Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0027066 (myoclonus)
 4,275 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Clonic and tonic seizure-like movements of the extremities were observed during induction of anaesthesia with sevoflurane in a 9-yr-old girl. The tonic movements were associated with respiratory alkalosis and were not abolished by an i.v. injection of thiamylal 75 mg. Arterial pressure, heart rate and body temperature remained normal during the episode. Ventilation was assisted easily and then controlled via a face mask. No neurological abnormalities were obvious after the anaesthesia. The movements may have been the result of seizure activity in the central nervous system, or myoclonus of the extremities.
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PMID:Seizure-like movements during induction of anaesthesia with sevoflurane. 154 Apr 67

The dose-related time course and occurrence of different seizure subtypes was examined in mice after i.c.v. administration of N-methyl-D-aspartate (NMDA), kainate (KA) or quisqualate (QA). At doses of 0.2 to 1 nmol, NMDA dose-dependently induced a single clonic-tonic seizure. Low doses (0.1 to 0.3 nmol) of KA induced only mild myoclonus and whole body clonus, which were dose-dependently replaced by short-delay clonic-tonic seizures at higher doses (0.4 to 1.2 nmol). In contrast, mice treated with 13 to 32 nmol of QA exhibited either mild myoclonus or whole body clonus as well as clonic-tonic seizures. Clonic-tonic seizures induced by NMDA or KA appeared at shorter latencies than those induced by QA, whereas whole body clonus induced by KA or QA appeared with long onset latencies. These results clearly show that i.c.v. administration of NMDA, KA and QA produces different patterns of seizures in mice. This study confirms that NMDA, KA and QA induce convulsions through different underlying mechanisms and suggests that different anatomical pathways are involved in these models.
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PMID:Comparative analysis of seizures induced by intracerebroventricular administration of NMDA, kainate and quisqualate in mice. 157 1

The high pressure neurological syndrome (HPNS) occurs when man or animals are exposed to hyperbaric pressure. Four non-competitive N-methyl-D-aspartate (NMDA) antagonists - MK-801, phencyclidine (PCP), SKF 10,047 and ketamine were tested in rats for effects on the HPNS. All drugs were injected i.p. prior to compression; ketamine was also infused i.v. Control rats received saline. Rats were exposed individually to increasing helium pressure (PO2 0.5 atmospheres absolute ATA). Three endpoints were used to assess HPNS: onset pressures for tremor, myoclonus and convulsions. Neither MK-801 (0.03 and 0.3 mg/kg) nor SKF 10,047 (50 mg/kg) had any effect on the onset pressures for tremor, myoclonus or convulsions, although the type of seizure was modified from the clonic/tonic seizure seen in controls to purely clonic. PCP (5 mg/kg) had no effect on the endpoints, but pressure enhanced the excitation and stereotypy seen at 1 ATA. Ketamine (100 mg/kg i.p.) did not affect tremor or myoclonus; ketamine infused i.v. at pressure only prevented tremor and myoclonus at 'anaesthetizing' concentrations. Our results show that these non-competitive NMDA antagonists had little effect on HPNS, in contrast to competitive NMDA antagonists, such as AP7, which are highly effective. Possible explanations for this lack of effect include (1) interactions with NMDA receptor channels are pressure dependent; (2) other actions of these antagonists override their effects on the NMDA receptor channel.
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PMID:The effects of non-competitive NMDA receptor antagonists on rats exposed to hyperbaric pressure. 254 78

The effect of the somatostatin depleting substance, cysteamine (100 mg/kg, i.p.), on cortical and amygdaloid kindled seizures was investigated. Cysteamine was tested after the establishment of amygdaloid kindling (AM group) and at two different developmental stages of cortical kindling, namely 'focal-cortical' (FC group) and 'cortico-generalized' seizures (CG group). In control, non-kindled, sham operated animals, cysteamine did not induce any spike activity or myoclonus. However, in all kindled groups clustered spike bursting appeared in the cortex within 5-15 min of the injection. The kindled bursting appeared in the cortex within 5-15 min of the injection. The kindled rats exhibited myoclonic jerks at 10 to 30 min after cysteamine injection, which coincided with the cortical spikes, and continued for about 40 min. In contrast, relatively small amounts of spiking were observed in the amygdala and this did not correlate with the myoclonus. At 4 h after cysteamine injection, the motor seizure and afterdischarge durations of the kindled seizure were prolonged in all kindled groups compared with preinjection levels. However, 24 h later the motor seizure duration and the afterdischarge duration were markedly reduced from the preinjection level in the AM and the CG groups and the tonic seizure component was suppressed in the FC group. This inhibitory effect on seizure activity lasted several days and gradually disappeared. These modifying effects of cysteamine were more marked in cortical kindled, than in amygdaloid kindled animals. The results suggest that the cortex is more sensitive to the effect of cysteamine on kindled seizures involves two phases. The first of these effect of cysteamine on kindled seizures involves two phases.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Myoclonus inducing and seizure modifying effect of cysteamine on cortical and amygdaloid kindled rats. 314 96

Generalized clonic and tonic seizure-like movements were observed during emergence from anesthesia with sevoflurane in a 32-year-old man. The movements lasted 40 sec and necessitated no therapy. There were no significant effects of the incident on the cardiovascular system, such as hypotension, arrhythmia or bradycardia. No neurological abnormalities were obvious after the anesthesia. The movements may have been the result of seizure activity in the central nervous system, or myoclonus of the whole body.
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PMID:Postoperative seizure-like activity following sevoflurane anesthesia. 890 34

