Recognizing Infantile Spasms: A Parent’s Guide to Identifying Early Symptoms.
Startling is a really normal thing that newborns and infants do.” They spread their arms and legs wide, then bring them together. This is a normal reflex called the startle, or Moro, reflex, in most cases. Few movements, however, can be a symptom of a rare but serious condition known as infantile spasms.
Afsaneh Talai, MD, pediatric neurologist at Children’s Health℠ and assistant professor at UT Southwestern, shares how to differentiate between the normal movements of a – and an infantile spasm.
What are infantile spasms?
Infantile spasms is a rare form of childhood epilepsy that occurs in about 1 in 2,000 infants and children in the U.S. each year. The spasms are small seizures that can disrupt a baby’s development. Infantile spasms typically start when a baby is 3 to 12 months old.
Without early diagnosis and treatment, infantile spasms can lead to serious, permanent changes to a child’s developing brain. Medication or surgery usually halts the spasms, but some children have a risk of other kinds of seizures in later life. Children who are diagnosed and effectively treated early are more likely to develop healthily.
What is the difference between infantile spasms and West syndrome?
In contrast, infantile spasms (IS) refer to a specific type of seizure, whereas West Syndrome describes a clinical constellation that includes IS. Infantile spasms and three of the following are present:
- Hypsarrhythmia, an abnormal pattern of electrical waves in the brain. This pattern is measured by a test called the electroencephalogram (EEG).
- Developmental regression (where a child loses the ability to do something they were previously doing, like walking or talking) or developmental delays (meeting milestones later than other children their age).
What causes infantile spasms?
Infantile spasms can be related to:
- Genetic disorders like Down syndrome or tuberous sclerosis
- Metabolic disorders
- Brain injuries or infections
- Abnormal blood vessels in the brain
- Differences in how the brain developed in the womb
- Rarely, because of a vitamin B6 deficiency
For approximately 30% of children diagnosed with infantile spasms, there’s no identifiable cause.
What do infantile spasms look like?
Since these tiny seizures can be subtle, or appear as a normal startle reflex or reflux, it’s not unusual for parents to miss them. (A baby experiencing an infantile spasm might stiffen and extend their arms while they scrunch up their knees or bend their neck forward.)
“With infantile spasms, the baby will typically extend the arms out suddenly and the body may scrunch forward at the waist with the knees pulled up,” Dr. Talai explains. “But infantile spasms can also be mild and appear just to be a head bob or the baby’s eyes rolling up.
Infantile spasms last just a second or two but tend to happen in a cluster (multiple spasms in succession). Infantile spasms tend to happen at times of sleep, particularly when a child is waking up. Babies typically are fussy or cry after a spasm.
Infantile spasms vs. startle reflex
Infantile spasms and a startle reflex can look similar, but some key characteristics can help you tell the difference:
- Cause: Loud noises, bright light or sudden movement can cause a startle reflex. Infantile spasms can happen any time. They often happen when a baby is waking up and rarely happen when a baby is sleeping.
- Frequency: With a startle reflex, babies typically only do a movement once. Infantile spasms typically happen back-to-back, or in clusters. Each spasm may last only a second or two, or they can have a cluster of spasms lasting several minutes.
- Age: The startle reflex is most noticeable in newborns and slowly disappears by 4 to 6 months of age at the latest. Infantile spasms often occur between the ages of 3 to 12 months of age, when the startle reflex has already started to go away.
- Decline in development: If you notice the above symptoms and a decline in development, that could be a sign of infantile spasms. For example, you may notice your baby is not doing the same things they used to be able to do (like walking or talking) or see changes in how your child interacts, such as less eye contact or smiling.
What should I do if I think my baby has infantile spasms?
Infantile spasms affect your baby’s brain development. Early diagnosis and treatment are critical to stopping the seizures and reducing their impact on your baby’s development. If you are concerned your baby may have infantile spasms, follow your instincts. Talk to your baby’s pediatrician right away.
You can prepare for the visit and help the doctor with diagnosis by:
- Recording video of a few of the spasms
- Documenting when episodes happen, how long they last and how your baby reacted
- Tracking changes in developmental milestones, such as smiling and interacting
Your child’s pediatrician may refer you to a specialist for additional testing if needed.
How are infantile spasms diagnosed?
Infantile spasms are diagnosed by a pediatric neurologist, a doctor who specializes in conditions that affect the brain and nervous system. They may use one or more of the following tests to diagnose your child and to determine the cause of your child’s symptoms:
- EEG (electroencephalogram): This test measures the brain waves or electrical activity in your child’s brain. This test is vital to make the diagnosis of infantile spasms.
- Imaging tests: such as computed tomography scans (CAT scan, CT scan) or magnetic resonance imaging (MRI) that allow doctors to examine your child’s brain structure.
- Genetic testing: To check for specific causes of your child’s infantile spasms.
