Neuroleptic malignant syndrome: a study of CSF monoamine metabolism

Case reports of neuroleptic malignant syndrome in context of quetiapine use

A retrospective analysis was followed on 20 case reports covering the possible correlation between the atypical antipsychotic, quetiapine, and neuroleptic malignant syndrome (NMS), determined by the study of 7 different NMS criteria guidelines. A great majority (19) of the case studies did not meet the requirements of all 7 guidelines, frequently due to unreported information. Nor was quetiapine proven to be the sole cause of the possible NMS in the two age groups investigated. Only one case was found to have no other medication or medical conditions confounding the relationship of quetiapine and NMS symptoms, and that case was in the context of a significant quetiapine overdose. The other 19 cases demonstrated the difficulty of identifying the cause of NMS when polypharmacy and other medical conditions are involved. The authors note the need for caution in deciding both the presence of NMS and the causal factors of the symptoms.

Temporal changes in serum creatine kinase concentration and degree of muscle rigidity in 24 patients with neuroleptic malignant syndrome

Neuroleptic malignant syndrome (NMS) is a dangerous adverse response to antipsychotic drugs. It is characterized by the four major clinical symptoms of hyperthermia, severe muscle rigidity, autonomic dysfunction, and altered mental state. Serum creatine kinase (CK) elevation occurs in over 90% of NMS cases. In the present study, the detailed temporal changes in serum CK and degree of muscle rigidity, and the relationship between CK concentration and degree of muscle rigidity over the time course from fever onset, were evaluated in 24 affected patients. The results showed that serum CK peaked on day 2 after onset of fever and returned to within normal limits at day 12. Mild muscle rigidity was observed before the onset of fever in 17 of 24 cases (71%). Muscle rigidity was gradually exacerbated and worsened until day 4 after onset of fever. These findings confirm physicians' empirical understanding of serum CK concentrations and muscle rigidity in NMS based on data accumulated from numerous patients with the syndrome, and they indicate that serum CK may contribute to the early detection of NMS.

Neuroleptic malignant syndrome and its controversies

PURPOSE

Neuroleptic malignant syndrome (NMS) is a rare and life threatening condition usually defined as a complication of treatment with antipsychotics characterized by severe rigidity, tremor, fever, altered mental status, autonomic dysfunction, and elevated serum creatine phosphokinase and white blood cell count. The literature on this topic is rather extensive, but many aspects related to the syndrome are thought to be controversial. The aim of this paper, written with the clinician in mind, is to summarize some of the most prominent controversies that may have importance in usual clinical practice.

METHODS

The literature was searched for reviews, reports on the series of cases, individual case reports of NMS, and other clinically and theoretically important information.

RESULTS

There are controversies associated with virtually all important aspects of NMS. At the moment, it is not clear if this drug reaction is idiosyncratic or not, what diagnostic criteria are the most appropriate for usual clinical practice, and it seems that the estimated incidence is not in accordance with the number of treated patients. There are rather different approaches to the pathophysiological mechanisms, differential diagnosis, and treatment.

CONCLUSIONS

Some of the controversies related to NMS have an influence on our understanding of the condition and may have importance in clinical practice. There is a need for further research that should elucidate these controversies.

Association Between Selective Serotonin-Reuptake Inhibitors, Second-Generation Antipsychotics, and Neuroleptic Malignant Syndrome

Objective

To review the published reports of neuroleptic malignant syndrome (NMS) associated with the use of selective serotonin-reuptake inhibitors (SSRIs) and second-generation antipsychotics.

Data Source:

Information was selected from a MEDLINE search of English-language literature (1950–May 2008). Manual search of all published cases indexed in MEDLINE (English language only) of NMS associated with second-generation antipsychotics was also performed.

Study Selection And Data Extraction:

Pertinent information from all reports obtained was included, with specific emphasis on patient age, sex, second-generation antipsychotic involved, SSRI or other antidepressant involved, time of onset of NMS symptoms in relation to medication changes, treatment administered, and outcome of the reaction.

