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)

Coloured filters are used to protect the lens, retina and other ocular tissues against the hazard of light damage and to improve the quality of vision mainly in cases of ocular media opacities. Four types of yellow, amber and orange filters have been designed as tinted glasses, shields and colour covering of spectacles. They were tested on 15 adult patients with partial cataract and on 80 children with congenital pathology (i.e. macular hypoplasia, albinism, aphakia after congenital cataract). The majority of the children had nystagmus. The filters with particular spectral characteristics provide reduction of light intensity in the light-damaging range by at least a factor of five. Optimal filters were selected by examination of visual acuity, contrast frequency sensitivity, glare sensitivity and subjective selection by the patients. The effects of filters were: 11-43% increase in corrected visual acuity, 27-34% increase in contrast sensitivity function (CSF) for all frequencies and a marked reduction in glare sensitivity. All patients reported subjective improvement including reduction of photophobia, eye-strain and eye discomfort. It is concluded that coloured filters are able to contribute substantially to rehabilitation of low-vision patients.
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PMID:Spectral filters in low-vision correction. 1096 99

Short-radius centrifugation is a potential countermeasure to long-term weightlessness. Unfortunately, head movements in a rotating environment induce serious discomfort, non-compensatory vestibulo-ocular reflexes, and subjective illusions of body tilt. In two experiments we investigated the effects of pitch and yaw head movements in participants placed supine on a rotating bed with their head at the center of rotation, feet at the rim. The vast majority of participants experienced motion sickness, inappropriate vertical nystagmus and illusory tilt and roll as predicted by a semicircular canal model. However, a small but significant number of the 28 participants experienced tilt in the predicted plane but in the opposite direction. Heart rate was elevated following one-second duration head turns. Significant adaptation occurred following a series of head turns in the light. Vertical nystagmus, motion sickness and illusory tilt all decreased with adaptation. Consequences for artificial gravity produced by short-radius centrifuges as a countermeasure are discussed. Grant numbers: NCC 9-58.
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PMID:Artificial gravity: head movements during short-radius centrifugation. 1166 11

This study considered whether the monothermal (MT) caloric test could predict the normality of the full conventional bithermal (BT) caloric test, and therefore be an alternative to full caloric investigation. This would have the advantages of reducing test time and patient discomfort as only two caloric tests would be needed instead of four. 744 BT caloric investigations were examined, and the unilateral weakness and directional preponderance calculated for the BT and the MT stimuli. By defining the BT results as the standard, the false-positive and false-negative results of the MT test were derived. Overall using very strict MT difference criteria of less than 5% and no spontaneous nystagmus, false-negative rates for the cool MT were very low (< 1%) and better than the warm MT (< 7.1%) suggesting that the cool MT was a reliable screen test. However, unacceptably high false-positive rates were produced reflecting more than 3/4 of normal BT results failing the MT criterion. This unacceptable false-positive rate decided against implementing the MT test at our facility. The results of this study however have guided the use of the cool air-stimulus first during BT testing and, when completion of the BT is not possible or inadvisable, satisfying the stringent MT criterion confidently indicates with a probability of > 99% the absence of an abnormal BT result.
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PMID:A comparison of the monothermal and bithermal caloric tests. 1475 14

The tissue tolerance of N-chlorotaurine (NCT), a mild endogenous antimicrobial oxidant, has been investigated by application to the guinea pig middle ear. The animals were implanted with a novel cannula system that allows chronic external drug delivery to the round window niche. In the first part of the study, 3 animals each received 100 microL of 0.1% NCT (5.5 mmol/L) and 1% NCT, respectively, in aqueous solution twice daily for 8 days. In the second part, NCT was dissolved in phosphate-buffered saline solution to 300 milliosmolar (isotonic), and 27 microL was injected in 3 additional animals twice daily for 7 days. The guinea pigs injected with 100 microL of NCT developed immediate dizziness and nystagmus and did not thrive. Other reactions included mucosal thickening in the middle ear, rupture of the tympanic membrane, and blood and gelatinous material in the cochlea accompanied by hair cell loss and a 10- to 90-dB elevation of the hearing threshold as determined by auditory brain stem responses. The effects seemed to be dose-dependent, but the rate of variability was high across animals. In contrast, the guinea pigs treated with 27 microL of isotonic NCT showed no signs of discomfort, no or only moderate thickening of the middle ear mucosa, no shift of the hearing threshold, and no hair cell loss. Positive control animals injected with 10% neomycin sulfate developed extensive hair cell loss. Provided that the membranes of the inner ear are intact and that low single-dose volumes are used to avoid increased middle ear pressure, isotonic NCT seems to be well tolerated in the tympanic cavity. The new drug delivery system proved to be advantageous for ototoxicity studies.
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PMID:Tolerability of N-chlorotaurine in the guinea pig middle ear: a pilot study using an improved application system. 1476 79

