T
The Daily Insight

What is an infantile spasm

Author

Robert Spencer

Published Mar 18, 2026

Infantile spasms is a seizure disorder in babies. The seizures (or spasms) make muscles in the arms and legs stiff and bend the baby’s head forward. They look very much like a startle.

How do I know if my baby has infantile spasms?

Infantile spasms often look like a sudden, brief stiffening of a baby’s muscles. Symptoms may include: a cluster of spasms that may be associated with waking from sleep. jackknife seizures, where the body bends forward, the knees are pulled up, and the arms are thrown out to the side.

What is the difference between infantile spasms and seizures?

An infantile spasm is a seizure with sudden stiffening of the body and brief bending forward or backward of the arms, legs and head. Each seizure lasts only a second or two and usually in a series. Seizures are most common just after waking up and rarely occur during sleep.

Can infantile spasm be cured?

Many children with infantile spasms develop other kinds of epilepsy. (Watch examples of infantile spasms.) “Some of these children can be cured, but successful treatment often depends on prompt diagnosis,” said Hussain.

Can a baby with infantile spasms live a normal life?

An etiologic diagnosis is very important because it can lead to initiation of a specific therapy that may markedly improve the long-term developmental outcome. In fact, some children with infantile spasms may ultimately lead normal lives, but only if they are diagnosed and treated correctly.

Are infantile spasms an emergency?

As we continue to navigate the COVID-19 pandemic, it’s critical to remember infantile spasms are still medical emergencies that need urgent care. Any delay in seeking emergency treatment can increase your child’s risk for brain damage.

Do babies grow out of infantile spasms?

Infantile spasms usually stop by age five, but may be replaced by other seizure types. Many underlying disorders, such as birth injury, metabolic disorders, and genetic disorders can give rise to IS, making it important to identify the underlying cause.

What do I do if my baby has infantile spasms?

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.

Do infantile spasms cause mental retardation?

Infantile spasms (IS), i.e., West syndrome, as an epileptic encephalopathy, represents one of the major causes of acquired mental retardation in early childhood (Roger and Dulac, 1994).

Do infantile spasms hurt?

They may have many series of spasms per day. This type of seizure is usually only seen in young children. After a spasm, the baby may cry or laugh. The spasms do not cause pain, but the baby may cry because the quick jerking movement surprises them.

Article first time published on

Do infantile spasms happen while sleeping?

Though there is almost always a cluster of spasms in the morning when the child awakens from sleep, infantile spasms can occur at any time during the day or night.

What happens if infantile spasms are left untreated?

Left untreated, infantile spasms can lead to serious outcomes, including an estimated infant mortality rate of between 5% and 6%. The most significant concern, however, is that infantile spasms are associated with autism and intellectual deficits that permanently affect quality of life.

Can infantile spasms cause cerebral palsy?

More than 50 genetic/metabolic diseases are associated with infantile spasms, and many patients have other disorders that cause developmental delays (e.g., cerebral palsy, Down syndrome, tuberous sclerosis, etc.)

How long does an infantile spasm last?

Often occur in a series, called a cluster. Clusters help make the diagnosis. Spasms within a cluster often have a regular pattern. The time between each spasm can last from 3 to 30 seconds.

Do infantile spasms show on EEG?

Infantile spasms are a very specific type of seizure with a characteristic age of onset (a typical age when seizures start). They are nearly always accompanied by a very characteristic pattern on the electroencephalogram (EEG). This pattern is called ‘hypsarrhythmia’.

Why does my baby jerk around so much?

Newborns have an immature nervous system. The pathways that carry the signals from the brain to the parts of the body aren’t yet fully developed, so their movements can appear jerky and twitchy. The jerking and twitching will become less frequent after the first few weeks of life as the baby’s nervous system matures.

How early can infantile spasms start?

Most infants with infantile spasms develop a pattern of movements called spasms, sometimes also referred to as epileptic spasms. The most common age for these spasms to begin is between 3 and 6 months of age. They can begin earlier than 3 months and sometimes begin after 12 months of age.