Although many commonly associate seizures with body-shaking convulsions, this is just one type of seizure that can occur. There are many different types and severities of seizures, and some can involve very subtle changes or no outward physical symptoms.
This means that, unless you know what to look for, it can be easy to miss the warning signs of a seizure.
What is a Seizure?
Your brain is made up of billions of cells called neurons. These cells send electrical signals to each other, allowing your brain to control everything from your heartbeat and digestion to your thoughts, feelings, and body movements.
A seizure happens when there is a sudden, abnormal, and uncontrolled change in the electrical activity of your brain. This can cause many symptoms depending on which part of your brain is affected.
Types of Seizures
There are two main types of seizures: focal and generalized.
Focal seizures (also called partial seizures) occur when the abnormal electrical activity is limited to one part of the brain. Generalized seizures involve the whole brain.
Focal seizures can be further divided into three subtypes:
- Simple partial seizure (also called a focal aware seizure): Consciousness is not impaired, meaning you remain aware of what’s happening around you. However, you may experience strange sensations such as a change in smell, flashing lights, strange noises, or slight twitches. Only one small area of the brain is affected.
- Complex partial seizure (also called a focal impaired-awareness seizure): Multiple brain areas are affected. Consciousness is impaired, meaning confusion, dizziness, unresponsiveness, or memory loss.
- Secondary generalized seizure: Begins as a focal seizure but quickly spreads to involve the whole brain.
Generalized seizures can be divided into six subtypes:
- Absence (petit-mal): typical characteristics include staring or eye flickering and little or no body movements. No convulsions.
- Clonic: Rapid, repetitive body movements. Jerking convulsions.
- Tonic: Body stiffness or rigidity.
- Myoclonic: Symmetric jerking of extremities.
- Tonic-clonic (grand-mal): Tonic stiffening followed by clonic convulsions.
- Atonic: Sudden limpness or loss of posture.
Warning Signs of a Seizure
Seizures typically progress in stages, typically beginning with a prodrome, then an aura stage, before the actual seizure begins.
The prodrome stage may include symptoms such as:
- a “strange” or “funny feeling.”
Then, the aura stage may involve symptoms including:
- intensifying anxiety, fear, irritability, or confusion
- a feeling of déjà vu
- nausea or uneasiness in the stomach
- loss of bladder or bowel control
- sudden change in heart rate or blood pressure
- numbness or tingling
- muscle twitches
If you experience any of these symptoms or notice someone else going through these phases, get into a safe position and be aware that a fall or collapse may occur. Loosen tight clothing and put something soft under their head.
Do not put anything in the person’s mouth, and do not attempt CPR. Do not hold them down or try to stop their movements. Call for emergency medical assistance and stay with the person until help arrives.