ConditionBrain & nerves
Post-Traumatic Seizures
Post-traumatic seizures are seizures caused by a traumatic brain injury. They are grouped by timing: immediate (within 24 hours), early (within the first week) and late (more than a week after injury). Two or more unprovoked late seizures mean post-traumatic epilepsy, which accounts for a meaningful share of acquired epilepsy. Risk is highest after severe injuries with bleeding in the brain, skull fractures that penetrate the brain or contusions. Anti-seizure medicines prevent early seizures and treat epilepsy.
Also called: Post-traumatic epilepsy, seizures after head injury, PTS, PTE
At a glance
- What it is
- Seizures caused by a brain injury, classified by when they occur after the injury.
- Timing
- Immediate (under 24 hours), early (1 to 7 days), late (over 7 days). Late seizures carry high recurrence risk.
- Higher risk with
- Severe TBI, brain bleeding, contusions, penetrating injury, depressed skull fracture, early seizures, older age.
- When late seizures happen
- Most within 2 years, but risk stays raised for many years.
- Treatment
- Short-term preventive medicine after severe TBI. Ongoing anti-seizure medicine for post-traumatic epilepsy.
When to get help
Call 911 or go to the ER
- A seizure lasting more than 5 minutes, or repeated seizures without waking in between: call 911 or your local emergency number
- Any seizure after a recent head injury
- A seizure with difficulty breathing, injury, or in water
- A first-ever seizure in anyone
See a doctor within a day or two
- New confusion, drowsiness, worsening headache or vomiting after a head injury
- Unusual episodes such as staring spells, jerking of one limb or strange sensations in someone with a past brain injury
Book a routine appointment
- Planning to stop anti-seizure medicines
- Questions about driving, work or pregnancy with post-traumatic epilepsy
What to do during a seizure
- Stay calm and note the time.
- Protect from injury: move hard objects away and cushion the head.
- Do not hold them down and do not put anything in their mouth.
- Turn them onto their side once jerking stops, to keep the airway clear.
- Call 911 or your local emergency number if the seizure lasts more than 5 minutes, another follows, they are injured, pregnant, in water, or it is their first seizure.
- Stay with them until fully aware.
- Give rescue medicine if prescribed (such as a nasal benzodiazepine) according to their plan.
Types by timing
| Type | Timing | Significance |
|---|---|---|
| Immediate | Within 24 hours | Often a reaction to the impact. Lower long-term epilepsy risk |
| Early | Day 1 to day 7 | Provoked by acute brain changes. Increases later epilepsy risk |
| Late | After day 7 | Reflects lasting brain scarring. High risk of recurrence (post-traumatic epilepsy) |
How brain injury leads to seizures
Injury causes bleeding, swelling and nerve cell damage. Iron from blood breakdown, inflammation and scarring (gliosis) can rewire brain circuits over months, making them prone to abnormal electrical activity. This process, called epileptogenesis, explains why seizures can start long after the injury.
Risk factors
- severe traumatic brain injury (Glasgow Coma Scale 8 or lower)
- penetrating injuries, such as gunshot wounds
- bleeding in or around the brain, especially subdural hematoma
- cerebral contusions, particularly in both hemispheres or the temporal lobes
- depressed skull fracture
- early post-traumatic seizures
- loss of consciousness or amnesia for more than 24 hours
- age over 65
- need for brain surgery
- chronic alcohol use
Mild concussions carry a much smaller increase in risk.
Symptoms
Post-traumatic seizures can be:
- focal seizures: starting in one area of the brain, causing twitching of one side, odd sensations, déjà vu, staring or automatic movements, with or without impaired awareness
- focal to bilateral tonic-clonic seizures: spreading to cause convulsions of the whole body
- subtle seizures in hospitalized patients, detected only on EEG
Diagnosis
- detailed history from witnesses
- CT or MRI of the brain to show injury, bleeding and scarring
- EEG (electroencephalogram), including continuous EEG in intensive care for comatose patients
- blood tests to exclude low sodium, low blood sugar or alcohol withdrawal
Treatment
Preventing early seizures
The Brain Trauma Foundation guidelines support anti-seizure medicine, such as levetiracetam or phenytoin, for 7 days after severe TBI to reduce early seizures. Longer preventive treatment has not been shown to prevent late epilepsy.
Post-traumatic epilepsy
- anti-seizure medicines such as levetiracetam, lamotrigine, carbamazepine or others, selected for side effects and other conditions
- epilepsy surgery if seizures persist despite medicines and arise from a defined scar
- vagus nerve stimulation or other neuromodulation for drug-resistant epilepsy
Living with post-traumatic epilepsy
- take medicines consistently and get enough sleep
- avoid excess alcohol
- follow local driving laws (often a seizure-free period is required)
- take water and height safety precautions
- discuss pregnancy plans, since some medicines need changing
- address mood, memory and other effects of the brain injury
Outlook
Many people with early seizures never develop epilepsy. Once post-traumatic epilepsy develops, seizures can often be controlled with medicine, though it is more often drug-resistant than some other epilepsies. Research continues into treatments that prevent epilepsy after injury.
Frequently asked questions
Can a head injury cause seizures years later?
Yes. Late post-traumatic seizures can begin months to years after a brain injury, though most start within 2 years. The risk is greatest after severe injuries with bleeding, contusions or penetrating wounds.
What is post-traumatic epilepsy?
Post-traumatic epilepsy is a tendency to have recurring seizures caused by brain scarring from a traumatic injury. It is diagnosed after unprovoked seizures occurring more than a week after the injury.
Do all head injuries cause seizures?
No. Most people with mild head injuries never have seizures. The risk rises with the severity of the injury, bleeding in the brain, skull fractures and early seizures.
How long should I take anti-seizure medicine after a brain injury?
After severe TBI, preventive medicine is usually given for about 7 days. If late seizures occur and epilepsy is diagnosed, longer treatment is needed. Never stop anti-seizure medicine without talking to your doctor.
Is a seizure after a concussion serious?
Any seizure after a head injury needs emergency evaluation to check for bleeding or brain injury. A brief convulsion at the moment of a concussion is usually less concerning long term, but must still be assessed.
Sources
This guide was written from current patient and clinical guidance, including:
- Brain Trauma Foundation: Guidelines for the management of severe traumatic brain injury (seizure prophylaxis)
- Epilepsy Foundation: Post-traumatic epilepsy
- International League Against Epilepsy (ILAE): Definition of epilepsy
- CDC: Traumatic brain injury and concussion
- National Institute of Neurological Disorders and Stroke (NINDS): Epilepsy and seizures