Seizures

SEIZURE DISORDERS (EPILEPSY)

The brain contains billions of nerve cells that create and receive electrical impulses. Neurons  (nerve cells) communicate through these electrical impulses. When there is abnormal and excessive  electrical activity in the brain, a seizure occurs. This  causes an altered level of awareness, changes in behavior, and/or muscle contractions and movements typically seen during a seizure. Characteristics of  seizures depend on location and path of electrical discharges. Generally this activity only lasts for seconds to minutes.
 

TYPES OF SEIZURES

Seizures have many forms depending upon the type and cause. Symptoms can be mild or severe. Seizures are classified according to the patient’s appearance or behavior during the seizure and the pattern of electrical activity in the brain, as measured by an electroencephalogram (EEG).   

It is difficult, even for trained physicians, to classify seizures based on what someone looks like while having a seizure. Though it is good to know the different types of seizures as listed below, when you witness and report a seizure, it is more important to be able to describe what you saw rather than classify it or give it a name. Pay attention to what the individual is  doing; what movements you see, what may have triggered it, the duration, etc., rather than trying to give it a name. Write these down on the seizure sheet and make sure they are reported to the physician.   


Partial Seizures (or Focal Seizure):   

Partial seizures arise from one area on one side of the brain and are also referred to as focal seizures. They are subdivided according to whether the  person is aware and conscious during the seizure or whether there is some impairment or change of consciousness. Partial seizures can spread and  become a generalized seizure, in which there is a loss of consciousness and the abnormal electrical activity affects most or all of the brain. Partial seizures are  the most common type of seizure.   

Simple partial seizures: affect enough of the brain to cause symptoms but not interfere with consciousness. Symptoms vary depending on the  region of the brain involved and may be sensory or motor:

Sensory:

feeling an unusual sensation such as odd taste or smell

seeing or hearing something specific

a feeling of emotion such as sudden fear or anger an uncontrolled rhythmic

twitching or stiffening movement in a limb

difficulty speaking

Motor (focal motor):

Caused by an outburst of activity in the brain causing a contraction of a group of muscles

Aura:  

A seizure aura is a simple partial seizure which can occur as an isolated event or may precede complex partial or generalized seizures.  Auras can be warning signs.

Examples of  auras:

nausea

dizziness

headache and visions

difficulty with speech or difficulty breathing

numbness of hands, lips or tongue

an unpleasant taste

palpitations

smells or hearing things


Complex partial seizure: involves impairment of consciousness. The  person affected may stare into space and may either remain motionless or engage in repetitive behaviors called automatisms. This type of seizure  may be preceded by an aura and may lead to a generalized seizure.

Automatisms include:  

facial grimacing

chewing, lip smacking, swallowing

gesturing or snapping fingers

repeating words or phrases

walking, running, undressing

During the seizure, a person is not aware of his or her movements or surroundings. A person may become hostile or aggressive if physically  restrained during a complex partial seizure. This type of seizure can last  several minutes. Afterwards, the person will feel confused or tired and will  not remember the events that occurred during the seizure. This is called a  postictal state.

Generalized seizures:
    
Generalized seizures occur as a result of abnormal electrical activity throughout the brain. The person will be unconscious and unresponsive and  may stiffen and have abnormal, jerking movements or few to no abnormal movements. Generalized seizures are classified as follows:    

Absence seizures (petit mal):

During this type of seizure, a person may appear to be staring or daydreaming, and will not respond if spoken to. If  the seizure lasts for 10 or more seconds, there may also be eye blinking or lip smacking (automatisms). There is no postictal state after the seizure  and the person is usually unaware that anything has happened. These  are often seen in childhood and disappear later in life.  

The difference between absence and complex partial seizures:

No aura occurs in an absence seizure.  
An absence seizure comes on suddenly, with no warning.
Absence seizures do not last very long.
People recover quickly from absence seizures.  

Tonic-clonic seizures:

These are also referred to as grand mal seizures, major motor seizures or convulsions. They are associated with a sudden  loss of consciousness.  

Tonic phase: all muscles of arms, legs become stiff and extended or flexed (skin may appear blue or cyanotic)

Clonic phase: muscles begin to jerk or twitch
Usually lasts a couple of minutes
Followed by postictal period, sometimes followed by a headache
Recovery can take several minutes to hours

Myoclonic seizures:

“Myo” means muscle and “clonic” means contraction. Myoclonic seizures cause quick movements or jerks in a group of muscles on one or both sides of the body. This may cause the person to drop or  throw objects they are holding. The person may fall off a chair and can fall  to the ground. Because the seizure is so brief, consciousness is not  usually impaired. These often occur in clusters and tend to occur upon  awakening from sleep.   

Atonic seizures:

Also known as drop seizures, cause a sudden loss of muscle tone. These can involve the entire body and cause the person to  suddenly drop or collapse. They may also involve just the head and neck  causing a sudden head nod. There is a risk of head and facial injuries  associated with this type of seizure, and protective head gear may be recommended.   

Status epilepticus:   

The term status epilepticus generally refers to the occurrence of a single unremitting (not stopping) seizure with a duration longer than 5 to 10 minutes (a continuous state of seizure). It can also refer to recurrent seizures without  regaining consciousness between the seizures. The person does not have time  to recover from the first seizure before the next one begins. Status epilepticus is  considered a medical emergency as ongoing seizure activity results in damage to brain cells. However in rare cases, a person’s usual seizure activity could meet  the criteria for status epilepticus and that person should have a protocol in place for how one should treat seizures that are unremitting.