The occurrence of a seizure is not necessarily an indication for initiating anticonvulsant medication. Most medications have significant side effects, and the benefits of treating should outweigh the risks. Reasons for avoiding anticonvulsants include:
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- If the witnessed history is not clear.
- If seizure is “provoked” by a stimulus that is unlikely to recur:
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- In head injury a single post concussion seizure in isolation is not significantly associated with an overall increased risk of further seizures unless there are associated impairments or other risk factors as listed below.
- Seizures that occur in response to drug or alcohol misuse or withdrawal might be considered to be “provoked”.
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Reasons to consider anticonvulsant medication following TBI or factors that indicate an 
increased risk of seizure recurrence are:
- Late post traumatic seizure (seizure occurring more than one week after injury).
- Repeated seizures.
- Intra cranial haemorrhage associated with midline shift or pressure effect.
- Depressed skull fracture.
- Intracranial sepsis (abscess/meningitis/encephalitis).
- Injury Severity based on factors such as duration of loss of consciousness/Post Traumatic Amnesia or lowest GCS at presentation.
- Association with focal neurological signs e.g. localised weakness.
- Young age (below 16 years).
- Older age (over 65 years).
- Alcohol/Drug Misuse or potential for withdrawal.
- Family history of epilepsy.
- Baclofen for spasticity can lower seizure threshold (increase the likelihood of seizures).
- Antidepressant medication can lower seizure threshold – but untreated mood disorder can also lower threshold.
Other than the first two factors, none of these factors in isolation is an indicator for initiating anticonvulsant treatment. If in doubt discuss with senior colleagues or consult your health authority’s seizure protocols.
There is a significant risk of developing post-traumatic epilepsy following traumatic brain injury:
- In severe TBI, seizure risk is increased approximately 20-fold in the first six months of injury, but reduces to a 5-fold risk of development by five years post injury.
- In mild TBI seizure risk is increased approximately 5- fold in the first six months after injury, but with no greater risk relative to normal population after 5 years.
- More detail is available in relation to risks in “Long-term risk of epilepsy after traumatic brain injury in children and young adults: a population-based cohort study”, Jakob Christensen et al, Lancet, Volume 373, No. 9669, p1105–1110, 28 March 2009
When accepting responsibility for a patient transferred to your care, if anticonvulsant 
medication have already been started, and if the patient is now medically more stable, you should re-assess the risk factors and consider whether continuation of anticonvulsant medication remains appropriate. Unnecessary anticonvulsant treatment may serve to inappropriately sedate patients, so the risk to benefit ratio needs to be reviewed.
Management of Seizures
Psychosocial Consequences of Epilepsy Diagnosis