While infantile spasms is a rare form of epilepsy, it can be identified by its distinct (unique) characteristics if physicians and caregivers are aware of the telltale signs. Infantile spasms can be mistaken for colic or an exaggerated Moro reflex, but these do not typically occur in the clusters that are typical of IS. Infantile spasms is typically diagnosed by observing spasms in an infant who also displays hypsarrhythmic EEGs.

Patients with spasms will present in a variety of ways, but the most typical is a recognition of little flexion jerks that can be mistaken for a little startle reflex in children, and that happens fairly commonly. The one thing that really triggers a sense that there's something seriously wrong is when a child's development either stops advancing or actually regresses with loss of developmental milestones. Even if the spasms are infrequent or subtle, the problem with developmental delay or regression is a red flag that will catch the attention of a medical professional.