← Diagnosis and Management Guides
New-Onset Seizure
Key considerations: Status epilepticus, CNS infection, Brain tumor
Cannot miss
- Status epilepticus
- CNS infection
- Brain tumor
- Intracranial hemorrhage
- Eclampsia
Likely diagnoses
- Provoked seizure (metabolic, toxic)
- Unprovoked seizure (epilepsy)
- Syncope mimicking seizure
- Psychogenic non-epileptic event
Red flags
- Ongoing seizure activity
- Focal neurologic deficit
- Fever with seizure
- Pregnancy
Workup
- history: Witnesses, prodrome, postictal state, medications, substance use, pregnancy; exam: Neurologic exam, signs of head trauma, tongue bite, incontinence; labs: Glucose, BMP (Na, Ca, Mg), CBC, toxicology screen, prolactin (limited utility); Pregnancy test in women of childbearing age; imaging: CT head (emergent); MRI brain (outpatient for first unprovoked); bedside: Glucose check, continuous SpO2
Management
- immediate: ABCs, position patient safely, benzodiazepines if ongoing seizure; Glucose if hypoglycemic; Treat underlying cause; general: First unprovoked seizure: AEDs not always required; Start AED if recurrence risk high, abnormal MRI, or EEG; Driving restrictions per state law
Disposition
- admit: Status epilepticus, acute symptomatic seizure, abnormal imaging, recurrent seizures; discharge: First unprovoked seizure with normal CT, neuro exam, and labs — with neuro follow-up; consults: Neurology for EEG and follow-up
Clinical pearls
- Most first seizures do not require chronic AED therapy — risk of recurrence is ~40% after first unprovoked seizure
- Always check glucose and pregnancy test — two rapidly treatable/dangerous causes
Source and review
- AAN First Seizure Practice Guideline 2015. Last reviewed: 2024-11-01