It is the second neurological disease after migraine: 600,000 individuals suffered from epilepsy in France in 2018, according to Inserm. In the collective imagination, an individual having an epilepsy crisis refers to the vision of an unconscious person, paralyzed and agitated by convulsions.
This crisis exists: it is called generalized tonic. However, this is just one of the many that can occur when you have epilepsy. We thus speak of “epilepsies” in the plural, because the disease manifests itself in very different crises depending on the part of the brain affected: a distinction is made between generalized crises and so-called focal or partial crises.
A single mechanism is responsible for epileptic seizures: hyperactivity of neurons which creates too much electrical intensity in the brain. When they are generalized, they are caused by the excitation of a diffuse network of neurons in the two hemispheres of the brain. When the crises are focal, the electric discharge only affects one region of the latter.
The “tonicoclonic” or “convulsive” crisis is the most typical manifestation of a generalized crisis. During one to three minutes, the patient falls, utters a possible cry and paralyzes. Then, it is agitated by large shakes, sometimes loses its urine and secretes saliva in greater quantity.
A generalized crisis can also be revealed by what are called “absences”, which are frequent in children. The patient suddenly loses consciousness, his gaze becomes fixed, and this for about ten seconds.
Regarding partial seizures, which affect more than two thirds of patients, the symptoms differ according to the location of the brain concerned and are manifested for example by stiffening, uncontrolled movements, tingling or even auditory and visual hallucinations .
Stiffness, tingling and hallucinations
Additional complexity, the causes of epilepsy vary widely. “Each age group will have its own causes,” explains Sophie Dupont, neurologist at the AP-HP at La Pitié-Salpêtrière. In childhood, they tend to be genetic or metabolic, but can also result from birth accidents.