In the Torok monothermal differential caloric test, each ear is irrigated with 10 ml and 100 ml of water at 20 degrees C in 5 and 20 sec., respectively. The intensity of the induced nystagmus is expressed in terms of frequency at culmination. The ratio between the weak and strong caloric responses may be normal of disproportionately large or small. When large, the ratio exceeds 3.5 and is called vestibular decruitment, a sign of labyrinthine disease. A ratio of 1.1 or less is called vestibular decruitment, a sign indicative of posterior fossa abnormality. Of 54 patients showing decruitment, a central lesion was confirmed in 51, an identification rate of 94%. The test is thus valuable in differentiating labyrinthine from retrolabyrinthine lesions.
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PMID:Diagnostic advantages of the Torok monothermal differential caloric test. 728 98

To clarify the role of central velocity storage in caloric nystagmus, 20 normal subjects in the lateral recumbent position underwent recording and analysis using ENG and an infra-red video camera in darkness. The caloric stimulus was applied by pouring 10 ml of water at 20 degrees C for 20 seconds into the ear canal. After irrigation, each subject then turned to an ear-up or an ear-down lateral position. Ninety-nine percent of the rapid phases of the horizontal components were directed to the up-side ear with no relation to the irrigated ear. Sixty-six percent of the vertical components showed vertical nystagmus toward the lower eyelid, and the remaining 34% of the vertical components showed no vertical nystagmus. The direction of the torsional components was from the up-side ear to the leg with no relation to the irrigated ear. After the first phase, the nystagmus was more significantly reversed in the ear-up lateral position than in the ear-down lateral position (p < 0.01). The maximum slow-phase velocity of the first phase horizontal component and the nystagmus frequency of the first phase horizontal and vertical components were significantly smaller in the irrigated ear-up lateral position than in the ear-down lateral position (p < 0.01). The maximum slow-phase velocity of the first phase vertical component was also smaller in the ear-up lateral position (p < 0.05). However, the duration of the first phase vertical component revealed no difference between the two positions. These findings indicate that factors other than endolymph convection are involved in the first phase horizontal and vertical components. A role for central velocity storage in the vertical, components was suggested. When caloric nystagmus was analyzed as one response, including not only the horizontal component but also the vertical and torsional components, the possibility of otolithic involvement was suggested as one of the non-convection factors.
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PMID:[Caloric nystagmus in the lateral recumbent position in normal subjects--the possibility of a participation of velocity storage and other non-convection factors]. 762 44

Both the furosemide test, and the glycerol test have been reported as being effective for detection of endolymphatic hydrops. In the furosemide test, the caloric test is performed first, and then repeated 40 minutes after i.v. injection of furosemide, 20 mg. The maximum velocities of each caloric nystagmus are compared, so the caloric stimulus conditions must be constant. In the original method, the caloric test is performed by irrigation with 50 ml of water at 30 degrees C or 44 degrees C for 20 seconds. Since it is difficult to accurately maintain the water temperature at a constant level, however, we use the air caloric stimulator NCA-105 (ICS) for the furosemide test. By using this stimulator, we can always perform the caloric test under the same conditions. The conditions of air irrigation in 28 normal subjects were set at 37 +/- 11 degrees C, 61/min, and 60 seconds. These conditions were confirmed in other normal subjects to fairly well correspond to water irrigation (30 degrees C or 44 degrees C, 50 ml, 20 seconds). Next we reassessed the furosemide test by using the air caloric stimulator in normal subjects. As a result, positive effects were observed in 7.4% of the normal subjects. This finding was similar to that reported in the literature (Futaki et al., 1971). The air caloric test is considered to be a more useful examination than the water caloric test because it is less unpleasant for the subject and easily provides the same conditions before and after furosemide administration.
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PMID:[Evaluation of the furosemide test using the air caloric stimulator]. 762 45

Dizziness is a nonspecific symptom caused by many different pathophysiologic mechanisms. Vertigo, an illusion of movement, indicates a lesion within the vestibular system. The duration of attacks and associated symptoms helps to determine the site of lesion and likely diagnosis. Examination of the dizzy patient should include a careful assessment of gait and balance and a search for spontaneous and positional nystagmus. The vestibulo-ocular reflex can be evaluated qualitatively at the bedside with the doll's eye, dynamic visual acuity, and ice water caloric tests. Each test provides different information about vestibular function.
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PMID:Approach to the evaluation of the dizzy patient. 857 Feb 43

