Lennox-Gastaut Syndrome

What Is Lennox-Gastaut Syndrome?

Lennox-Gastaut syndrome (LGS) is a rare and severe form of epilepsy, characterized by treatment-resistant seizures and developmental delays.

3-5 years old

LGS develops over time, beginning in early childhood between the ages of 3 and 5 years old.

~80%-90%

About 80%-90% of children with LGS will continue to experience seizures into adulthood.

3%-4%

LGS accounts for 3%-4% of all children with epilepsy.

~48,000 people

There are about 48,000 people in the US with LGS.

What Are the Symptoms of Lennox-Gastaut Syndrome?

LGS appears as multiple seizure types that regularly continue despite treatment:

  • Tonic seizures (body stiffening, often during sleep)
  • Atonic seizures (sudden loss of muscle tone, causing falls)
  • Atypical absence seizures (staring spells)
  • Nonconvulsive status epilepticus (confusion, coma)
Each seizure carries risk, including injury, hospitalization, or even sudden and unexpected death in epilepsy (SUDEP).

In addition, most individuals living with LGS experience at least one behavioral-, motor-, or cognitive-associated condition, which persists into adulthood, including:

  • Sleep difficulties
  • Physical impairments, including bone or joint disorders, vision or eye disorders, and gastrointestinal disorders
  • Disruptive behavior
  • Learning and intellectual disabilities
  • Behavioral issues

What Causes Lennox-Gastaut Syndrome?

The causes of LGS are not fully understood, but it may evolve from other severe childhood seizure disorders, such as West syndrome.

25% and 35%

Between 25% and 35% of LGS cases do not have an identifiable cause.

Causes can include:

  • Changes in brain structure from birth or early injury (e.g., low oxygen or blood flow)
  • Tuberous sclerosis complex
  • Brain and/or nerve infections that start before birth
  • Brain malformations
  • Certain gene mutations that may disrupt brain development or function, even when MRI appears normal (genetic mutations associated with LGS are often classified as “de novo” mutations, or spontaneous errors, in a person’s DNA)
  • Rare conditions that affect how the body processes nutrients, sometimes causing toxic buildup in the brain

How Is Lennox-Gastaut Syndrome Diagnosed?

Getting an accurate diagnosis of LGS can be a challenging journey. LGS can be difficult to identify, because several different seizure types may be present.

The road to diagnosis may include a series of tests meant to evaluate:

  • Neurodevelopmental delays
  • Seizure types
  • Abnormal electrical activity in the brain, measured by electroencephalogram (EEG)
  • Potential structural causes of LGS, including cortical malformations, tuberous sclerosis, tumors, and acquired brain injury, by MRI
  • Metabolic, infectious, and autoimmune causes of LGS
  • Potential genetic causes of LGS

Early treatment and a holistic approach are key to enhancing the quality of life for people living with LGS.