Data Synthesis:

NMS has been reported with every second-generation antipsychotic agent. It is unclear whether concomitant therapy with other agents may increase the risk of NMS development via pharmacodynamic or pharmacokinetic mechanisms or both, The suggested pharmacodynamic mechanism for increased risk of NMS with concomitant use of SSRIs is the effect of serotonin on dopamine release. Serotonin further inhibits dopamine release and thereby may worsen a hypodopaminergic state induced by antipsychotics. Pharmacokinetic factors may also play a role in some NMS cases involving an SSRI by increasing antipsychotic concentrations. An examination of case reports seems to indícale that at least in some casos, a temporal relationship exists with the addition of an SSRI to existing antipsychotic therapy.

Conclusions:

The use of SSRIs may be associated with an increased risk of NMS development in (hose receiving second-generation antipsychotics. Clinicians should closely monitor patients for the potential development of NMS.

Managing an effective treatment for neuroleptic malignant syndrome

INTRODUCTION

Neuroleptic malignant syndrome (NMS) is a rare, but sometimes fatal, adverse reaction to neuroleptics characterized principally by fever and rigor. The aim of this study was to prove the efficacy of different NMS treatment strategies, focusing on the efficacy of dantrolene.

METHODS

Altogether, 271 case reports were included. These cases were categorized into four treatment groups and compared to each other according to effectiveness of therapy within 24 hours, mortality, complete time of remission in days, effectiveness due to increase of dosage, relapse on the basis of decrease of dosage, and improvement of symptoms.

RESULTS

Between the four treatment groups, the complete time of remission was significantly different (analysis of variance, F = 4.02; degrees of freedom = 3; p = 0.008). In a logistic regression with adjustment for age, gender, and severity code, no significant predictor of the treatment for the complete time of remission (dichotomized by median) could be found. However, if the premedication was a monotherapy with neuroleptics, the complete time of remission was significantly shorter with dantrolene monotherapy (t = -2.97; p = 0.004).

CONCLUSION

The treatment of NMS with drugs that are combined with dantrolene is associated with a prolongation of clinical recovery. Furthermore, treatment of NMS with dantrolene as monotherapy seems to be associated with a higher overall mortality. Therefore, dantrolene does not seem to be the evidence-based treatment of choice in cases of NMS but might be useful if premedication consisted of a neuroleptic monotherapy.

Neuroleptic malignant syndrome and serotonin syndrome

This chapter is focused on drug-induced hyperthermia with special regard to use of antipsychotics and antidepressants for the treatment of schizophrenia and major depression, respectively. Neuroleptic malignant syndrome (NMS) develops during the use of neuroleptics, whereas serotonin syndrome is caused mainly by serotoninergic antidepressants. Although both syndromes show various symptoms, hyperthermia is the main clinical manifestation. In this review we describe the historical background, clinical manifestations, diagnosis, and differential diagnosis of these two syndromes based on our observations on the experimental and clinical data.

Association in Japanese patients between neuroleptic malignant syndrome and functional polymorphisms of the dopamine D(2) receptor gene

A genetic predisposition to the development of neuroleptic malignant syndrome (NMS) has been suggested by clinical studies. Although the molecular basis of NMS is unclear, a dopaminergic blockade mechanism has been considered the main cause. We therefore investigated the association between NMS and three functional polymorphisms of the dopamine D(2) receptor (DRD(2)) gene: TaqI A, -141C Ins/Del, and Ser311Cys. Subjects included 32 Japanese patients, previously diagnosed with NMS, and 132 schizophrenic patients treated with neuroleptics without occurrence of NMS. Polymerase chain reaction and restriction fragment length polymorphism analyses were performed to determine each genotype. We found significant differences in genotypic and allelic frequencies of the -141C Ins/Del polymorphism between patients with and without NMS. The -141C Del allele was significantly more frequent in the NMS group (23.4 vs 11.7%, P=0.026). Similarly, the proportion of -141C Del allele carriers was significantly higher in the NMS group (40.6 vs 20.5%, P=0.022). No significant differences between the two groups were seen for allelic and genotypic frequencies of the TaqI A and Ser311Cys polymorphisms. This result suggests that the -141C Ins/Del polymorphism is likely to predispose toward the development of NMS, probably together with other unidentified factors.

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.

