Evidence for Susceptibility to Malignant Hyperthermia in Patients with Exercise-induced Rhabdomyolysis

2001 ◽  
Vol 94 (1) ◽  
pp. 95-100 ◽  
Author(s):  
Frank Wappler ◽  
Marko Fiege ◽  
Markus Steinfath ◽  
Kamayni Agarwal ◽  
Jens Scholz ◽  
...  
Keyword(s):  
Malignant Hyperthermia ◽  
Receptor Gene ◽  
Heat Stroke ◽  
Histologic Examination ◽  
In Vitro Contracture Test ◽  
Genetic Abnormalities ◽  
History Of ◽  
Exercise Induced ◽  
Muscle Biopsies

Background Malignant hyperthermia (MH), heat stroke, and exercise-induced rhabdomyolysis (ER) were suspected to be related syndromes. However, it is not known whether individuals with history of ER have an increased incidence of susceptibility to MH. To establish an association between ER and susceptibility to MH, the authors determined the MH status in patients with a history of MH-like episodes induced by physical stress. Methods Twelve unrelated patients with ER, 18 patients with anesthesia-induced MH, and 28 controls were investigated with the in vitro contracture test (IVCT) according to the European MH Group protocol and the ryanodine contracture test. In addition, all patients were screened for genetic mutations, and histology was performed on muscle specimens. Results Ten ER patients had positive IVCT results, one patient had a negative test result, and one patient showed equivocal responses. Samples from patients with positive IVCT results showed pronounced contractures after exposition to ryanodine, as opposed to specimens from patients with negative IVCT results, which developed contractures slowly. Three ER patients had mutations at the ryanodine receptor gene. All anesthesia-induced MH patients had positive IVCT results, two of them presented the C1840T mutation. The control patients had normal contracture test results and no typical MH mutations. Histologic examination determined no specific myopathies in any patient. Conclusions Regarding these results, the authors recommend performing muscle biopsies for histologic examination and IVCT in patients with ER. In addition, the patient should be seen by a neurologist and screened for genetic abnormalities to shed light on the genetics of MH.

scholarly journals Rhabdomyolysis following Severe Physical Exercise in a Patient with Predisposition to Malignant Hyperthermia

1998 ◽  
Vol 26 (3) ◽  
pp. 315-318 ◽  
Author(s):  
A. Köchling ◽  
F. Wappler ◽  
G. Winkler ◽  
J. Schulte Am Esch
Keyword(s):  
Physical Exercise ◽  
Malignant Hyperthermia ◽  
Heat Stroke ◽  
Muscular Diseases ◽  
Impaired Consciousness ◽  
Specific Therapy ◽  
In Vitro Contracture Test ◽  
Strenuous Physical Exercise ◽  
Laboratory Investigations

A 21-year-old man suffered from exertional heat stroke with impaired consciousness and rhabdomyolysis after strenuous physical exercise. Within two weeks the patient recovered completely without any specific therapy. Based on the symptoms and laboratory investigations, this episode suggested a moderate form of malignant hyperthermia. An in vitro contracture test was performed and a predisposition to malignant hyperthermia was diagnosed; other muscular diseases were excluded by histological examination. At present, the in vitro contracture test is the only method used to determine susceptibility to malignant hyperthermia and should be performed when the diagnosis is suggested on clinical grounds.

Suspected Malignant Hyperthermia Reactions in New Zealand

2002 ◽  
Vol 30 (4) ◽  
pp. 453-461 ◽  
Author(s):  
A. N. Pollock ◽  
E. E. Langton ◽  
K. Couchman ◽  
K. M. Stowell ◽  
M. Waddington
Keyword(s):  
New Zealand ◽  
Malignant Hyperthermia ◽  
Dna Analysis ◽  
Anaesthetic Agent ◽  
Clinical Signs ◽  
Malignant Hyperthermia Susceptibility ◽  
In Vitro Contracture Test ◽  
Grading Scale ◽  
Clinical Grading

