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What Are the Different Kinds of Seizures?
Doctors have described more than 30 different types of
seizures. Seizures are divided into two major categories partial seizures and
generalized seizures. However, there are many different types of seizures in each
of these categories.
Partial seizures occur in just one part of the brain. About 60 percent of people with epilepsy have partial seizures. These seizures are frequently described by the area of the brain in which they originate. For example, someone might be diagnosed with partial frontal lobe seizures.
In a simple partial seizure, the person will remain
conscious but may experience unusual feelings or sensations that can take many forms. The
person may experience sudden and unexplainable feelings of joy, anger, sadness, or nausea.
He or she also may hear, smell, taste, see, or feel things that are not real.
In a complex partial seizure, the person has a
change in or loss of consciousness. His or her consciousness may be altered, producing a
dreamlike experience. People having a complex partial seizure may display strange,
repetitious behaviors such as blinks, twitches, mouth movements, or even walking in a
circle. These repetitious movements are called automatisms. They also may fling
objects across the room or strike out at walls or furniture as though they are angry or
afraid. These seizures usually last just a few seconds.
Some people with partial seizures, especially complex
partial seizures, may experience auras unusual sensations that warn of an
impending seizure. These auras are actually simple partial seizures in which the person
maintains consciousness. The symptoms an individual person has, and the progression of
those symptoms, tends to be stereotyped, or similar every time.
The symptoms of partial seizures can easily be confused
with other disorders. For instance, the dreamlike perceptions associated with a complex
partial seizure may be misdiagnosed as migraine headaches, which also can cause a
dreamlike state. The strange behavior and sensations caused by partial seizures also can
be mistaken for symptoms of narcolepsy, fainting, or even mental illness. It may take many
tests and careful monitoring by a knowledgeable physician to tell the difference between
epilepsy and other disorders.
Generalized seizures are a result of abnormal neuronal activity in many parts of the brain. These seizures may cause loss of consciousness, falls, or massive muscle spasms.
There are many kinds of generalized seizures. In absence
seizures, the person may appear to be staring into space and/or have jerking or
twitching muscles. These seizures are sometimes referred to as petit mal seizures,
which is an older term. Tonic seizures cause stiffening of muscles of the body,
generally those in the back, legs, and arms. Clonic seizures cause repeated jerking
movements of muscles on both sides of the body. Myoclonic seizures cause jerks or
twitches of the upper body, arms, or legs. Atonic seizures cause a loss of normal
muscle tone. The affected person will fall down or may nod his or her head involuntarily. Tonic-clonic
seizures cause a mixture of symptoms, including stiffening of the body and repeated
jerks of the arms and/or legs as well as loss of consciousness. Tonic-clonic seizures are
sometimes referred to by an older term: grand mal seizures.
Not all seizures can be easily defined as either partial
or generalized. Some people have seizures that begin as partial seizures but then spread
to the entire brain. Other people may have both types of seizures but with no clear
pattern.
Societys lack of understanding about the many
different types of seizures is one of the biggest problems for people with epilepsy.
People who witness a non-convulsive seizure often find it difficult to understand that
behavior which looks deliberate is not under the persons control. In some cases,
this has led to the affected person being arrested, sued, or placed in a mental
institution. To combat these problems, people everywhere need to understand the many
different types of seizures and how they may appear.
Source: National Institute of Neurological Disorders and Stroke