Lennox-Gastaut Syndrome: Symptoms & Treatments

Lennox-Gastaut syndrome (LGS) is a rare and severe form of childhood epilepsy that continues throughout life. Please keep reading to learn more about this condition.

What is Lennox-Gastaut syndrome?

Lennox-Gastaut is a type of severe epilepsy in which there are multiple seizure types. It usually starts in infancy or early childhood. The seizures begin typically before age 4 years, and it is rare for LGS to be diagnosed after age 10. People with this syndrome may have the following types of seizures:

Tonic seizures in which there is stiffening of the body, dilation of the pupils, gazing upwards, and changes in breathing patterns
Atonic seizures in which there is a short-lived loss of muscle tone which can result in falls
Atypical absence seizures in which there are staring spells
Generalized tonic-clonic seizures (also called generalized seizures or grand mal seizures) in which there is stiffening of the muscles and a rhythmic jerking
Myoclonic seizures in which there are sudden muscle jerks

There can be periods of frequent, uncontrollable seizures interspersed with relatively seizure-free intervals. However, there is no cure for this condition, and achieving complete freedom from seizures is rare.

Notably, most children with Lennox-Gastaut also have developmental delays and progressive cognitive impairment.

In addition to the developmental delay, there are behavioral problems such as aggression, agitation, hyperactivity, and autism.

Lennox-Gastaut is called a childhood epileptic encephalopathy because it is a condition in which frequent seizures lead to worsening cognitive and behavioral problems.

How is Lennox-Gastaut diagnosed?

Children, adolescents, and adults with Lennox-Gastaut have a recognizable pattern of abnormal electrical activity in the brain that can be identified on an electroencephalogram (EEG).

However, even though the seizures typically begin in early childhood, it can take time, even years after seizure onset, before this condition is diagnosed. This is because all the features of Lennox-Gastaut may not be present in the beginning.

In many children, LGS develops after another type of epilepsy, such as infantile spasms (West syndrome), epilepsy in infancy with migrating partial or focal seizures, or Ohtahara syndrome.

What causes Lennox-Gastaut?

In approximately 25% of children with Lennox-Gastaut, the cause remains unknown. Known causes of this condition include an underlying brain disorder such as:

Congenital brain malformations due to a genetic abnormality or an injury or infection during early pregnancy causing abnormal brain development
Acquired brain injury due to hypoxia (lack of oxygen), stroke, bleeds, infections, brain injuries, or neurological disorders
Genetic disorders such as tuberous sclerosis complex which are associated with structural abnormalities in the brain

How do doctors treat Lennox-Gastaut?

The following epilepsy therapies are used to control seizures in people with Lennox-Gastaut.

Antiseizure medications

Doctors treat seizures in people with Lennox-Gastaut with antiseizure medications. In most people with LGS, one medicine cannot completely stop seizures, and two or more anti-seizure medications are needed to control recurrent seizures and multiple types of seizures. Even multiple medications may only provide partial seizure control. Even if there is a reduction in seizure activity, the side effects of multiple anticonvulsant medications can be difficult to tolerate. Some of the anti-epileptic medications prescribed to people with Lennox-Gastaut include topiramate, lamotrigine, clobazam, rufinamide, felbamate, cannabidiol, and fenfluramine.

Benzodiazepines such as diazepam (Valium), midazolam (Versed), and lorazepam (Ativan) are used to treat clusters of seizures called status epilepticus, which is a medical emergency. The US Food and Drug Administration (FDA) has approved a rectal diazepam gel (Diastat) for use at home when seizures happen in clusters or repetitively.

Dietary therapy

Various diets such as the ketogenic diet, low-carbohydrate diet, low glycemic index diet, and modified Atkins diet have been found to potentially decrease seizure frequency. Dietary changes may even allow a person to come off some anti-seizure medications. However, some of these restrictive diets, such as the ketogenic diet, can be difficult to follow long-term. They also require careful monitoring by a physician and dietician, as well as dietary management by caregivers.

Epilepsy surgery

A common procedure in people with Lennox-Gastaut is the placement of a pacemaker-like device called a vagus nerve stimulator in the chest. This device sends regular, mild electrical pulses to the brain. Vagus nerve stimulation can help lower the severity and frequency of seizures in people with LGS.

In people with frequent drop attacks (which increase the risk of injuries), doctors may recommend a type of brain surgery called corpus callosotomy, in which a small part of the brain is removed, or nerve fibers are separated to help with seizure control.

Other treatments

Children with LGS need an individualized education plan. Other therapies may be needed to help manage behavior problems. Children and adults with Lennox-Gastaut may also benefit from ongoing physical therapy, occupational therapy, and speech therapy.

What is the life expectancy for Lennox-Gastaut syndrome?

People with Lennox-Gastaut syndrome can live well into adulthood and even older ages. However, there is a higher risk of death due to structural damage to the brain from frequent seizures and injuries from falls associated with seizures. As a result, the death rate in people with Lennox-Gastaut is approximately 3-7% over a 10-year period after diagnosis.

Additionally, sometimes there is a sudden unexpected death in people with uncontrolled seizures. This possibility can be frightening for families. However, taking anti-epileptic medications as prescribed and avoiding seizure triggers can help to lower the risk of this happening.

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