This review deals with two syndromes, oscillopsia and visual vertigo. Oscillopsia is the illusion of oscillation of the visual surroundings. For diagnosis purposes one should ask, when does the oscillopsia occur? If oscillopsia is only present during head (or whole body) movements, the likely underlying cause is a bilateral defect in the vestibulo-ocular reflex (VOR). The more common causes are post meningitic vestibular damage, gentamicin ototoxicity or bilateral idiopathic vestibular failure. When oscillopsia develops after specific head positions, it is usually due to a positional nystagmus, usually the result of brainstem-cerebellar disease. When the oscillopsia is largely unrelated to head movements, one should ask, is it fairly constant or is it in attacks (paroxysmal)? If the oscillopsia is constant it is usually due to the presence of a clinically observable nystagmus; the most common is downbeat nystagmus but the most visually disabling is pendular nystagmus. If the oscillopsia comes in brief attacks it is usually due to a paroxysmal nystagmus as observed in irritative VIII nerve and brainstem lesions. However, the most common cause of paroxysmal oscillopsia is a non organic condition called voluntary nystagmus. Treatment of oscillopsia is often pharmacological but disappointing; the best chance of success is carbamazepine for paroxysmal disorders secondary to structural vestibular nerve/nuclear lesions.Visual vertigo should not be confused with oscillopsia. It can be defined as dizziness provoked by visual environments with large size (full field) repetitive or moving visual patterns. Patients with visual vertigo report discomfort in supermarkets and when viewing movement of large visual objects, eg crowds, traffic, clouds or foliage. Visual vertigo is present in many patients with a history of a peripheral vestibular disorder, particularly those who are visually dependent (ie subjects who use vision preferentially for postural and space orientation control). Patients with visual vertigo benefit from the addition to their standard vestibular rehabilitation of optic flow (optokinetic) stimuli and exercises involving visuo-vestibular conflict.
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PMID:Vision and vertigo: some visual aspects of vestibular disorders. 1508 81

Aim of this study was to determine sensitivity and specificity of the mastoid vibration test in patients who had suffered an attack of vestibular neuritis. Results were compared with the caloric test and two bedside tests of vestibular function (head shaking test and head thrust test). Results are reported in 28 patients who had a residual vestibular deficit 6 months after acute neuritis and in 25 healthy subjects. Mastoid vibration nystagmus was evoked in 21 patients but not in controls. In these patients, mastoid vibration test had a sensitivity of 75% and specificity of 100%. Since one patient had inverted mastoid vibration nystagmus, specificity of identification on the pathological side was 95%. Sensitivity of the test increased with increasing severity of the vestibular lesion. Indeed, mastoid vibration nystagmus was induced in 93% of patients with caloric paralysis and in 58% of those with caloric paresis. Nystagmus could usually be modulated or elicited by stimulation of either mastoid. In the few patients in whom mastoid vibration nystagmus was elicited only from one side, or when there was a clear difference in intensity of the nystagmus induced on the two sides, the stimulated side was more often the affected side. Four patients still showed spontaneous nystagmus. The caloric test was abnormal in 26/28 patients (93%) with paralysis in 16 and paresis in 12; 71% of patients had a head shaking induced nystagmus: 64% had an asymmetrical response in head thrust test. In conclusion, mastoid vibration test was overall more sensitive than head thrust test. Mastoid vibration test was slightly less sensitive than head shaking test in patients with severe residual deficit and more sensitive in patients with partial deficit. Mastoid vibration test, a valid, low cost clinical screening test for rapid detection of asymmetrical vestibular function, does not cause patient discomfort. It is suggested that this test be included in the diagnostic workup of all patients with suspected vestibular dysfunction.
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PMID:Sensitivity and specificity of mastoid vibration test in detection of effects of vestibular neuritis. 1660 25

