What do EEG patterns look like in children with infantile spasms? 

Some infants with infantile spasms and TSC show clinical and EEG findings that are different from typical infantile spasms.  In the beginning, the spasms may look like focal motor seizures.  The movements affect primarily or only one side of the body. Video EEG monitoring has made it easier to classify these seizures. In many situations, they are found to come from one or more areas in the brain.

  • Focal (in one brain area) or multifocal (in several brain areas) abnormalities may be found when the EEG is performed between the newborn period and the development of infantile spasms. 
  • At first, infants with infantile spasms have a particular EEG with patterns of spike discharges and irregular slow activity in several brain areas (Westmoreland, 1988; Curatolo, 1991).  
  • Although the EEG changes can be located in any part of the brain, the most common location for infantile spasms is the posterior temporal and occipital regions. 
  • Drowsiness increases the slow-wave activity and an increase in the amount of epileptiform activity may be observed during REM sleep.  
  • The EEG changes tend to generalize, affecting both sides of the brain and at the same time.
  • The epilepsy discharges develop and resemble the EEG pattern called hypsarrhythmia (Dulac et al., 1984). 
  • Severe sleep problems occur frequently, and are mainly due to seizure activity during sleep. All-night sleep studies in children with infantile spasms have shown an increased number and duration of awakenings after sleep onset, and a marked reduction in total sleep time and in REM sleep time (Curatolo, 1994).

What are some of the obstacles to diagnosing IS?

Diagnosing infantiles spasms can be more difficult than you think. The unusual seizure can easily be overlooked by parents and health care providers who are unaware of its significance. Thus, getting a timely and accurate diagnosis may depend on parents insisting on getting help when they suspect that there's something wrong with their child or they think that their child is having infantile spasms. 

A diagnosis of infantile spasms may be dismissed too easily if:

  • The child’s EEG does not show hypsarrythmia. 
  • The child is considered too old for spasm onset. 
  • The spasms are asymmetrical or atypical in appearance.
  • Spasms evolve from or into another seizure type.
  • The spasm occurs singly rather than in a more typical cluster. 

It's important to realize that none of these conditions is enough to rule out a diagnosis of infantile spasms in children with TSC.

What can parents do to help in diagnosing these seizures?

If you are concerned that a diagnosis of infantile spasms may have been overlooked, begin by broaching the subject directly with your child’s health care provider. If you are still not satisfied or have trouble getting your concerns heard, consider the following options: 

  • Video record your child’s episodes and show them to your child’s health care providers
  • Get a second opinion at a Comprehensive Pediatric Epilepsy Center, TSC Clinic, or with a neurologist with expertise in treating TSC
  • Check into the emergency room of a children’s hospital, stating you believe your child is having infantile spasms
Reviewed By: 
Patricia O. Shafer RN MN
Reviewed Date: 
Sunday, December 15, 2013