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Query: UMLS:C0028738 (nystagmus)
 7,431 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We report here two cases of two young diplegic patients with cystic periventricular leukomalacia who systematically, and with high sensitivity, perceive translational motion of a random-dot display in the opposite direction. The apparent inversion was specific for translation motion: Rotation and expansion motion were perceived correctly, with normal sensitivity. It was also specific for random-dot patterns, not occurring with gratings. For the one patient that we were able to test extensively, contrast sensitivity for static stimuli was normal, but was very low for direction discrimination at high spatial frequencies and all temporal frequencies. His optokinetic nystagmus movements were normal but he was unable to track a single translating target, indicating a perceptual origin of the tracking deficit. The severe deficit for motion perception was also evident in the seminatural situation of a driving simulation video game. The perceptual deficit for translational motion was reinforced by functional magnetic resonance imaging studies. Translational motion elicited no response in the MT complex, although it did produce a strong response in many visual areas when contrasted with blank stimuli. However, radial and rotational motion produced a normal pattern of activation in a subregion of the MT complex. These data reinforce the existent evidence for independent cortical processing for translational, and circular or radial flow motion, and further suggest that the two systems have different vulnerability and plasticity to prenatal damage. They also highlight the complexity of visual motion perception, and how the delicate balance of neural activity can lead to paradoxical effects such as consistent misperception of the direction of motion. We advance a possible explanation of a reduced spatial sampling of the motion stimuli and report a simple model that simulates well the experimental results.
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PMID:Inversion of perceived direction of motion caused by spatial undersampling in two children with periventricular leukomalacia. 1821 Dec 46

We report the case of a 50-year-old man with paraneoplastic cerebellar degeneration (PCD) and Lambert-Eaton myasthenic syndrome (LEMS) associated with primary double lung cancer. He developed acute progressive double vision, slurred speech, and gait disturbance. Neurological examination revealed diplopia, mild ptosis, bilateral horizontal gaze-evoked nystagmus, and cerebellar limb and truncal ataxia. The diffusion image of brain magnetic resonance imaging (MRI) revealed no abnormal findings in the cerebellum. On the basis of the diagnosis of acute cerebelitis, he was given methylprednisolone pulse therapy followed by oral prednisolone, which gradually improved his neurological signs and symptoms. The analysis of the possible etiology suggested that the PCD was induced by lung cancer, which led to ataxia. A chest computed tomography scan revealed mass lesions of irregular shape and unclear margins in the upper lobe of the right lung and a small nodule tumor in the upper lobe of the left lung. We performed transbronchial needle aspiration and detected the bronchioloalveolar carcinoma of the right lung. An electromyogram showed waxing phenomenon in the ulnar nerve at high-frequency (50Hz) stimulation. The serum levels of anti-P/Q-type voltage-gated calcium channel (VGCC) antibody were elavated in the patient. These findings confirmed that the pathogenesis of the condition of this patient to be associated with LEMS. His cerebellar symptoms were considered to be caused by the PCD, and the diplopia, ptosis, and hyporeflexia were attributed to LEMS. We performed upper left lobectomy with mediastinal lymphnode dissection via video-assisted thoracoscopic surgery. A histological study detected small cell carcinoma. A diagnosis of double primary lung cancer was made. Physicians need to be aware that patients may develop PCD and LEMS associated with anti-VGCC antibody caused by small cell lung cancer, and a mass survey should be conducted and careful examinations performed.
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PMID:[Paraneoplastic cerebellar degeneration and Lambert-Eaton myasthenic syndrome associated with anti P/Q-type voltage-gated calcium channel antibody in a patient with primary double lung cancer]. 1980 9

We report a case showing apogeotropic nystagmus with the lesion of the brain stem, and discuss a possible mechanism of central apogeotropic nystagmus. The case was a 73-year-old male. We analyzed his nystagmus three-dimensionally. He showed apogeotropic nystagmus. Axis angles of slow phase eye velocity of his apogeotropic nystagmus were not in line with the axes perpendicular to the plane of horizontal semicircular canals, but with the patient's vertical axis. We then found that his nystagmus including the apogeotropic nystagmus was positioning, but not positional and that the direction of his positioning nystagmus was the same direction of postrotatory nystagmus after his head movement. His MRI scans showed an infarction around the prepositus hypoglossi nucleus of the brain. His apogeotropic nystagmus seemed to consist of a combination of prolonged postrotatory nystagmus after his head rotation to the left and right lateral position because the axis of postrotatory nystamus was in line with the axis of the head rotation. Therefore, it is suggested that a possible mechanism of central apogeotropic nystagmus is a prolonged postrotatory nystagmus after his head movement in the supine position due to the brain lesion involving the velocity storage mechanisms.
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PMID:A case of apogeotropic nystagmus with brainstem lesion: An implication for mechanism of central apogeotropic nystagmus. 2058 Jan 72

