Neuroleptic malignant syndrome

Movement disorder emergencies

Movement disorders may present acutely, and failure to recognize and exclude important differential diagnoses can result in significant morbidity or mortality. Unfortunately, much of the literature pertaining to this topic is scattered and not easily accessible. This review aims to address this deficit. Movement disorder emergencies are discussed according to their most likely mode of presentation. Diagnostic considerations and early management principles are reviewed, along with appropriate pathophysiology where relevant.

Multiple complications and withdrawal syndrome associated with quetiapine/venlafaxine intoxication

OBJECTIVE

To report a case of quetiapine/venlafaxine intoxication associated with multiple complications and to review their possible relationship with these 2 drugs.

CASE SUMMARY

A 53-year-old white man was admitted to the hospital for loss of consciousness secondary to voluntary intoxication with venlafaxine and quetiapine. Several complications were attributable to this intoxication including seizures, prolonged coma, respiratory depression, neuroleptic malignant syndrome, prolonged QRS and QTc intervals, and a possible venlafaxine withdrawal syndrome.

DISCUSSION

Quetiapine could be responsible for the neuroleptic malignant syndrome presented in this case. Moreover, venlafaxine intoxication, fever, autonomic instability, and myoclonus presented serotonin syndrome as a differential diagnosis. Potential causes of seizures and prolongation of the QRS and QTc intervals are reviewed. Finally, prolonged coma and late venlafaxine withdrawal are discussed with regard to the pharmacodynamics and pharmacokinetics of drug elimination in the context of intoxication.

CONCLUSIONS

Clinicians should be aware of possible complications following intoxication with atypical antipsychotics and anti-depressants, including protracted altered mental status.

Neuroleptic malignant syndrome associated with ziprasidone in an adolescent

BACKGROUND

Neuroleptic malignant syndrome (NMS) is a rare but potentially fatal disorder characterized by fever, muscular rigidity, delirium, and autonomic instability. Although the classic presentation of NMS has been most commonly associated with the typical neuroleptic medications, sporadic cases in association with atypical neuroleptic medications have been reported.

OBJECTIVE

We describe a case report of a pediatric patient with NMS associated with the use of the atypical antipsychotic medication ziprasidone hydrochloride.

METHODS

After a MEDLINE search of relevant literature (key terms: atypical antipsychotic, ziprasidone, neuroleptic malignant syndrome, and NMS; years: 1995-2004), no reports of NMS in association with ziprasidone in the pediatric population were identified.

RESULTS

The patient was a 15-year-old male adolescent with a history of schizoaffective disorder treated with ziprasidone capsules, 80 mg QD for 8 weeks prior to presentation. He was brought to the emergency department because the family noted that the child had a tactile fever; was rigid, diaphoretic, tremulous, and difficult to arouse; and had persistent urinary incontinence. The patient was admitted to the pediatric intensive care unit, where he remained rigid and unresponsive except for incoherent speech. He was treated for a presumptive diagnosis of NMS with IV dantrolene sodium (2 mg/kg q6h) to reduce the sequele of NMS; urinary alkalinization with sodium bicarbonate to maintain a urinary pH of 6.5 to 7.0; cardiac, pulse oximetry, and vital sign monitoring; and supportive care, including IV saline hydration.

CONCLUSION

We present this case to alert physicians of the possibility of NMS in adolescent patients treated with ziprasidone.

The evaluation and management of patients with neuroleptic malignant syndrome

NMS is a rare but fatal syndrome that needs to be considered in the perioperative period. Although many aspects remain unexplored and controversial, with greater awareness of the condition, new concepts are coming into light. Definitive treatment guidelines remain an important issue to be addressed. Efforts have been initiated in that direction and all cases can be reported on a toll-free hotline ( 1-888-667-8367) or online (www.nmsis.org).

