What is the recommended workup and initial management for a patient presenting with a seizure?

Seizure Workup and Initial Management

For adult patients presenting with a first generalized convulsive seizure who have returned to baseline, emergency physicians need not initiate antiepileptic medication in the ED for unprovoked seizures without evidence of brain disease or injury 1.

Initial Diagnostic Evaluation

History and Physical Examination - Key Elements

When evaluating seizure presentations, obtain:

• Witness accounts of the event, including smartphone videos if available 2
• Semiological features: duration, focal vs. generalized onset, post-ictal state
• Provoking factors: sleep deprivation, alcohol/drug use, medication changes, metabolic disturbances
• Past medical history: prior stroke, traumatic brain injury, CNS infection, tumor - these constitute "remote symptomatic" seizures with higher recurrence risk 1

Laboratory Workup

Emergency blood tests should include:

• Glucose (hypoglycemia as acute cause)
• Electrolytes, particularly sodium (hyponatremia)
• Drug/alcohol screening when clinically indicated 3
• Additional metabolic panels based on clinical context

Neuroimaging

Brain imaging is essential to differentiate provoked from unprovoked seizures:

• CT head is appropriate for initial ED evaluation, particularly for first seizures 3
• MRI with epilepsy protocol is preferred when available and provides superior detection of structural lesions 4, 5

Electroencephalography (EEG)

EEG helps characterize seizure type and recurrence risk but is typically obtained in the outpatient setting rather than emergently in the ED 4, 5.

Decision to Initiate Antiepileptic Medication

DO NOT Start Antiepileptic Drugs For:

1. Provoked (acute symptomatic) seizures - treat the underlying cause instead (hypoglycemia, hyponatremia, infection, drug toxicity) 1

2. First unprovoked seizure without brain disease/injury - recurrence risk is only 33-50% over 5 years, and early treatment doesn't change long-term outcomes 1

CONSIDER Starting Antiepileptic Drugs For:

First unprovoked seizure WITH remote history of:

• Stroke
• Traumatic brain injury
• CNS infection
• Structural brain lesion on imaging

These patients have substantially higher recurrence risk (approaching 75%) 1. The decision may be initiated in the ED or deferred in coordination with neurology follow-up.

Important caveat: For first unprovoked seizures, the number needed to treat is 14 to prevent one recurrence in the first 2 years, and 5-year outcomes are identical whether treatment starts immediately or after a second seizure 1.

Management of Status Epilepticus

First-Line Treatment: Benzodiazepines

Administer optimal dosing of benzodiazepines immediately for ongoing seizure activity.

Second-Line Treatment for Refractory Status Epilepticus

Emergency physicians should administer a second-line agent for seizures refractory to appropriately dosed benzodiazepines. Fosphenytoin, levetiracetam, or valproate may be used with similar efficacy 6.

The 2024 ACEP guideline provides Level A evidence that these three agents have equivalent efficacy for benzodiazepine-refractory status epilepticus 6.

Medication Options and Dosing:

Levetiracetam 1:

• Dose: 30-50 mg/kg IV (typically 2,500-3,000 mg) at 100 mg/min
• Advantages: Minimal hypotension, no cardiac dysrhythmias, safe adverse effect profile
• Adverse effects: Nausea, transient transaminitis (rare)
• Efficacy: 67-73% seizure cessation in refractory status epilepticus

Fosphenytoin 1, 6:

• Dose: 18-20 PE/kg IV
• Adverse effects: Hypotension, cardiac dysrhythmias
• Efficacy: 56-88% depending on study

Valproate 1:

• Dose: 20-30 mg/kg IV at 40 mg/min (or 30 mg/kg at 6 mg/kg/hour)
• Advantages: No hypotension compared to phenytoin, effective in 88% of cases
• Adverse effects: Thrombocytopenia, liver toxicity, hyperammonemia
• Superior to phenytoin as second-line agent: 79% vs 25% efficacy (NNT 1.9) 1

Third-Line Options for Continued Refractory Status:

If seizures persist after benzodiazepines plus one second-line agent:

Propofol 1:

• Dose: 2 mg/kg bolus, may repeat in 3-5 minutes; maintenance 5 mg/kg/hour
• Requires intubation and mechanical ventilation
• Fewer ventilator days than pentobarbital (4 vs 14 days)
• Less hypotension than barbiturates (42% vs 77%)

Phenobarbital 1:

• Dose: 10-20 mg/kg; may repeat 5-10 mg/kg at 10 minutes
• Adverse effects: Respiratory depression, hypotension
• Efficacy: 58% as initial medication in VA cooperative trial

Disposition Decisions

Emergency physicians need not admit patients with a first unprovoked seizure who have returned to their clinical baseline in the ED 1.

Admission Criteria:

Consider admission for:

• Status epilepticus or recurrent seizures in ED
• Persistent altered mental status
• Acute symptomatic seizure requiring treatment of underlying condition
• Significant comorbidities or inability to ensure outpatient follow-up

Outpatient Follow-up:

Standardized pathways reduce time to neurology follow-up from 41 days to 23.5 days 3. Arrange neurology consultation within 2-4 weeks for:

• EEG evaluation
• Epilepsy-protocol MRI if not obtained
• Seizure recurrence risk stratification
• Antiepileptic drug decision-making if indicated

Safety Counseling:

Provide explicit counseling on:

• Driving restrictions per state law (typically 3-12 months seizure-free)
• Avoiding heights, swimming alone, operating heavy machinery
• Seizure precautions and rescue plans
• Medication compliance if treatment initiated

Common Pitfalls

1. Over-treating first unprovoked seizures: Most patients don't require immediate antiepileptic drugs; outcomes at 5 years are identical whether treatment starts after first or second seizure 1

2. Under-recognizing remote symptomatic seizures: History of stroke, TBI, or CNS disease substantially increases recurrence risk and may warrant treatment after first seizure 1

3. Inadequate benzodiazepine dosing before declaring status epilepticus "refractory": Ensure optimal first-line treatment before escalating 1

4. Choosing phenytoin over safer alternatives: Valproate and levetiracetam have superior safety profiles with equivalent or better efficacy 1, 6

5. Failing to search for treatable causes: Always evaluate for hypoglycemia, hyponatremia, hypoxia, infection, drug toxicity, and withdrawal syndromes 1