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)

Spontaneous nystagmus and locomotor equilibrium function were repeatedly tested before and after unilateral labyrinthectomy in 12 squirrel monkeys in order to study the effect of physical exercise on the vestibulo-oculomotor and vestibulo-locomotor compensation. Post-operatively, 6 of the monkeys received forced physical exercise in the rotating cage, while the other 6 did not. The provocation of post-operative spontaneous nystagmus was less in the exercise group. The statistical studies showed a certain contribution of physical exercise toward the oculomotor balance compensation and maintenance, probably at the level of the brain stem. Statistical comparison of the locomotor equilibrium performance did not depict a significant difference between the exercise and non-exercise groups; however, there was a possibility that the present testing maneuver which involves physically advanced tasks might have concealed the effect of the physical exercise.
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PMID:Effect of physical exercise upon nystagmus and locomotor dysequilibrium after labyrinthectomy in experimental primates. 113 60

Primary tumors of the pineal body can produce dyscoordinative movements of the eye, pupillary dilatation, paralysis of adduction during convergence and nystagmus. Obstruction of the aqueduct can cause hydrocephalus, increased intracranial pressure and papilledema. Diabetes insipidus may be a presenting symptom. Pinealocytes and the photoreceptors of the eye contain several autoantigens. In man, the best known is the S-antigen. This antigen can be detected in the cerebrospinal fluid of patients with primary tumors of the pineal body. The S-antigen, and possibly other related autoantigens, can elicit an autoimmune mediated reaction causing inflammatory eye symptoms. This recently described paraneoplastic neurologic syndrome shares properties in common with other known cancer-associated ophthalmologic syndromes characterised by rapid development of eye symptoms, rapid loss of sight and by eye manifestations prior to evident appearance of symptoms related to primary tumor growth. A primary tumor of the pineal body should be considered in patients where a monosymptomatic uveoretinitis presents without associated provoking factors. Furthermore, analyses of S-antigen in the spinal fluid can be useful in the clinical diagnosis of the same primary tumors.
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PMID:[Physiopathologic mechanisms behind eye symptoms in primary tumors of the pineal body]. 843 Apr 65

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 have reported that the recently described circling behavior rat (CLX) is a hereditary mutant controlled by a single sex-linked recessive gene (gene symbol: clx). This mutant shows intermittent circle walking and/or running and head tossing with the neck twisted. The abnormal behavior begins to appear around weaning and continues throughout life. In the present study, behavioral tests were performed during the suckling and post-weaning periods and when the rats reached maturity, and the following peculiar abnormalities were revealed: (1) in the righting reflex test, the CLX young show a tendency to take a longer time to revert to normal posture; (2) in the negative geotaxis test, they had difficulty moving upward at 12 days of age; (3) in the air righting reflex test, they frequently fell on their backs or shoulders even after weaning; (4) almost none of the CLX rats showed nystagmus, which is invariably observed in normal rats after rotating stimulation, at 20 weeks of age; and (5) they showed hyperactivity in the open field test at the age of 5 or 6 weeks and a higher degree of locomotor activity in the home cage at the age of 7 and 15 weeks. These results suggest that CLX mutant rats may have some defect in vestibular function (balance sense) or abnormalities in an area of the central nervous system responsible for posture control, e.g., in the dopaminergic or GABAergic neurons.
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PMID:Defective balancing ability and hyperactivity in the CLX (circling behavior linked to the X-chromosome) mutant rat. 1504 81

Hemi-seesaw nystagmus (hemi-SSN) is a jerk-waveform nystagmus with conjugate torsional and disjunctive vertical components. Halmagyi et al. in Brain 117(Pt 4):789-803 (1994), reported hemi-SSN in patients with unilateral lesions in the vicinity of the Interstitial Nucleus of Cajal (INC) and suggested that an imbalance in projections from the vestibular nuclei to the INC was the source of the nystagmus. However, this hypothesis was called into question by Helmchen et al. in Exp Brain Res 119(4):436-452 (1998), who inactivated INC in monkeys with muscimol (a GABA(A) agonist) and induced failure of vertical gaze-holding (neural integrator) function but not hemi-SSN. We injected 0.1-0.2 microl of 2% muscimol into the supraoculomotor area, 1-2 mm dorso-lateral to the right oculomotor nucleus and caudal to the right INC. A total of seven injections in two juvenile rhesus monkeys were performed. Hemi-SSN was noted within 5-10 min after injection for six of the injections. Around the time the hemi-SSN began, a small skew deviation also developed. However, there was no limitation of horizontal or vertical eye movements, suggesting that the nearby oculomotor nucleus was not initially compromised. Limitations in eye movement range developed about (1/2)-1 h following the injections. Clinical signs that were observed after the animal was released to his cage included a moderate to marked head tilt toward the left (contralesional) side, consistent with an ocular tilt reaction. We conclude that hemi-SSN can be caused by lesions just caudal to the INC, whereas lesions of the INC itself cause down-beat nystagmus and vertical gaze-holding failure, as demonstrated by Helmchen et al. Combined deficits may be encountered with lesions that involve several midbrain structures.
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PMID:Muscimol inactivation caudal to the interstitial nucleus of Cajal induces hemi-seesaw nystagmus. 2068 90