Understanding Epilepsy
Classification of Seizures
The Brain and Epilepsy
What happens during a seizure?
An epileptic seizure is an abnormal electrical discharge in one or more regions of the brain. Symptoms vary depending on the affected area, the intensity, and the duration of the discharge.
The brain is an organ as impressive as it is sensitive. A true conductor of the human body, it regulates thought, movement, emotions, memory… and much more. When an epileptic seizure occurs, it’s like a short circuit: excessive and sudden electrical activity disrupts the brain’s normal functioning. Understanding how this happens — and the different forms it can take — helps one live better with the condition or support a loved one.
The Brain, an Electrical Organ
- It weighs approximately 1.3 kg, 75% of which is water.
- It represents only 2% of body weight but consumes 20% of the body's energy.
- It contains over 100 billion neurons.
- It communicates via electrical impulses measurable by EEG.
The Major Regions of the Brain and Their Role
Frontal Lobe
Language, planning, emotions, voluntary movements
Temporal Lobe
Memory, recognition, hearing, emotions
Parietal Lobe
Sensations (touch, temperature…), body awareness
Occipital Lobe
Vision, image interpretation
Brainstem
Coordination, balance
Cerebellum
Automatic vital functions (respiration, heart rate)
Types of Epileptic Seizures
Why is this classification useful?
Knowing the type of seizure allows for:
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a better diagnosis
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a more targeted treatment
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a clearer understanding by the person and their loved ones
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better communication with healthcare professionals
Focal Seizures
These seizures begin in a specific area of the brain. They include:
Focal Aware Seizure
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Déjà vu sensation
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Tingling or numbness
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Tremors on one side of the body
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Changes in senses (sight, sounds, smells)
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The person remains conscious
Focal Impaired Awareness Seizure
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Blank stare
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Automatic movements (lip smacking, repetitive movements)
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Difficulty understanding or speaking
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Memory loss related to the episode
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Disorientation after the seizure
Duration: a few seconds to 1-2 minutes
Generalized Seizures
These seizures involve both cerebral hemispheres from the outset. They include several types:
Generalized Tonic-Clonic Seizure (Formerly "Grand Mal")
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Sudden muscle stiffness (tonic phase)
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Followed by rhythmic jerking (clonic phase)
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Loss of consciousness
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Possible initial cry, tongue biting, loss of urine
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Fatigue and confusion after the seizure
Duration: 1 to 2 minutes
Atonic Seizure
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Sudden muscle relaxation → abrupt fall
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Brief loss of consciousness
Myoclonic Seizure
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Rapid tremors of one or more muscle groups
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Without loss of consciousness
Focal Impaired Awareness Seizure
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Fixed gaze, immobility, apparent inattention
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Often in children
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May go unnoticed
Duration: a few seconds
Seizures of unknown onset
When the origin of the seizure cannot be precisely identified, it is referred to as unknown onset. This type may be reclassified later with more information (e.g., by EEG).
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