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)

1. In precollicular decerebrate cats the electrical activity of single pontine neurons was recorded before, during and after the episodes of postural atonia produced by i.v. injection of 0.03-0.1 mg/kg of eserine sulphate. These episodes were characterized by the regular occurrence of horizontal conjugate eye movements, which were mainly grouped in bursts of REM; moreover, a burst of REM in one direction was generally followed by a burst of REM in the opposite direction. 2. Among the recorded units, 32 showed an increase in their discharge rate during these cataplectic episodes. However, while these units fired at regular frequency when postural rigidity was present, they showed periodic changes in their discharge rate as soon as the bursts of REM appeared in the electrooculogram. In particular a nearly sinusoidal increase in the discharge rate was related to the appearance of an ocular burst in one direction, while a decrease in the unit discharge occurred during an ocular burst in the opposite direction. In some instances neighbouring pontine units located within each side of the brain stem showed reciprocal rate profiles during REM bursts oriented in a given direction, making it likely that the cyclic alternation of their activity depended upon their reciprocal interaction. 3. The alternative hypothesis, i.e., that these periodic changes in unit discharge depend upon the proprioceptive feedback due to the eye movements was excluded by the fact that these changes started before the occurrence of the bursts of REM and began to decline before the end of the burst. Moreover no variation in their firing rate was observed during the positional nystagmus induced by tilting the animal in the control period, i.e., when postural rigidity had reappeared following the end of the cataplectic episode. 4. Most of the neurons showing periodic changes in their discharge frequency during the bursts of REM were located in the pontine reticular formation. Scattered units were also found within the region of the locus coeruleus and the raphe system, close to the surrounding reticular structures. 5. In addition to these neurons, 60 pontine units were recorded, which did not show any changes in their discharge rate during transition from the control period to the cataplectic episode. However, phsiic increases or phasic decreases in their discharge rate appeared synchronously with the individual eye movements. Since in most instances these phasic changes in unit activity coincided with the appearance of the individual monophasic potentials recorded from the ascending MLB, which immediately preceded the rapid eye movements, these units could be attributed either to the premotor neurons responsible for these REM or to the closely related structures which generate their rhythmic discharge. In only a few instances did the discharge of these units not precede but follow the individual eye movements, indicating that they resulted from a proprioceptive feedback originating during the eye movements. 6...
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PMID:The oscillatory system responsible for the oculomotor activity during the bursts of REM. 19 Sep 62

We observed the attacks of nystagmus in a case of infantile spasms and carried out overnight sleep polygraphy. The following findings were obtained: (1) Awake time was prolonged to 56% of TIB, while sleep time was markedly shortened to 44% of TIB. Also REM sleep time was reduced to 20% of SPT and deep slow sleep (stage N3) was absent. (2) Attacks of nystagmus were observed only during wakefulness. At first, fast wave bursts appeared in the right occipital area, and were followed by left-upward deviations of eyeballs, and then the attacks of counterclockwise right-downward rotatory nystagmus. Also the fast wave bursts were succeeded by spreading of fast waves to adjacent areas. At the same time, EMG exhibited elevated muscle action potentials of mentalis and biceps femoris. During the attacks of nystagmus, there was alteration of respiratory movements. In NREM sleep, both fast wave bursts and the attacks of nystagmus were not observed. In REM sleep, the fast wave bursts and eye movements were observed but the attacks of nystagmus did not appear. During the fast wave bursts, alteration of respiratory movements were observed. From the results of this study, it was presumed that the brain lesions of this case were extended with severe degree of damage in the great parts of brain containing cerebral cortex and brain stem.
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PMID:The studies of the attacks of abnormal eye movement in a case of infantile spasms. 59 Aug 78