The cold-warm caloric test is performed with water irrigation, using a hot temperature of 44 degrees C and a cold temperature of 30 degrees C, which are thermally equidistant from the body temperature 37 degrees C. However, the 30 degrees C irrigation nearly always produces a stronger nystagmic response than that of the 44 degrees C stimulation. The purpose of this study is to investigate the difference in nystagmic response between cold and hot stimulation. The achieved hot (44 degrees C) and cold (30 degrees C) water samples were prepared, and irrigation was with a disposable plastic syringe. Temperature changes in the external auditory canal were monitored by tympanic thermometry during the cold-warm caloric test. Maximal slow phase velocity and the duration of induced nystagmus were recorded on an electro-nystagmograph. The following conclusions were drawn; 1) The average normal external auditory canal temperature was 36.8 degrees C, and there was no side difference between the right and left ears. External canal temperature was higher than that of the axilla. 2) When 20 ml of 30 degrees C water was instilled the temperature change in the external canal was larger than that in response to the 44 degrees C water and the maximal slow phase velocity of nystagmus for cold stimulation was stronger than that for hot. However, the duration of nystagmus for the cold was not significantly longer than that of the hot stimulation.
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PMID:[Relationship between external auditory canal temperature and caloric nystagmus--the problem with the ordinary cold-warm caloric test]. 828 45

Morphological vestibular changes caused by barotrauma were studied in guinea pigs. Animals were exposed to rapid decompression from 2 absolute atmospheric pressures (ATA) to 1 ATA, which causes inner ear barotrauma in the guinea pig. During decompression, spontaneous nystagmus was recorded, which consisted of irritative symptoms initially, followed by paralytic nystagmus. After pressure loading and observation to confirm the absence of Preyer's reflex with vertigo, the animals were tested for caloric nystagmus using ice water and then sacrificed at varying intervals. Then, morphological changes in vestibular organs and the organ of Corti were studied. Half of the experimental animals showed canal paresis on caloric testing. Damage to the organ of Corti was severe while that to vestibular organs was very slight. Damage to the sensory cells of the vestibular organs was not clear on light microscopy, despite a partial collapse of labyrinthine membranes. Under scanning electron microscopy, local damage was observed in a portion of the crista ampullaris of the semicircular canals. In this area, incomplete or complete disappearance of kinocilia and stereocilia, similar to that seen after rotatostimulation, was observed. However, no damage to sensory hairs was seen in the utricles and saccules. The observed vestibular organ damage, resulting from inner ear barotrauma, suggested effects on endolymphatic flow.
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PMID:[Vestibular changes due to barotrauma]. 829 63

The Torok Monothermal Caloric Test has been described as offering a strong advantage over bithermal caloric testing because it can distinguish labyrinthine from retrolabyrinthine lesions. Weak and strong irrigations of room-temperature water are administered to each ear and the ratios of strong to weak nystagmus responses compared to those of normal individuals. Ratios that fall below normal are said to represent decruitment and to denote retrolabyrinthine disease. Ratios that exceed normal are said to represent recruitment and to denote labyrinthine lesions. We attempted to verify the clinical value of the Monothermal Caloric Test by examining patients with known labyrinthine (N = 9) and retrolabyrinthine (N = 25) lesions. Ten patients with dysequilibrium and nonlocalizing testing were also examined. The test was performed exactly as described by the originator. Decruitment was found either unilaterally or bilaterally in 56% of patients with retrolabyrinthine lesions. However, it occurred on the side of the lesion in only 42%. Decruitment was also found in 47% of patients without retrolabyrinthine lesions, including 63% of those with unilateral Meniere's disease. Recruitment was never found on the side of a labyrinthine lesion. A description of the test and a summary of our results are presented. We conclude that the Monothermal Caloric Test is moderately sensitive to the presence of retrolabyrinthine lesions, but lateralizes poorly and is not highly selective. The test was found to be insensitive to the presence of labyrinthine disease.
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PMID:Clinical evaluation of the monothermal caloric test. 843 71

