What are neonatal seizures?
Neonatal (newborn) seizures are episodes of abnormal electrical activity in the developing newborn brain and occur in babies who are less than 28 days old. Many different problems can cause neonatal seizures.
Most neonatal seizures are considered provoked seizures, rather than a true epilepsy syndrome. A baby with neonatal seizures will not necessarily go on to have epilepsy later in life, although their chances of developing epilepsy are much higher.
What do neonatal seizures look like?
Seizures in a newborn can appear as noticeable jerking movements, or the signs may be short and subtle. If your baby has more subtle signs, it can be difficult to tell whether they are actually having a seizure.
There are many different types of neonatal seizures, and each type has unique characteristics.
- Clonic seizures: Clonic seizures can be rhythmic jerking movements that can affect the arms, legs or face. The jerking usually has a rhythm that can last for several seconds to minutes.
- Tonic seizures: Tonic seizures are characterized by a sudden stiffening of the body or limbs, which can cause the baby to appear rigid or tense.
- Myoclonic seizures: Myoclonic seizures can be very brief, with shock-like jerks involving a single muscle or a group of muscles. They are typically very quick and may occur in clusters.
- Electrographic-only seizures: The most common type of seizures observed in the newborn period are electrographic-only seizures. These can only be detected through brain monitoring.
Many of these movements may also occur in a newborn without seizures, so it is crucial to get an EEG to confirm that they are really seizures.
What causes neonatal seizures?
The causes of neonatal seizures are varied and can include:
- Hypoxic-ischemic encephalopathy (HIE): This condition occurs due to a lack of oxygen and blood flow to the baby’s brain around the time of birth. HIE is the most common reason for seizures in term newborns.
- Infections: Newborns can develop infections such as meningitis (inflammation of the membranes surrounding the brain and spinal cord) or sepsis (a widespread infection in the body that can lead to seizures).
- Metabolic disorders: These involve imbalances in the baby’s blood chemistry, such as low blood sugar, low calcium levels or low magnesium levels.
- Intracranial hemorrhage: Bleeding within the brain, which can occur due to birth trauma or other reasons, can also cause seizures. This is the most common cause of seizures in very preterm infants.
- Genetic conditions: Rare genetic disorders affecting brain function can lead to seizures. These conditions might be identified through genetic testing. The risk of seizures is higher if the baby is premature or of low birth weight.
How do you know that a child has neonatal seizures?
Many of the movements that are caused by seizures in newborns also occur in babies who do not have seizures. If a newborn is suspected of having seizures, they will undergo testing to confirm the diagnosis.
What types of monitoring and testing do babies with neonatal seizures undergo?
To fully understand a baby’s condition and to monitor a baby’s progress, each baby undergoes a series of tests. These tests include:
- Blood work: Regular blood tests help monitor a baby’s metabolic balance, check for infections and assess organ function.
- Brain ultrasound: A brain ultrasound can show the structure of the baby’s brain and help the health-care team detect any major abnormalities. It is a non-invasive procedure that can be performed at the bedside.
- Cerebral function monitoring with aEEG: This is a simplified form of brain monitoring that provides a continuous recording of the brain’s electrical activity. It helps detect seizures and monitor brain function over time. This tool is particularly useful in making timely decisions about a baby’s care if they have a seizure. Most seizures can be detected by cerebral function monitoring.
- Continuous video EEG monitoring: Continuous video EEG monitoring involves recording the brain’s electrical activity alongside synchronized video footage of the baby. This allows the team to see if any abnormal brain activity happens at the same time as physical movements or behaviours. The results give a detailed understanding of seizure activity and overall brain function, which is useful for tailoring treatments and interventions to a baby’s specific needs.
- Brain MRI: A brain MRI uses magnetic fields and radio waves to create detailed images of the brain, which help the health-care team assess the extent and location of any injury. The procedure is safe and non-invasive. The MRI is usually performed soon after a baby is admitted to the NICU with neonatal seizures. It gives the health-care team the most accurate understanding of a baby’s condition so they can tailor care to meet each baby’s specific needs. After obtaining the brain MRI, the health-care team will meet with the family and provide them with more information about the nature of the injury and next steps in a baby’s care.
In addition to these tests, the health-care team conducts standardized neurological examinations on a regular basis to monitor each baby.
How are neonatal seizures treated?
A newborn baby with seizures will usually be admitted to the neonatal intensive care unit (NICU). The NICU provides a controlled environment and close observation of babies with seizures. The health-care team can perform necessary tests and start treatments promptly. This specialized care helps stabilize a baby’s condition, control seizures and address any underlying issues that may be causing the seizures.
A key part of treating neonatal seizures is identifying a cause and tailoring treatment for each baby. In the NICU, there is an established seizure management plan specifically for newborns. This plan is based on the latest evidence and includes several medications that are effective in controlling seizures. Monitoring in the NICU allows the health-care team to ensure the seizures are controlled with treatment.
Next steps and long-term follow-up
After your baby is discharged from the NICU, it is very important to return for check-ups in the neonatal neurodevelopmental follow-up clinic to keep track of your baby’s growth and development. During each visit, the health-care team will carefully check your baby’s progress, including their growth, movements and if they are learning new things. If any issues or delays in your baby’s development are identified, the health-care team can step in early with special therapies or treatments as early help can make a big difference. The clinic offers support and resources for babies and their families to help navigate this journey.
If needed, some babies will be referred to a neurologist for extra care. Keeping up with these follow-up visits over the long term is very important as it helps the health-care team ensure your child gets the best care and support as they continue to grow.
What is the outlook for a child with neonatal seizures?
There are so many possible causes of neonatal seizures that it is difficult to give general information about the outlook. It depends partly on the underlying cause and on the type of seizures. Talk to your child’s health-care provider about their situation, the likelihood that they will develop epilepsy, and the warning signs to look for.
At SickKids
Our dedicated team
At SickKids, every baby is cared for by a large team of dedicated experts from various disciplines. This includes neonatologists, neurologists, nurse practitioners, nurses, respiratory therapists, occupational and physical therapists, social workers and other specialists. Each member of the team plays a critical role in each baby’s care, bringing their expertise and compassion to support your family during this challenging time. They work closely together to provide comprehensive, coordinated care that addresses all aspects of every baby’s health and development.