We present an interesting and relatively uncommon case of vestibular pneumolabyrinth in a young child post-trauma. His initial clinical exam and imaging studies of the head and cervical spine were negative. He subsequently developed nystagmus and a dedicated temporal bone study demonstrated a subtle fracture and vestibular pneumolabyrinth. Temporal bone fractures can be difficult to appreciate, and therefore, associated findings of fluid in the middle ear, stapes dislocation, or vestibular pneumolabyrinth must be carefully evaluated. Temporal bone computed tomography is a high resolution study, utilizing dynamic focal spot mode which leads to increased sampling and resolution, thereby reducing aliasing artifacts but a longer scan time and increased radiation dose. CT head and cervical spine normally obtained without using this technique leads to aliasing artifacts where even the normal endolymph in the inner ear structures appear hypodense mimicking pneumolabyrinth, thereby obscuring true pneumolabyrinth. It is important to be aware of this finding and technique-related artifact, if a temporal bone injury is suspected, to ensure an earlier diagnosis and optimum management.
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PMID:Vestibular pneumolabyrinth: why assessment with temporal bone computed tomography utilizing dynamic focal spot mode is important for the diagnosis. 2082 98

William Charles Wells retained an interest in vision throughout his life. His first book was on single vision with two eyes; he integrated vision and eye movements to determine principles of visual direction. On the basis of experiments and observations he formulated three principles of visual direction, which can readily be demonstrated. In the course of these studies, he also examined visual acuity, accommodation and convergence, visual persistence, and visual vertigo. Insights into visual processing were mainly derived from observations of afterimages that were used to provide an index of how the eyes moved. His experiments enabled him to distinguish between the consequences of active and passive eye movements (later called outflow and inflow) as well as describing nystagmus following body rotation. After providing a brief account of Wells's life, his neglected research on vision is described and assessed.
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PMID:The singular vision of William Charles Wells (1757-1817). 2125 34

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

We report a rare case of optic nerve atrophy with severe disc cupping resulting from methanol poisoning. A 30-year-old man presented to the hospital complaining of decreased visual acuity in both eyes a day after drinking alcohol containing methanol. His initial visual acuity allowed for only visualizing hand motion and not corrected in either eye. Initial intraocular pressure was within normal limits in both eyes. Initial fundus examination showed optic disc swelling in both eyes. Four years later, he visited our hospital for an eye evaluation. Visual acuity in both eyes still only allowed for visualizing hand motion. No nystagmus was observed in either eye during the optokinetic nystagmus test, and no waves were found in a visual evoked potential test. No specific change was noted on brain magnetic resonance imaging. On fundus examination, there was disc pallor in both eyes and disc cupping with a high cup/disc (C/D) ratio above 0.9 in the left eye. C/D ratio of the right eye was 0.5. Methanol poisoning may induce glaucomatous disc cupping in the late stage as well as optic atrophy. One possible mechanism of disc cupping is ganglion cell loss due to acute demyelination of the retrobulbar optic nerve. This report is the first photographic evidence of methanol induced optic disc cupping in Korea.
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PMID:A case of optic nerve atrophy with severe disc cupping after methanol poisoning. 2213 88

A 72-year-old man with positional vertigo and tinnitus was referred to us. He did not want to perform provoking test except once due to his fear. No positional nystagmus was provoked. He found that his attacks usually occurred when he lay on his right ear. From his clinical history, benign paroxysmal positional vertigo was suspected. Conventional pharmacotherapy as well as non-specific physical therapy did not have significant effect. His feeling of positional vertigo with pyrosis was actually presyncope. We suspected cardiovascular disorders, and referred him to a cardiologist. Portable cardiogram monitoring revealed paroxysmal bradycardia. He was diagnosed with neurally mediated syncope, and a pacemaker was implanted. His paroxysmal dizziness soon disappeared. It is important to study the clinical history of the patients in detail, as they are not always able to accurately explain their symptoms. We should carefully rule out cardiovascular disorders, especially when we see the patients with suspected BPPV without the characteristic positional nystagmus.
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PMID:Neurally mediated syncope presenting with paroxysmal positional vertigo and tinnitus. 2206

Autosomal dominant microphthalmia with late-onset keratitis and iris coloboma/aniridia has not been reported before. Here we report a Chinese family with these phenotypes and a novel PAX6 mutation. Microphthalmia, late-onset keratitis, iris coloboma, and nystagmus were present in the proband. His son had microphthalmia, aniridia, foveal hypoplasia, and nystagmus. A novel c.649C>T (p.Arg217X) mutation in PAX6 was detected in the proband and his affected son. This study expands the phenotypic spectrum of PAX6 mutation and enriched our knowledge of the genetic cause for microphthalmia and late-onset keratitis.
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PMID:Microphthalmia, late onset keratitis, and iris coloboma/aniridia in a family with a novel PAX6 mutation. 2217 86

A patient with downbeat nystagmus subsequent to ankylosing spondylitis was studied. His nystagmus was found to exhibit both increasing- and decreasing-velocity exponential slow phases as well as the linear form more often reported. Alternation between waveforms sometimes occurred on a beat-to-beat or even intrabeat basis. Possible explanations for all three waveforms are presented in terms of short-term gain changes in cerebellar compensation for leaky brainstem neural integrators. A computer model was developed and its results are discussed.
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PMID:Variable waveforms in downbeat nystagmus imply short-term gain changes. 2250 87


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