Neuroleptic malignant syndrome: risk factors, pathophysiology, and treatment

Neuroleptic malignant syndrome (NMS) is associated with the administration of antipsychotic agents and other drugs such as l-dopa, antidepressants, and antihistaminic agents. Unexpected changes in mental status, new-onset catatonia, episodic tachycardia, tachypnea, hypertension, dysarthria, dysphagia, diaphoresis, sialorrhea, incontinence, low-grade temperature elevations, and rigidity should arouse suspicion. Several lines of evidence provide support for the involvement of dopamine. Most of the drugs implicated in NMS are D2 dopamine receptor antagonists. Central noradrenergic activity is also possibly related to the disorder, as sympathetic hyperactivity is associated with the active phase of NMS. Currently, the definitive role of GABA deficiency in NMS is yet to be established. Differential diagnosis should include malignant hyperthermia, lethal catatonia, lithium toxicity, serotonin syndrome, and heat stroke. A high degree of suspicion and the discontinuation of antipsychotic agents even if the diagnosis is not established are essential for the safety of the patient. Treatment of NMS should be individualized and be based empirically on the character, duration, and severity of the clinical signs and symptoms noted. The initial step in the treatment of NMS is the removal of the offending agent. Full-blown NMS is a serious condition and requires immediate supportive, nutritive, and electrolyte therapies. The administration of drugs that can improve NMS, such as IV dantrolene and/or oral bromocriptine, may also be taken into consideration, based on the severity and nature of the NMS.

Safety and tolerability of atypical antipsychotics in patients with bipolar disorder: prevalence, monitoring and management

Atypical antipsychotics are associated with fewer movement disorders and a lower risk of tardive dyskinesia than conventional antipsychotics, but are not without side-effects. Metabolic side-effects associated with some of the atypical antipsychotics are a concern for both clinicians and patients. Adverse events related to central nervous system effects, weight gain, and alterations in glucose, lipid, and prolactin levels in patients with depression, bipolar, and anxiety disorders have been reported. Balancing the significant benefits of treatment with these agents against the potential risks of metabolic disturbances and other adverse effects is crucial. Emerging data are making it possible to determine the risk-benefit analysis for specific atypical antipsychotics in individual patients and allow for targeted selection of treatment. A new concept of effectiveness is emerging that attempts to balance adverse effects of treatment with patient quality of life. Patients treated with atypical antipsychotics should have their weight, waist circumference, glucose, and lipids monitored on a regular basis. Monitoring of prolactin levels is not suggested; however, a baseline measurement before initiating treatment can be useful, with subsequent assessment only if a patient demonstrates symptoms. Prevention of weight gain is important. Diet and exercise should be considered for prevention and management, with the use of pharmacologic strategies approached with caution in patients with mood disorders. If a patient is at high risk of developing diabetes, certain pharmacologic agents have been shown to delay the onset of overt diabetes. Once diabetes or dyslipidemia are diagnosed, management should proceed in accordance with approved guidelines for these conditions.

Olanzapine-associated neuroleptic malignant syndrome: Is there an overlap with the serotonin syndrome?

Background

The neuroleptic malignant syndrome is a rare but serious condition mainly associated with antipsychotic medication. There are controversies as to whether "classical" forms of neuroleptic malignant syndrome can occur in patients given atypical antipsychotics. The serotonin syndrome is caused by drug-induced excess of intrasynaptic 5-hydroxytryptamine. The possible relationship between neuroleptic malignant syndrome and serotonin syndrome is at present in the focus of scientific interest.

Methods

This retrospective phenomenological study aims to examine the seventeen reported olanzapine – induced neuroleptic malignant syndrome cases under the light of possible overlap between neuroleptic malignant syndrome and serotonin syndrome clinical features.

Results

The serotonin syndrome clinical features most often reported in cases initially diagnosed as neuroleptic malignant syndrome are: fever (82%), mental status changes (82%) and diaphoresis (47%). Three out of the ten classical serotonin syndrome clinical features were concurrently observed in eleven (65%) patients and four clinical features were observed in seven (41%) patients.

Conclusion

The results of this study show that the clinical symptoms of olanzapine-induced neuroleptic malignant syndrome and serotonin syndrome are overlapping suggesting similarities in underlying pathophysiological mechanisms.

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.

Drug-induced hyperthermia and muscle rigidity: a practical approach

Body thermoregulation can be violently offset by drugs capable of altering the balance between heat production and dissipation. Such events may rapidly become fatal. The drugs that are involved in the eruption of such syndromes include inhalation anaesthetics, sympathomimetic agents, serotonin antagonists, antipsychotic agents and compounds that exhibit anticholinergic properties. The resultant hyperthermia is frequently accompanied by an intense skeletal muscle hypermetabolic reaction that leads to rapidly evolving rigidity, extensive rhabdomyolysis and hyperkalemia. The differential diagnosis should, however, rule out non-drug-induced causes, such as lethal catatonia, central nervous system infection or tetanus, strychnine poisoning, thyrotoxic storm and pheochromocytoma. Prompt life-saving procedures include aggressive body temperature reduction. Patients with a suspected drug (or non-drug) hypermetabolic reaction should be admitted into an intensive care area for close monitoring and system-oriented supportive treatment. We present six conditions, in decreasing order of gravity and potential lethality, in which hyperthermia plays an essential role, and suggest a clinical approach in such conditions.

Olanzapine induced neuroleptic malignant syndrome--a case review

Neuroleptic malignant syndrome is the rarest and the most serious of the neuroleptic induced movement disorders. Although potent neuroleptics are more frequently associated with NMS, atypical antipsychotic drugs may also be a cause of NMS. Three databases were searched using the terms 'olanzapine' and 'neuroleptic' 'malignant syndrome'. Case reports were selected and reviewed from among all articles that fulfilled the search criteria. Twenty six cases were reviewed. Twenty cases fulfilled the criteria published by Sachdev et al. Olanzapine was the most probable cause of NMS in 16 cases. The absence of rigidity was described in only two of 16 highly probable olanzapine induced NMS cases, which is not as often as it is reported in clozapine associated NMS (36%). It was found that prior NMS is an important risk factor in NMS.

Neuroleptic malignant syndrome in an adolescent receiving olanzapine-lithium combination therapy

A 16-year-old boy developed fever, generalized rigidity, leukocytosis, and increased serum transaminase and creatine kinase levels while receiving treatment with olanzapine and lithium. When both drugs were discontinued, his fever and rigidity subsided and biochemical irregularities spontaneously returned to normal, without any complications. Classic neuroleptic malignant syndrome (NMS) was diagnosed. Concomitant administration of lithium with olanzapine may place patients at risk for NMS. Clinicians need to be aware of this rare but potentially fatal side effect in patients of all ages, and especially in adolescents receiving both drugs.

Neuroleptic malignant syndrome induced by atypical antipsychotics

A review of the English literature confirms that neuroleptic malignant syndrome (NMS) occurs with both traditional and atypical antipsychotic medications. Published reports of NMS induced by the traditional antipsychotics have given the practitioner valuable information on the prevention and treatment of this adverse effect. Case reports have also been published concerning NMS and clozapine, risperidone, olanzapine and quetiapine. By evaluating the case reports of atypical antipsychotic-induced NMS, valuable information may be obtained concerning similarities or differences from that induced by the traditional antipsychotics. The case reports of NMS with atypical antipsychotics were evaluated for diagnosis, age/sex of patient, risk factors, antipsychotic doses and duration of use, symptoms of NMS, and clinical course.

Risk factors in neuroleptic malignant syndrome. A case-control study

OBJECTIVE

To determine whether environmental temperature, agitation, neuroleptic use, mental retardation, and affective disorders were risk factors for neuroleptic malignant syndrome (NMS).

