A post traumatic seizure (PTS) refers to an initial or recurrent seizure episode, not attributable to another obvious cause, after penetrating or non-penetrating traumatic brain injury (TBI).

Post traumatic epilepsy refers to recurrent late seizure episodes, not attributable to another cause.

Immediate: within 24 hours

Early: within seven days

Late: after seven days

Risk factors

• Glasgow Coma Scale score of <10
• cortical contusion
• depressed skull fracture
• epidural haematoma
• intracerebral haematoma
• wounds with dural penetration
• seizure within the first week of injury
• prolonged length of coma
• prolonged length of post traumatic amnesia

Risk of seizures is greatest in the first two years following TBI, with 80% occurring within this timeframe. The risk of PTS decreases with time and reaches the normal value for the population at around five years post injury.

Incidence

• 5% to 7% of all hospitalized patients with TBI
• 11% of patients with severe non-penetrating TBI
• up to 35% to 50% of patients with penetrating TBI

Suggested, evidence-based approach

• Anti epileptic drugs (AED) to be prescribed during first seven days following TBI for the prevention of early seizure (eg. phenytoin, carbamazepine).
• In patients with no seizures or seizures in the first 48 hours only, withdraw AED after seven days.
• Always anticipate the development of seizures by having appropriate emergency treatment written up on drug chart (eg. buccal midazolam).
• If late seizures develop, treat with appropriate AED.

Rehabilitation considerations

• commonly used AEDs (phenytoin, carbamazepine, valproate) may all impair cognitive function especially memory
• side-effect profiles differ between different drugs
• check AEDs stopped after seven days when appropriate
• seizure management education for patient, family and carers
• DVLA advice