What is the approach to seizure prophylaxis (seizure prevention) in patients with stroke?

Seizure Prophylaxis in Stroke

Routine seizure prophylaxis is not recommended for patients with stroke, regardless of whether it is ischemic or hemorrhagic in nature. 1

Epidemiology and Risk Factors

Post-stroke seizures are classified as:

• Early seizures: Occurring within the first 7 days (most commonly within 24 hours)
• Late seizures: Occurring after 7 days from stroke onset

The incidence of post-stroke seizures varies:

• 2-23% in the first few days after stroke (likely closer to the lower end) 1
• 3-67% for late seizures 1
• Higher risk in patients with:
  • Cortical involvement 2
  • Hemorrhagic stroke vs. ischemic stroke 1, 3
  • Large territorial infarcts 2
  • Hemorrhagic transformation 1
  • Pre-existing dementia 1

Evidence Against Prophylactic AED Use

1. Lack of efficacy evidence: No data support prophylactic administration of antiepileptic drugs after stroke 1, 4

2. Potential harm:

   • Prophylactic AEDs may be associated with poorer outcomes 1
   • Many antiepileptic medications (especially phenytoin and benzodiazepines) can dampen neural plasticity mechanisms that contribute to post-stroke recovery 1

3. Cochrane review evidence: A 2022 meta-analysis found insufficient evidence to support routine AED use for primary or secondary seizure prevention after stroke (RR 0.65,95% CI 0.34-1.26) 4

Management Algorithm

1. For Patients Without Seizures

• Do not initiate prophylactic antiepileptic drugs 1
• Monitor for clinical seizures, especially in high-risk patients (cortical involvement, large infarcts, hemorrhagic stroke)
• Consider EEG monitoring for 24-48 hours in patients with unexplained decreased level of consciousness 1

2. For Patients Who Develop Seizures

• Initiate standard seizure management 1:
  • Search for reversible causes of seizures
  • Start appropriate antiepileptic medication
  • Consider levetiracetam as a preferred agent due to:
    • Fewer drug interactions
    • Favorable side effect profile
    • Ability to rapidly load IV 2

3. Special Considerations for Subarachnoid Hemorrhage

• While routine prophylaxis is still not generally recommended, some clinicians advocate for prophylactic therapy in specific high-risk subgroups with:
  • Thicker clot
  • Rebleeding 1
• If prophylaxis is considered, short-duration therapy may be inadequate 5

Monitoring and Follow-up

• For patients who have experienced a seizure after stroke:
  • Treat with standard antiepileptic approaches 1
  • Consider time-limited therapy for early seizures (within first week) as they may not require long-term treatment 3
  • For late seizures, longer-term antiepileptic therapy is typically warranted 3

Common Pitfalls to Avoid

1. Unnecessary prophylaxis: Exposing patients to potential medication side effects without proven benefit 2

2. Overlooking non-convulsive seizures: Failure to consider EEG monitoring in patients with unexplained altered mental status 1, 2

3. Inappropriate medication selection: Using agents like phenytoin that may impair recovery through effects on neural plasticity 1

4. Indefinite continuation: Failing to reassess the need for antiepileptic drugs in patients with early post-stroke seizures 2

5. Ignoring drug interactions: Not reviewing potential interactions between antiepileptic drugs and other stroke medications 2

The evidence clearly indicates that while seizures are a recognized complication of stroke, prophylactic antiepileptic medication does not improve outcomes and may potentially harm recovery. Treatment should be reserved for patients who actually develop seizures.