Is antiepileptic medication required in patients with subdural hematoma?

From the Guidelines

Anti-epileptic medication is not routinely required for all patients with subdural hematoma, and prophylactic use should be individualized based on the patient's specific clinical situation and risk profile. The most recent and highest quality study, published in 2023 1, recommends that prophylactic antiseizure medication may be reasonable to prevent seizures in patients with high-seizure-risk features, such as ruptured MCA aneurysm, high-grade SAH, ICH, hydrocephalus, and cortical infarction. However, in patients without high-seizure-risk features, prophylactic treatment with antiseizure medication is not beneficial.

Key Considerations

• The incidence of post-traumatic seizures in patients with subdural hematoma is relatively low, ranging from 2.2% to 11.9% in the first year after injury 1.
• Risk factors for delayed clinical seizures include brain contusion, acute subdural hematoma, skull fracture, initial loss of consciousness or amnesia for more than 24 hours, and age over 65 years 1.
• The use of antiepileptic drugs for primary prevention of post-traumatic seizures has not been shown to be effective, and may even be associated with increased side effects and worsening neurological outcome 1.
• When anti-seizure medication is indicated, levetiracetam (Keppra) is commonly prescribed at 500-1000 mg twice daily, or phenytoin (Dilantin) with a loading dose of 15-20 mg/kg followed by maintenance doses of 300-400 mg daily.

Treatment Recommendations

• Prophylactic anti-seizure medications should only be recommended for patients who have experienced seizures after the hematoma or who have high risk factors for seizures.
• Treatment decisions should be individualized based on the patient's specific clinical situation, neurological status, and risk profile.
• Continuous EEG monitoring should be considered in patients with depressed mental status that is disproportionate to the degree of brain injury 1.

From the Research

Seizure Prophylaxis in Subdural Hematoma

• The use of anti-epileptic medication in subdural hematoma is a topic of ongoing research, with studies investigating the efficacy of different medications in preventing seizures 2, 3, 4, 5, 6.
• A study comparing levetiracetam and phenytoin for seizure prophylaxis in subdural hematomas found that both medications had similar efficacy, but levetiracetam was associated with a lower risk of adverse events 2.
• Another study found that acute-on-chronic subdural hematoma has a high risk of acute symptomatic seizures and is associated with unfavorable outcomes and high mortality, suggesting that prophylactic treatment with antiepileptic drugs may be beneficial in this patient population 3.
• A systematic review of epileptic seizures in adults with subdural hematomas found that the overall incidence of early and late post-traumatic seizures was 28% and 43% in acute subdural hematoma, and 5.3% and 10% in chronic subdural hematoma 4.
• The review also found that phenytoin and levetiracetam had similar efficacy in preventing post-traumatic seizures, but levetiracetam was associated with significantly lower adverse effects 4.
• A prospective, randomized, case-control study found that levetiracetam did not reach therapeutic levels in cerebrospinal fluid when loaded at standard dosing regimens in the acute setting, while phenytoin did reach therapeutic levels when dosages approximated weight-based dosing 5.
• A review of the medical management of subdural hematomas emphasized the importance of seizure prevention and treatment, as well as the management of intracranial hypertension, maintenance of adequate cerebral perfusion, and maintenance of normothermia, eucarbia, euglycemia, and euvolemia 6.

Risk Factors for Seizures in Subdural Hematoma

• Studies have identified several risk factors for seizures in patients with subdural hematomas, including:
  • Low Glasgow Coma Score (GCS) 4
  • Craniotomy 4
  • Alcohol abuse 4
  • Change of mental status 4
  • Previous stroke 4
  • Density of hematoma in computer tomography 4
• The presence of these risk factors may indicate a higher likelihood of seizures in patients with subdural hematomas, and may inform the decision to use prophylactic anti-epileptic medication 4.

Anti-Epileptic Medication in Subdural Hematoma

• The choice of anti-epileptic medication in subdural hematoma depends on several factors, including the patient's medical history, the presence of risk factors for seizures, and the potential for adverse effects 2, 4, 5.
• Levetiracetam and phenytoin are two commonly used medications for seizure prophylaxis in subdural hematomas, with levetiracetam associated with a lower risk of adverse events 2, 4.
• However, phenytoin may be more effective in reaching therapeutic levels in cerebrospinal fluid in the acute setting, particularly when dosages approximate weight-based dosing 5.