Infantile Spasms: What Pediatricians Should Know

Though seizures in children are always worrisome, pediatricians should be especially watchful for infantile spasms, a type of epilepsy that occurs in young infants typically between ages 3 and 8 months, a CHOC Children’s neurologist says.

These seizures should be considered a medical emergency due to the potentially devastating consequences on the developing brain, Dr. Mary Zupanc says. Many children with infantile spasms go on to develop other forms of epilepsy because a developing brain undergoing an epileptic storm essentially becomes programmed for ongoing seizures and cognitive/motor delays.

To that end, here’s what pediatricians should look for:

  • Infantile spasms often occur in clusters, with each spasm occurring every five to 10 seconds over a period of minutes ranging from three to 10 minutes or longer.
  • 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.

Infantile spasms can be easily missed because they can mimic common symptoms and conditions such as sleep disturbances, gastroesophageal reflux, startle and shuddering attacks.

Diagnosis, treatment

If infantile spasms are suspected, a pediatrician should quickly refer the child to a pediatric neurologist. CHOC neurologists admit these children urgently for long-term video electroencephalogram (EEG) monitoring to confirm the diagnosis.

Infantile spasms are diagnosed on the basis of clinical spasms, in association with a markedly abnormal EEG showing a hypsarrhythmia pattern. A hypsarrhythmia pattern is characterized by very high amplitude electrical activity and multifocal areas of the brain demonstrating epileptic discharges.

High-dose adrenocorticotropic hormone, or ACTH, is CHOC neurologists’ first line of treatment for infantile spasms, per the American Academy of Neurology’s 2004 practice parameter. Vigabatrin (Sabril), the parameter states, is probably effective in the treatment of infantile spasms, especially in children with tuberous sclerosis and infantile spasms.

If started within four to six weeks of seizure onset therapy has better success at stopping spasms, eliminating the hypsarrhythmia pattern and improving developmental outcomes regardless of etiology.

The course of treatment is approximately six weeks. During this time, and for two to three months after the ACTH course, immunizations should not be administered. The effectiveness of ACTH may be as high as 85 percent, though a recent published study placed the efficacy at a slightly lower percentage, regardless of etiology.

Side effects, causes

Side effects of ACTH, a steroid, include high blood pressure, increased appetite and weight gain, increased sugar in the blood, temporary suppression of the immune system, and sometimes gastritis. All side effects are monitored during the time of the ACTH, and they disappear after the course of treatment.

Successful therapy is marked by two achievements: the cessation of the infantile spasms and the elimination of the hypsarrhythmia pattern. But because clinical spasms can be very subtle and the hypsarrhythmia pattern may sometimes only be seen during deep sleep, therapy’s success can only be confirmed through objective long-term video EEG monitoring.

The etiologies for infantile spasms can include:  tuberous sclerosis; cortical dysplasias; stroke; infection including meningitis and encephalitis; hypoxic-ischemic injury; trauma; or genetic conditions such as Down syndrome and metabolic disorders.