LGS Foundation
Lennox-Gastaut Syndrome (LGS)
Lennox-Gastaut Syndrome (LGS) is a severe epilepsy syndrome that develops in children and often leads to lifelong disability. Nobody is born with LGS. It develops over time.
4 Core Features of LGS
- Seizure onset in childhood
- More than one type of seizure
- SSW & GPFA on the EEG Test
- Developmental delay*
30% of kids are typically developing at seizure onset but development becomes delayed when LGS begins.
In LGS:
- Seizures usually begin before age 5 years but can begin anytime in childhood.
- More than one seizure type is always present.
- Tonic seizures are present in all with LGS at some point.
- Seizures are nearly always treatment-resistant.
- Many LGS-associated disorders exist, including issues with sleep, behavior, movement, feeding, toileting, communication, and others.
- The EEG test shows slow spike and wave (SSW) and Generalized Paroxysmal Fast Activity (GPFA), which occur in all with LGS.
- SSW and GPFA emerge over time from uncontrolled seizures.
- SSW and GPFA occur between seizures and can worsen seizures, development, sleep, and behavior problems. These EEG features are signs that brain development has been altered.
Who has LGS?
- 1-2% of people with epilepsy
- 3-4% of children with epilepsy
- 48,000 children and adults in the U.S.
- 1,000,000 children and adults have LGS worldwide
What causes seizures in LGS?
- Brain Injury During Early Life33%
- Abnormal Brain Formation in the Womb17%
- Genetic Factors15%
- Brain Infections15%
- Unknown10%
- Metabolic Disorders9%
- Immune Disorders<1%
- In LGS, the brain is affected at a critical time in its development. Seizures and developmental problems result.
- There are many causes of seizures that can evolve into LGS. In most but not all cases, a cause can be found. Finding it can take extensive testing. In some cases, more than one cause is found.
- Knowing the cause of seizures can help identify an effective treatment in some cases.
- Most with LGS may have abnormal brain imaging seen on the MRI test, but some have normal brain imaging prior to developing LGS.
- LGS can also develop from other epilepsy syndromes such as West, Ohtahara, EIEE, Hypothalamic Hamartoma, Infantile Spasms, etc.
How does LGS change over time?
- There is no cure for LGS.
- Seizures in LGS may go into remission, and may also recur.
- 30-50% of children with infantile spasms will develop LGS.
- 80-90% of children with LGS will continue to have seizures into adulthood.
- Over 95% with LGS are intellectually disabled.
- Up to 70% with LGS will no longer show slow spike-and-wave (<3Hz) on EEG in adulthood.
- Over 50% suffer behavioral issues including hyperactivity, sleep disturbances, rage attacks, aggression, and autistic features.
- Those with LGS are 14 times more likely to die prematurely. Premature death in LGS is often due to SUDEP*, aspiration pneumonia, seizures, injury, or the underlying brain disorder.
SUDEP – Sudden Unexpected Death in Epilepsy.
Some genes and genomic regions that cause seizures that can evolve into LGS
GABRB3 · SCN1A · SCN2A · SCN8A · CDKL5 · DNM1 · FOXG1 · STXBP1 · CHD2 · ALG13 · DOCK7 · FLNA · GABRA1 · GLI3 · GNAO1 · GRIN1 · GRIN2A · GRINBB · HNRNPU · KCNT1 · KCNQ2 · MAGI2 · MEF2C · NEDDL4 · NDP NRXN1 · CACNA2D2 · CLN1/2/5 · ARX · PCDH19 · SLC35A2 · PIGA · SPTAN1 · PLCB1 · ST3GAL3 · PPP3CA · PTEN · TBD1D24 S · CA2TCF4 · SCN1A · TSC1/2 · SCN2A · WWOX · SCN8A · Dup 15q · SETBP1 · 22q Del · SIK1 · Trisomy 21 · SLC25A22 · and many more . .
The LGS Foundation is committed to finding a cure for this devastating disorder!