Atypical neuroleptic malignant syndrome: A systematic review of case reports

Overcoming clozapine's adverse events: a narrative review of systematic reviews and meta-analyses

INTRODUCTION

Clozapine is the gold standard treatment for treatment-resistant schizophrenia, however adverse events remain a clinical challenge.

AREAS COVERED

This review presents a narrative synthesis of systematic reviews and meta-analyses that have reported the onset, incidence, prevalence, and management of clozapine's adverse events. We conducted a systematic literature search using PubMed, Embase, PsycINFO, OvidMEDLINE, CINAHL, and the Cochrane Database of Systematic Reviews from inception to April 2024.

EXPERT OPINION

Effective management of clozapine's adverse events necessitates multi-faceted, individualized, and shared-decision strategies. Despite a lack of high-quality systematic evidence, expert inter-disciplinary solutions are provided to help address a critical need for clinical guidance. This 35-year update offers an evidence-based framework to assist clinicians, patients, and caregivers navigate the adverse events associated with clozapine therapy.

Muscle hypertrophy following acquired neurogenic injury: systematic review and analysis of existing literature

OBJECTIVES

Neurogenic muscle hypertrophy (NMH) is a rare condition characterized by focal muscle hypertrophy caused by chronic partial nervous injury. Given its infrequency, underlying mechanisms remain poorly understood. Inspired by two clinical cases, we conducted a systematic review to gain insights into the different aspects of NMH.

METHODS

We systematically searched online databases up until May 30, 2023, for reports of muscle hypertrophy attributed to acquired neurogenic factors. We conducted an exploratory analysis to identify commonly associated features. We also report two representative clinical cases.

RESULTS

Our search identified 63 reports, describing 93 NMH cases, to which we added our two cases. NMH predominantly affects patients with compressive radiculopathy (68.4%), negligible muscular weakness (93.3%), and a chronic increase in muscle bulk. A striking finding in most neurophysiological studies (60.0%) is profuse spontaneous discharges, often hindering the analysis of voluntary traces. Some patients exhibited features consistent with more significant muscle damage, including higher creatine phosphokinase levels, muscle pain, and inflammatory muscle infiltration. These patients are sometimes referred to in literature as "focal myositis." Treatment encompassed corticosteroid, Botulinum Toxin A, decompressive surgery, antiepileptic medications, and nerve blocks, demonstrating varying degrees of efficacy. Botulinum Toxin A yielded the most favorable response in terms of reducing spontaneous discharges.

INTERPRETATION

This systematic review aims to provide a clear description and categorization of this uncommon presentation of an often-overlooked neurological disorder. Though questions remain about the underlying mechanism, evidence suggests that aberrant fiber overstimulation along with increased workload that promotes focal damage may result in muscle hypertrophy. This may serve as a guide for therapeutic interventions.

What clinical analysis of antipsychotic-induced catatonia and neuroleptic malignant syndrome tells us about the links between these two syndromes: A systematic review

OBJECTIVES

Antipsychotic-induced catatonia (AIC) and neuroleptic malignant syndrome (NMS) are life-threatening adverse reactions to antipsychotic medication. We conducted a systematic review of literature following the PRISMA statement guidelines to obtain a description of these syndromes (population, context of occurrence, antipsychotic agents implicated) and draw conclusions about their links.

METHODS

We searched Medline and Web of science databases from January 1951 to May 2019 (further restricted from 2000 to 2019) using search terms including "catatonia", "neuroleptic malignant syndrome" and "antipsychotic agents" for case reports, case series and analytic studies. After screening 4082 records, 410 full-text articles (describing 555 events) were assessed for eligibility. We included events of AIC and/or NMS according to Diagnostic and Statistical Manual (DSM) criteria and extracted data about patients' characteristics, context of occurrence, antipsychotic agent(s) involved and treatment outcomes.

RESULTS

We included 165 events (16 AIC, 129 NMS and 20 AIC + NMS) from 144 case reports and case series. The most reported diagnosis was schizophrenia. Comorbid pre-existing conditions such as central nervous system diseases and acute medical events were common. Most of the events (63.3 %) occurred during antipsychotic monotherapy. Second-generation antipsychotics (SGAs, 63.8 %) were overall more implicated than first-generation antipsychotics (FGAs, 36.2 %).

DISCUSSION

Our findings highlight that any antipsychotic medication, even SGA monotherapy prescribed at recommended dose, is at risk for these side effects. FGAs and polypharmacy seem to represent risk factors for malignant catatonia in AIC. The clinical overlap observed between AIC and NMS events in our review suggests a clinical continuum between catatonia and NMS.

