From the Guidelines

Keppra (levetiracetam) is not recommended for primary prevention of post-traumatic seizures in patients with subdural hematoma.

The evidence suggests that antiepileptic drugs, including levetiracetam, do not have a significant effect in preventing early or delayed post-traumatic seizures in patients with traumatic brain injury, including those with subdural hematoma 1.
The study found that the incidence of early clinical seizures was 2.2% and delayed seizures was 2.1%, but it was 11.9% in the first year for severe TBI patients, and risk factors for delayed clinical seizures included brain contusion, acute subdural haematoma, and others 1.
Eleven clinical trials studied primary prevention of post-traumatic seizures, including 7 that compared phenytoin versus levetiracetam, and found no significant effect of antiepileptic drugs in preventing seizures, and increased side effects of phenytoin were shown 1.
However, levetiracetam may be considered in patients with risk factors, such as chronic subdural haematoma, or past history of epilepsy, due to its higher degree of tolerance compared to phenytoin 1.
It is essential to weigh the potential benefits and risks of using antiepileptic drugs in patients with subdural hematoma, and consider individual patient factors, such as the presence of risk factors for post-traumatic seizures.

From the Research

Levetiracetam is used for seizure prophylaxis in patients with subdural hematoma (SDH) 2, 3, 4, 5.
The incidence of posttraumatic epileptic seizures (PTS) in patients with acute SDH is higher (28% for early PTS and 43% for late PTS) compared to those with chronic SDH (5.3% for early PTS and 10% for late PTS) 2.
Risk factors for PTS in patients with acute SDH include low Glasgow Coma Score (GCS), craniotomy, and preoperative GCS below 8, while risk factors for PTS in patients with chronic SDH include alcohol abuse, change of mental status, previous stroke, and density of hematoma in computer tomography 2.
Levetiracetam has been shown to have similar efficacy to phenytoin in preventing clinical and/or electrographic seizures following acute/subacute SDH diagnosis, with a lower risk of adverse drug effects 4.
However, some studies suggest that levetiracetam may be associated with a higher risk of electrographic seizures in patients with midline shift >0 mm 4.
Levetiracetam can cause adverse effects such as asymptomatic elevation of liver enzymes 3, delirium 6, and other neuropsychiatric effects.
The use of levetiracetam for seizure prophylaxis in patients with SDH should be carefully considered, taking into account the individual patient's risk factors and potential for adverse effects 2, 4, 5.

Levetiracetam has been compared to phenytoin in several studies, with mixed results regarding efficacy and safety 2, 4.
A prospective observational study found no significant difference in the incidence of early seizures between patients who received levetiracetam and those who did not receive seizure prophylaxis 5.
The safety profile of levetiracetam is generally considered favorable, with a lower risk of adverse effects compared to phenytoin 4.
However, levetiracetam can cause rare but serious adverse effects, such as delirium and asymptomatic elevation of liver enzymes 3, 6.

The decision to use levetiracetam for seizure prophylaxis in patients with SDH should be based on individual patient factors, including risk of seizures and potential for adverse effects 2, 4, 5.
Patients with SDH should be closely monitored for signs of seizures and adverse effects, and the use of levetiracetam should be adjusted accordingly 2, 4.
Further research is needed to fully understand the role of levetiracetam in the management of SDH and to determine the optimal treatment strategies for seizure prophylaxis in these patients 2, 4, 5.