Early clinical signs, triggering agents, time to onset of reaction, mortality and methods of treatment were identified in 123 suspected malignant hyperthermia reactions. In vitro contracture test results were compared with clinical signs and the Malignant Hyperthermia Clinical Grading Scale. Increased end-tidal carbon dioxide is the earliest sign when not preceded by masseter spasm. Earlier diagnosis reduces the incidence of rigidity and severe metabolic acidosis. The combination of suxamethonium and a potent volatile anaesthetic agent triggers an earlier reaction compared with a volatile agent alone. There has been zero mortality since 1981, essentially due to a combination of advanced monitoring capability, increased anaesthetist awareness of malignant hyperthermia, and dantrolene availability. DNA analysis has identified nine New Zealand families with ryanodine receptor gene mutations. A positive DNA test indicates malignant hyperthermia susceptibility with “causative” mutations but discordance requires that negative DNA tests are confirmed with in vitro contracture test. This test also demonstrated the shortcomings of the Malignant Hyperthermia Clinical Grading Scale.

In-vitro Contracture Test with Theophylline - An Alternative in Diagnosis of Malignant Hyperthermia?

2002 ◽  
Vol 96 (Sup 2) ◽  
pp. A1201
Author(s):  
Marko Fiege ◽  
Frank Wappler ◽  
Ralf Weisshorn ◽  
Kerstin Kolodzie ◽  
Jochen Schulte am Esch
Keyword(s):  
Malignant Hyperthermia ◽  
In Vitro Contracture Test

Results of Contracture Tests with Halothane, Caffeine, and Ryanodine Depend on Different Malignant Hyperthermia-associated Ryanodine Receptor Gene Mutations

2002 ◽  
Vol 97 (2) ◽  
pp. 345-350 ◽  
Author(s):  
Marko Fiege ◽  
Frank Wappler ◽  
Ralf Weisshorn ◽  
Mark Ulrich Gerbershagen ◽  
Markus Steinfath ◽  
...  
Keyword(s):  
Malignant Hyperthermia ◽  
Ryanodine Receptor ◽  
Time Course ◽  
Clinical Symptoms ◽  
Receptor Gene ◽  
Gene Mutations ◽  
Onset Time ◽  
Release Channel ◽  
Ryr1 Gene

Background More than 20 mutations in the gene encoding for the ryanodine receptor (RYR1), a Ca2+ release channel of the skeletal muscle sarcoplasmic reticulum, have been found to be associated with malignant hyperthermia (MH). This study was designed to investigate the effects of different mutations in the RYR1 gene on contracture development in in vitro contracture tests (IVCT) with halothane, caffeine, and ryanodine. Methods Ninety-three MH-susceptible (MHS) patients, diagnosed by the standard IVCT with halothane and caffeine, were included in this prospective study. Surplus muscle specimens were used for an IVCT with 1 microm ryanodine. The contracture course during the ryanodine IVCT was described by the attainment of different time points: onset time of contracture and times when contracture reached 2 mN or 10 mN. In addition, all patients were screened for mutations of the RYR1 gene. Results In 36 patients, four different mutations of the RYR1 gene (C487-T, G1021-A, C1840-T, G7300-A) were found. The IVCT threshold concentrations of halothane and caffeine were lower in patients with the C487-T mutation compared with patients without a detected mutation in the RYR1 gene. In the IVCT with ryanodine, contracture levels of 2 mN and 10 mN were reached earlier in muscle specimens from patients with C487-T, C1840-T, and G7300-A mutations compared with specimens from patients with the G1021-A mutation and patients without detected mutation in the RYR1 gene. Conclusions The differences between the groups in the halothane and caffeine IVCT threshold concentrations and in the time course of contracture development in the ryanodine IVCT underline the hypothesis that certain mutations in the RYR1 gene could make the ryanodine receptor more sensitive to specific ligands. This may be an explanation for varying clinical symptoms of MH crisis in humans.

scholarly journals Muscle Biopsy and In Vitro  Contracture Test in Subjects with Idiopathic HyperCKemia

2008 ◽  
Vol 109 (4) ◽  
pp. 625-628 ◽  
Author(s):  
Alessandro Malandrini ◽  
Alfredo Orrico ◽  
Carmen Gaudiano ◽  
Simona Gambelli ◽  
Lucia Galli ◽  
...  
Keyword(s):  
Malignant Hyperthermia ◽  
Muscle Biopsy ◽  
Malignant Hyperthermia Susceptibility ◽  
Manual Muscle Testing ◽  
In Vitro Contracture Test ◽  
Muscle Testing ◽  
Malignant Hyperthermia Susceptible ◽  
Fiber Size ◽  
Precise Diagnosis

