Neuroleptic malignant syndrome in children and adolescents: Systematic review of case reports

Abstract

Introduction: Neuroleptic malignant syndrome (NMS) is a rare and potentially fatal drug adverse reaction. There are still few studies of this entity in the child-adolescent population. Objectives: Describe the clinical, laboratory and therapeutic characteristics of children and adolescent patients with NMS. Analyse the grouping of symptoms present in NMS in the same population. Material and methods: A MEDLINE/PubMed search of all reported cases of NMS from January 2000 to November 2018 was performed and demographic, clinical, laboratory and therapeutic variables were identified. A factorial analysis of the symptoms was performed. Results: 57 patients (42 males and 15 females) were included, (mean age 13.65 ± 3.89 years). The onset of NMS occurred at 11.25 ± 20.27 days with typical antipsychotics and at 13.69 ± 22.43 days with atypical antipsychotics. The most common symptoms were muscle stiffness (84.2%), autonomic instability (84.2%) and fever (78.9). The most common laboratory findings were CPK elevation and leucocytosis (42.1%). The most used treatment was benzodiazepines (28.1%). In the exploratory factorial analysis of the symptoms we found 3 factors: 1) “Catatonic” with mutism (0.912), negativism (0.825) and waxy flexibility (0.522); 2) “Extrapyramidal” with altered gait (0.860), involuntary abnormal movements (0.605), muscle stiffness (0.534) and sialorrhoea (0.430); and 3) “Autonomic instability” with fever (0.798), impaired consciousness (0.795) and autonomic instability (0.387). Conclusions: NMS in children and adolescents could be of 3 types: catatonic, extrapyramidal and autonomic unstable.