This is the first report of unilateral palatal myoclonus with which two different ocular movements were synchronized. A 55-year-old woman was admitted to our hospital due to intubation and dysarthria of sudden onset after three similar attacks for these four years. On admission right ptosis, hypalgesia in the right face, right facial nerve palsy, dysarthria, bilaterally increased deep tendon reflexes and trunkal ataxia were noted. Continuous repetitive contractions at 110/min frequencies were observed in the left soft palate, pharynx and larynx. On electronystagmography and electro-magnetic search coil system (Skala system), two different ocular movements, i.e., rotary oscillation with torsion and nystagmus to the right, successively alternated each other at random during eyelids closure. They were synchronized with palatal myoclonus. True nystagmus synchronized with palatal myoclonus has not been reported. When she calculated, rotary oscillation disappeared. In sleep polygraphy, rotary oscillation reduced in amplitude in stage 1 and disappeared in stages 2, 3, 4 and REM. On the other hand, the nystagmus reduced in amplitude in stage 1 and 2 and disappeared in stages 3, 4 and REM. The direction of nystagmus was converted to the left in stages 1 and 2. Similarly, in a drowsy state induced by intravenous injection of 7 mg diazepam, the direction of the nystagmus was converted to the left. On brain magnetic resonance imaging (MRI) right inferior olive was identified as a well circumscribed, enlarged increased signal area on T2-weighted and proton density-weighted images in addition to the lesions of infarcts in left corona radiata, posterior limb of right internal capsule and tegmentum pontis.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[Unilateral palatal myoclonus with peculiar ocular movements--neurotological studies and MRI]. 275 41

Eye movements were investigated in 14 patients with manifest Huntington's Chorea, 10 offspring and 10 normal subjects with electronystagmography (ENG) and during REM sleep. In choretic patients the following abnormalities were found: 1. Voluntary saccades were slowed in 10 of 14 patients and were more disturbed in the vertical than the horizontal direction. 2. Also, the velocity of the fast phase of optokinetic nystagmus was clearly reduced, especially in the vertical plane. 3. Horizontal, pendular pursuit movements are often superimposed by square wave opposite jerks. 4. Vestibular nystagmus was disturbed, too, especially in the fast phase. 5. During paradoxical sleep, rapid eye movements are less frequent. 6. In ten offspring, eight showed similar oculomotor disturbances.
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PMID:Disturbance of eye movements in Huntington's chorea. 645 5

The subjects of this study were 25 patients. Sixteen cases with nystagmus referable to brain stem lesion were divided into two groups; one group was 7 vertical nystagmus (vertical group) and the other group was 9 horizontal nystagmus (horizontal group). Other 9 cases consisted of congenital group (4 cases), cerebellar group (3 cases) and labyrinthine group (2 cases). Normal controls were 8 male volunteers who had no history of particular psychiatric and somatic illness. The results were as follows: 1) Nystagmus observed during wakefulness in all nystagmus groups disappeared during all stages of sleep. 2) The vertical component of nystagmus in the vertical group showed significantly enhanced REM-density compared with that of normal subjects. 3) Both horizontal and vertical REM-densities of the horizontal and labyrinthine group were almost as high as those of normal subjects. 4) Both REM-densities of the congenital group were significantly lower than those of normal subjects. 5) The horizontal REM-density of the cerebellar group was significantly higher than that of normal subjects.
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PMID:Nystagmus and REM-density during sleep in patients with various brain lesions. 728 32

Epileptic nystagmus (EN) is a rare form of nystagmus that occurs only during epileptic seizures. We report a case in which EN was first noted in an 8 year-old boy. Neuro-imaging was normal. Sharp waves from the left occipital lobe characterised the interictal EEG. Ictal video-EEG showed the aspects of electric seizures during clinical manifestations e.g. nystagmus. Ambulatory EEG displayed numerous diurnal and nocturnal seizures, but exclusively in REM sleep. After two weeks of sodium valproate treatment, the seizures, EEG focus spikes and nystagmus, as well as the squint, disappeared. During a two-year follow-up the child had no further seizures, EEG was normal and the school performance was unaffected. This case has the main features of benign epilepsy, although there are unusual features such as epileptic nystagmus, permanent squint, reduction of EEG paroxysmal abnormalities during NREM, and the presence of seizures during REM sleep. The observation and the significance of EN are discussed with reference to the literature.
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PMID:Epileptic nystagmus: electroclinical study of a case. 1131 21

