Psych - Neuroleptic Malignant Syndrome

Question 1

What is NMS?

Answer 1

• Rare, dangerous condition in patients taking antipsychotics.
• 10% mortality, usually occurs with atypical antipsychotics or dopaminergic drugs for Parkinson’s disease (usually when drug is stopped suddenly)

Question 2

What is the pathophysiology of NMS?

Answer 2

• Unknown
• Theory is that the dopamine blockages induced by antipsychotics triggers a massive glutamate release and there is subsequent neurotoxicity and muscle damage

Question 3

When does NMS occur? What are the features?

Answer 3

-Within hours of starting an antipsychotic

PC

• Pyrexia
• Muscle rigidity
• Autonomic lability: HTN, tachycardia and tachypnea
• Agitated delirium with confusion

Question 4

What are important Ix and Ex finding for NMS?

Answer 4

Investigations

• Raised creative kinase
• AKI (secondary to rhabdomyolysis)
• Leukocytosis

Examination

• Slower onset (hours-days)
• Hyporeflexia
• Lead pipe rigidity
• Normal pupils

Question 5

What is the management for someone with NMS?

Answer 5

• Stop antipsychotic
• Transfer patient to a medical ward if they are on psych ward
• IV fluids to prevent renal failure
• Dantrolene: thought to work by decreasing excitation-contraction coupling in the skeletal muscle by binding to the ryanodine receptor and decreasing the release of calcium from sarcopasmic reticulum
• Bromocriptine: dopamine agonist