Skip to main content

Or 34,00 After 66% tax deduction

I make a monthly donation I make an IFI donation
Imagerie médicale Baulac

Epilepsy

Causes, biological mechanisms, symptoms, diagnosis and treatment

The name ‘epilepsy’ comes from a Greek word meaning ‘struck by surprise’, reflecting the sudden and unpredictable onset of seizures.

In France, 600,000 people are affected by this chronic neurological disease, which can manifest itself in different ways depending on the area of the brain affected. Around 50% of epilepsies begin before the age of 10.

Epileptic seizures are the manifestation of excessive cerebral activity resulting from ‘hyperexcitation’ of the nerve cells - the neurons of the cerebral cortex - and their synchronisation.

A distinction is made between :

  1. generalised epilepsies, affecting around 1/3 of patients, when all the neurons in the cortex are recruited from the outset
  2. focal epilepsies, which begin in a specific region of the brain.

Epilepsy can have various causes, such as a brain lesion, in which case it is known as structural epilepsy (formerly symptomatic), or it can be genetic (idiopathic epilepsy), metabolic or self-induced.

There is not one epilepsy but several epilepsy syndromes of varying severity, defined by the age of onset of seizures, their cause, nature and frequency, and response to drug treatment.

Diagnosis of this disease is based on clinical symptoms reported by the patient and his or her family during epileptic seizures and on analysis of an electroencephalogram (EEG), i.e. a recording of the electrical activity of the brain's neurons. Cerebral MRI can also be used to detect damage to the cortex.

Today, drug treatments are effective in more than 2/3 of patients, although 30% are drug-resistant. Surgery should be considered for these patients, because when the seizure source can be identified and operated on, patients may no longer have seizures.

13.02.2023 Understanding epilepsy in 2 minutes
Causes and mechanisms

The causes and biological mechanisms of epilepsy

There are many causes of epilepsy, classified according to international criteria: structural causes (or symptoms of damage to the cortex), genetic causes, metabolic causes (e.g. an enzyme disease), autoimmune causes (inflammation localized in the brain). Sometimes, no cause is identified.

Whatever the origin, epilepsies can be generalised (about 1/3 of cases) to the entire cerebral cortex or focal (partial), i.e. restricted to a precise, delimited area of the brain in 2/3 of patients.

 Symptoms and diagnosis

Symptoms and diagnosis of epilepsy

An epileptic seizure is a transient clinical manifestation linked to abnormal electrical activity in a specific region or throughout the brain.

The diagnosis of epilepsy is based on questioning patients and their relatives, watching a video of their seizure, and electroencephalic (EEG) recording between seizures, and sometimes during a seizure. Identifying the cause requires additional data: brain imaging, and sometimes biological tests (blood samples, or even a lumbar puncture).

Treatments

Treatments for epilepsy

The treatment of epilepsy depends on whether it is focal or generalised.

Anti-epileptic drugs control seizures in more than two-thirds of patients. Sometimes, several drugs may be combined to control the epilepsy.

In some forms of epilepsy, treatment can be stopped after several years.

When focal epilepsy is not controlled by anti-epileptic drugs, surgery should be considered.

Our news on the subject

épilepsie
Status epilepticus: new inflammatory markers to improve patient care
Unlike classic epileptic seizures that last only a few seconds or minutes, " status epilepticus" refers to a state of neuronal hyperactivity in the cerebral cortex that persists for several hours or days. When this condition occurs without a readily ...
03.31.2023 Research, science & health
image dépression
Ketamine and depression: a mechanism of the antidepressant effect reveal
Researchers from Inserm, CNRS, Sorbonne University and clinicians from the AP-HP and at Paris Brain Institute identified one of the mechanisms explaining ketamine effect as an antidepressant. Ketamine, usually used as an anesthetic, was administered ...
10.06.2022 Research, science & health
image
Status Epilepticus: new biomarkers to improve the prognosis of patients admitted to the ICU
A major neurological emergency, status epilepticus is defined as a persistent epileptic seizure. Exposing patients to irreversible brain lesions that cause serious cognitive sequelae, it requires intensive care, which may lead to sedation (artificial ...
07.06.2022 Research, science & health
image
Cardiac investigations in genetic epilepsy
A rare and tragic consequence of epilepsy is Sudden Unexpected Death in Epilepsy (SUDEP), which occurs after a seizure. The mechanisms involved, whether respiratory, cardiac or cerebral, are not yet fully understood. However, this risk is very low ...
11.24.2021 Research, science & health
cerveau
Epilepsy: Lacosamide alone is effective to treat focal seizures
A stage 3 clinical trial has proven the efficacy of lacosamide alone to treat focal seizures, specifically as a first-line treatment for newly diagnosed epilepsy. ...
12.27.2016 Research, science & health
Image pour visualiser l'épilepsie
When Epileptic seizures interrupt conscious processes: a step forward in neural mechanisms
During generalized seizures, in which epileptic activities affect the entire cerebral cortex, patients undergo an interruption of their conscious processes and are unable to deal efficiently with sensory stimuli. Using a genetic model of absence ...
09.07.2016 Research, science & health
See all our news