Infantile spasms (IS) is a rare but serious epilepsy syndrome in young children. It is estimated to occur in roughly one out of 3,000 births. Symptoms typically appear the first year of life, most commonly between four to six months. Because the symptoms can be subtle and are often confused with other conditions, it can take time to get an accurate diagnosis.

Types of Infantile Spasms

Flexion Spasms

Flexion spasms appear as truncal flexion, often described as “jackknife” like the child is performing a stomach crunch. In some children, all that is noticed is a head nod.

Extensor Spasms

Extensor spasms usually have back arching with upper body extension.

Mixed Spasms (most common)

Mixed spasms often have truncal and/or head flexion with upper body extension. The spasms are quite brief and have a quick initial phase with a slightly slower relaxation phase. They tend to cluster, often upon falling asleep or waking up, and your child will cry afterward.