Diagnosis
Hunter Criteria
- Must have a serotonergic exposure
- The diagnosis is made in any of the following situations:
- Spontaneous clonus
- Either ocular clonus or inducible clonus, plus either agitation or diaphoresis
- Tremor plus hyperreflexia
- Hypertonia, plus temperature over 38C, plus either ocular clonus or inducible clonus
- Sensitivity 84% and specificity 97%
Sternbach Criteria
- Recent addition or increase in a known serotonergic agent
- Absence of other possible etiologies such as infection, substance abuse
- No recent addition or increase of a neuroleptic agent
- At least three of the following:
- Mental status changes such as confusion or hypomania
- Agitation
- Myoclonus
- Hyperreflexia
- Diaphoresis
- Shivering
- Tremor
- Diarrhea
- Incoordination or ataxia
- Fever
- False positives are common
Clinical Manifestations
- Fever, rigidity, clonus, diaphoresis, tremor, and agitation
- Compared to NMS, SS is more likely to have:
- Acute onset
- Sialorrhea, hyperactive bowel sounds
- Hyperreflexia and clonus
- Mydriasis
Management
- Stop all serotonergic drugs
- Supportive therapy
- Sometimes can use
- Cyproheptadine but is PO and takes 24-48h
- Olanzapine 10mg IV BID
