Should patients with intracerebral hemorrhage receive seizure prophylaxis, and what regimen is recommended for high‑risk cases?

Seizure Prophylaxis in Intracerebral Hemorrhage

Routine prophylactic antiseizure medications should NOT be used in patients with intracerebral hemorrhage, as they do not prevent seizures or improve functional outcomes and may cause harm. 1

Core Recommendation

The 2022 AHA/ASA guidelines explicitly advise against routine seizure prophylaxis in ICH patients. Prophylactic antiseizure drugs have been shown to increase adverse events and worsen functional outcomes at 90 days without reducing early or late seizure occurrence. 1 The most recent Neurocritical Care Society guideline (2025) reinforces this, suggesting avoidance of prophylactic ASMs in hospitalized adults with acute nontraumatic ICH 2.

When to Treat (Not Prophylax)

Antiseizure medications should ONLY be initiated when:

• Clinical or electrographic seizures are documented and suspected to contribute to impaired consciousness 1
• The patient has impaired or fluctuating consciousness out of proportion to the degree of brain injury or metabolic abnormalities 1

Monitoring Strategy for High-Risk Patients

If seizures are clinically suspected:

• Obtain continuous EEG monitoring for at least 24 hours (minimum) 1
• For comatose patients, extend monitoring to 48 hours or longer - 36% of comatose patients required >24 hours to detect first seizure, and 94% of all electrographic seizures were detected by 48 hours 1
• Do not rely on clinical observation alone - many seizures are purely electrographic without obvious motor manifestations 1

Evidence Against Prophylaxis

Why Prophylaxis Fails:

• No reduction in early seizures (<14 days): Meta-analyses show prophylactic ASMs do not prevent early seizures 1, 3, 2
• No reduction in late seizures (>7 days): Prophylaxis does not prevent long-term seizure development 1, 3, 2
• Worse functional outcomes: Increased risk of poor functional outcomes (mRS ≥3) at 90 days with prophylaxis 2
• Increased adverse events: Higher rates of adverse events without mortality benefit 2
• Cognitive impairment: Specific cognitive domains may be negatively affected 1

Historical Context:

Earlier studies showing harm used phenytoin, which was associated with worse outcomes 1. While levetiracetam has become more common as a supposedly safer alternative 1, even newer meta-analyses with levetiracetam show no functional benefit 2, 4.

Conflicting Evidence Caveat

Important nuance: Two recent studies (2025) suggest prophylactic ASMs may reduce early seizures in highly selected high-risk subgroups:

• Lobar hemorrhage location 3, 5
• Age <65 years with lobar ICH and volume ≥10 mL 5
• Patients undergoing surgical intervention 3

However, even in these studies, seizure reduction did not translate to improved functional outcomes 3, 5, 4. The 2025 Neurocritical Care Society guideline reviewed this evidence and still recommended against routine prophylaxis 2.

If Prophylaxis is Used Despite Guidelines

In the rare circumstance where prophylaxis is deemed necessary (e.g., institutional protocol for surgical cases):

• Agent of choice: Levetiracetam over phenytoin/fosphenytoin (less harm, though no proven benefit) 1, 2
• Duration: ≤7 days maximum - longer duration provides no additional benefit and increases adverse events 2
• Do NOT use risk scores (e.g., CAVE score) to guide continuation - no evidence that ASMs prevent late seizures regardless of risk stratification 1

Alternative Consideration:

One network meta-analysis (2026) suggested valproate had the best ranking for preventing early seizures and improving functional outcomes, though this was based on very low certainty evidence and ranking probabilities rather than statistically significant differences 6. This requires validation in prospective trials before clinical adoption.

Common Pitfalls to Avoid

• Do not reflexively start ASMs for lobar hemorrhage - while clinicians commonly do this 3, guidelines do not support it 1, 2
• Do not continue prophylaxis beyond 7 days - no benefit and increased harm 2
• Do not use phenytoin - if ASMs are necessary, levetiracetam is preferred 1, 2
• Do not skip EEG monitoring in patients with unexplained altered consciousness - purely electrographic seizures are common and require detection for treatment 1

Clinical Algorithm

1. ICH patient with normal consciousness or proportionate impairment: No prophylaxis 1, 2

2. ICH patient with impaired/fluctuating consciousness out of proportion to injury:

   • Initiate continuous EEG monitoring (24-48 hours) 1
   • If electrographic seizures detected → treat with ASM 1
   • If no seizures detected → no ASM 1, 2

3. Clinical seizure witnessed: Treat with ASM (this is treatment, not prophylaxis) 1

The evidence is clear: prophylaxis does not improve outcomes that matter to patients (mortality, disability, quality of life) and may cause harm. 2