The use of clonidine in the management of autonomic overactivity in neuroleptic malignant syndrome

The aim of this study was to identify the effectiveness of clonidine in the recovery of patients with neuroleptic malignant syndrome and autonomic dysfunction, including blood pressure lability. Nine patients with neuroleptic malignant syndrome and autonomic dysfunction were treated with clonidine in the intensive care unit, according to a protocol, and the results were compared with those of seven patients with the same syndrome who were not treated with clonidine. Clonidine was administered until blood pressure stability was fully restored, and thereafter the dose was gradually reduced. There was a significant reduction in the duration of ventilation and stay in the intensive care unit in the clonidine group. Three patients from the nonclonidine group died. The data suggest that in the clonidine group, patients with neuroleptic malignant syndrome and autonomic dysfunction appear to have better and faster recovery, especially in blood pressure control, after intravenous clonidine treatment.

Risperidone, neuroleptic malignant syndrome and probable dementia with Lewy bodies

1. Conflicting reports are available regarding the sensitivity of patients with Dementia with Lewy bodies (DLB) to risperidone. 2. The authors studied a rare familial case of probable DLB, who developed a documented episode of neuroleptic malignant syndrome (NMS) following the exposure to risperidone. Previously, the patient had had an episode of NMS on trifluoperazine. 3. The discontinuance of risperidone, in combination with a mild increase of dopaminergic therapy, led to a complete recovery in few days. 4. In patients with DLB, a continued vigilance for extrapyramidal side effects, including NMS, would be advisable during the use of risperidone.

Susceptibility to neuroleptic malignant syndrome in Parkinson's disease

OBJECTIVE

To determine susceptibility to neuroleptic malignant syndrome (NMS) in patients with PD in relation to central monoamine metabolism.

METHODS

CSF levels of homovanillic acid (HVA), 3-methoxy-4-hydroxy phenyletilene glycol (MHPG), and 5-hydroxyindole acetic acid (5-HIAA) were assayed in 98 PD patients (mean age, 77.2 years), including 11 patients with a prior NMS-like episode, by high-performance liquid chromatography with electrochemical detection.

RESULTS

Patients with a previous NMS-like episode had worse parkinsonian disability as measured by Hoehn & Yahr scale (3.7 +/- 0.8 versus 3.0 +/- 1.1; p = 0.038) and lower CSF HVA levels (20.9 +/- 17.3 versus 44.7 +/- 22.2 ng/mL; p = 0.001) compared to those without, despite similar age, disease duration, and daily dosages of antiparkinsonian drugs between groups. Logistic regression analysis showed that the CSF HVA level (p = 0.008), but not 5-HIAA level (p = 0.621), was significantly and independently related to NMS, and that the MHPG level (p = 0.070) was tendentially associated with the disorder. Odds ratios (95% confidence intervals) corresponding to 10 ng/mL increment in CSF HVA, MHPG, and 5-HIAA levels were 0.30 (0.13 to 0.73), 4.03 (0.89 to 18.2) and 1.29 (0.47 to 3.58), respectively.

CONCLUSIONS

Central dopaminergic and possible noradrenergic activity contributes to NMS development in an elderly population of PD patients. Measuring CSF levels of monoamine metabolites may provide a means for identifying NMS susceptibility in PD patients.

Nigrostriatal dopaminergic activities in dementia with Lewy bodies in relation to neuroleptic sensitivity: comparisons with Parkinson's disease

BACKGROUND

In dementia with Lewy bodies (DLB) mild extrapyramidal symptoms are associated with moderate reductions in substantia nigra neuron density and concentration of striatal dopamine. Many DLB patients treated with typical neuroleptics suffer severe adverse reactions, which result in decreased survival.

METHODS

In a series of DLB cases, with and without neuroleptic sensitivity, substantia nigra neuron densities, striatal dopamine and homovanillic acid concentrations, and autoradiographic [3H]mazindol and [3H]raclopride binding (to the dopamine transporter and D2 receptor, respectively) were analyzed and compared to control and idiopathic Parkinson's disease cases.

RESULTS

D2 receptors were up-regulated in neuroleptictolerant DLB and Parkinson's disease compared to DLB without neuroleptic exposure and controls. D2 receptors were not up-regulated in DLB cases with severe neuroleptic reactions. Dopamine uptake sites were reduced concomitantly with substantia nigra neuron density in Parkinson's disease compared to controls, but there was no significant correlation between substantia nigra neuron density and [3H]mazindol binding in DLB groups. There was no significant difference in substantia nigra neuron density, [3H]mazindol binding, and dopamine or homovanillic acid concentration between neuroleptic-tolerant and -sensitive groups.

