Infantile Spasms

Infantile spasms are seizures that look like quick jerks or tensing in your baby’s body. They’re a rare kind of epilepsy that usually starts between 3 and 12 months old.

They may look like a startle reflex. Each spasm lasts one to two seconds. They usually repeat every five to 10 seconds. They often happen when your baby wakes up.

When spasms happen along with a specific brain wave pattern on an EEG (called hypsarrhythmia) and developmental delay or loss of skills (regression), it’s called West syndrome. Not all babies with spasms have West syndrome, but the two are closely related.

If your baby is experiencing spasms, it’s important to see their healthcare provider as soon as possible.

These seizures aren’t common. There are fewer than 1 case per 1,000 live births in the U.S. each year.

Infantile spasms signs and symptoms

Infantile spasms might look like:

• Sudden stiffening or body tensing
• Arching of their back
• Bending arms, legs or head forward
• Grimacing face
• Nodding head (repeatedly)
• Pulling their head to one side
• Rolling their eyes upward
• Twitching chin

These movements often happen in groups or clusters. There are short pauses of five to 10 seconds between each spasm. Sometimes, it only affects one side of your baby’s body. Infantile spasms usually happen just after your baby wakes up. They rarely occur during sleep.

After spasms, you might notice:

• Crying (not always)
• Less social interaction or smiling
• Increased fussiness or unusual quietness

Some babies have just a few spasms a day, while others may have up to 100. If you notice even one or two spasms, talk to your child’s doctor right away. If spasms continue for several days or a few weeks, you might notice loss of developmental milestones (like rolling over, sitting, crawling and babbling).

Causes of infantile spasms

An infantile spasm can happen if part of your child’s brain isn’t working as expected, or if there are problems affecting their whole brain. These could include:

• An issue with how their body uses energy (metabolic disorders, like inborn errors of metabolism and vitamin B6 deficiency)
• An abnormality in genes, which may be inherited or happen randomly (genetic conditions, like Down syndrome, Aicardi syndrome, tuberous sclerosis, neurofibromatosis)
• Brain malformations (like cortical dysplasia, lissencephaly), or abnormal blood vessels (like hemangiomas, arteriovenous malformations)
• A head injury or lack of blood or oxygen supply to their brain (like perinatal stroke or hypoxic-ischemic encephalopathy)
• A brain infection (like meningitis, or infection due to syphilis, Zika virus, cytomegalovirus)

Sometimes, the cause is unknown.

Risk factors for infantile spasms

These factors may increase the chances of your baby developing infantile spasms around the time of birth:

• A low birth weight
• Birth complications that cause a lack of oxygen to their brain
• Very low blood sugar (neonatal hypoglycemia)

These may affect your baby after they’re born:

• A serious head injury (from an accident or trauma)
• Brain infections
• Brain tumors
• Near drowning (when their brain goes without oxygen for too long)

Complications of infantile spasms

Infantile spasms are a medical emergency. Even a few days or weeks of untreated spasms can rapidly lead to poor growth and development of your child’s brain. It could cause more seizures later in life. This may lead to problems with:

• Hearing
• Speech
• Vision
• Writing
• Learning and thinking (intellectual disability)
• Small movements (like using their fingers to grab something)
• Large movements (like crawling or walking)

Some cases of infantile spasms are life-threatening.

How doctors diagnose infantile spasms

Your child’s provider will ask detailed questions about their symptoms and medical history. They’ll also do a physical exam and offer tests. Sometimes, your child may need to see a specialist, like a pediatric neurologist.

If you can, try to take videos of your child’s symptoms. This can be very helpful and can be sent to your provider even before your appointment. It helps them plan for appropriate testing in a timely manner.

What tests diagnose infantile spasms?

Your child’s provider will order an electroencephalogram (EEG) to confirm a diagnosis. An EEG measures your child’s brain’s electrical activity.

They may also order other tests to find the cause. These are usually blood, pee or imaging tests that could include:

• Genetic tests
• Metabolic tests
• MRI

At what age do infantile spasms start?

Most cases are diagnosed in children younger than 12 months. The average age is between 4 and 7 months.

When symptoms appear after 12 months, doctors usually call them epileptic spasms. This is just another name for the same condition.

Infantile spasms treatment

Treatment may include:

• Hormone therapy: The adrenocorticotropic hormone (ACTH) is a hormone that helps your body respond to stress. Your child will get a synthetic form of ACTH by injection. Another option is prednisolone, which is given by mouth.
• Antiseizure medication: Vigabatrin is a medicine taken by mouth (liquid or pill). It helps reduce seizures by affecting their brain’s chemical messaging system. Vigabatrin can affect your child’s vision. Their provider will do regular eye exams to check for side effects.
• Ketogenic diet: This high-fat, low-carbohydrate meal plan may help reduce symptoms by changing how your child’s brain uses energy. A doctor and dietitian will guide this treatment safely.
• Surgery (rare): If brain scans show a specific area of their brain is causing the spasms, surgery may be the treatment of choice if other treatments don’t work. Timely (early) and safe surgery in the hands of an experienced surgical team can make a big difference in the seizure outcome and overall development of your child.

When should I see my child’s healthcare provider?

If you think your baby may be having infantile spasms, talk to their provider right away. It’s important to remember that infantile spasms are a medical emergency.

If your baby has already been diagnosed, they’ll need regular visits to check that the treatment is working. They’ll also need to see their pediatrician for their wellness visits, in addition to their specialist visits for therapy and supportive services.

Infantile spasms prognosis

Your child’s provider will be able to give you the most accurate outlook. It can vary based on:

• The underlying cause
• Whether the cause can be treated
• How early the spasms were diagnosed and treated
• If your baby was meeting developmental milestones before the spasms began

About 6 out of 10 children with infantile spasms continue to have seizures or developmental challenges as they grow.

The earlier treatment starts, the better the chance for a more positive outcome.

Do children grow out of infantile spasms?

Children need treatment for infantile spasms. It’s not something that goes away on its own. With the right treatment plan, spasms may stop. But the condition can still cause long-term effects.

Getting an early diagnosis and starting treatment quickly can lower the risk of these long-term problems. However, every child’s situation is different, and outcomes can vary.

Infantile spasms life expectancy

Life expectancy can vary. Some children have a normal lifespan, especially if treatment begins early. But if a child has serious brain conditions or developmental delays before the spasms start, it may shorten their lifespan.

Again, every child is different, and outcomes don’t always match the statistics. Talk to your child’s provider for guidance specific to your situation.