Epilepsy

​​​​​​Epilepsy is a neurological disorder characterised by recurrent convulsive seizures. Seizures can vary in intensity and duration, and can manifest themselves in a number of ways, including sudden muscle jerks, loss of consciousness, mental confusion, abnormal sensations or behavioural changes.

Epilepsy is a chronic disease characterised by the occurrence of epileptic seizures. These seizures reflect a sudden and transient disturbance in the electrical activity of the brain. They appear without any identified cause, or are linked to another condition.

An epileptic seizure is characterised by transient physical manifestations resulting from sudden and excessive electrical discharges of nerve impulses in the brain, veritable "lightning bolts" travelling through numerous neurons. These discharges occur in the peripheral part of the brain (or cortex).

An epileptic seizure is :

focused. The abnormal nerve impulse remains localised in an area of the brain called the "epileptogenic focus". This can give rise to a wide variety of symptoms, affecting only certain parts of the body (known as a partial epileptic seizure).
generalised. In this case, the excessive discharges spread to all the neurons. The symptoms of the disease then affect the whole body (known as a generalised epileptic seizure).
As the basic cell of the nervous system, the neuron can collect information sent by the brain, produce new information and transmit it to other neurons. This information takes the form of electrical discharges, or nerve impulses, which travel along the nerves.

During an epileptic seizure, this electrical activity increases suddenly and disorderly. The level of activity above which a seizure is triggered is known as the "epileptogenic threshold". This threshold, which is different for each individual, can be kept high with appropriate drug treatments.

Here are some examples of biomarkers that have been studied for epilepsy:

• Levels of certain chemicals in the blood or cerebrospinal fluid (CSF) can be used as biomarkers for epilepsy, such as prolactin, lactate dehydrogenase and interleukin-6 (IL-6).
• The levels of certain proteins in the brain can be used as biomarkers for epilepsy, such as the S100B protein, which is released by brain cells after injury.
• Brain imaging, such as functional MRI, can help identify brain areas involved in epileptic seizures and can be used to monitor changes in the brain over time.
• Electroencephalogram (EEG) can help identify electrical abnormalities in the brain that occur during epileptic seizures, and can be used to monitor the effectiveness of treatments.