What is the appropriate post-seizure evaluation and management for a patient with a history of seizures?

Post-Seizure Evaluation and Management for Patients with a History of Seizures

For patients with a history of seizures who have experienced a new seizure event, a neuroimaging study should be performed in the emergency department when feasible, with careful assessment of risk factors for seizure recurrence to guide treatment decisions. 1

Initial Assessment

Immediate Evaluation

• Assess vital signs and neurological status
• Determine if patient has returned to baseline mental status
• Evaluate for any focal neurologic deficits
• Check for signs of trauma from seizure

Laboratory Testing

• Essential tests:
  • Serum glucose and sodium levels 1
  • Pregnancy test for women of childbearing age 1
• Consider based on clinical suspicion:
  • Complete metabolic panel (especially if on antiepileptic drugs)
  • Drug levels if patient is on antiepileptic medication
  • Toxicology screen if substance use is suspected 1

Neuroimaging

• Brain imaging (CT or MRI) is recommended in the ED for patients with:
  • New focal neurologic findings
  • History of trauma, malignancy, immunocompromise
  • Persistent headache
  • Anticoagulation therapy
  • Age >40 years
  • Focal seizure onset before generalization 1
• Deferred outpatient neuroimaging may be acceptable only when reliable follow-up is available 1

Risk Assessment for Recurrence

High Risk Factors for Seizure Recurrence

• Age ≥40 years
• Alcoholism
• Hyperglycemia
• Glasgow Coma Scale score <15
• History of CNS injury (stroke, trauma, tumor)
• Abnormal findings on neuroimaging 1

Early Seizure Recurrence Data

• Mean time to first seizure recurrence: 121 minutes
• 85% of early recurrences occur within 360 minutes (6 hours) 1
• Highest risk group: Alcoholic patients with history of seizures (25.2% recurrence rate) 1
• Lowest risk group: Non-alcoholic patients with new-onset seizures (9.4% recurrence rate) 1

Treatment Decisions

Antiepileptic Medication Initiation

1. For patients with provoked seizures:

   • Antiepileptic medication need not be initiated in the ED
   • Identify and treat the precipitating medical condition 1

2. For patients with unprovoked seizures without evidence of brain disease/injury:

   • Antiepileptic medication need not be initiated in the ED 1
   • Consider observation for at least 6 hours to monitor for recurrence

3. For patients with unprovoked seizure with history of brain disease/injury:

   • Consider initiating antiepileptic medication in the ED
   • Higher recurrence risk justifies treatment after a single seizure 1

Medication Selection (if treatment indicated)

• Levetiracetam may be preferred over phenytoin/fosphenytoin due to:
  • Fewer adverse effects 2
  • Demonstrated efficacy in reducing seizure frequency by 17-26% compared to placebo 3
  • Better cognitive outcomes 2

Disposition Decisions

Admission Criteria

• Patients who have not returned to baseline mental status
• Patients with new focal neurologic deficits
• Patients with abnormal findings on neuroimaging
• Patients with high risk of early seizure recurrence (alcoholics, abnormal CT)
• Patients without reliable follow-up

Safe for Discharge

• Patients with a first unprovoked seizure who have returned to clinical baseline in the ED need not be admitted 1
• Ensure:
  • Normal neurological examination
  • No concerning findings on neuroimaging (if performed)
  • Reliable follow-up arranged
  • Patient/family education about seizure precautions

Follow-up Planning

• Arrange neurology follow-up within 2-4 weeks
• Predictors of successful follow-up include:
  • Discharge on antiseizure medications
  • Younger age
  • Proximity to hospital 4
• Consider EEG as outpatient to evaluate for epileptiform abnormalities
• Provide clear instructions on medication management if initiated

Common Pitfalls to Avoid

• Failing to identify provoked seizures: Always search for medical causes including organ failure, electrolyte imbalance, medication effects, or withdrawal 5
• Inadequate observation time: Most early seizure recurrences occur within 6 hours of the initial seizure 1
• Missing non-convulsive status epilepticus: Consider in any patient with confusion or altered mental status 5
• Overlooking psychogenic non-epileptic seizures: Assess postictal breathing pattern (epileptic seizures typically have deep, regular, loud breathing with prolonged phases) 6
• Unnecessary long-term antiepileptic treatment: Most patients with secondary seizures do not have epilepsy and don't require long-term treatment 5