METHOD

Cases and age- and sex-matched psychiatric controls admitted to a regional acute psychiatric unit over a 10-year period.

RESULTS

Both uni- and multivariate analysis revealed statistically significant differences between patients with NMS (n=15) and controls (n=45) with regard to the presence of mental retardation, psychomotor agitation, and a number of variables relating to neuroleptic use (newly introduced or increased, intramuscular administration, and dosage). We found no differences between NMS patients and psychiatric controls in respect of changes in environmental temperature.

CONCLUSION

Our study supports the need for caution when using intramuscularly administered, abruptly increasing, high-dose neuroleptics, particularly in mentally retarded or agitated patients, regardless of environmental temperature.

Is neuroleptic malignant syndrome a neurogenic form of malignant hyperthermia?

Neuroleptic malignant syndrome is a rare and potentially lethal disorder associated with the use of antipsychotic medications. Heightened vigilance on the part of clinical providers has reduced morbidity and mortality caused by this disorder over the past decade, but there is still no consensus regarding its diagnosis, pathophysiology, or treatment. Efforts to demonstrate a direct link between neuroleptic malignant syndrome and malignant hyperthermia have been unsuccessful, indicating mutually distinct etiologies despite striking clinical similarities. This paper concisely reviews essential aspects of electromechanical transduction in muscle and nerve cells and current knowledge concerning the pathophysiology of malignant hyperthermia and neuroleptic malignant syndrome. Utilizing this conceptual framework, the author proposes that neuroleptic malignant syndrome may be caused by a spectrum of inherited defects in genes that are responsible for a variety of calcium regulatory proteins within sympathetic neurons or the higher order assemblies that regulate them. In this proposed model, neuroleptic malignant syndrome may be understood as a neurogenic form of malignant hyperthermia.

Olanzapine-associated neuroleptic malignant syndrome

Neuroleptic malignant syndrome (NMS) is an uncommon but serious idiosyncratic reaction associated with antipsychotic medication. The purpose of this study was to reveal and analyze the clinical characteristics of the reported cases of NMS in patients given the novel antipsychotic olanzapine. A MEDLINE search related to olanzapine-induced NMS cases reported in the international literature was conducted. All cases were critically reviewed and examined against three different sets of NMS diagnostic criteria (DSM-IV, Addonizio, Levenson). The authors identified 17 cases of possible NMS associated with olanzapine. Ten of the reported NMS cases were definitely NMS meeting all three sets of criteria and three cases were probable NMS meeting two sets of criteria. Most of the patients exhibited a full-blown NMS. There were four definite NMS cases associated with olanzapine monotherapy. Three of them had concurrent serious physical illnesses and one had a previous NMS episode. Olanzapine can cause NMS, mainly in susceptible or predisposed patients.

Atypical neuroleptic malignant syndrome associated with olanzapine

Neuroleptic malignant syndrome (NMS) is a potentially life-threatening adverse effect of antipsychotic agents. It generally is characterized by fever, altered mental status, rigidity, and autonomic dysfunction. A 53-year-old man developed NMS without rigidity while taking olanzapine. Such atypical cases may support either a spectrum concept of NMS or the theory that NMS secondary to atypical antipsychotics differs from that caused by conventional neuroleptics. More flexible diagnostic criteria than currently mandated by the the Diagnostic and Statistical Manual of Mental Disorders, Fourth Revision, may be warranted.

Clinical risk factors for neuroleptic malignant syndrome

Pharmacological risk factors for neuroleptic malignant syndrome (NMS) are better defined than clinical risk factors. We examined the psychopathological status preceding the onset of NMS in 20 patients. We evaluated four key psychiatric symptoms (psychomotor agitation, catatonia, disorganization and confusion) and grouped them into definite clinical syndromes. Six patients presented with an acute and severe catatonic syndrome, with all the four key psychiatric symptoms. Twelve patients presented with an acute and severe disorganized psychotic episode, with two or three key psychiatric symptoms, but not catatonia. Our study suggests that a clinical syndrome of acute disorganization, in addition to acute catatonia, is a potential clinical risk factor for NMS. The two syndromes, which can occur in the context of different mental disorders, are related to each other as both implicate alteration in behavioural monitoring, and were, in our experience, unresponsive to neuroleptics. In conclusion, we hypothesize that the recognition of these two syndromes should reduce NMS occurrence. We recommend a judicious use of neuroleptics not only in patients with acute catatonia, but also in patients with acute disorganization.

