What is hypsarrhythmia?

Hypsarrhythmia [hips-a-rith-me-ya] is a disorganized, chaotic pattern of brain waves that occurs in children with infantile spasms (IS) but not in other seizure disorders. Unlike spasms, this is not a symptom that you can see. It can only be detected by a noninvasive, painless test called an electroencephalogram (EEG).

This pattern is very different from a normal EEG, as shown in these examples:

Because hypsarrhythmia is so important to the diagnosis of IS, it's important to capture the pattern when it occurs. A routine EEG, which can typically take a couple of hours, may not last long enough to do this successfully. Your doctor may order a 24-hour EEG for your child if he or she suspects IS. This is conducted while your child is in the hospital and can be monitored continuously.

If your child's EEG shows this unusual brain-wave pattern, your doctor will likely begin working with you on a treatment plan.

Helpful Resources

Parent and Caregiver Brochure

Learn more about your child's IS and treatment with Acthar Gel from this helpful and informative brochure.

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Acthar Hub

See the many ways the Acthar Hub can help you get Acthar Gel for your child with IS.

Step-by-step injection guide

Download this informative injection guide to keep handy during your child’s injections.

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