From the Guidelines
Patients with acute subdural hematoma (SDH) should not be put on antiseizure medication prophylactically, as the current evidence does not support its use in reducing the incidence of post-traumatic seizures. The study by Annegers et al. 1 found that the incidence of early clinical seizures was 2.2%, and the incidence of delayed seizures was 2.1%, but the use of antiepileptic prophylaxis did not show a significant effect in preventing the occurrence of early or delayed post-traumatic seizures.
Key Points to Consider
- The incidence of post-traumatic seizures in patients with acute SDH is relatively low, with 2.2% experiencing early clinical seizures and 2.1% experiencing delayed seizures 1.
- Eleven clinical trials studied primary prevention of post-traumatic seizures, but all had a low level of evidence and did not show a significant effect of antiepileptic drugs (AEDs) in preventing the occurrence of early or delayed post-traumatic seizures 1.
- The use of AEDs, such as phenytoin, has been associated with increased side effects and even a worsening of the neurological outcome 1.
- Levetiracetam may be considered in case of risk factors, such as chronic subdural hematoma, or past history of epilepsy, due to its higher degree of tolerance compared to phenytoin 1.
Clinical Implications
- The decision to use antiseizure medication prophylactically should be made on a case-by-case basis, taking into account the individual patient's risk factors and medical history.
- Patients with acute SDH should be closely monitored for signs of seizures, and treatment should be initiated only if seizures occur.
- The use of antiseizure medication should be weighed against the potential risks and benefits, and alternative treatments should be considered if necessary.
From the Research
Seizure Prophylaxis in Acute Subdural Hematoma
- The use of antiseizure medication prophylactically in patients with acute subdural hematoma (SDH) is a topic of debate, with some studies suggesting its potential benefits and others highlighting the lack of conclusive evidence 2, 3.
- A study comparing levetiracetam and phenytoin for seizure prophylaxis in acute or subacute SDH found no significant difference in clinical and/or electrographic seizure risk, but a decreased risk of adverse events with levetiracetam 2.
- Another study found that acute-on-chronic subdural hematoma (acSDH) has a high risk for acute symptomatic seizures (ASz) and is associated with unfavorable outcomes and high mortality, suggesting that prophylactic treatment with antiepileptic drugs may be beneficial in this specific cohort of patients 4.
- A systematic review of epileptic seizures in adults with subdural hematomas found that posttraumatic epileptic seizures (PTS) are a serious complication, particularly in acute SDH, and that the "prophylactic use" of antiepileptic drugs may be beneficial in patients with cumulative risk factors 3.
Risk Factors for Seizures in Acute SDH
- Risk factors for PTS in patients with acute SDH include a 24h postoperative Glasgow Coma Score (GCS) below 9, craniotomy, and preoperative GCS below 8 3.
- Other studies have found that male gender and A/A pupils are associated with lower probability of achieving independence living at hospital discharge, and that A/A pupils, low GCS at admission, spontaneous etiology, and craniectomy are associated with the worst outcome 5.
Antiepileptic Drugs for Preventing Seizures
- The use of antiepileptic drugs for preventing seizures in patients with chronic subdural hematoma is controversial, with significant variations in clinical practice 6.
- A systematic literature review found no controlled randomized trials evaluating the risk/benefit of the prophylactic use of anticonvulsants for people with chronic subdural hematoma, and retrospective studies showing contradictory results 6.
- Levetiracetam and phenytoin have been found to have similar efficacy in preventing clinical and/or electrographic seizures, but levetiracetam is associated with a lower risk of adverse drug effects 2, 3.