Epilepsy After Perinatal Brain Injury

How brain injury around birth can later become the basis of a structural epilepsy

Perinatal brain injury refers to injury occurring around the time of birth and early neonatal life. Causes can include hypoxic-ischaemic injury, perinatal arterial ischaemic stroke, intracranial haemorrhage, cerebral sinovenous thrombosis, severe infection and complications of extreme prematurity.

Some babies have seizures during the acute illness and never develop epilepsy. Others later develop recurrent unprovoked seizures because the injury leaves an enduring epileptogenic network.

The key distinction is therefore between neonatal acute symptomatic seizures and later structural epilepsy.

Perinatal brain injury is not one diagnosis

The term covers several different mechanisms of injury. They should not be treated as though they have the same prognosis or seizure pattern.

Hypoxic-ischaemic encephalopathy (HIE) follows insufficient oxygen and blood flow to the brain.
Perinatal arterial ischaemic stroke causes a focal area of infarction in an arterial territory.
Intracranial haemorrhage can injure developing brain tissue directly or through secondary effects.
Cerebral sinovenous thrombosis can cause venous infarction and haemorrhage.
Prematurity-related injury can include intraventricular haemorrhage and periventricular white-matter injury.
Infection can cause neonatal encephalitis, meningitis or secondary brain injury.

Each pattern can alter future epilepsy risk in a different way.

Neonatal seizure does not automatically mean epilepsy

Many seizures in newborns are acute symptomatic seizures: they occur because the brain is undergoing an acute insult.

The International League Against Epilepsy distinguishes these from epilepsy, which implies an enduring predisposition to recurrent unprovoked seizures.

This means a baby can have electrographic seizures during HIE or neonatal stroke, recover from the acute event and never develop chronic epilepsy.

Conversely, a child may develop epilepsy months or years later because the structural injury has become part of a persistent seizure-generating network.

Why neonatal seizures can be difficult to recognise

Seizures in newborns often look different from seizures in older children and adults.

Some have obvious focal clonic or tonic movements, but others are subtle or entirely electrographic. After antiseizure treatment, a phenomenon called electroclinical dissociation can occur, where the visible movement stops but seizure activity continues on EEG.

For this reason, continuous conventional EEG is an important tool in high-risk neonates.

The ILAE neonatal seizure guidance emphasises EEG-based seizure detection and treatment because clinical observation alone can miss a substantial seizure burden.

Hypoxic-ischaemic encephalopathy

HIE is one of the best-known causes of neonatal encephalopathy and can lead to seizures during the first days of life.

A major 2025 review notes that neonatal encephalopathy and HIE remain important causes of later neurological disability, including cerebral palsy and epilepsy.

Risk is strongly influenced by the severity and distribution of brain injury rather than by the diagnostic label alone.

Some children with relatively limited injury have no later seizures. Others with extensive cortical, deep grey or watershed-pattern injury develop structural epilepsy.

Therapeutic hypothermia

For eligible term and near-term infants with moderate or severe HIE, therapeutic hypothermia is an established neuroprotective treatment when started within the appropriate early window.

Cooling reduces death and major neurological disability at a population level and has changed the long-term outlook for HIE.

European neonatal care standards also report a reduction in epilepsy at two years among cooled infants compared with historical untreated populations.

Therapeutic hypothermia reduces risk; it does not guarantee that epilepsy or other neurological complications will not develop.

Seizure burden matters

In HIE, seizure burden is associated with the severity of brain injury and later neurodevelopmental outcome.

This does not mean that every brief neonatal seizure independently causes future epilepsy. Severe brain injury can produce both a high seizure burden and poor outcome.

However, prolonged or repeated seizures may add further stress to already vulnerable brain tissue, which is one reason careful EEG monitoring and treatment are important.

Perinatal arterial ischaemic stroke

Perinatal arterial ischaemic stroke is a focal stroke occurring around birth.

Seizures are one of its most common early presentations. In otherwise well newborns, a focal clonic seizure beginning after the first several hours of life can be an important clue.

Because the injury is focal, later epilepsy is often focal as well.

The affected network depends on the arterial territory and cortical regions involved. Later seizures can therefore include focal motor events, impaired-awareness seizures or other focal manifestations.

Epilepsy can appear years after a perinatal stroke

A child does not have to develop epilepsy immediately after the neonatal event.

Some remain seizure-free for a prolonged period before recurrent unprovoked seizures emerge in childhood.

This delayed presentation reflects maturation and reorganisation of the injured brain as well as the long-term consequences of cortical scarring.

It is one reason a remote perinatal stroke remains clinically relevant even when the neonatal seizures resolved years earlier.

Intracranial haemorrhage

Haemorrhage around birth can range from small, limited bleeds to extensive intraventricular, parenchymal or cerebellar injury.

Future epilepsy risk depends on the location and extent of brain damage, whether cortical tissue was injured and whether secondary complications occurred.

A haemorrhage that leaves focal cortical injury can create an epileptogenic scar, while a small haemorrhage without significant tissue injury may never lead to epilepsy.

Prematurity and brain injury

Very preterm infants are vulnerable to several forms of brain injury, including intraventricular haemorrhage, periventricular haemorrhagic infarction and white-matter injury.

Later epilepsy risk is particularly related to the severity and distribution of structural brain injury rather than prematurity alone.

This distinction matters because most people born prematurely do not automatically develop epilepsy.