For the treatment of intractable generalized epilepsies, two-staged total callosotomy was performed in five patients. In all patients, preceded anterior callosotomy failed to obtain satisfactory seizure control. All patients showed mental retardation with various degrees. Mean age at the first operation was 10.2 years and 4 patients were operated in their childhood. All patients showed various types of seizures; drop attack (DA) in 3 patients, tonic seizure (TS) in 2, myoclonus (MY) in 2, complex partial seizure (CPS) in 2, atypical absence (AA) in 1, and head drop (HD) in 2. After anterior callosotomy, complete cessation of CPS and 50-80% reduction of DA was obtained in one, respectively. However, only less than 50% reduction of seizures was obtained in other types of seizures. Two years after anterior callosotomy, posterior portion of the corpus callosum was divided. After staged total callosotomy, complete cessation of DA was obtained in all patients and 80-100% reduction of AA was obtained in one patient. One adult patient showed the disconnection syndrome which did not affect activities of his daily life. Our study revealed the efficacy of posterior callosotomy in DA patients with unsatisfactory results after anterior callosotomy. This strategy should be considered especially in childhood cases, since obvious complication was not observed in such cases.
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PMID:[Staged total callosotomy for medically intractable seizures]. 1119 41

A 50-year-old man who first noticed shaking of the hands at age of 18 and had previous history of three convulsive episodes was admitted to our department because of the generalized tonic seizure with loss of consciousness. Family history showed that 7 members had similar shaking and one had generalized seizure. On neurological examination, rhythmic myoclonic jerks were noted in the bilateral upper limbs, and was remarkably more severe on the left. Other neurological findings were normal. Based on the benign clinical course, familial history, and the normal range of pyruvate and lactate levels in serum and cerebrospinal fluid, we diagnosed familial essential myoclonus and epilepsy (FEME)/benign adult familial myoclonic and epilepsy (BAFME). After admission, we performed electrophysiological test. EEG showed spike discharge mainly in the left parietooccipital lobe. Jerk-locked back averaging (JLA) showed spikes 30 msec precedings the trigger in the left parietooccipital lobe. Because JLA spikes are commonly found 20 msec precedings the trigger, we consider the subtraction time of 10 msec was due to the conduction through the corpus callosum. Some reports showed that in progressive myoclonus epilepsy patients, transcallosal excitation of one hemisphere by the other was critical for generalized seizure. In cases of FEME/BAFME, epileptic focus in the hemisphere ipsilateral to the myoclonus limbs has not previously reported. Our case suggested that generalization of the seizure was caused by the interhemispheric excitation through the corpus callosum.
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PMID:[A case of familial essential myoclonus and epilepsy with suspected focus in the hemisphere ipsilateral to myoclonus limbs]. 1532 40

Zolpidem and diazepam are widely used drugs acting via benzodiazepine binding sites on GABA(A) receptors. While diazepam is non-selective, zolpidem has a high affinity for alpha1-, and no affinity for alpha5-containing receptors. Several studies suggested that behavioral effects of zolpidem might be more similar to classical benzodiazepines than previously thought. To compare the sedative and anticonvulsant properties of these drugs and to evaluate the importance of GABA(A) receptor subunits for development of tolerance during chronic treatment, we tested the effects of acute and repeated administration of zolpidem and diazepam on ambulatory locomotor activity (a measure of sedation) and on the threshold for myoclonic, clonic and tonic seizures in response to i.v. infusion of pentylenetetrazole (PTZ). Both drugs given acutely in doses 0.3, 1 and 3 mg/kg reduced locomotion, and in doses 1 and 3 mg/kg elevated the threshold for PTZ-induced seizures. The effects of zolpidem and diazepam on the tonic seizure threshold were greater than on myoclonus and clonic seizure threshold. Diazepam and zolpidem (3 mg/kg), given 18 or 42 h after repeated drug treatment (10 days, 5 mg/kg, twice daily), decreased the PTZ seizure threshold and increased the locomotor activity as compared to control mice, indicating development of tolerance to their anticonvulsant and sedative effects. After repeated treatment the PTZ seizure threshold was not different between the two drugs, while differences in sedation became larger than after the acute treatment. The results suggest that alpha5-containing GABA(A) receptors are not crucial for the development of sedative and anticonvulsant tolerance.
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PMID:Effects of acute and repeated zolpidem treatment on pentylenetetrazole-induced seizure threshold and on locomotor activity: comparison with diazepam. 1934 34

Ictal tachycardia and bradycardia are common arrhythmias; however, ictal sinus pause and asystole are rare. Ictal arrhythmia is mostly reported in adults with temporal lobe epilepsy. Recently, ictal arrhythmia was recognized as a major warning sign of sudden unexpected death in epilepsy. We present an interesting case of a child with ictal sinus pause and asystole. A 27-month-old girl was hospitalized due to 5 episodes of convulsions during the past 2 days. Results of routine electroencephalography (EEG) were normal, but she experienced brief generalized tonic seizure for 3 days. During video-monitored EEG and echocardiography (ECG), she showed multiple myoclonic seizures simultaneously or independently, as well as frequent sinus pauses. After treatment with valproic acid, myoclonus and generalized tonic seizures were well controlled and only 2 sinus pauses were seen on 24-hour Holter ECG monitoring. Sinus dysfunction should be recognized on EEG, and it can sometimes be treated successfully with only antiepileptic medication.
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PMID:Ictal sinus pause and myoclonic seizure in a child. 2801 65