Lennox-Gastaut is a rare epilepsy syndrome that only affects between 1 to 5 children out of every 100 that have epilepsy. It’s also well known to be one of the most difficult childhood epilepsies to treat, also known as ‘intractable’. Lennox-Gastaut syndrome usually starts in children between the ages of 3 to 5, although it has been known to start as early as 18 months and as late as 7.
Seizures can vary in type and severity and caregivers often note a variety of different types of seizures within each child who has Lennox-Gastaut. However, most commonly will be atonic and tonic seizures. Previously, these used to called ‘drop seizures’ as the child would always fall to the ground during a seizure. Atonic seizures cause the child to become limp and fall, whereas during a tonic seizure the child will stiffen. There is always a danger of injury during these types of seizures.
Focal seizures are also common with Lennox-Gastaut, many of which will happen whilst the child is asleep. Focal seizures can present in a number of ways as it depends on which area of the brain is affected. This can include focal aware and focal impaired seizures, the former of which is when the person is aware of their surroundings and the latter when they are not.
Other types of seizures are less common but possible with Lennox-Gastaut, including generalised tonic-clonic and myoclonic seizures.
In addition, all children with Lennox-Gastaut will develop learning difficulties to some degree. These can vary in severity from child to child, but will most likely mean that they need to attend a school that can cater to their needs from a young age.
An electroencephalogram (EEG) test is used to detect any irregularities in the brains electrical impulses. The patterns detected are known as ‘slow spike and slow-wave’ and ‘fast spike activity’ activity. These can often be detected in between seizure activity.
Genetic conditions such as tuberous sclerosis or brain malformation are known causes of Lennox-Gastaut, as well as acquired causes such as brain trauma or lack of oxygen during childbirth. However, in over 50% of Lennox-Gastaut cases, the cause remains unknown.
As previously mentioned, treatment for Lennox-Gastaut can be incredibly difficult. Some anti-epileptic drugs (AEDs) may prove effective, including sodium valproate, lamotrigine, levetiracetam, topiramate, clobazam and phenytoin. In some cases, it can be very difficult to find the right combination of medications to treat Lennox-Gastaut.
The ketogenic diet has proved effective in some cases, after which one or more medications can be gradually withdrawn.
Very recently, another treatment, known as Epidiolex, a cannabis-based medication has been approved for use within the EU for cases of Lennox-Gastaut and Dravet syndrome specifically. In some cases, the medication has shown promising results at reducing the number of seizures in children, particularly atonic and tonic.
Epilepsy surgery may be considered to reduce the number and severity of seizures, although there is no guarantee that it will work. Corpus callosotomy and vagus nerve stimulation (VNS) are the two types that might be considered.
Unfortunately, the long term prognosis for Lennox-Gastaut can be difficult in terms of controlling seizures and learning difficulties. A small number of those affected will see some improvement by the time they reach their teenage years, however, many will continue to have seizures into adulthood on a daily basis.
Behavioural problems can also be common as a result of Lennox-Gastaut, which may require a child psychologist/psychiatrist.