Cerebral palsy and epilepsy are related but not identical

Perinatal brain injury can cause both cerebral palsy and epilepsy, so the two conditions frequently coexist.

But cerebral palsy does not mean epilepsy is inevitable, and epilepsy can occur after perinatal injury without cerebral palsy.

Both diagnoses may arise from the same underlying brain injury while representing different neurological consequences.

What does MRI show later?

MRI may reveal the structural footprint of the original injury years after the neonatal period.

Depending on cause, findings can include:

areas of encephalomalacia or tissue loss;
gliosis;
old infarction;
cystic change;
asymmetric cerebral volume loss;
periventricular white-matter injury;
deep grey-matter injury;
secondary enlargement of the adjacent ventricle.

These abnormalities can support the diagnosis of structural epilepsy, but the visible lesion and the seizure-onset zone are not always identical.

What can EEG show later?

EEG can show focal slowing, focal epileptiform discharges, multifocal abnormalities or more widespread disturbance depending on the injury and epileptic network.

Children with extensive early brain injury can sometimes develop bilateral or generalised-looking EEG abnormalities even when the original structural injury was asymmetric.

A normal routine EEG does not exclude epilepsy.

Serial EEG may be useful because the electrical pattern can change as the child’s brain matures.

Development and epilepsy interact

Children with perinatal brain injury may also have motor, cognitive, language, visual or behavioural difficulties.

These can result from the original injury itself, while uncontrolled epilepsy and medication adverse effects can add further burden.

It is therefore important not to assume that every developmental difficulty is caused by seizures, or that controlling seizures will reverse all consequences of the original brain injury.

Antiseizure medication

Once epilepsy is established, treatment generally follows the principles used for other structural focal epilepsies.

The specific medication depends on seizure type, age, other medical problems, interactions and adverse-effect considerations.

There is no single antiseizure medication that is uniquely correct for epilepsy caused by perinatal brain injury.

Should neonatal antiseizure medication always continue long term?

No.

The ILAE neonatal seizure guideline recommends that when acute provoked neonatal seizures have stopped and there is no evidence of neonatal-onset epilepsy, antiseizure medication should usually be discontinued before discharge, irrespective of MRI or EEG findings.

This is an important distinction from treating established epilepsy later in childhood.

Continuing medication indefinitely after an acute neonatal seizure does not necessarily prevent future epilepsy and can expose infants to unnecessary treatment.

Drug-resistant epilepsy

Some people develop seizures that remain uncontrolled despite appropriate antiseizure medications.

If two suitable and tolerated medication schedules fail to achieve sustained seizure freedom, the usual ILAE definition of drug-resistant epilepsy applies.

At that point, specialist epilepsy-surgery assessment should be considered rather than simply continuing medication changes indefinitely.

Can epilepsy surgery help?

Yes, in selected cases.

Early brain injury can sometimes leave a sharply defined unilateral or focal epileptogenic region. If seizures consistently arise from that region and it can be treated safely, resection, disconnection or other surgical approaches may offer substantial seizure improvement.

Children with large unilateral destructive lesions can sometimes be candidates for hemispheric disconnection procedures when severe drug-resistant epilepsy arises predominantly from one damaged hemisphere.

Other children have bilateral or multifocal injury that makes surgery less straightforward.

Plasticity changes the surgical question

The developing brain has greater capacity for functional reorganisation than the adult brain.

After an early unilateral injury, language, motor and other functions may partially reorganise to the opposite hemisphere.

This can sometimes make surgery possible even when imaging shows extensive damage, but neuroplasticity is not unlimited and careful functional assessment remains essential.

Perinatal stroke is different from adult post-stroke epilepsy

Both conditions involve a vascular brain injury, but the developing neonatal brain responds differently from an adult brain.

Network maturation, plasticity, language reorganisation, motor development and the timing of epilepsy emergence all differ.

For that reason, this page is separate from Post-Stroke Epilepsy, which primarily addresses epilepsy after stroke later in life.

Long-term follow-up matters

Some effects of perinatal brain injury become obvious only when developmental demands increase.

A young child may initially appear to be progressing well and later develop subtle motor asymmetry, learning difficulties, visual-perceptual problems or seizures.

Long-term developmental and neurological surveillance is therefore important after significant neonatal brain injury, even when early recovery appears reassuring.

The global picture

Perinatal brain injury contributes to epilepsy worldwide, but risk and outcome are strongly shaped by access to obstetric care, neonatal resuscitation, intensive care, therapeutic hypothermia, EEG, MRI, infection treatment and long-term rehabilitation.

These resources are unevenly distributed.

The same biological injury can therefore have very different consequences depending on where a baby is born and what neonatal and follow-up care is available.

The key distinction

Perinatal brain injury can cause acute neonatal seizures, later structural epilepsy, or both.

They should not be treated as interchangeable diagnoses.

A newborn can have acute seizures and never develop epilepsy. A child can develop epilepsy years after an apparently resolved neonatal event. Cerebral palsy can coexist with epilepsy but does not define it. And an old MRI lesion can support the explanation without automatically identifying the entire seizure network.

The lasting neurological outcome depends on the cause, timing, location and severity of injury, together with how the developing brain reorganises around it.

Sources and further reading

Evidence checked: September 2026.

This page is for general education and does not replace individual assessment by a neonatal, paediatric neurology or epilepsy team.