Pronounced visual loss can lead to nystagmus, provoking oscillopsia and distressing ocular sensations. The treatment of acquired nystagmus remains difficult and various therapeutic options are attempted with limited results. We report the case of a man with acquired nystagmus and excessive ocular discomfort, successfully treated with repeated retrobulbar injections with botulinum toxin.
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PMID:Repeated bilateral retrobulbar injection of botulinum toxin in a blind patient with retinitis pigmentosa and incapacitating nystagmus. 1706 61

Nystagmus can be associated with strong discomfort due to oscillopsia, blurry vision and dizziness. Since generally no curative treatment methods exist, studies focus on potential pharmaceuticals to dampen the nystagmus. An overview is given on which forms of nystagmus can be treated with what kind of pharmacological substances and their possible mechanism of nystagmus dampening. Controlled studies found gabapentin and memantine to be effective in acquired pendular nystagmus and early-onset idiopathic nystagmus, and an efficacy of 4-aminopyridine in downbeat nystagmus.
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PMID:[Pharmacological treatment of nystagmus]. 2125 46

We report a case of surgical treatment for Hallermann-Streiff syndrome in a patient with ocular manifestations of esotropia, entropion, and blepharoptosis. A 54-year-old man visited Yeouido St. Mary's Hospital complaining of ocular discomfort due to cilia touching the corneas of both eyes for several years. He had a bird-like face, pinched nose, hypotrichosis of the scalp, mandibular hypoplasia with forward displacement of the temporomandibular joints, a small mouth, and proportional short stature. His ophthalmic features included sparse eyelashes and eyebrows, microphthalmia, nystagmus, lower lid entropion in the right eye, and upper lid entropion with blepharoptosis in both eyes. There was esodeviation of the eyeball of more than 100 prism diopters at near and distance, and there were limitations in ocular movement on lateral gaze. The capsulopalpebral fascia was repaired to treat the right lower lid entropion, but an additional Quickert suture was required to prevent recurrence. Blepharoplasty and levator palpebrae repair were performed for blepharoptosis and dermatochalasis. Three months after lid surgery, the right medial rectus muscle was recessed 7.5 mm, the left medial rectus was recessed 7.25 mm, and the left lateral rectus muscle was resected 8.0 mm.
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PMID:Surgical correction of Hallermann-Streiff syndrome: a case report of esotropia, entropion, and blepharoptosis. 2146 Dec 30

Objective: The Epley maneuver (EM) has an immediate effect: rapid reduction of positional nystagmus. Benign paroxysmal positional vertigo (BPPV) causes BPPV fatigue, which constitutes fatigability of positional nystagmus and vertigo with repeated performance of the Dix-Hallpike test; notably, BPPV fatigability becomes ineffective over time. We hypothesized that the immediate effect of the EM is caused by BPPV fatigue. Therefore, we suspected that performance of the EM with intervals between head positions would worsen the immediate reduction of positional nystagmus in patients with BPPV, because BPPV fatigability would become ineffective during performance of this therapy. Methods: Forty patients with newly diagnosed BPPV were randomly assigned to the following two groups; one group performed the EM without intervals between positions (group A), and the other group performed the EM with 3 min intervals between positions (group B). The primary outcome measure was the ratio of maximum slow-phase eye velocity (MSPEV) of positional nystagmus soon after the EM, compared with that measured before the EM. Secondary outcome included whether a 30 min interval after the EM enabled recovery of MSPEV of positional nystagmus to the original value. This study followed the CONSORT 2010 reporting standards. Results: In both groups A and B, the immediate effect of the EM could be observed, because MSPEV during the second Dix-Hallpike test was significantly smaller than MSPEV during the first Dix-Hallpike test (p < 0.0001 in group A, p < 0.0001 in group B). The primary outcome measure was larger in group B than in group A (p = 0.0029). The immediate effect faded 30 min later (secondary outcome). Conclusions: This study showed that the EM had an immediate effect both with and without interval time in each head position of the EM. Because setting interval time in each head position of the EM reduced the immediate effect of the EM, interval time during the EM adds less benefit. This finding can reduce the effort exerted by doctors, as well as the discomfort experienced by patients with pc-BPPV, during EM. However, this immediate effect may be caused by BPPV fatigue, and may fade rapidly. Classification of Evidence: 1b.
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PMID:Effects of Interval Time of the Epley Maneuver on Immediate Reduction of Positional Nystagmus: A Randomized, Controlled, Non-blinded Clinical Trial. 3101 86


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