Seizure Prophylaxis in Intracerebral Hemorrhage
Prophylactic antiseizure medications should NOT be routinely administered to patients with intracerebral hemorrhage, as they do not prevent seizures and are associated with worse functional outcomes and increased adverse events. 1, 2
Evidence Against Routine Prophylaxis
The 2022 AHA/ASA guidelines clearly state that prophylactic antiseizure drugs after spontaneous ICH have not consistently shown benefit for preventing early (<14 days) or long-term seizures, and may negatively affect cognitive function. 1
- Meta-analyses demonstrate that seizure prophylaxis does not prevent early or late seizures in ICH patients. 1
- Prophylactic antiseizure medications are associated with increased adverse events and higher risk of poor functional outcomes at 90 days. 2
- Earlier studies with phenytoin showed worse outcomes, and while levetiracetam has a better safety profile, it still does not demonstrate clear benefit for prophylaxis. 1
- The Neurocritical Care Society 2025 guidelines recommend avoiding prophylactic antiseizure medications in hospitalized adults with acute nontraumatic ICH (weak recommendation, very low quality evidence). 2
When to Treat Seizures (Not Prophylaxis)
Antiseizure medications should be initiated only when clinical or electrographic seizures are documented and suspected to contribute to impaired consciousness. 1
Clinical Scenarios Requiring EEG Monitoring:
- Patients with impaired or fluctuating level of consciousness out of proportion to the degree of brain injury or metabolic abnormalities. 1
- Continuous EEG monitoring for at least 24-48 hours is reasonable when seizures are clinically suspected, as 28% of electrographic seizures are detected after 24 hours, and 94% by 48 hours. 1
- Among comatose patients, 36% required >24 hours of monitoring to detect the first seizure. 1
Treatment of Documented Seizures:
- Clinical or electrographic seizures contributing to altered mental status should be treated with antiseizure medications. 1, 3
- Levetiracetam is preferred over phenytoin/fosphenytoin due to better tolerability and fewer adverse effects. 3, 2
- If prophylaxis is used despite guidelines, duration should be ≤7 days rather than long-term. 2, 4
Risk-Guided Approach (If Prophylaxis Considered)
If clinicians choose to use prophylaxis despite guideline recommendations against routine use, a decision analysis suggests a risk-guided strategy using the 2HELPS2B score: 4
- Low-risk patients (2HELPS2B score = 0): Short-term (7-day) secondary prophylaxis only after documented early seizure
- Higher-risk patients (2HELPS2B score ≥1): Consider short-term (7-day) primary prophylaxis
- Long-term therapy only after documented late seizure (>7 days)
High-Risk Features for Seizures:
- Lobar hematoma location (most influential factor, 30% weight in physician decision-making). 5
- Depressed level of consciousness (24% weight). 5
- Larger hematoma volume (>10 mL). 5
- Cortical involvement. 1, 3
Common Pitfalls to Avoid
- Do not use risk scores to justify continuation of prophylactic antiseizure drugs beyond 7 days, as there is no evidence they prevent late seizures. 1
- Do not assume that early seizures worsen outcomes—prospective studies show early seizures are not independently associated with worse neurological outcomes or mortality. 1, 3
- Avoid phenytoin if antiseizure medication is necessary, as it has been specifically associated with poor outcomes in ICH. 1
- Recognize that electrographic seizures occur in 28-31% of selected ICH cohorts on continuous EEG, despite most receiving prophylactic medications, indicating prophylaxis is ineffective. 3
Medication Selection (When Treatment Required)
If treating documented seizures or if prophylaxis is deemed necessary despite guidelines: