The association between the neuroleptic malignant syndrome and malignant hyperthermia

HyperCKemia and rhabdomyolysis in the neuroleptic malignant and serotonin syndromes: A literature review

Neuroleptic malignant syndrome and serotonin syndrome are two syndromes whose molecular bases remain poorly understood. The phenotypes of both syndromes overlap with other syndromes that have a clear genetic background, in particular RYR1-related malignant hyperthermia. Through a literature review, performed according to the PRISMA guidelines, we aimed to report the clinical features of both syndromes, and the results of genetic testing performed. 10 case series and 99 case reports were included, comprising 134 patients. A male predominance of 58% was found. The median age was 35 (range 4-84) years. Eight patients experienced recurrent episodes of rhabdomyolysis. Genetic analysis was performed in eleven patients (8%), revealing four RYR1 variants, three likely benign (p.Asp849Asn, p.Arg4645Gln, p.Arg4645Gln) and one variant of uncertain significance (p.Ala612Thr). This review underlines that a subset of patients with neuroleptic malignant syndrome and serotonin syndrome develop recurrent episodes of rhabdomyolysis. This recurrent pattern suggests a possible underlying (genetic) susceptibility. However, the genetic background of neuroleptic malignant syndrome and serotonin syndrome has only been investigated to a very limited degree so far. The increasing availability of next generation sequencing offers an opportunity to identify potentially associated genetic backgrounds, especially in patients with recurrent episodes or a positive family history.

Neuroleptic Malignant Syndrome: No Longer Exclusively a “Neuroleptic” Phenomenon

Objective:

To review the literature concerning the incidence of neuroleptic malignant syndrome (NMS) associated with the use of atypical antipsychotics.

Data Sources:

Cases were identified through a search of MEDLINE (1986–March 2004) using the terms neuroleptic malignant syndrome, antipsychotic, clozapine, risperidone, olanzapine, quetiapine, ziprasidone, and aripiprazole.

Study Selection and Data Extraction:

Case reports of possible NMS secondary to second-generation antipsychotics were selected for review. Reports meeting the Diagnostic and Statistical Manual of Mental Disorders, 4th edition, criteria for NMS were considered. Case reports in which 1 of the 2 major diagnostic criteria was met were also included in the analysis. Furthermore, at least one minor criterion was met. Case reports in which patients received traditional antipsychotics were excluded.

Data Synthesis:

NMS is a rare and sometimes fatal disease. Several theories exist as to how NMS develops, and an equally large amount of diagnostic criteria are available. However, the majority of available data are based on the first-generation neuroleptics and very few exist with regard to the second-generation antipsychotics.

Conclusions:

Although there are numerous case reports of NMS occurring secondary to the use of second-generation antipsychotics, the incidence has never been fully elucidated. While the reasons for this remain uncertain, not all cases of second-generation–induced NMS fulfill the diagnostic criteria established for traditional neuroleptics and therefore may not be reported as such.

Anesthetic management of a pediatric patient with neuroleptic malignant syndrome

Neuroleptic malignant syndrome (NMS) is a rare disorder which is clinically similar to malignant hyperthermia (MH). It is characterized by hyperthermia, autonomic instability, muscle rigidity, coma, rhabdomyolysis, and acidosis. Without immediate and appropriate therapy, mortality may result. NMS is associated with administration of antipsychotic medications, anti-emetic medications, and changes in the dosage of anti-parkinsonian drugs. As several similarities exist between NMS and MH, differentiating between them can be a challenge for the clinician. We report anesthetic care during magnetic resonance imaging of the brain of a 14-year-old female with bipolar and schizoaffective disorders and the recent onset of NMS.

Malignant neuroleptic syndrome following deep brain stimulation surgery: a case report

Background

The neuroleptic malignant syndrome is an uncommon but dangerous complication characterized by hyperthermia, autonomic dysfunction, altered mental state, hemodynamic dysregulation, elevated serum creatine kinase, and rigor. It is most often caused by an adverse reaction to anti-psychotic drugs or abrupt discontinuation of neuroleptic or anti-parkinsonian agents. To the best of our knowledge, it has never been reported following the common practice of discontinuation of anti-parkinsonian drugs during the pre-operative preparation for deep brain stimulation surgery for Parkinson's disease.

Case presentation

We present the first case of neuroleptic malignant syndrome associated with discontinuation of anti-parkinsonian medication prior to deep brain stimulation surgery in a 54-year-old Caucasian man.

