New classification of epileptic seizure types (Prof Dr Lagae)

 Clarity for better diagnosis and therapy 

In 2017 the International League against Epilepsy (ILAE) published a new classification of epileptic seizure types. Prof. dr. Lieven Lagae, pediatric neurologist at UZ Gasthuisberg and Chairman of the European Pediatric Neurology Society, highlights the importance of the new classification and clarifies what is truly "new".

One disorder – many experiences and outcomes

Epilepsy is often associated with convulsions and foam on the mouth. Nonetheless, epilepsy has many manifestations, different causes and diverse seizure types. 

The new classification highlights the different seizures types. It supports the fact that epilepsy is multifaceted, and hence facilitates communication between doctor and patient and between experts themselves. A clear and simple communication is crucial. The better the patient is able to describe a seizure, the better the diagnosis of the doctor will be. The outcome? The applied therapy will be more effective. Moreover, a clear description advances the prognosis. It enables the doctor to better predict the expected evolution of the disorder.

Painting a clearer picture of the experience

The new classification does not alter the definition of epilepsy, nor the classification of the different appearances. The added value compared to the 1981 version is two-folded. Firstly, the new classification recognizes an "unknown category". This category reassembles seizure types where experts are still uncertain; seizures that require further investigation. Previously, these seizures were artificially classified into a fixed category. Secondly, the new classification focuses much more on what concretely happens during a seizure: what the patient really undergoes and what outsiders see ... or not. This strongly contrasts to the 1981 classification, which contained old and more vague terms such as "complex partial seizures" or "secondarily generalized". In the new classification, two separated dimensions create clarity.

1. The first dimension follows from the distinction between focal and generalized seizures. Focal seizures start from - and are limited to – one area in the brain. They physically express themselves partially. For example, the patient gets a shock in his right arm, but nowhere else. However, if the seizure spreads out to the rest of the body, we speak about a generalized seizure.
2. A second dimension focuses on the motoric skills of the patient. It makes a distinction between motor and non-motor seizures. A motor seizure by definition implies some form of movement. On the contrary, a non-motor seizure expresses itself through others symptoms, such as changes in feelings, thoughts or sensations.

Both dimensions capture the process experienced during a seizure more clearly. Nerve pulls, shakes or stiffening of limbs, as well as automatisms (such as licking and smacking) are now included in the category "focal motor onsets". This is much more plain than the abstract "complex partial seizure".

Shedding new light on absences

And absences? Which category does this seizure type belong to? During an absence seizure, it seems like the person is no longer there. He blanks out or stares into space. This disorientation and loss of attention to surroundings lasts from a few seconds to several minutes. The new classification labels this kind of temporary consciousness disorder (sometimes with automatisms or repeated movements) as a non-motoric, generalized seizure. That description is more precise than the expression petit mal, which absences have been misleadingly labelled as in the past. The new classification sheds new light on absences.

A break-down of the new classifications

How Epihunter can help

The non-motor nature of absence seizures makes reporting very difficult. This is where Epihunter comes "in the picture". Epihunter creates awareness in the classroom and allows parents to get an overview of brain activity and absence seizures. Moreover, the Epihunter team builds functionalities that support the neurologist in diagnosis and optimization of treatment. The team is rolling up its sleeves and, together with the Flemish Epilepsy League and academic partners, it is working to get the necessary clinical validations.

Want to know more? Contact us now!

Reference: Epilepsy Foundation