Saccades, including fast phases of nystagmus, disappear during drowsiness and non-rapid eye movement (NREM) sleep, but are present during the alert state and REM sleep. The purpose of this study was to determine whether spontaneous nystagmus is present in patients with vestibular neuritis during REM sleep. Eight patients with spontaneous nystagmus due to vestibular neuritis and eight control patients without any nystagmus underwent at least one night of polysomnography. Fast phases of nystagmus were analyzed. The number of right and left horizontal saccades were counted, first during 3-5 minute samples of the awake state before sleep onset, then during the first REM episode and the last REM episode of nocturnal sleep, and finally during the alert state in the morning after nocturnal sleep. All patients with vestibular neuritis showed significantly more saccades (fast phases) towards the side contralateral to their vestibular lesion in the awake state before and after the polysomnography. This reflects their spontaneous nystagmus. By contrast, during REM sleep the patients with vestibular neuritis showed no preponderance in saccade direction. The eye movement pattern in REM was the same for patients and controls. In conclusion, peripheral vestibular imbalance producing nystagmus in vestibular neuritis in the awake state is not active at the brain stem level during REM sleep.
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PMID:Absence of nystagmus during REM sleep in patients with vestibular neuritis. 1151 16

A 50-year-old woman developed gait disturbance and hypersomnia over a period of a month. General physical examination revealed axillary lymph node swelling. On neurological examinations she was fully orientated but hypersomnic; short term memory disturbance, horizontal gaze evoked nystagmus and ataxic gait were observed. Electroencephalography disclosed a tendency for easily decreasing vigilance with delta activities but normal dominant rhythm. Cerebrospinal fluid examinations showed increased protein amounts (109 mg/dl) without either pleocytosis or atypical cells. An echogram of the breasts revealed a tiny mass in the left side. Pathological studies on a biopsied lymph node and the mass in her left breast showed a mammillary duct carcinoma. Brain MRI was normal, and no anti-neuronal antibody was detected in sera by two dimensional immunoblotting using human brain crude antigens. She was diagnosed as having paraneoplastic limbic encephalitis (PLE) associated with breast cancer. Over 42 hours polysomnography showed long total sleep time (TST) with a high ratio of sleep stage 1/TST and no REM sleep abnormalities; this resembled a thalamic-hypothalamic damaged sleep pattern. At first she was treated with plasma exchanges, but no improvement was observed. Hormonal and chemotherapies produced partial resolution of her neurologic symptoms and there were signs of reduction of the breast mass. Most reported PLE cases with hypersomnia have been associated with testicular cancer and anti-Ma antibodies. The present case is an extremely rare example manifesting hypersomnia without either testicular cancer or anti-Ma antibody. Since anti-tumor therapy successfully ameliorated her neurologic symptoms, cell-mediated immunity against a common tumor and neuronal antigens rather than hormonal immunity may have played a role in the development of her PLE.
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PMID:[A patient with paraneoplastic limbic encephalitis induced by breast cancer presenting with hypersomnia]. 1618 Jul 5

There exist a large number of drugs belonging to the benzodiazepine family. These include the 1,4-benzodiazepines such as diazepam, temazepam and oxazepam, the often more potent diazolo- and triazolo-groups represented by alprazolam, midazolam, triazolam etc. These drugs represent a large range of potencies from submilligram doses to over 100 mg and a range of polarities. Consequently, blood or plasma concentrations associated with prescribed use range from sub-nanogram per mL to near-microgram per mL. Their medical use varies, but they are predominantly used as hypnotics and sedatives. Some members are also used in the treatment of post-traumatic stress and obsessive-compulsive disorders, alcohol withdrawal, muscle spasm, and seizures. Recreationally, drug users favor these drugs to reduce the symptoms of withdrawal and unpleasant effects of heroin and cocaine. They are also commonly used as "date-rape" drugs to render a victim incapable of resisting an attack. Benzodiazepines elicit a large number of physiological and psychological responses in humans that often can lead to significant behavioral changes and adverse effects on skills required for safe driving. These include reduced lane control, increased reaction times, reduced hand-eye coordination and cognitive impairment. Impairment can exceed that seen with 0.05 g% ethanol. In high doses benzodiazepines can cause persons to exhibit classical features of CNS-depressant drugs such as nystagmus, ataxia, slurred speech, and impaired divided attention skills. As one would expect with hypnotics and sedatives, any sleep deprivation, or situations involving monotonous driving can lead to a reduced ability to concentrate and maintain vigilance. Adverse effects on REM and NREM sleep patterns will exacerbate fatigue-related components to driving. Persons with sleep abnormalities, e.g., sleep apnea, may be more likely to be affected by benzodiazepines than those with normal sleep patterns. Ethanol and narcotic analgesics also affect sleep patterns and may compound any CNS-depressant effects associated with the use of benzodiazepines.
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PMID:Benzodiazepines - Effects on Human Performance and Behavior. 2625 85