CONCLUSIONS

Failure to up-regulate D2 receptors in response to neuroleptic blockade or reduced dopaminergic innervation may be the critical factor responsible for neuroleptic sensitivity.

The neuroleptic malignant syndrome: a logical approach to the patient with temperature and rigidity

The neuroleptic malignant syndrome is a rare, potentially fatal, adverse reaction to neuroleptic drugs characterised by severe rigidity, high temperature and autonomic dysfunction. In the light of the hypothesized pathophysiology of this condition, a rational approach to the management of patients presenting with temperature and rigidity is provided. The aims of this approach are three-fold: to reduce the incidence of the condition, to be able to recognise it early so as to treat before life-threatening complications arise, and to be able to recognise early those conditions which mimic neuroleptic malignant syndrome, so as not to delay their specific treatment.

Neurochemical studies of schizophrenia in Japan

Neurobiological research in schizophrenia has been hampered by several confounding factors such as the heterogeneity of the illness and the paucity of biological markers. Recent progress in research methods, however, has enabled the improvement in our understanding its pathophysiology. This paper reviews recent neurochemical investigations of schizophrenia and its animal models which were conducted in Japan in the last decade. The research areas reviewed are (i) monoamine and their metabolites in body fluids, (ii) phospholipids and prostaglandins, (iii) neurochemistry in autopsy brains, (iv) immunological measures, (v) magnetic resonance spectroscopy, (vi) regional cerebral blood flows (rCBF), (vii) molecular genetics, and (viii) animal models. It is worth noting that there exist abnormalities of amino acidergic (glutamatergic and GABAergic) neurotransmission as well as monoaminergic (dopaminergic and serotonergic) one in postmortem schizophrenic brains. These abnormalities and also the findings of altered rCBF indicate the existence of disturbed neuronal circuits that contribute to the diverse symptoms of schizophrenia. Also, dysfunction of membrane phospholipids derived from studies on magnetic resonance spectroscopy may underlie negative symptoms in schizophrenia. Given that schizophrenia is considered to comprise a group of disorders with a diverse heterogeneity of etiologies, research in the next decade is expected to identify putative genes that are involved in vulnerability to schizophrenic phenotype.

Recognition and Treatment of the Catatonic Syndrome

We define the catatonic syndrome and review the history of the concept of catatonia, including its recent acceptance as a syndrome. Diagnosis of the catatonic syndrome, with its associated extensive differential diagnoses related to systemic and mental disorders, is addressed. Catatonia is related to variants of the syndrome, such as lethal (malignant) catatonia and the neuroleptic malignant syndrome (NMS). Medical sequelae of these conditions are outlined. The literature on the treatment of the catatonic syndrome is reviewed, and a suggested approach to treatment and management of catatonic patients in the intensive care unit is provided. An hypothesis regarding the neuropathophysiological basis for the syndrome is also offered.

Plasma homovanillic acid concentrations in catatonia

We investigated the dopamine metabolite plasma homovanillic acid (plasma HVA) levels in 37 catatonic patients on the day of admission before initial medication as well as in 17 healthy controls. In a prospective study catatonic syndrome was diagnosed according to criteria of Lohr and Wiesniwski (1987) and Rosebush et al (1990) whereas comorbid diagnosis was made by Diagnostic and Statistical Manual of Mental Disorders, 3rd ed, revised (DSM III/R) (APA 1987). On the day of admission blood samples were taken before initial medication. Compared to controls (80.1 +/- 40.1 pmol/mliter) catatonic patients showed significantly (P = 0.0286) increased plasma HVA (140.9 +/- 53.6 pmol/mliter). Catatonic patients free of neuroleptic medication (n = 21) differed significantly (p = 0.0416) from controls whereas neuroleptically treated catatonics (n = 16) did not. Our findings of increased plasma HVA in catatonia are explained by an alteration in either mesolimbic or mesocortical dopaminergic function, as is assumed in the case of schizophrenia. As an alternative, it may be due to increased nigrostriatal function, which can lead, as shown in animal experiments with the dopamine agonist amphetamine, to hypokinetic states resembling catatonia in humans.

