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So let’s get started by answering the question, what is a seizure?
Well at a very basic level, a seizure is an abrupt, sudden episode
of abnormal brain cell electrical activity.
Essentially, the brain’s electrical system malfunctions.
This can be caused by abnormal repetitive firing of brain cells
or over-coordination of brain cells firing together.
The seizure lasts as long as the triggering cells
continue to fire at a fast and disorganized pace.
This may fatigue brain cells, but neurologists believe
that in most cases, it doesn’t cause brain cell injury.
The period of time after the seizure is called the postictal period.
This is the time when the brain cells are tired from working so hard.
They're not injured, but just fatigued.
They can function, but prefer not to,
similar to how you feel after a long physical work-out.
Now, a distinction needs to be made between an epileptic seizure,
and a non-epileptic provoked or triggered seizure.
As we said before, a seizure is an abrupt and sudden
episode of abnormal brain cell electrical activity.
This can be due to an influence outside of the brain,
which is provoking or triggering a physiologic seizure
or it can be due to untriggered spontaneous electrical
discharge from within the brain cells.
Some things that can trigger a physiologic seizure include:
low blood pressure, like with fainting,
low oxygen, like during an infant or toddler breathholding spell,
or other causes like fever, a minor head blow, drugs or medications.
If a seizure occurs multiple times, and they are not triggered,
we call this epilepsy.
If the seizure has only occurred once,
or the seizures are always triggered, then it is not epilepsy.
Another distinction that we should make
is about non-epileptic psychogenic events.
These events can look like a seizure, but are not associated
with any unusual brain wave activity.
They are caused by some type of psychological stress,
which may or may not be immediately apparent.
It is an important distinction to recognize, because
non-epileptic psychogenic events are best treated
with counseling rather than with seizure medications.
Here is a graphic example of normal
and abnormal brain electrical activity.
This analogy will help make the distinction
between an epileptic and a non-epileptic or triggered seizure.
The top picture represents our normal brain activity.
There is a level above our normal brain activity called the seizure threshold.
If our brain waves reach this threshold, it will cause a seizure.
Now this can happen in one of two ways.
First, the seizure threshold can be lowered
until it reaches the normal brain wave activity.
This will trigger a seizure, but it's caused by
something outside of the brain lowering the threshold.
Some examples of things which can lower the threshold include:
low blood flow during a faint, severe sleep deprivation, fever,
head injury, drugs or certain medications.
When this happens, it is a triggered or physiologic seizure.
These are best treated, not with medicine,
but by avoiding the trigger.
The second way that a seizure can occur is when
the brain wave activity abnormally spikes and reaches
the normal seizure threshold.
This abnormal brain wave activity represents an epileptic seizure.
Epileptic seizures are best treated with anti-seizure medicines.
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