Neuroleptic Malignant Syndrome in Patients With Dementia: Experiences of A Single Memory Clinic

OBJECTIVES

Neuroleptic malignant syndrome (NMS) is a life-threatening condition that occurs as an adverse reaction to antipsychotic and antiemetic agents or sudden withdrawal of dopaminergic medications. Given the metabolic and functional reserves and the comorbidities in older adults, NMS may show an atypical course.

METHODS

The medical records of patients with neurodegenerative diseases leading to dementia between 2013 and 2020 were reviewed for the diagnosis of NMS. Demographic and clinical characteristics of the patients were obtained from the records of laboratory parameters, management, and length of stay.

RESULTS

Fifteen older adults (19 episodes) diagnosed with NMS were included. The median age was 76 years, and 5 were female. Ten of 15 NMS patients were atypical. Most of them had an infection accompanying NMS. Neuroleptic malignant syndrome was caused by antidopaminergic agents (5 antipsychotics, 1 metoclopramide) in 6 episodes and discontinuation of a dopaminergic agent, l -DOPA, in 12 episodes. In 1 patient, it was associated with simultaneous use of domperidone and amantadine withdrawal. Rigidity in NMS due to l -DOPA discontinuation was higher than in those due to antipsychotic use ( P = 0.027). Two of our patients needed intensive care, and 1 died.

CONCLUSIONS

This study highlights the high frequency of atypical NMS and the importance of early recognition of this potentially fatal syndrome, which can accompany neurodegenerative diseases and infections in older adults.

Serotonin Syndrome: The Role of Pharmacology in Understanding Its Occurrence

Serotonin syndrome (SS) is a potentially fatal adverse drug reaction characterized by an exaggerated increase in serotonergic activity in the central and peripheral nervous systems. It presents a constellation of signs and symptoms related to behavioral changes, neuromuscular excitability, and autonomic instability. These symptoms can occur in both mild and severe forms. SS can be triggered by the therapeutic use of a drug that increases serotonin (5-HT) availability in the synaptic cleft or by the co-administration of two or more drugs that provide this increase. With the escalating use of antidepressants by the world's population, this adverse reaction may be more recurrent. However, SS is often overlooked by patients or not diagnosed by doctors. This review aims to improve awareness about SS and provide a pharmacological perspective to explain its occurrence. Evidence shows that other neurotransmitters may also be involved with the pathology of SS. Furthermore, SS and neuroleptic malignant syndrome (NMS) seem to be part of the same pathological spectrum, especially in atypical NMS cases. The emergence of the syndrome's symptoms may be closely related to pharmacokinetic and/or pharmacodynamic polymorphisms that lead to an increase in the 5-HT available to or 5-HT signaling by specific receptors, thus constituting an important area for future investigations.

Síndrome neuroléptico maligno asociado con intoxicación aguda por un organofosforado: reporte de caso

El síndrome neuroléptico maligno es una condición clínica rara y potencialmente letal que frecuentemente se asocia con el uso de antipsicóticos. En la literatura especializada se encontró únicamente un reporte de caso relacionado con la ingestión de organofosforados. Se presenta un paciente con un cuadro clínico correspondiente al síndrome neuroléptico maligno posterior a la ingestión de clorpirifós. Como resultado de un intento de suicidio con el mencionado organofosforado, el hombre de 57 años presentó deterioro agudo del estado de consciencia, evolución neurológica tórpida e inestabilidad autonómica asociada a rigidez e hipertermia persistentes, así como incremento de la creatina-fosfocinasa (creatine phosphokinase, CPK). Se le administró tratamiento con bromocriptina, con lo cual el cuadro clínico remitió, y fue dado de alta sin secuelas. El diagnóstico del síndrome neuroléptico maligno es clínico y debe contemplarse en cualquier caso de exposición a sustancias que puedan resultar en una desregulación de la neurotransmisión dopaminérgica, con el fin de iniciar el tratamiento oportuno y contrarrestar efectivamente los efectos.

Widening spectrum of neuroleptic malignant syndrome: Case series

Neuroleptic malignant syndrome (NMS) is a rare and rapidly progressive syndrome with mortality rate of 5.6%. The spectrum of onset, progression and outcome is heterogeneous and is associated with number of risk factors. In our case series, we entail the triggers, hospital course and outcome of five interesting in-patient cases that were admitted to our service in a tertiary care hospital in Northern India. This case series is to highlight the first ever reported case of NMS triggered by levosulpiride administration, along with one of the few first cases of NMS after programming of DBS, hypothyroid disorders, levodopa readjustment and selective basal ganglia and cerebellar injury following the hyperthermic syndrome. This is also to bring to attention of clinicians worldwide the atypical risk factors of NMS, and stress the importance of staying vigilant for the same by frequent follow-ups and high degree of clinical suspicion. We also aim to generate epidemiological data about these atypical triggers.

