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

The industrial solvents xylene, styrene, trichloroethylene and methylchloroform administered to rabbits caused a positional nystagmus and disturbances in the nystagmus response to rotatory acceleration. The positional nystagmus had a beat direction the opposite to positional alcohol nystagmus, which was in similar experiments elicited by methanol, ethanol and propanol. The three alcohols needed a ten times higher blood concentration to cause a nystagmus than the solvents did.
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PMID:On the mechanism of vestibular disturbances caused by industrial solvents. 31 38

Exposure to microgravity causes alterations in postural, locomotor and oculomotor functions. The vestibular abnormalities experienced by astronauts entail immediate reflex motor responses, including postural illusions, sensations of rotation, nystagmus, dizziness and vertigo, as well as space motion sickness. Adaptation to the microgravity environment usually occurs within one week, and a subsequent re-adaptation period of several months is often required upon return to Earth. Some astronauts experience recurrences of dizziness, nausea, and vomiting, as well as marked disturbances in postural equilibrium in the absence of vision during this readaptation period. The mechanisms underlying such adaptation processes remain unclear, although current evidence favors some type of sensory conflict. The purpose of the present study was to explore the structural basis for the reorganization in the central vestibular system that underlies the process of adaptation to altered gravitational environments. Hindbrain tissue was obtained from rats flown on the Neurolab shuttle mission (STS-90) that launched on April 17, 1998. Tissue for the present report was obtained from four adult Fisher 344 rats sacrificed on orbit during flight day 2 (FD2), 24 hr after launch. Equal numbers of vivarium control animals and cage-controls were sacrificed 48 and 96 hr, respectively, after the flight dissections. Following decapitation, each hindbrain was immersion-fixed for 45 min in 4% paraformaldehyde/0.1% glutaraldehyde in 0.1M phosphate buffer pH 7.3, and then transferred to a 4% paraformaldehyde solution in 0.1M phosphate buffer for 18 days at 4 degrees C. After this fixation, the cerebellum was dissected away from the ventral portion of the brainstem by severing the cerebellar peduncles. The entire cerebellum of each rat was cut by Vibratome into 100 micrometers thick sections in the parasagittal plane. These sections were collected serially and processed for electron microscopy by osmication, dehydration in a graded series of methanol solutions, infiltration with resin, and embedment in Epon-Araldite resin between plastic coverslips.
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PMID:Anatomical observations of the rat cerebellar nodulus after 24 hr of spaceflight. 1154 23

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