Neuroleptic malignant syndrome

Diagnostic and statistical manual of mental disorders (DSM-5-TR)[38]American Psychiatric Association. Diagnostic and statistical manual of mental disorders, 5th ed., text revision (DSM-5-TR). Washington, DC: American Psychiatric Publishing; 2022.​​

• Exposure to dopamine antagonist within past 72 hours

• Hyperthermia (>38.0°C [>100.4°F] on at least 2 occasions, measured orally) associated with profuse diaphoresis is a distinguishing feature from other neurological side effects of antipsychotic medications and other dopamine receptor blocking agents

• Generalised rigidity is a cardinal feature; may be associated with other neurological symptoms (e.g., tremor, sialorrhoea, akinesia, dystonia, trismus, myoclonus, dysarthria, dysphagia, rhabdomyolysis)

• Mental status alteration (delirium or altered consciousness ranging from stupor to coma)

• Creatine kinase elevation (at least 4 times upper limit of normal)

• Autonomic activation and instability, manifested by:

  • Tachycardia (rate >25% above baseline)

  • Blood pressure elevation (systolic or diastolic ≥25% above baseline)

  • Blood pressure fluctuation (≥20 mmHg diastolic change or ≥25 mmHg systolic change within 24 hours)

  • Diaphoresis

  • Urinary incontinence

  • Pallor

• Tachypnoea (rate >50% above baseline) is common, and respiratory distress can occur (due to metabolic acidosis, hypermetabolism, chest wall restriction, aspiration pneumonia, or pulmonary emboli) and may lead to sudden respiratory arrest.

ICD-11 classification of mental and behavioural disorders[56]World Health Organization. International statistical classification of diseases and related health problems. 11th revision. January 2022 [internet publication]. https://www.who.int/standards/classifications/classification-of-diseases

Chapter 8, Diseases of the nervous system; Movement disorders; Certain specified movement disorder (8A07); Other specified movement disorder (8A07.Y).