Conclusion

The characteristic neuroleptic malignant syndrome symptoms can be attributed to other, more common causes associated with deep brain stimulation treatment for Parkinson's disease, thus requiring a high index of clinical suspicion to timely establish the correct diagnosis. As more centers become eligible to perform deep brain stimulation, neurologists and neurosurgeons alike should be aware of this potentially fatal complication. Timely activation of the deep brain stimulation system may be important in accelerating the patient's recovery.

Perioperative Management for Chronic Schizophrenic Patients

Schizophrenic patients are at increased risk for perioperative complications, as their biological response to stress is impaired. The increased complications are associated with physical disorders, antipsychotic or hazardous health behaviors, and interactions between antipsychotics and anesthetic drugs. Thus, anesthesiologists must not only be aware of the perioperative problems of these patients but must also learn how to manage their perioperative course.

Dantrolene--a review of its pharmacology, therapeutic use and new developments

Human malignant hyperthermia is a life-threatening genetic sensitivity of skeletal muscles to volatile anaesthetics and depolarizing neuromuscular blocking drugs occurring during or after anaesthesia. The skeletal muscle relaxant dantrolene is the only currently available drug for specific and effective therapy of this syndrome in man. After its introduction, the mortality of malignant hyperthermia decreased from 80% in the 1960s to < 10% today. It was soon discovered that dantrolene depresses the intrinsic mechanisms of excitation-contraction coupling in skeletal muscle. However, its precise mechanism of action and its molecular targets are still incompletely known. Recent studies have identified the ryanodine receptor as a dantrolene-binding site. A direct or indirect inhibition of the ryanodine receptor, the major calcium release channel of the skeletal muscle sarcoplasmic reticulum, is thought to be fundamental in the molecular action of dantrolene in decreasing intracellular calcium concentration. Dantrolene is not only used for the treatment of malignant hyperthermia, but also in the management of neuroleptic malignant syndrome, spasticity and Ecstasy intoxication. The main disadvantage of dantrolene is its poor water solubility, and hence difficulties are experienced in rapidly preparing intravenous solutions in emergency situations. Due to economic considerations, no other similar drugs have been introduced into routine clinical practice.

Genetic predisposition to neuroleptic malignant syndrome : implications for antipsychotic therapy

The pathogenetic mechanism of neuroleptic malignant syndrome (NMS), a potentially lethal adverse effect of antipsychotics, is not well understood. In addition to acquired risk factors, clinical observations suggest a number of genetic factors predisposing patients to NMS. Recent findings in pharmacogenetics indicate that the genetic polymorphisms for drug-metabolizing enzymes, drug transporters, and possibly drug-targeting molecules, are associated with the interindividual differences in drug responses concerning both efficacy and adverse reactions. Genetic association studies have sought to identify polymorphisms influencing susceptibility to NMS, especially with respect to the dopamine D(2) receptor, serotonin receptor, and cytochrome p450 2D6. While a few candidate polymorphisms were associated with NMS, a large controlled study is needed to attain statistical power. On the other hand, NMS might include heterogeneous conditions with common characteristic symptoms but different causative mechanisms. Further analysis of individuals with identified genetic mutations or polymorphisms should advance our understanding of mechanisms underlying NMS.

[Malignant hyperthermia: new developments in diagnosis and clinical management]

OBJECTIVE

To analyse the current knowledge concerning anaesthetic malignant hyperthermia.

DATA SOURCES

References were obtained from computerized bibliographic research (Medline), recent review articles, the library of the service and personal files.

DATA SYNTHESIS

Knowledge to possess, about the diagnosis and treatment of the acute hyperthermia crises and about "safe-anaesthesia" for malignant hyperthermia susceptible patients, are explained. The pathophysiology chapter give information about the calcium's transport and the defect existing in MH. Molecular genetics of MH find linkage to the region encoding the RyR1. The profile of hyperthermia episodes has changed over time due to the endtidal carbon dioxide-monitoring. Clinical aspects of MH are exposed. The treatment of the acute hyperthermia crises consist mainly to stop all triggering agents instantly and infuse dantrolene sodium. The gold standard for the diagnosis of malignant hyperthermia susceptibility relies on the in vitro contracture test (halothane and caffeine). Associated to genetic studies, it could lead to an non-invasive screening of the MH susceptibility. A protocol for "safe-anaesthesia" is proposed. Some syndromes with features similar to those of MH should be known (central core disease and exertionnal rhabdomyolysis).

