Genetics
Manoj Ramachandran, Tom Nunn in Basic Orthopaedic Sciences, 2018
Clinically, Turner syndrome is seen as a short female with skeletal abnormalities, including cubitus valgus, medial tibial exostosis and a short fourth metacarpal/metatarsal. The condition is inherited. The paternal X chromosome is more likely to be missing, usually as a sporadic event. The diagnosis is usually made on the basis of a delay in puberty. Other physical features are webbed neck, flat chest with widely spaced nipples, low hairline, low-set ears, and a higharched palate. It is associated with anomalies of the urinary tract system and coarctation of the aorta. No treatment is usually required for the increased cubitus valgus angle and short fourth and fifth metacarpals. Idiopathic scoliosis should be treated in the standard fashion. Malignant hyperthermia is common with anaesthetic use.
Basic Thermal Physiology: What Processes Lead to the Temperature Distribution on the Skin Surface
Kurt Ammer, Francis Ring in The Thermal Human Body, 2019
Hyperthermia, malignant: A pharmacogenetic myopathy characterized by a rapid rise in body temperature in genetically susceptible subjects during anaesthesia (triggering agents: halothane, succinyl choline, etc.). Malignant Hyperthermia stems from impairment (genetically originated) in the sarcoplasmic reticulum, leading to alteration in handling of the excess cytosolic Ca++, skeletal muscle rigidity and spasticity and, in-turn, increased heat production. The often, fatal hyperthermia is the result of heat production in skeletal muscle and supported by the limitations of active heat dissipation during anaesthesia. It is complicated by sympathetic activation, excessive lactate production and acidosis, muscle rigidity, myoglobinaemia, and disturbances of cellular permeability [2].
Diseases of Muscle and the Neuromuscular Junction
John W. Scadding, Nicholas A. Losseff in Clinical Neurology, 2011
Central core disease is an autosomal dominant disorder associated with mutations in the ryanodine receptor gene (RYR1). It often presents with hypotonia and muscle weakness at birth followed by developmental motor delay. However, some patients have mild symptoms and are subsequently diagnosed on muscle biopsy with a raised CK only. The pattern of muscle weakness may be proximal or generalized and is not usually associated with significant wasting. There may be associated kyphoscoliosis or pes cavus. Cardiac and respiratory involvement can occur. The EMG shows a myopathic pattern. Muscle biopsy shows myopathic features, but the most prominent abnormality is the presence of central cores in muscle fibres, which probably comprise eccentric myofibrils. The cores are most easily seen in histochemical stains of oxidative enzymes, where the cores appear as regions of negative staining. There is often associated type I fibre predominance. Some patients also have malignant hyperthermia.
Limb girdle muscle dystrophy and caesarian delivery: Anesthetic management and brief review of literature
Published in Egyptian Journal of Anaesthesia, 2018
Sumit Soni, Amarjyoti Hazarika, Balbir Kumar
General anesthesia has to be considered in patients who are unable to tolerate supine position despite respiratory support, or patients having bulbar muscle involvement [2]. Our patient had weakness only in proximal muscles and no cardio-respiratory involvement. Hence we planned to give spinal anesthesia to our patient with NPPV if required. Additionally, we avoided general anesthesia because these patients may be susceptible to malignant hyperthermia. However, the operating room was prepared well beforehand to avoid exposure to volatile anesthetics and succinylcholine. The availability of neuromuscular blockade, nasopharyngeal temperature, bispectral index monitoring, capnography and adequate quantity of dantrolene in the pharmacy were also ensured. Moreover SAB is preferred mode of anesthesia for caesarean section if, there is no contradiction to it.
Thermoregulation: From basic neuroscience to clinical neurology, part 2
Published in Temperature, 2019
Zoltán Szelényi, Sámuel Komoly
Three other chapters describe the classical forms of hyperthermia, such as heat exhaustion (chapter 31), heatstroke (chapter 32) and malignant hyperthermia (chapter 38). The first two topics are well-treated as types of the continuum in insufficient defense against excessive heat-generation by emphasizing the pathophysiological background and explaining the progressive burden on circulatory function, salt-water homeostasis and energy balance. It is rightly pointed out that the upper part of the body temperature scale (the range of body core temperature in homeothermic animals and man compatible with survival) is much more dangerous that the lower part. Malignant hyperthermia is a special form of potentially life-threatening hyperthermia that results from the combination of a genetic trait affecting skeletal muscles, as well as the use of certain anesthetics or muscle relaxants. The good news is that a drug has been available for some decades to efficiently prevent or counterbalance this form of otherwise deadly hyperthermia (see chapter 38).
Exertional rhabdomyolysis and causes of elevation of creatine kinase
Published in The Physician and Sportsmedicine, 2020
Henrik Constantin Bäcker, Morgan Busko, Fabian Götz Krause, Aristomenis Konstantinos Exadaktylos, Jolanta Klukowska-Roetzler, Moritz Caspar Deml
In analyzing rates of serious medical complications associated with exertional rhabdomyolysis, one patient had to be resuscitated who was otherwise healthy during a long-distance run. No comorbidities were found in the further examination. It remains unclear if the rhabdomyolysis was the cause or consequence of resuscitation as mentioned earlier as this patient likely suffered from an exertional heat stroke. In addition, the mechanic resuscitation and especially fluid resuscitation are known to develop edema of the limb and muscles, which can cause even compartment syndrome and therefore rhabdomyolysis [32]. Otherwise, the patients were relatively healthy without serious complications. However, only in the patient who had to be resuscitated, further examinations for metabolic myopathies or genetic mutations like ryanodine receptor 1 (RYR1) were performed which revealed negative. This mutation causes neuromuscular diseases ranging from congenital myopathies to malignant hyperthermia. The prevalence between genetic mutation (RYR1 and 2 CACNAIS) and malignant hyperthermia is estimated at 1 in 3000 cases; however, the true incidence remains unknown. Hereby, malignant hyperthermia causes hyperthermia, hypermetabolism and muscle breakdown which share triggers such as in exercises [33]. Especially heat and exercises trigger rhabdomyolysis without exertional myalgia and in rare occasion isolated exertional myalgia [34].
Related Knowledge Centers
- Hyperkalemia
- Mutation
- Tachycardia
- Rhabdomyolysis
- General Anaesthesia
- Tetany
- Hyperthermia
- Inhalational Anesthetic
- Suxamethonium Chloride
- Ryanodine Receptor 1