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 2,500 babies each year will be diagnosed with the disease in the United States. These seizures or spasms generally occur before a child is 1 year old, with most cases occurring when babies are about four months old.

According to a review article published in the Iranian Journal of Child Neurology, only 8 percent of cases are diagnosed in babies over a year old.

Read on to learn more about this condition.

Symptoms of infantile spasms

An infantile spasm can consist of something as simple and slight as a head drop. According to the American Epilepsy Society, they more commonly involve a series of sudden, jerking movements of the legs and arms, with a bending at the waist or a fast drop of the head. The spasms themselves usually only last a couple of seconds, but they tend to occur in clusters.

Experts from the Washington University School of Medicine in St. Louis report that up to 80 percent of infantile spasms occur in clusters of 2 to over 100 seizures. Infantile spasms also usually occur upon waking, unlike benign myoclonic seizures, which tend to occur in babies as they fall asleep.

Causes of infantile spasms

Infantile spasms is a disorder caused by a brain abnormality or injury that can occur before or after birth. According to the Child Neurology Foundation, 70 percent of infantile spasms have a known cause. Causes may include things like:

  • brain tumors
  • genetic or chromosomal abnormalities
  • a birth injury
  • brain infection
  • a problem with brain development while a 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 the frequent spasms. In the rest of the cases, the cause of the spasms is unknown, but may be the result of an unidentified neurological problem.

How infantile spasms are diagnosed

If a doctor suspects infantile spasms, they will order an electroencephalogram (EEG), which is easy to obtain and usually diagnostic. If this test is inconclusive, they may order a test called a video-electroencephalogram (video-EEG). With this test, as with a regular EEG, electrodes are placed on the baby’s skull to help doctors visualize brain wave patterns. A video then captures the baby’s behavior. A doctor, usually a pediatric neurologist, will watch the brain wave activity during and in between 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. Most children with infantile spasms will have disorganized brain wave activity. This is known as modified hypsarrhythmia. Very chaotic brain wave activity to a milder response, known as hypsarrhythmia, can be seen in about two-thirds of children with the disorder.

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

It’s important that you seek 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 intervention.

In a recent study presented at the annual meeting of the American Epilepsy Society, nearly half of babies with the disorder weren’t properly diagnosed for a month or more, and some went undiagnosed for years. It’s important to be aggressive in your search for answers.

Complications of infantile spasms

Babies with infantile spasms frequently have mental and developmental problems. In research published in the Annals of Indian Academy Neurology, at three years after diagnosis, roughly 88 percent of the children studied had problems in some or all of the following:

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

Additionally, nearly 75 percent of the participants had some autistic traits. In another study cited by the researchers, 80 percent of 10-year-olds with diagnosed infantile spasms had some type of intellectual disability.

Some children will have no complications, however. 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 develop normally.

Treatment for infantile spasms

One of the major drugs used to treat infantile spasms is adrenocorticotropic hormone (ACTH). ACTH is a hormone that is naturally produced in the body. It’s injected into a child’s muscles and has been shown to be very effective in stopping spasms. Because it’s an extremely powerful drug that can cause very dangerous side effects, it’s generally given in low doses for a short amount of time. Side effects may include:

Doctors sometimes use an anti-seizure medication called vigabatrin (Sabril) and steroid therapies, like prednisone. Like ACTH, both these drugs have significant side effects.

You and your doctor will have to assess which is the right course of treatment for your baby. ACTH may be slightly more effective than vigabatrin in treating the disorder, but the evidence is weak. There’s also not enough evidence to show whether steroid therapies are as good as ACTH in controlling infantile spasms.

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 may also reduce some symptoms. A ketogenic diet is a high-fat, low-carbohydrate eating plan.

Outlook for this condition

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

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