Do patients with subdural hematomas require prophylactic Keppra (levetiracetam)?

Prophylactic Levetiracetam for Subdural Hematomas

Prophylactic antiepileptic drugs are not recommended for patients with subdural hematomas who have not experienced seizures. This recommendation is based on current evidence showing limited benefit and potential harm from routine seizure prophylaxis.

Evidence-Based Recommendation

The 2018 guidelines for management of severe traumatic brain injury explicitly state that antiepileptic drugs are not suggested for primary prevention of post-traumatic seizures 1. Multiple studies have shown no significant effect of antiepileptic drugs in preventing early or delayed post-traumatic seizures, with some evidence suggesting potential worsening of neurological outcomes with prophylactic use.

Risk Assessment for Subdural Hematomas

The risk of seizures in patients with isolated subdural hematomas and preserved consciousness is remarkably low:

• Only 2.2% of patients with isolated subdural hematomas and preserved consciousness experience seizures during hospitalization 2
• No significant difference in seizure rates between patients who received prophylactic antiepileptic drugs (2.3%) and those who did not (1.9%) 2

Specific Considerations

When evaluating subdural hematoma patients, consider:

1. Hematoma thickness: The only variable significantly associated with increased seizure risk is greater thickness of the subdural hematoma (OR 1.16, p=.005) 2

2. Chronic subdural hematomas: These may have different risk profiles than acute subdurals, with one older study suggesting benefit from prophylaxis 3, though this has not been supported by more recent evidence

3. Midline shift: Patients with midline shift >0mm may have an increased risk of electrographic seizures when on levetiracetam compared to phenytoin 4

When Seizure Prophylaxis Might Be Considered

While routine prophylaxis is not recommended, certain high-risk situations might warrant consideration:

• Patients with a history of epilepsy
• Chronic subdural hematomas with specific risk factors
• Patients undergoing neurosurgical procedures with additional risk factors

Choice of Antiepileptic Drug When Needed

If seizure prophylaxis is deemed necessary based on individual risk factors:

• Levetiracetam is preferred over phenytoin due to its better side effect profile 1
• Dosing of >1000mg total daily dose may be more effective than lower doses 5
• Levetiracetam is associated with fewer adverse effects than phenytoin 4

Monitoring Recommendations

For patients who do require seizure prophylaxis:

• Monitor for behavioral side effects with levetiracetam
• Consider EEG monitoring in patients with depressed neurological examination or fluctuating level of consciousness
• Limit prophylaxis duration as extended use has not shown benefit in preventing late seizures

Key Pitfalls to Avoid

1. Assuming all brain injuries require seizure prophylaxis
2. Continuing prophylactic antiepileptic drugs beyond the acute period without clear indication
3. Using phenytoin as first-line therapy due to its less favorable side effect profile
4. Overlooking potential drug interactions with other medications

The evidence clearly shows that routine seizure prophylaxis for subdural hematomas does not improve outcomes and may potentially cause harm through medication side effects and interactions.