Lennox-Gastaut syndrome

A severe seizure disorder that typically developing before four years of age,

Also known as Lennox syndrome.

A childhood-onset epilepsy that most often appears between the second and sixth year of life.

Difficult to treat and is characterized by frequent seizures and different seizure types.

Often accompanied by developmental delay, psychological and behavioral problems.

Seizures can begin before age two, or after age six.

Daily multiple seizures are typical.

The range of seizures is larger than that of any other epileptic syndrome.

The most frequently occurring seizure type in L-G syndrome is tonic seizures.

90% of associated tonic seizures are nocturnal.

The second most frequent type of associated seizures are myoclonic, which often occur when the person is over-tired.

Atonic, atypical absence, tonic, complex partial, focalized and tonic–clonic seizures are also common manifestations of L-G syndrome.

About half of patients will have status epilepticus, usually the nonconvulsive type, which is characterized by dizziness, apathy, and unresponsiveness.

The seizures can cause sudden falling, and loss of balance, which is why patients often wear a helmet to prevent head injury.

In addition to daily multiple seizures of various types, children frequently have arrested/slowed psycho-motor development and behavior disorders.

The syndrome is also characterized by an interictal EEG featuring slow spike-wave complexes.

Seen in approximately 4% of children with epilepsy, and is more prevalent in males than females.

Children can have no neurological problems prior to diagnosis, or have other forms of epilepsy.

West syndrome is diagnosed in 20% of patients before it evolves into LGS at about 2 years old.

The mortality rate ranges from 3-7% in a mean follow up period of 8.5 to 9.7 years.

Death is often related to accidents.

There is no uniform cause.

Associated with developmental delays.

There is no cure.

Treatment is difficult, and complete recovery is rare.

Symptoms include the atonic seizure, also known as a “drop attack”, during which brief loss of muscle tone and consciousness cause abrupt falls.

The medical history frequently includes infantile spasms or focal and generalized seizures.

The most common type of LGS (

70–78% of LGS is symptomatic including encephalopathy or another disease and/or developmental disorder.

Frequent causes include tuberous sclerosis, hereditary metabolic diseases, encephalitis, meningitis, toxoplasmosis; hypoxia injury, other birth injuries; and lesions of the frontal lobe.

Patients with known causes tend to have a worse prognosis than those with idiopathic LGS.

Up to one-third of cases are cryptogenic.

May be associated with neurovisceral porphyrias including acute intermittent porphyria, hereditary coproporphyria and variegate porphyria.

Has clinical overlap,with other syndromes.

Has no uniform cause.

The diagnosis is often a question of probability rather than certainty.

The diagnosis is obvious when the epilepsy has frequent and manifold attacks, with the classic pattern on the electro-encephalogram with a slowed rhythm with Spike-wave-pattern, or with a multifocal and generalizing Sharp-slow-wave-discharges at 1.5–2.5 Hz.

During sleep, frequently, tonic patterns can be seen. But variations of these patterns are known in patients with no diagnosis other than LGS, and they can differ bilaterally, and from time to time, within the same patient.

Evaluation usually reveals developmental delay and cognitive deficiencies in children with true LGS, which may precede development of seizures, or require up to two years after the seizures begin, in order to become apparent.

Exclusion of organic or structural brain lesions is also important in establishing a correct diagnosis.

LGS seizures are often treatment resistant.

Treatment options include anticonvulsants, anesthetics, steroids, and immunoglobulins.

No drug is highly efficacious for treatment and rufimamide, lamotrigine, topiramate and felbamate may help as add-on therapy.

First-line drugs include Rufinamide

valproates (valproic acid, sodium valproate and valproate semisodium)


benzodiazepines, specifically clonazepam, and clobazam

Second-line drugs include: topiramate, lamotrigine, Felbamate, Zonisamide

Surgical possibilities include vagus nerve stimulation and corpus callosotomy

A ketogenic diet is a diet that causes ketosis, and is a treatment for treating intractable epilepsy.

Intravenous immunoglobulin therapy has been used in Lennox–Gastaut syndrome.

I Lamotrigine significantly reduces the frequency of LGS seizures, and is one of two medications known to decrease the severity of drop attacks.

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