Failed challenge with quetiapine after neuroleptic malignant syndrome with conventional antipsychotics

Neuroleptic malignant syndrome (NMS) is an uncommon but potentially life-threatening adverse effect associated with conventional antipsychotic agents. The syndrome is characterized by muscular rigidity, hyperpyrexia, altered consciousness, and autonomic dysfunction. Few cases of quetiapine-induced NMS have been reported. A 54-year-old man was unsuccessfully challenged with quetiapine after conventional antipsychotic-induced NMS.

Treatment of neuroleptic malignant syndrome with subcutaneous apomorphine monotherapy

A 20-year-old psychiatric patient receiving haloperidol treatment developed acute-onset fever, rigidity, and mental changes. Subcutaneous apomorphine was given alone for treatment. The patient had rapid clinical improvement after the treatment. Serial blood examinations showed decline and subsequent normalization of the creatine phosphokinase levels.

An autopsy case of neuroleptic malignant syndrome (NMS) and its immunohistochemical findings of muscle-associated proteins and mitochondria

Neuroleptic malignant syndrome (NMS) is a rare but potentially fatal disorder. In forensic cases, post-mortem diagnosis of NMS is sometimes difficult if ante-mortem information, such as neuroleptic ingestion or signs and symptoms, cannot be obtained. A 39-year-old Japanese male on a neuroleptic treatment regimen suddenly became agitated and died. Autopsy revealed muscle rigidity and hyperthermia. Post-mortem examination of blood revealed elevation of creatine phosphokinase-MM (CK-MM) and lactate dehydrogenase-4 and dehydrogenase-5 (LDH-4 and LDH-5). In renal glomeruli and tubules, myoglobin was stained immunohistochemically. From these findings, the cause of death was considered to be NMS. To support the diagnosis of NMS, both skeletal and cardiac muscles were stained with actin, myoglobin, desmin and mitochondria antibodies immunohistochemically. Actin, myoglobin, desmin, and mitochondria had been lost from skeletal, but not from the cardiac muscle, which suggested that only the skeletal muscle was damaged. Moreover, because mitochondria had disappeared only from the skeletal muscle, it was considered that skeletal muscle degeneration was caused by mitochondrial damage. Therefore, it is suggested that immunostaining of skeletal muscle by antibodies for muscle-associated proteins and mitochondria is useful to corroborate a diagnosis of NMS.

Is Lorazepam a treatment for neuroleptic malignant syndrome?

The authors assessed the ability of lorazepam and other benzodiazepines to affect the course of neuroleptic malignant syndrome (NMS). Records of inpatients who met both stringent research criteria and criteria under the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, (DSM-IV) (n=11) or DSM-IV criteria alone (n=5) for NMS were identified. All received lorazepam or related benzodiazepines within 24 hours of NMS onset or hospital admission. The records were reviewed for resolution of clinical signs of NMS. Rigidity and fever abated within 24-48 hours, while secondary features of NMS were relieved within 64 hours. These results compared favorably with prior reports of 5-day to 10-day recovery periods. Benzodiazepine administration appeared to be well tolerated. Lorazepam and related benzodiazepines may reduce recovery time in NMS.

