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Query: UMLS:C0024591 (malignant hyperthermia)
 2,353 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Malignant hyperthermia (MH) is a life-threatening disorder characterized by skeletal muscle rigidity and elevated body temperature in response to halogenated anesthetics such as isoflurane or halothane. Mutation of tyrosine 522 of RyR1 (the predominant skeletal muscle calcium release channel) to serine has been associated with human malignant hyperthermia. In the present study, mice created harboring this mutation were found to represent the first murine model of human malignant hyperthermia. Mice homozygous for the Y522S mutation exhibit skeletal defects and die during embryonic development or soon after birth. Heterozygous mice, which correspond to the human occurrence of this mutation, are MH susceptible, experiencing whole body contractions and elevated core temperatures in response to isoflurane exposure or heat stress. Skeletal muscles from heterozygous mice exhibit increased susceptibility to caffeine- and heat-induced contractures in vitro. In addition, the heterozygous expression of the mutation results in enhanced RyR1 sensitivity to activation by temperature, caffeine, and voltage but not uncompensated sarcoplasmic reticulum calcium leak or store depletion. We conclude that the heterozygous expression of the Y522S mutation confers susceptibility to both heat- and anesthetic-induced MH responses.
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PMID:Heat- and anesthesia-induced malignant hyperthermia in an RyR1 knock-in mouse. 1628 4

We report on a patient who developed two episodes of severe muscle rigidity, increased endtidal CO2 and increased creatine phosphate kinase associated with sevoflurane anesthesia. Dysrhythmias and hyperthermia were not observed and dantrolene was not administered. Genetic testing for the 17 known mutations associated with malignant hyperthermia (MH) was negative. Although we cannot rule out MH or other neuromuscular diseases we suggest that this rare event may be a direct effect of sevoflurane.
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PMID:Repeat episodes of severe muscle rigidity in a child receiving sevoflurane. 1697 40

Neuroleptic malignant syndrome (NMS) is a rare disorder seen most often in patients exposed to antipsychotic medications. This syndrome is generally manifested by hyperthermia, muscle rigidity, autonomic instability, altered mental status, tremors, elevated serum creatinine phosphokinase and leucocytosis. It was first described by Delay during the 1960s. It is considered a medical emergency and is fatal if not promptly addressed. It is clinically relevant not only to psychiatrists but all clinicians since patients taking neuroleptics are seen by physicians from virtually every specialty. Relevant studies report a mortality rate of 10-20%. Conditions that share some features of NMS but have different treatment regimens include serotonergic syndrome, lethal catatonia, malignant hyperthermia, infections and various heat disorders. The importance of recognition and prompt intervention can not be overemphasized. Fever is a predominant symptom in NMS. The authors present an unusual case of NMS in a schizophrenic patient without fever who had been on aripiprazole. To date, there are only three possible reported cases of NMS related to aripiprazole. This case report serves to remind clinicians of the essential features in the diagnosis and management of NMS.
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PMID:A case report of neuroleptic malignant syndrome without fever in a patient given aripiprazole. 1701 30

Malignant hyperthermia (MH) is a pharmacogenetic disorder of skeletal muscle that presents as a hypermetabolic response to potent volatile anesthetic gases such as halothane, sevoflurane, desflurane and the depolarizing muscle relaxant succinylcholine, and rarely, in humans, to stresses such as vigorous exercise and heat. The incidence of MH reactions ranges from 1:5,000 to 1:50,000-100,000 anesthesias. However, the prevalence of the genetic abnormalities may be as great as one in 3,000 individuals. MH affects humans, certain pig breeds, dogs, horses, and probably other animals. The classic signs of MH include hyperthermia to marked degree, tachycardia, tachypnea, increased carbon dioxide production, increased oxygen consumption, acidosis, muscle rigidity, and rhabdomyolysis, all related to a hypermetabolic response. The syndrome is likely to be fatal if untreated. Early recognition of the signs of MH, specifically elevation of end-expired carbon dioxide, provides the clinical diagnostic clues. In humans the syndrome is inherited in autosomal dominant pattern, while in pigs in autosomal recessive. The pathophysiologic changes of MH are due to uncontrolled rise of myoplasmic calcium, which activates biochemical processes related to muscle activation. Due to ATP depletion, the muscle membrane integrity is compromised leading to hyperkalemia and rhabdomyolysis. In most cases, the syndrome is caused by a defect in the ryanodine receptor. Over 90 mutations have been identified in the RYR-1 gene located on chromosome 19q13.1, and at least 25 are causal for MH. Diagnostic testing relies on assessing the in vitro contracture response of biopsied muscle to halothane, caffeine, and other drugs. Elucidation of the genetic changes has led to the introduction, on a limited basis so far, of genetic testing for susceptibility to MH. As the sensitivity of genetic testing increases, molecular genetics will be used for identifying those at risk with greater frequency. Dantrolene sodium is a specific antagonist of the pathophysiologic changes of MH and should be available wherever general anesthesia is administered. Thanks to the dramatic progress in understanding the clinical manifestation and pathophysiology of the syndrome, the mortality from MH has dropped from over 80% thirty years ago to less than 5%.
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PMID:Malignant hyperthermia. 1745 35