Background Persistent high creatine kinase (CK) levels may reflect underlying subclinical myopathies. In most cases, pathogenesis is unknown and clinical management is unclear. Though clinically asymptomatic, these subjects are potentially susceptible to malignant hyperthermia. Methods The authors analyzed 37 subjects with persistent elevation of CK without significant weakness or other neurologic symptoms. Neurologic examination was performed according to manual muscle testing. Muscle biopsy and the in vitro contracture test were performed in all subjects. Results Twenty-three subjects (51.1%) were completely asymptomatic. The others had minor symptoms such as occasional cramps (11 subjects, 24.4%), fatigue (5 subjects, 11.1%), a combination of cramps and fatigue (5 subjects, 11.1%), and muscle pain (1 case, 2.2%). Muscle biopsy enabled precise diagnosis in 3 cases and was normal in 3 cases. The more frequent changes were variation in fiber size (31.1%), a combination of nuclear internalization and variation in fiber size (26.6%), nuclear internalization (6.6%), minor mitochondrial changes (4.4%), and neurogenic atrophy (4.4%). Immunocytochemical analysis was normal in all patients. In vitro contracture testing detected one malignant hyperthermia-susceptible and one malignant hyperthermia-equivocal subject. Conclusions The evidence of malignant hyperthermia susceptibility by in vitro contracture test seems to be relatively infrequent among subjects with idiopathic hyperCKemia, but the incidence of true malignant hyperthermia in idiopathic hyperCKemia is unknown. Muscle biopsy should be considered a useful, though not very sensitive, diagnostic tool in idiopathic hyperCKemia, because it enables potentially treatable disorders, such as inflammatory myopathies, to be discovered. No uniform morphologic finding typical of idiopathic hyperCKemia or malignant hyperthermia susceptibility was identified by muscle biopsy.

scholarly journals RYR1-related myopathies: Expanding the spectrum of morphological presentation

2021 ◽  
Vol 154 (9) ◽  
Author(s):  
Vincenzo Sorrentino
Keyword(s):  
Malignant Hyperthermia ◽  
Heat Stroke ◽  
Transmembrane Helices ◽  
Structural Domains ◽  
Muscle Disorders ◽  
Large N ◽  
Recent Developments ◽  
Exercise Induced ◽  
Definition Of ◽  
Opposing Effects

Mutations in the RYR1 gene are the most common cause of nondystrophic congenital myopathies. Mutations in RYR1 were initially identified in individuals susceptible to malignant hyperthermia, a pharmacogenetic disorder triggered by volatile anesthetics and succinylcholine. Shortly after, mutations in RYR1 were identified in patients with central core disease, which is the most frequent congenital myopathy, and in other muscle disorders, collectively referred to as RYR1-related myopathies. RYR1 mutations are also responsible of some acute pathological conditions triggered by heat- and exercise-induced stress, named exertional heat stroke and exertional-induced rhabdomyolysis, which, similarly to malignant hyperthermia, occur in otherwise healthy individuals with normal skeletal muscle functions. Hundreds of causative mutations linked to RYR1-related diseases have been identified. These mutations are clustered in three regions that are referred to as the N-terminal, central, and C-terminal hot spots. Recent developments in cryo-EM techniques have provided high-resolution reconstructions of the channel, allowing a much better definition of the structural domains within the large N-terminal cytoplasmic region and in the C-terminal domain containing six transmembrane helices and the pore region of the channel. RYR1 mutations may either activate or inhibit channel function or, in some cases, can reduce the expression levels of RYR1 protein. However, similar clinical phenotypes can result from mutations with opposing effects on RYR1 function, or little or no correlation can be found between the observed clinical phenotype and localization of mutations in the structural domains of the RYR1 channel, even though recent studies indicate that clinically severe cases are mostly recessive or due to mutations located in the bridging solenoid. Recent results on the identification of RYR1 mutations in patients with myopathies will be presented.

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