Types of Seizures

There are more than 40 different types of seizures. Most fall under two main categories:

1. Generalized seizures occur when there is widespread seizure activity in the left and right hemispheres of the brain. The most common forms of generalized seizures are:

Some people experience an aura – a partial seizure preceding a generalized seizure – which is often seen as a warning sign. An aura may be emotional (e.g. fear, anxiety), physical (e.g. dizziness, nausea), or sensory (e.g. tingling or crawling sensation on the skin, spots or colours before the eyes, strange tastes or smells).

2. Focal (or partial) seizures occur when seizure activity is limited to a part of one brain hemisphere. There is a site, or a focus, in the brain where the seizure begins. The most common forms of focal seizures are:

If you have epilepsy or suspect you had a seizure-like episode, learning the names and terms for your symptoms can help you describe it accurately to others. Health care providers in particular rely on this information to make a correct diagnosis of your condition.

Possible Seizure Triggers

Medication

  • Not taking one’s anti-epileptic medication
  • Other medications that are taken in addition to anti-epileptic medication

Internal Factors

  • Stress, excitement and emotional upset
    • This type of over-stimulation may lower the person’s resistance to seizures by affecting sleeping or eating habits.
  • Boredom
    • Research shows that individuals who are happily occupied are less likely to have a seizure.
  • Lack of sleep can change the brain’s patterns of electrical activity and can trigger seizures.
  • Fevers may make some children more likely to have a seizure.
  • Menstrual cycle
    • Many females find their seizures increase around this time of their period. This is referred to as catamenial epilepsy and is because of changes in hormone levels, increased fluid retention and changes in anti-epileptic drug levels in the blood.

External Factors

  • Alcohol can affect the rate at which the liver breaks down anti-epileptic medication.
    • This may decrease the blood levels of anti-epileptic medications, affecting an individual’s seizure control.
  • Poor diet
    • Many seizures take place when blood sugar is low.
    • Stimulants such as tea, coffee, chocolate, sugar, sweets, soft drinks, excess salt, spices and animal proteins may trigger seizures by suddenly changing the body’s metabolism.
    • Some parents have reported that allergic reactions to certain foods (e.g. white flour) also seem to trigger seizures in their children.
    • Certain nutrient shortages, such as a lack of calcium, have also been found to trigger seizures.
  • Very warm weather, hot baths or showers, especially when there is a sudden change in temperature.
  • Television, videos and flashing lights
    • The “strobe effect” from fast scene changes on a bright screen, rapidly changing colours or fast-moving shadows or patterns can all be trigger seizures.

Additional Seizure Types and Syndromes

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