When to discontinue prophylactic antiepileptic (anti-seizure) medications after Traumatic Brain Injury (TBI)?

From the Guidelines

Prophylactic antiseizure medications after traumatic brain injury (TBI) should not be used for primary prevention to reduce the incidence of post-traumatic seizures, as the current evidence does not support their effectiveness in preventing early or delayed seizures. The use of antiepileptic drugs (AEDs) for primary prevention of post-traumatic seizures has been studied in several clinical trials, but none of them have shown a significant effect in preventing the occurrence of early or delayed post-traumatic seizures 1. In fact, the use of AEDs, such as phenytoin, has been associated with increased side effects and even a worsening of the neurological outcome 1.

The risk factors for delayed clinical seizures, such as brain contusion, acute subdural haematoma, skull fracture, initial loss of consciousness or amnesia for more than 24 hours, and age over 65 years, do not necessarily warrant the use of AEDs for primary prevention 1. However, in cases where there are risk factors, such as chronic subdural haematoma, or past history of epilepsy, the use of AEDs, preferably levetiracetam, may be considered 1.

Some key points to consider when deciding whether to use prophylactic antiseizure medications include:

• The incidence of early clinical seizures (within 7 days after the brain injury) is relatively low, at 2.2% 1
• The incidence of delayed seizures (after 7 days) is also relatively low, at 2.1% 1
• The use of AEDs has not been shown to prevent late seizures or improve neurological outcomes 1
• The potential side effects of AEDs, such as phenytoin, should be carefully considered when deciding whether to use these medications 1

In general, the decision to use prophylactic antiseizure medications after TBI should be made on a case-by-case basis, taking into account the individual patient's risk factors and medical history. However, the current evidence does not support the routine use of AEDs for primary prevention of post-traumatic seizures.

From the Research

Seizure Prophylaxis after Traumatic Brain Injury

• The use of prophylactic antiseizure medications (ASMs) in patients with moderate-severe traumatic brain injury (TBI) is a topic of ongoing debate 2.
• Current guidelines suggest that ASMs may be used in patients hospitalized with moderate-severe TBI, but the quality of evidence is low 2.
• The choice of ASM, either levetiracetam (LEV) or phenytoin/fosphenytoin (PHT/fPHT), does not appear to have a significant impact on early or late seizures, although LEV may be associated with fewer adverse events 2.

Duration of Prophylaxis

• The optimal duration of ASM prophylaxis is unclear, but current guidelines suggest that a short duration (≤ 7 days) may be sufficient 2.
• Longer durations of ASM use do not appear to be associated with improved outcomes, and may be associated with worse cognitive outcomes and more adverse events 2.
• The Brain Trauma Foundation recommends using phenytoin for early posttraumatic seizure (PTS) prophylaxis for 7 days after TBI 3.

Monitoring and Discontinuation

• The decision to discontinue ASM prophylaxis should be based on individual patient factors, including the risk of seizures and the presence of other complications 2.
• Electroencephalographic (EEG) monitoring may be useful in identifying patients at high risk of seizures, but its role in guiding the discontinuation of ASMs is unclear 4.
• Patients treated with levetiracetam had a higher incidence of abnormal EEG findings, including seizure tendency, compared to those treated with phenytoin 4.