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Infantile Spasms

What Are Infantile Spasms?

Infantile spasms is a rare but serious type of epilepsy. It's associated with a unique, very abnormal brain wave pattern that can cause serious harm to a young, developing brain. This seizure type can happen during the first 2 years of life, most commonly between 5–7 months of age.

Babies with the condition also might have slowed development or loss of skills (like babbling, sitting, or crawling). The spasms can be very hard to control, and many children go on to have other kinds of seizures later in life.

The term West syndrome is used when a baby has infantile spasms, a unique EEG pattern (called hypsarrhythmia), and developmental delay.

What Do Infantile Spasms Look Like?

Spasms start suddenly and last a second or two. They often come one after another in a cluster that lasts several minutes. They happen most often just after a child wakes up. They're often mistaken for startles, colic, reflux, or hiccupping.

A baby having a spasm might have:

  • the head bent forward with arms flung out and the knees pulled into the body (described as "jackknife")
  • the head bent back with the arms and legs straightened
  • small movements in the neck or other parts of the body, such as the eyes widening and rolling up

What Causes Infantile Spasms?

Infantile spasms can be caused by problems with the way the brain developed in the womb, infections, brain injury, or abnormal blood vessels in the brain (such as an arteriovenous malformations). Infantile spasms also can happen in babies with some types of metabolic and genetic disorders. In rare cases, a baby's infantile spasms are caused by vitamin B6 deficiency.

More and more gene mutations are being linked to infantile spasms. Often, the cause isn't known.

How Are Infantile Spasms Diagnosed?

Infantile spasms are diagnosed by a pediatric neurologist (a doctor who treats brain, spine and nervous system problems). Testing may include:

  • blood tests and urine tests (to look for infections or illnesses)
  • EEG to see brain waves/electrical activity in the brain. The hypsarrhythmia pattern often confirms the diagnosis, but not every child with infantile spasms will have this.
  • VEEG, or video electroencephalography (EEG with video recording)
  • CAT scan, MRI, and PET/MRI scans to look inside the brain

How Are Infantile Spasms Treated?

Infantile spasms usually are treated with seizure medicines or steroids. If medicines don't control the spasms, a special diet, such as the ketogenic diet, might help. Sometimes, doctors may recommend surgery.

What Problems Can Happen?

Children with infantile spasms often have problems throughout their lives with learning and development. These problems can vary and depend on:

  • the cause of infantile spasms
  • if the treatments work
  • if the child has other medical conditions
  • when the child is diagnosed with infantile spasms

How Can I Help My Child?

To help your child, follow the doctor's instructions to:

  • Give any medicines as prescribed.
  • Go for developmental assessments and therapies.
  • Go to all follow-up medical visits.

Your doctor and the care team can answer questions and offer support. They also might be able to recommend a local support group. Online organizations can help too, such as:

Reviewed by: Lily Tran, MD, Andrew I. Mower, MD
Date Reviewed: Feb 15, 2022

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