Epilepsy is a neurological disorder characterized by the appearance of episodes of abnormal electrical activity in the brain that cause seizures and mental absence, among other symptoms. It is due to alterations in the morphology or functioning of the nervous system, especially the brain.
Among early-onset epilepsies we find the Lennox-Gastaut syndrome, characterized by frequent and heterogeneous seizures and variable intellectual disability. In this article we will describe what the Lennox-Gastaut syndrome is, what its causes and symptoms are and how it is usually treated by medicine.
What is Lennox-Gastaut syndrome?
Lennox-Gastaut syndrome is a very severe form of epilepsy that usually starts during childhood, between 2 and 6 years of age ; however, symptoms may start before or after this period.
It was described in 1950 by William G. Lennox and Jean P. Davis thanks to the use of electroencephalography, which allows the analysis of the bioelectric activity of the brain, detecting altered patterns like those typical of epilepsy.
It is a rare disorder that accounts for only 4% of total epilepsy cases. It is more common in males than females. It is resistant to treatment, although in some cases the intervention can be effective. In half of the cases the disease gets worse over time, while in a quarter the symptoms improve and in 20% they disappear completely .
Between 3 and 7% of children diagnosed with this syndrome die between 8 and 10 years after diagnosis, usually as a result of accidents: it is very common for falls to occur during seizures, so it is advisable to put a helmet on children with the disorder.
It is believed that there is a relationship between Lennox-Gastaut syndrome and West’s syndrome , also known as infantile spasm syndrome, which has similar characteristics and includes the occurrence of sharp contractions of the muscles of the arms, legs, torso, and neck.
Symptoms of this disorder
This syndrome is characterized by the presence of three main signs: the appearance of recurrent and varied epileptic seizures, the slowing down of the brain’s electrical activity and moderate or severe intellectual disability. He also suffers from memory and learning problems, as well as motor disorders.
In half of the patients the seizures tend to be long, lasting more than 5 minutes, or occur with little time separation; we know this as “status epilepticus”. When these symptoms occur, the person tends to be apathetic and dizzy, and does not respond to external stimulation.
In the cases of Lennox-Gastaut the psychomotor development is usually altered and delayed as a result of the brain involvement. The same applies to personality and behaviour, which are influenced by the epileptic problems.
The epileptic seizures that occur in Lennox-Gastaut syndrome can be very different from each other, which makes this disorder peculiar. The most frequent seizures are the tonic type , which consist of periods of muscular rigidity, especially in the extremities. They usually occur during the night, while the person is sleeping.
Myoclonic epileptic seizures are also common, i.e. those that cause spasms or sharp muscle contractions . Myoclonic seizures tend to occur more easily when the person is tired.
Tonic, atonic, tonic-clonic, partial complex and atypical absence crises are also relatively frequent in the Lennox-Gastaut syndrome, although to a lesser extent than the previous ones. If you want to know more about the different types of epilepsy you can read this article.
Causes and factors that favor it
There are several causal factors that may explain the development of Lennox-Gastaut syndrome, although not in all cases it is possible to deduce which of them is responsible for the disorder.
Among the most frequent causes of this alteration are the following:
- Development as a consequence of West’s Syndrome.
- Injuries or trauma to the brain during pregnancy or childbirth
- Infections in the brain, such as encephalitis, meningitis, toxoplasmosis or rubella.
- Malformations of the cerebral cortex (cortical dysplasia).
- Hereditary metabolic diseases.
- Presence of tumors in the brain due to tuberous sclerosis.
- Lack of oxygen during birth (perinatal hypoxia) .
The Lennox-Gastaut syndrome is very difficult to treat: unlike most types of epilepsy, in this disorder there is often resistance to drug treatment with anticonvulsants .
Among the most commonly used anticonvulsant drugs in the management of epilepsy are valproate (or valproic acid), topiramate, lamotrigine, rufinamide, and felbamate. Some of them can produce side effects such as viral diseases or liver toxicity.
Benzodiazepines such as clobazam and clonazepam are also given with some frequency. However, the efficacy of none of these drugs has been definitively demonstrated in Lennox-Gastaut syndrome.
Although until recently it was believed that surgery was not effective in treating this disorder, some recent studies and research have found that endoventricular callosotomy and vagus nerve stimulation are two promising interventions.
A ketogenic diet , consisting of eating few carbohydrates and a lot of fat, is usually recommended for epilepsy . This appears to reduce the likelihood of epileptic seizures. However, the ketogenic diet carries certain risks and should be prescribed by medical professionals.