Central pontine myelinolysis

HSV Encephalitis

Neuroleptic Malignant SyndromeRia Dancel, MD

November 24, 2008

Neuroleptic Malignant Syndrome

• A rare but life-threatening reaction to a neuroleptic medication characterized by:– Mental status changes– Severe muscle rigidity – Fever– Autonomic instability

• Mortality estimated to be 10-20%

Clinical Manifestations1. Mental status changes:

– Initial symptom in 82%– Agitated delirium with confusion– Catatonic signs– Mutism– Evolution to profound encephalopathy and coma is typical

2. Muscular rigidity– “Lead pipe rigidity” throughout range of motion– Superimposed tremor– Sialorrhea, dysarthria, dysphagia

3. Hyperthermia4. Autonomic instability

– Tachycardia most common– Labile blood pressure– Tachypnea– Diaphoresis

Pathophysiology

The Usual Suspects

• Most often seen with typical antipsychotics– Haloperidol– Fluphenazine

• Also seen with low potency and atypical antipsychotics– Chlorpromazine (Thorazine)– Risperidone (Risperdal)– Olanzepine (Zyprexa)– Clozapine (Clozaril)

• And antiemetic drugs– Promethazine (Phenergan)– Metaclopramide (Reglan)– Prochlorperazine (Compazine)

Risk factors

• Male:female::2:1• Agitation or catatonia• Rapid initiation or dose escalation of

neuroleptics• Parenteral administration• Concomitant use of lithium or anticholinergics• History of organic brain disorder• Dehydration• Prior episode of NMS

Complications

• Rhabdomyolysis• Renal failure• Seizures• Respiratory failure• Aspiration pneumonia• Decompensation of psychiatric disease

with the withdrawal of neuroleptics• DIC

Management

• Admit to ICU• Stop offending agent and potentially

contributing psychotropic agents (lithium, anticholinergics, serotonergics)

• IVF to maintain euvolemia; even high volume IVF in cases of rhabdo

• Cooling methods• Lower BP with clonidine or nitroprusside

Management

• Pharmacologic therapy is largely unsupported by clinical trials

• Dantrolene – direct-acting muscle relaxant

• Bromocriptine – a dopamine agonist used to restore dopaminergic tone. Can also use amantidine

• Benzodiazepines – aid in muscle relaxation and anxiety

References

• Strawn JR, Keck PE, Caroff SN. Neuroleptic malignant syndrome. Am J Psychiatry 164: 870-876, June 2007

• Adnet P, Lestavel P, Krivosic-Horber R. Neuroleptic malignant syndrome. British Journal of Anaesthesia 85,1: 129-135, 2000

• Uptodate