General pediatric emergencies. Malignant hyperthermia syndrome

Anesthesiologists always undertake the challenge of keeping themselves informed about advances in medical knowledge aggressively; however, they have not been particularly active in the areas of patient education and advocacy. Malignant hyperthermia syndrome is a unique condition that anesthesiologists as clinicians understand well--in most cases, better than other specialists. They are positioned best to inform patients initially about the significance of malignant hyperthermia syndrome susceptibility and to provide an ongoing resource for counseling. The physician-patient relationship, according to the American Society of Anesthesiologists' Guidelines for the Ethical Practice of Anesthesiology, "involves special obligations for the physician that include placing the patient's interest foremost, faithfully caring for the patient, and being truthful." The care, counseling, and support that anesthesiologists bring to the patient susceptible to malignant hyperthermia syndrome truly fulfills this relationship.

[Malignant hyperthermia susceptibility in 3 patients with malignant neuroleptic syndrome]

Hyperthermia, skeletal muscle rigidity, rhabdomyolysis, acidosis and multiple system insufficiency characterize malignant hyperthermia. Anaesthetic malignant hyperthermia follows halogenated volatile agents and/or depolarizing muscle relaxants utilization. Diagnosis is based on in vitro muscle contracture in response to halothane and/or caffeine exposure. Neuroleptic malignant syndrome affects patients taking neuroleptic drugs; clinical findings include hyperthermia, extrapyramidal rigidity, acidosis, neurovegetative instability and neurological signs. We report three neuroleptic malignant syndrome patients with positive muscle contracture tests which shows that muscle from neuroleptic malignant syndrome patients may in some instances show alterations similar to those of anaesthetic malignant hyperthermia.

Malignant hyperthermia

Malignant hyperthermia is a rare autosomal dominant trait that predisposes affected individuals to great danger when exposed to certain anaesthetic triggering agents (such as potent volatile anaesthetics and succinylcholine). A sudden hypermetabolic reaction in skeletal muscle leading to hyperthermia and massive rhabdomyolysis can occur. The ultimate treatment is dantrolene sodium a nonspecific muscle relaxant. Certain precautions should be taken before anaesthesia of patients known to be susceptible to malignant hyperthermia. These include the prohibition of the use of triggering agents, monitoring of central body temperature and expired CO2, and immediate availability of dantrolene. In addition, careful cleansing of the anaesthesia machine of vapours of halogenated agents is recommended. If these measures are taken, the chances of an MH episode are greatly reduced. When malignant hyperthermia-does occur in the operating room, prompt recognition and treatment usually prevent a potentially fatal outcome. The most reliable test to establish susceptibility to malignant hyperthermia is currently the in vitro caffeine-halothane contracture test. It is hoped that in the future a genetic test will be available.

[Lack of sensitivity to per-anesthetic malignant hyperthermia in 32 patients who developed neuroleptic malignant syndrome]

The aim of this study was to verify whether a relationship exists between neuroleptic malignant syndrome (NMS) and anaesthetic-induced malignant hyperthermia (MH) or not. The in vitro halothane-caffeine tests were performed on muscle tissue obtained from 32 patients with documented NMS episodes. The diagnosis of NMS relied on Levenson's criteria. The results, expressed in accordance with the criteria of the European MH Group, defined 29 subjects as MH non-susceptible. Three patients were classified as MH equivocal. These findings demonstrate the lack of any link between NMS and MH. Therefore, patients with a history of NMS are not likely to be at risk of developing MH and special measures against MH are not required for anaesthesia in these patients.

Drug-induced hyperthermia

Drugs with antidopaminergic properties and those capable of stimulating serotonin release can be responsible for hyperthermia syndromes such as neuroleptic malignant syndrome and serotonin syndrome. Dopamine and serotonin are important neurotransmitters in temperature regulation and it is likely that these reactions result from drug-induced changes in neurotransmitter levels. We describe three cases of drug-induced hyperthermia, discuss their aetiology and management, with both general measures and therapies designed to redress neurotransmitter imbalance.

Neuroleptic malignant syndrome and malignant hyperthermia. Important issues for the medical consultant

Neuroleptic malignant syndrome and malignant hyperthermia share two cardinal clinical features: hypothermia and rigidity. Both syndromes can result in rhabdomyolysis and have high mortality rates if left untreated. This article reviews each syndrome and its pathogenesis and treatment.

Fatal hyperthermia in a quadriplegic man. Possible evidence for a peripheral action of haloperidol in neuroleptic malignant syndrome

A patient with a cervical cord transection isolating his hypothalamic thermoregulatory centers from peripheral effectors suffered a fatal hyperthermic episode after receiving haloperidol. This suggests that neuroleptic malignant syndrome is caused by a peripheral, not central, effect of haloperidol.