The LGS Foundation IS committed to providing education and increasing awareness of Infantile Spasms, another rare and severe form of epilepsy that often occur before the diagnosis of LGS. Infantile Spasms typically occur before one year of age and affect only 2,500 children in the U.S. Spasms can be mistaken for startle reflex or colic, but are, in fact, a much more serious neurological condition. If a timely diagnosis does not occur and medical intervention is delayed, IS can have devastating consequences. IS can precede LGS in 20% to 62% of cases(1)


Know the signs.

Identifying spasms is critical for parents, caregivers and providers.


Because infantile spasms can be mistaken for other conditions or seen as not harmful, prompt diagnosis and appropriate treatment are critical for the child’s best developmental outcome.


  • Most pediatricians will only see one or two IS cases throughout their entire career.

    • A qualified child neurologist can help confirm a diagnosis.

  • If a parent or caregiver is concerned that infantile spasms has been overlooked, they need to broach the subject directly with their health care provider.

  • The earlier a child is diagnosed, the greater the chances that the spasms can be treated.

    • Once the spasms are treated, a child’s brain has more time to recover and gain developmental ground that may have been lost while the spasms occurred.

    • Many children respond well to treatment and go on to develop normally for their age.

Research is critical.

  • We need more research about infantile spasms

  • Between 20% - 62% of individuals with LGS have a history of infantile spasms.  

  • The existing literature shows a large discrepancy in the figures that describe the relationship of IS to LGS. Below is a graphic that illustrates the disparities. 

  • The LGSF recommends an increase in modern, longitudinal studies of infantile spasms and LGS. It is our hope that increased awareness of IS, more timely diagnoses, and immediate medical intervention can prevent infantile spasms from developing in to Lennox-Gastaut Syndrome.