Residual catatonic state following neuroleptic malignant syndrome

Neuroleptic malignant syndrome (NMS) is usually a self-limited disorder, with most cases resolving within 2 weeks after antipsychotic drug discontinuation. However, the course of NMS may not always be short-lived. In this report, the authors describe five patients who developed a residual catatonic state that persisted after acute hyperthermic symptoms of NMS had subsided and compare them with 27 similar cases in the literature. Two of our patients recovered gradually with supportive treatment. Three patients were treated with electroconvulsive therapy (ECT). Of these, two showed a positive response, although one died later of intercurrent pneumonia. A third patient did not respond to ECT, but recovered gradually thereafter. Although dopamine agonists or benzodiazepines have been advocated for the treatment of residual symptoms in previous case reports, ECT was the treatment most often associated with a rapid response and no mortality, even in patients refractory to pharmacotherapy. In conclusion, catatonic and parkinsonian symptoms of NMS may persist as a residual state lasting for weeks to months after more fulminant acute symptoms abate. These residual symptoms may be more likely to develop in patients with pre-existing structural brain disorders. Although patients may improve gradually with supportive care or pharmacotherapy, ECT can often be highly effective in treating the residual catatonic state that follows NMS.

Asphyxial death during prone restraint revisited: a report of 21 cases

Determining the cause of death when a restrained person suddenly dies is a problem for death investigators. Twenty-one cases of death during prone restraint are reported as examples of the common elements and range of variation in these apparently asphyxial events. A reasonable diagnosis of restraint asphyxia can usually be made after ruling out other causes and collecting supportive participant and witness statements in a timely fashion. Common elements in this syndrome include prone restraint with pressure on the upper torso; handcuffing, leg restraint, or hogtying; acute psychosis and agitation, often stimulant drug induced; physical exertion and struggle; and obesity. Establishing a temporal association between the restraint and the sudden loss of consciousness/death is critical to making a correct determination of cause of death.

Muscle changes in the neuroleptic malignant syndrome

AIMS

To characterise the skeletal muscle changes in the neuroleptic malignant syndrome (NMS).

METHODS

Detailed light and ultrastructural examination was carried out on skeletal muscle from three cases of NMS, two associated with recreational drugs (3,4-methlenedioxymethylamphetamine (MDMA, Ecstasy) and lysergic acid diethylamide (LSD)) and one with antipsychotic drugs (fluoxetine (Prozac) and remoxipride hydrochloride monohydrate (Roxiam)).

RESULTS

The muscles were grossly swollen and oedematous in all cases, in one with such severe local involvement that the diagnosis of sarcoma was considered. On microscopy, there was conspicuous oedema. In some fascicles less than 10% of fibres were affected whereas in others more than 50% were pale and enlarged. There was a spectrum of changes: tiny to large vacuoles replaced most of the sarcoplasm and were associated with necrosis. A striking feature in some fibres was the presence of contraction bands separating segments of oedematous myofibrils. Severe endomysial oedema was also detectable. There was a scanty mononuclear infiltrate but no evidence of regeneration.

CONCLUSIONS

The muscle changes associated with NMS are characteristic and may be helpful in differential diagnosis.

Drug Poisoning and Overdose for the Health Professional: Review of Select Over-the-Counter (OTC) and Prescription Medications

Exposure to over-the-counter and prescription medications can pose significant therapeutic and health hazards to patients, and present health care professionals with scenarios that require proper assessment and treatment. Knowing when an exposure to or overdose of a drug requires emergency medical attention is equally as important as to knowing when such assistance is not necessary—that simple treatment measures performed at home will suffice. This current discussion is intended to highlight select principles and clinical information pertaining to common drug exposures and overdoses, but not replace the full spectrum of information that would be available to health care professionals (and the lay public) by contacting their nearest poison control center. Many of the basic principles and concerns that are encountered with exposures to chemicals (i.e., route of exposure, patient medical history, quantity of the substance involved, elapsed time since the initial exposure, etc.) apply equally well to drug exposures. Likewise, evaluating each of these variables will determine which type of treatment approaches are, and are not, considered in situations of drug (or chemical) exposure and overdose.