Atypical neuroleptic malignant syndrome and non-alcoholic Wernicke's encephalopathy

We report the case of a middle-aged woman with a history of bipolar disorder, in the absence of alcohol or substance misuse. The patient had been maintained on fluphenazine decanoate depot and now presented acutely with cognitive dysfunction and rigidity. Laboratory tests revealed elevated creatine kinase, acute kidney injury with metabolic acidosis and transaminitis, leading to a provisional diagnosis of neuroleptic malignant syndrome (NMS). Neuroleptics were withheld; dialysis was commenced; and blood biochemistry parameters improved in tandem. However, mental status changes persisted, and re-evaluation revealed multidirectional nystagmus with bilateral past-pointing. MRI confirmed the diagnosis of Wernicke's encephalopathy (WE). Prompt recovery followed treatment with high-dose intravenous thiamine. We discuss the co-occurrence of NMS and non-alcoholic WE-highlighting the need for a high index of suspicion for these relatively rare neuropsychiatric diagnoses which are often missed in those with atypical presentations.

Atypical Neuroleptic Malignant Syndrome: Case Reports and Diagnostic Challenges

Neuroleptic malignant syndrome caused by atypical antipsychotic drugs may present in an atypical manner without symptoms such as hyperthermia and/or muscle rigidity. A detailed description of atypical neuroleptic malignant syndrome induced by atypical antipsychotic drugs, practical information to distinguish neuroleptic malignant syndrome from other related conditions, and the diagnostic criteria that may be used to settle the diagnosis of atypical neuroleptic malignant syndrome are highlighted in this paper. This study was conducted searching PubMed and Science Direct, resulting in 525 articles. 26 case reports that met inclusion criteria were identified. Atypical neuroleptic malignant syndrome was found to develop mainly in male patients suffering from schizophrenia (14 cases) and bipolar disorder (2), and was induced by clozapine (6 cases), olanzapine (5 cases), aripiprazole and quetiapine (4 cases). Muscle rigidity did not develop in patients treated with clozapine and quetiapine, whereas a lack of hyperthermia was common with aripiprazole and clozapine treatment. Atypical neuroleptic malignant syndrome is a difficult matter, especially when symptoms of hyperthermia or muscle rigidity is lacking, but using Levenson's or Adityanjee and Aderibigbe's criteria may increase it detectability, can permit earlier intervention and prevent development of life-threatening typical neuroleptic malignant syndrome.

COVID-19-associated psychosis: A systematic review of case reports

OBJECTIVES

To describe the comorbidities, presentations, and outcomes of adults with incident psychosis and a history of COVID-19.

METHODS

We completed a descriptive systematic review of case reports according to PRISMA guidelines, including cases of adult patients with incident psychosis and antecedent or concurrent COVID-19. We extracted patient demographics, comorbidities, clinical course, and outcomes, and assessed cases for quality using a standardized tool.

RESULTS

Of 2396 articles, we included 40 reports from 17 countries, comprising 48 patients. The mean age of patients was 43.9 years and 29 (60%) were males. A total of 7 (15%) had a documented psychiatric history, 6 (13%) had a substance use history and 11 (23%) had a comorbid medical condition. Delusions were the most common (44 [92%]) psychiatric sign and psychosis lasted between 2 and 90 days. A total of 33 (69%) patients required hospitalization to a medical service and 16 (33%) required inpatient psychiatric admission. The majority (26 [54%]) of cases did not assess for delirium and 15 (31%) cases were judged to be of high risk of bias.

CONCLUSIONS

Despite the growing awareness of COVID-19's association with incident psychosis at a population level, cases of COVID-19-associated psychosis often lacked clinically relevant details and delirium was frequently not excluded. PROSPERO registration number: CRD42021256746.

Reconsidering Rigidity in the Diagnosis of Neuroleptic Malignant Syndrome: A Case Report

Neuroleptic malignant syndrome (NMS) is a rare but potentially fatal syndrome classically encountered in patients receiving typical antipsychotic agents. However, many physicians have also reported the occurrence of NMS with atypical antipsychotics, notably with atypical presentations. In this report, we present a case in which a patient's antipsychotic regimen during a psychotic episode (which involved both typical and atypical antipsychotics) subsequently led to NMS. During his stay, the patient developed an altered level of consciousness, elevation of creatine phosphokinase, hemodynamic instability, and a fever. However, the patient did not have signs of rigidity, the cardinal sign of this syndrome. The authors concluded that patients could develop NMS without rigidity while receiving an antipsychotic. Given this presentation, the authors suggest that clinicians have a high level of suspicion for NMS to avoid misdiagnosis and subsequent adverse consequences. Hence, clinicians must be vigilant about atypical presentations of NMS without rigidity.