Cerebrospinal fluid levels of monoamine metabolites and gamma-aminobutyric acid in neuroleptic malignant syndrome

To investigate the pathophysiology of neuroleptic malignant syndrome (NMS), we measured various cerebrospinal fluid (CSF) parameters in 11 patients and compared them with 8 age-matched normal controls. Concentrations of homovanillic acid (HVA) were significantly decreased during the active phase of NMS. This finding indicates that the dopaminergic nervous system of the patients was in a state of hypofunction in this phase and supports the central dopamine blockade theory of NMS. Reduced CSF HVA levels were also found after recovery from NMS, suggesting that hypofunction of the dopaminergic system may continue subclinically. The levels of 5-HIAA were decreased in the active phase, but the change was not significant. Therefore, a relationship between the development of NMS and disturbances of serotonin metabolism remains unclear. The levels of noradrenaline and its major metabolite, 3-methoxy-4-hydroxyphenylethyleneglycol increased significantly during the active phase, but returned to normal after recovery. These results show the existence of sympathetic nervous system hyperactivity during the active phase of NMS. The levels of gamma-aminobutyric acid (GABA) were significantly lower in the patients than in the controls. These findings suggest that there is a GABAergic deficiency in NMS. Thus, our study indicates that, in addition to dopamine hypoactivity, disturbances in various neurotransmitter systems are involved in the pathophysiology of NMS.

Does dantrolene influence central dopamine and serotonin metabolism in the neuroleptic malignant syndrome? A retrospective study

Homovanillic acid (HVA) and 5-hydroxyindoleacetic acid (5-HIAA) levels in the cerebrospinal fluid (CSF) were determined twice in nine cases of neuroleptic malignant syndrome (NMS) during the active phase. During the test period, three cases received no dantrolene and six cases received dantrolene prior to the second CSF examination. In the group not administered dantrolene, the levels of HVA and 5-HIAA were lower on the second examination compared to the first, suggesting that the levels of these substances decreased during the course of NMS. In the group receiving dantrolene, the levels of HVA and 5-HIAA increased after administration compared with the preadministration levels. In particular, a significant difference in the changes in HVA was demonstrated between the two groups. This suggests that dantrolene influences central dopaminergic metabolism in the active phase of NMS.

Neuroleptic malignant syndrome

Neuroleptic malignant syndrome is a rare but potentially fatal reaction associated with neuroleptic drugs. It occurs in about 0.2% of patients treated with neuroleptics. Risk factors include previous episodes, dehydration, agitation, and the rate and route of neuroleptic administration. Although NMS has been reported in patients with diverse psychiatric diagnoses, as well as in normal subjects, patients with organic brain disorders or mood disorders, particularly when receiving lithium, may be at increased risk. Standardized criteria for the diagnosis of NMS have been developed and emphasize the classic findings of hyperthermia, muscle rigidity, mental status changes, and autonomic dysfunction. The syndrome lasts 7 to 10 days in uncomplicated cases receiving oral neuroleptics. Treatment consists primarily of early recognition, discontinuation of triggering drugs, management of fluid balance, temperature reduction, and monitoring for complications. Use of dopamine agonists or dantrolene or both should be considered and may be indicated in more severe, prolonged, or refractory cases. Electroconvulsive therapy has been used successfully in some cases and is particularly useful in the post-NMS patient. As a result of these measures, mortality from NMS has declined in recent years although fatalities still occur. Neuroleptics may be safely reintroduced in the management of the majority of patients recovered from an NMS episode, although a significant risk of recurrence does exist, dependent in part on time elapsed since recovery and dose or potency of neuroleptics used. Data drawn from clinical observations and basic studies support the primary role of an acute reduction in brain dopamine activity in the development of NMS. Additional studies of facilitating cofactors may lead to innovative risk-reduction strategies and the development of safer neuroleptic drugs.

Sympathoadrenomedullary activity in the neuroleptic malignant syndrome

Many clinical features of the neuroleptic malignant syndrome suggest that sympathetic nervous system hyperactivity is involved in the pathophysiology of this disorder. Only a few studies have examined levels of catecholamines or their metabolites in patients with NMS; results so far have been inconclusive. In the present study urinary catecholamine metabolites obtained during the course of NMS were studied with respect to frequently reported signs and symptoms of NMS. The principal findings are that (1) elevated urinary catecholamines and metabolites are a frequent but inconstant feature of NMS; (2) it is likely that sympathetic nervous system hyperactivity contributes to the picture of fulminant NMS; and (3) the role of the adrenal medulla in producing excess catecholamines during NMS is uncertain.