Neuroleptic malignant syndrome requiring intensive care unit admission: a case report

Introduction

Neuroleptic malignant syndrome (NMS) is a life-threatening condition associated with the use of dopamine receptor antagonist medications or the rapid withdrawal of dopaminergic agents. NMS has been linked to nearly all neuroleptic drugs but is more commonly reported with typical antipsychotics. The classic clinical features include altered mental status, fever, muscle rigidity, and autonomic instability. [1] Here, we present a complicated case of neuroleptic malignant syndrome requiring intensive care unit management.

Case A 47 year-old male patient with a diagnosis of schizophrenia was brought to the emergency department by his relatives due to impaired consciousness, muscle rigidity, and hypersalivation. He had been regularly taking clozapine 200 mg, fluvoxamine 100 mg, and paliperidone long acting injectable(LAI) 150 mg. In addition, intramuscular zuclopenthixol acetate had been administered at two day intervals, and paliperidone LAI was given 10 days earlier than scheduled, eleven days prior to admission to the emergency department.

Laboratory findings revealed elevated levels of transaminases, creatine kinase, and white blood cell count. After five days of treatment in the intensive care unit, he was referred to the neurology clinic. His level of consciousness was consistent with stupor, and marked “lead-pipe” rigidity was observed in both arms. He also presented with fever and tachycardia. A psychiatry consultation was requested. Discontinuation of antipsychotic medications, along with hydration, bromocriptine, and lorazepam treatment, was recommended. The patient’s general condition gradually improved during follow up, and he was transferred to the psychiatry clinic in the third week of hospitalization

Discussion

NMS is a neurological emergency, and delays in diagnosis and treatment can lead to significant morbidity and mortality. Discontinuation of the offending agent is the most critical step, followed by supportive therapy. [1] Major predisposing factors for NMS include male sex, young age, comorbid organic brain disease, alcoholism, Parkinson’s disease, hyperthyroidism, antipsychotic polypharmacy, and the combination of antipsychotics with selective serotonin reuptake inhibitors(SSRI)[2]. In this case, the patient was male, receiving multiple antipsychotic medications, and using a combination of antipsychotics and an SSRI. Supportive management such as correction of dehydration and electrolyte imbalances, prevention of infection and thrombosis, and management of hyperthermia is essential in reducing morbidity and mortality. Pharmacological treatment options commonly include dopaminergic agents such as bromocriptine. Amantadine, dantrolene, and benzodiazepines are also recommended. Treatment should be continued for at least two to three weeks until symptoms completely resolve. If antipsychotic therapy needs to be reinitiated after recovery, it should be started at low doses with slow titration, while avoiding dehydration. Electroconvulsive therapy may also be considered as an alternative treatment option.

Conclusion

In conclusion, NMS is a serious and life threatening condition. Early diagnosis and appropriate treatment are crucial in reducing morbidity and mortality. Although NMS is primarily a psychiatric diagnosis, its management requires a complex and systematic approach. Therefore, patients presenting with suspicious signs and symptoms following neuroleptic use should be carefully monitored, and appropriate treatment should be initiated promptly.

References

Simon LV, Hashmi MF, Callahan AL., 2023 Apr 24. Neuroleptic Malignant Syndrome. StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing. PMID:29489248
Taylor D, Gaughran F, Pillinger T., 2021. The Maudsley Practice Guidelines for Physical Health Conditions in Psychiatry, 1st ed. John Wiley & Sons Ltd