Neuroleptic malignant syndrome (NMS)

Neuroleptic malignant syndrome (NMS) is a rare but serious condition that affects the nervous system and causes a sudden change in how the body controls muscle movement and temperature. It usually happens after taking certain medications called antipsychotics that affect brain chemicals. People with NMS often develop a very high fever, severe muscle stiffness, and confusion. The condition can also cause problems with heart rate and blood pressure, making it dangerous if not treated quickly. NMS affects the body's ability to regulate itself, leading to symptoms that can worsen rapidly. It is important to recognize the signs early because it can be life-threatening without prompt medical care.

Neuroleptic malignant syndrome (NMS) is a life-threatening neurologic emergency characterized by dopamine receptor blockade in the central nervous system, typically triggered by exposure to dopamine antagonist medications such as antipsychotics or abrupt withdrawal of dopaminergic agents. The core pathology involves impaired dopaminergic transmission in the hypothalamus and basal ganglia, leading to hyperthermia, muscle rigidity, autonomic instability, and altered mental status. NMS presents with a classic tetrad of symptoms: severe muscle rigidity, hyperthermia, autonomic dysfunction (e.g., tachycardia, labile blood pressure), and altered consciousness ranging from agitation to coma. Laboratory findings often include elevated creatine kinase due to rhabdomyolysis and leukocytosis. The syndrome is a medical emergency due to risks of complications such as renal failure, respiratory failure, and cardiovascular collapse.