Neurocritical Care

Feature

Serotonin Syndrome

Neuroleptic Malignant Syndrome

Trigger drug

Drug with serotonergic effect

Drug with dopaminergic effect, often

antipsychotics

Onset

Usually within 24 hours

Onset over days to weeks

Remission of symptoms

Rapid remission following dis-

continuation of the trigger drug

Gradual remission following discontinuation

of the trigger drug

Neurologic symptoms

Neuromuscular hyperactivity:

tremor, clonus, hyperreflexia

Neuromuscular hypoactivity: Extrapyramidal

symptoms, hypokinesia, and lead tube rigidity

Information from: Mikkelsen N, Damkier P, Arnspang Pedersen S. Serotonin syndrome – a focused review. Basic Clin Pharmacol Toxicol. 2023;133(2):124-129. https://

doi.org/10.1111/bcpt.13912

Removal of precipitating drugs/factors – Mild symptoms may resolve in 24–72 hours; if caused by

antidepressants, may take weeks to resolve

Control of autonomic hyperactivity – Hypotension treatment with direct-acting sympathomimetics

Control of hyperthermia

Cooling blanket

Sedation, neuromuscular paralysis, intubation

Avoid succinylcholine.

Serotonin-2A antagonist blocks serotonin receptors implicated with serotonin syndrome.

Cyproheptadine 12–32 mg/24 hours by mouth or feeding tube. A 12-mg loading dose; then 2 mg

every 2 hours as symptoms continue

Chlorpromazine 50–100 mg intramuscularly

Catheters are typically inserted under sterile conditions at the bedside.

Antibiotic-coated catheters are available for patients at high risk of infection.

Temporary catheters

Used primarily in the ICU

Ventriculostomy (a.k.a. external ventricular drain) – Diagnostic and therapeutic

Catheter inserted into frontal horn of lateral ventricle

ii.

Transduces ICP; should be calibrated to zero routinely

iii.

Higher infection rate than with intraparenchymal catheter; insertion is more difficult

(particularly with brain swelling)

iv.

Permits drainage of CSF and intraventricular hemorrhage

Permits intraventricular drug administration

Intraparenchymal catheter

Wire that sits in brain tissue

ii.

Transduces ICP

iii.

Low infection rate, fewer complications with insertion