Conditions associated with nausea and vomiting, such as motion sickness or side effects of medications, are commonly associated with a clinical picture consistent with parasympathetic activation and sympathetic withdrawal. It can be postulated, therefore, that vestibular stimulation contributes to sympathetic withdrawal. To test this hypothesis five normal volunteers, 24-33 years old, were studied during caloric vestibular stimulation while monitoring muscle sympathetic nerve activity directly through a needle electrode placed in a peroneal nerve. The ear was irrigated with water at a flow rate of 450 ml/min and 37 degrees C. The water temperature was sequentially lowered by 7 degree C intervals until intolerable side effects developed or a temperature of 16 degrees C was reached. Nystagmus was induced in all subjects, but heart rate, blood pressure, muscle sympathetic nerve activity and plasma norepinephrine levels did not change significantly during or after caloric stimulation, even when the subjects felt dizzy and nauseated. No evidence of sympathetic withdrawal was observed in any subject either by muscle sympathetic nerve activity or plasma norepinephrine measurements. In conclusion, we have found that selective vestibular stimulation is not accompanied by significant changes in the sympathetic nervous system function. In particular, no sympathetic withdrawal was observed. It could be argued that lack of sympathetic stimulation is an inadequate response to the symptoms associated with caloric stimulation.
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PMID:Effect of neurovestibular stimulation on autonomic regulation. 856 62

Two cases of bilateral Lermoyez's syndrome and one case of unilateral Lermoyez's syndrome are reported. The patients had recurrent episodes of vertigo with improvement of hearing or tinnitus, which is characteristic is Lermoyez's syndrome. In case 1, a 48-year-old female, dehydration with glycerol or furosemide induced nystagmus and improved bilateral hearing and the gain of the vestibulo-ocular reflex, while overhydration with drinking water impaired bilateral hearing with disappearance of nystagmus. These findings indicate that she had endolymphatic hydrops in both ears, suggesting that simultaneous changes in bilateral cochlear and vestibular function induce Lermoyez's syndrome. In case 3, a 52-year-old female, which we already reported, endolymphatic collapse in both ears may have changed bilateral inner ear function, resulting in Lermoyez's syndrome. On the other hand, patients 2, a 47-year-old male, experienced a vertigo attack with improvement of unilateral hearing after defibrinogenation therapy. In this case, slowly developing insufficiency of the inner ear blood supply may have caused the gradual hearing loss. It seemed that decreasing blood viscosity by defibrinogenation allowed blood to rush into the labyrinth, causing vertigo but at the same time improving hearing. We proposed that there are two types of Lermoyez's syndrome, bilateral (cases 1 and 3) and unilateral (case 2).
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PMID:[Three cases of Lermoyez's syndrome and its pathophysiology]. 885 32

Crude oil pollution at drilling sites located within or in close proximity to agricultural pasture lands poses serious health risks to cattle raised on these lands. To investigate the clinical and systemic biochemical effects, cattle (8/group) were administered single oral doses of Pembina Cardium crude oil (PCCO) at 16.7, 33.4, and 67.4 g/kg, or water (control group) at 80 g/kg. Cattle exposed to PCCO showed dose-dependent clinical effects. At the lowest dosage, PCCO caused transient and minimal clinical effects; however, high dosages caused varied clinical signs which included tremors, nystagmus, vomiting, and pulmonary distress. On posttreatment day 7 or 30, four cattle from each treatment group were sacrificed and biochemical parameters were assayed in liver, lungs, and kidney cortex. In cattle monitored on posttreatment day 7, the PCCO-treated groups showed marked alterations from the control group in hepatic cytochrome P-450 (P-450), and in aryl hydrocarbon hydroxylase (AHH) and 7-ethoxycoumarin-O-deethylase (ECOD) activities of these tissues. Administration of PCCO caused significant increases (> 100%) in hepatic P-450, but produced variable effects on AHH and ECOD activities in each tissue. The activity of AHH was increased in all tissues; however, the effect was highest in kidney cortex (> 5000%), followed by liver (> 500%) and lungs (> 250%). The activity of ECOD was altered in a differential manner. It was either increased markedly (>1300%) in kidney cortex or increased slightly (20-30%) in liver, but decreased (> 80%) in lungs. The activities of respiratory chain enzymes (succinate-cytochrome c reductase, NADH-cytochrome c reductase and cytochrome oxidase), or NADPH-cytochrome c reductase and glutathione transferase were not changed significantly in any tissues. The alterations in P-450, AHH, and ECOD observed on day 7 were markedly reversed in cattle examined on day 30 posttreatment, indicating a recovery from induced changes. Studies in vitro with hepatic microsomal preparations from day 7 posttreatment groups showed that increases in AHH and ECOD activity in PCCO-treated cattle were due to induction of new isoforms of P-450, as evidenced by (1) the appearance of a 448-nm spectral peak, and (2) differential inhibitory effects of metyrapone and 7,8-benzoflavone on AHH and ECOD activities.
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PMID:Biochemical effects of Pembina Cardium crude oil exposure in cattle. 885 67


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