We investigated the transition of clinical signs of fulminant-type malignant hyperthermia (f-MH) by analyzing a database consisting of 383 cumulative cases of f-MH from 1961 to 2004. The cases were divided by time period into group 1 (1961-1984), group 2 (1985-1994), and group 3 (1995-2004). The variables considered were age, sex, type of agents used (succinylcholine and volatile anesthetics), dantrolene administration, clinical signs, laboratory data, and mortality. The level of statistical significance was considered to be less than 5%. Groups 1, 2, and 3 consisted of 196, 127, and 60 cases, respectively. In groups 1, 2, and 3, the rates of dantrolene administration were 18.4%, 93.6%, and 86.7%; the rates of occurrence of ventricular arrhythmia were: 75.2%, 55.6%, and 35.0%; and the rates of generalized muscle rigidity were 64.7%, 60.9%, and 23.9%, respectively. The mortality rate decreased over time, from 42.3% in group 1, to 15.0% in group 2 and group 3. We considered that this decrease occurred because of the increased use of dantrolene and the early diagnosis of malignant hyperthermia in the latter two groups.
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PMID:Fulminant-type malignant hyperthermia in Japan: cumulative analysis of 383 cases. 1745 63

Freeman-Sheldon syndrome, or distal arthrogryposis type 2A, is a rare congenital myopathy and dysplasia characterised by multiple contractures, abnormalities of the head and face, defective development of the hands and feet and skeletal malformations. The facial muscle contracture produces the typical 'whistling face' appearance. Anaesthetic issues include difficult intravenous access, difficult airway and postoperative pulmonary complications. Although an association with malignant hyperthermia has been suggested, this has not been confirmed. We report the management of a seven-year-old girl with Freeman-Sheldon syndrome undergoing anterior and posterior spinal surgery and describe a successful anaesthetic regimen based on a total intravenous anaesthesia technique with remifentanil and propofol without neuromuscular blocking agents. The child had an uneventful anaesthetic and postoperative course. We believe the presence of the myopathy warranted the use of a 'non-triggering' anaesthetic, as suxamethonium and volatile agents may be associated with significant complications such as muscle rigidity and rhabdomyolysis in myopathic patients, even in the absence of malignant hyperthermia.
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PMID:Anaesthetic management of a child with Freeman-sheldon syndrome undergoing spinal surgery. 1836 Oct 19

This case report details the onset of masseter muscle rigidity, elevated creatine kinase levels, and rhabdomyolysis following a sevoflurane mask induction and succinylcholine administration in a 12-year-old boy. The patient had no family or personal history of neuromuscular disease or malignant hyperthermia. Hyperkalemia, metabolic acidosis, and rhabdomyolysis occurred within 75 minutes of masseter muscle rigidity. Subsequent to this event, it was recommended that the patient undergo a workup for neuromuscular disease and malignant hyperthermia with muscle biopsy. Until this workup is completed, the family should advise anesthesia providers that the patient is "malignant hyperthermia susceptible." Masseter muscle rigidity, elevated creatine kinase levels, and rhabdomyolysis will be thoroughly discussed in this article.
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PMID:Masseter muscle rigidity, elevated creatine kinase, and rhabdomyolysis following succinylcholine administration: a case report. 1894 62

Malignant hyperthermia (MH) is a pharmacogenetic disorder of skeletal muscle in which volatile anesthetics trigger a sustained increase in intramyoplasmic Ca(2+) via release from sarcoplasmic reticulum and, possibly, entry from the extracellular milieu that leads to hypermetabolism, muscle rigidity, rhabdomyolysis, and death. Myotonias are a class of myopathies that result from gene mutations in various channels involved in skeletal muscle excitation-contraction coupling and sarcolemmal excitability, and unusual DNA sequence repeats that result in the inability of many proteins, including skeletal muscle channels that affect excitability, to undergo proper splicing. The suggestion has often been made that myotonic patients have an increased risk of developing MH. In this article, we review the physiology of muscle excitability and excitation-contraction coupling, the pathophysiology of MH and the myotonias, and review the clinical literature upon which the claims of MH susceptibility are based. We conclude that patients with these myopathies have a risk of developing MH that is equivalent to that of the general population with one potential exception, hypokalemic periodic paralysis. Despite the fact that there are no clinical reports of MH developing in patients with hypokalemic periodic paralysis, for theoretical reasons we cannot be as certain in estimating their risk of developing MH, even though we believe it is low.
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PMID:The myotonias and susceptibility to malignant hyperthermia. 1976 32

We describe a child who developed a malignant hyperthermia-like syndrome after exposure to succinylcholine and halothane. Many features of a typical malignant hyperthermia episode were present, including tachydysrhythmia, tachypnea, and fever in association with metabolic acidosis, hyperCKemia, myglobinemia, and rapid recovery without residual effects upon administration of dantrolene, sodium bicarbonate, and active cooling. Muscle rigidity, hypercarbia, and hyperkalemia were not observed. The patient was found to be heterozygous for a mutation in the carnitine palmitoyltransferase II gene (CPT2) encoding an arginine to cysteine substitution at amino acid 503 (R503C) with reduced activity of the enzyme.
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PMID:Malignant hyperthermia-like syndrome and carnitine palmitoyltransferase II deficiency with heterozygous R503C mutation. 1976 33

Malignant hyperthermia (MH) is an uncommon and potentially life-threatening pharmacogenetic disorder. This abnormality in muscle metabolism can be triggered by a variety of agents (particularly general anesthetics and stress), resulting in a rapid heart rate increase, muscle rigidity, acidosis, temperature elevation, rhabdomyolysis, and renal failure. Immediate discontinuing of triggering agents, oxygenation, cooling, and dantrolene are necessary to treat an episode. MH-susceptible patients often indicate a positive family history of experiencing an adverse event during anesthesia. Few diagnostic tests are available to screen patients; the most accurate test is a skeletal muscle biopsy. MH-susceptible patients can undergo surgical procedures as necessary. Careful exploration of the medical history will allow the clinician to make the necessary modifications to treat and manage an episode expediently.
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PMID:Malignant hyperthermia and its implications in general dentistry. 1981 13


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