82 - Neuroleptic Malignant Syndrome

Abstract

The neuroleptic malignant syndrome is a rare and potentially fatal syndrome of hyperthermia, rigidity, autonomic instability, and mental status derangement. It is an idiosyncratic reaction to drugs that alter the dopaminergic pathways of the central nervous system (CNS). This chapter describes the clinical features, associated medications and risk factors, differential diagnosis, and pathogenesis of neuroleptic malignant syndrome. The potential symptoms of neuroleptic malignant syndrome can be grouped into four general areas—namely, hyperthermia, muscular rigidity, mental status changes, and autonomic dysfunction. Phenothiazine, thiothixene, and butyrophenones are the agents most commonly implicated in causing neuroleptic malignant syndrome. The differential diagnosis of neuroleptic malignant syndrome includes other syndromes with hyperthermia as a prominent feature, fever complicating Parkinson's disease (PD) or other extrapyramidal syndromes, and lethal catatonia. Common infectious and metabolic disorders must be ruled out before making the diagnosis of neuroleptic malignant syndrome. Therapy with dopamine (DA) agonists—such as bromocriptine—reduces the recovery time of neuroleptic malignant syndrome. Early diagnoses resulting in prompt supportive measures in combination with drug therapy have significantly reduced the mortality from neuroleptic malignant syndrome.