Infantile Spasms (West Syndrome)

Infantile spasms can be described as short and sometimes subtle seizures that occur in babies. These seizures are actually a rare form of epilepsy.

Only about 2000 to 2500 children each year will receive a diagnosis of the disorder in the United States. These seizures or spasms generally occur before your child is 1 year old, with most babies experiencing them when they’re between 3 and 7 months old.

Read on to learn more about this condition.

An infantile spasm can consist of something as simple and slight as a head drop or nod. These spasms may be subtle and can appear in different ways. According to the Epilepsy Foundation, the spasms may consist of:

• your baby suddenly stiffening
• their arms flinging out as their knees pull up and with them bending at the waist
• their head being thrown back as their legs stiffen and straighten
• repeated uncontrolled movements such as head bobs or body crunching

The spasms usually only last a couple of seconds but tend to occur close together in a series. The National Institute of Neurological Disorders and Stroke finds that often your child will have multiple clusters of spasms at a time, and your child may have as many as hundreds of spasms throughout the day.

Infantile spasms also usually occur upon waking, unlike benign myoclonic seizures, which tend to occur in your baby as they fall asleep. Some organizations recommend taking a video of the events and showing them to a doctor or healthcare professional if you’re concerned that your child may be having spasms.

Infantile spasms are a kind of disorder caused by a brain abnormality or injury in your baby that can occur before or after birth. Known causes may include things such as:

• brain tumors
• genetic or chromosomal abnormalities
• a birth injury
• a brain infection
• a problem with brain development while your baby is still in the womb

While doctors don’t fully understand the reason for the connection, these things can cause chaotic brain wave activity, resulting in frequent spasms. In the rest of children, the cause of their spasms is unknown but may be the result of an unidentified neurological problem.

If a doctor suspects infantile spasms, they’ll order an electroencephalogram (EEG), which is easy to obtain and usually useful for giving a diagnosis. If this test doesn’t have clear results, a doctor may order a test called a video EEG.

With this test, as with a regular EEG, electrodes are placed on your baby’s skull to help doctors visualize brain wave patterns. A video then captures your baby’s behavior. A doctor, usually a pediatric neurologist (a doctor who treats children who have problems with their nervous system), will watch their brain wave activity during and in between your baby’s spasms.

These tests usually last from one to several hours and may be done in a doctor’s office, lab, or hospital. They may also need to be repeated after several days. Some children with infantile spasms will have disorganized brain wave activity. This is known as modified hypsarrhythmia.

If your child has received a diagnosis of infantile spasms, a doctor may also order other tests to see why the spasms are occurring. For example, an MRI can image their brain and show any abnormalities in its structure. Genetic testing can pinpoint genetic reasons contributing to their seizures.

It’s important that you get medical help right away if you think your baby is having infantile spasms. The disorder can have very serious developmental consequences, especially if it’s left untreated. Your child has the best chance of limiting those negative effects with early treatment.

Babies with infantile spasms frequently have mental and developmental problems. In research published in the Annals of Indian Academy Neurology, at 3 years after receiving their diagnosis, only 11.3 percent of the children studied were seizure free and developmentally neurotypical. Many had issues with:

• eyesight
• speech
• hearing
• writing skills
• fine and gross motor development

Additionally, 74 percent of the children in the study displayed some traits of the autism spectrum.

Some children will have no complications though. The researchers also noted that when there are no known health factors causing the seizures and diagnosis is prompt, 30 to 70 percent of children with the disorder will have neurotypical development.

One of the major medications used to treat infantile spasms is adrenocorticotropic hormone (ACTH). ACTH is a hormone that’s naturally produced in your child’s body. It’s injected into your child’s muscles and has been shown to be very effective in stopping spasms.

Because it’s an extremely powerful drug that can cause dangerous side effects, it’s generally given in low doses for a short amount of time. More common side effects may include:

• edema, or swelling from fluid retention
• weight gain
• irritability
• increased appetite
• low potassium in their blood
• high blood sugar

Rare but more serious side effects may include:

• high blood pressure
• mental status changes due to high blood pressure
• gastrointestinal bleeding
• infection

Doctors sometimes use an anti-seizure medication called vigabatrin (Sabril) and steroid therapies, such as prednisone. Limitations of ACTH treatment, such as high costs, availability issues, and side effects, can sometimes make these alternative medications a better option. But both of these alternative drugs can also have significant side effects.

A recent 2021 study found that initial treatment success rates were similar for the three types of treatment:

• ACTH: 46 percent
• oral steroids: 44 percent
• vigabatrin: 37 percent

These were the percentages of children who had no additional seizures after 30 days of starting initial therapy. You and a doctor will have to assess which is the right course of treatment for your baby.

When drug therapies fail to stop the spasms, some doctors may recommend other options. In some cases, surgery to remove the part of the brain causing the seizures may be recommended. A ketogenic diet has been studied to see if it could reduce some symptoms, though more research is needed to fully understand any potential benefits. A ketogenic diet is a high-fat, low-carbohydrate eating plan.

Infantile spasms are a complex and rare disorder that can have very serious consequences. It can lead to death in some children and cause intellectual disabilities and developmental problems in others. Even if the seizures are managed, the damaging brain effects can remain.

It’s important to note that some people with this condition will live healthy lives. This is more likely to be true if the brain abnormality that’s causing the seizures can be treated, no cause for the seizures can be identified, or diagnosis is given early, and the spasms are well managed.

What can trigger infantile spasms?

Brain abnormality or injury that can occur before or after your child’s birth may cause infantile spasms. Causes can include brain tumors, birth injury, or problems with brain development while your baby is still in the womb.

Are infantile spasms serious?

Yes, infantile spasms can be very serious. It’s essential for infantile spasms to be treated as quickly and effectively as possible to maximize your child’s developmental potential.

Can infantile spasms go away?

Yes, infantile spasms usually stop before 2 to 4 years of age. But according to the National Institute of Neurological Disorders and Stroke, most children with infantile spasms will develop other types of seizures.