Symptoms
Seizures are the only visible symptom of
epilepsy. There are different kinds of seizures, and
symptoms of each type can affect people differently. Seizures typically last
from a few seconds to a few minutes. You may remain alert during the seizure or
lose consciousness. You may not remember what happened during the seizure or
may not even realize you had a seizure.
Seizures that make you
fall to the ground or make the muscles stiffen or jerk out of control are easy
to recognize. But many seizures do not involve these reactions and may be
harder to notice. Some seizures make you stare into space for a few seconds.
Others may consist only of a few muscle twitches, a turn of the head, or a
strange smell or visual disturbance that only you sense.
Epileptic seizures often happen without warning,
although some people may have an
aura at the beginning of a seizure. A seizure ends
when the abnormal electrical activity in the brain stops and brain activity
begins to return to normal. Seizures may be either partial or
generalized.
Partial seizures
Partial seizures
begin in a specific area or location of the brain. The most common types of
partial seizures are:
- Simple partial seizures.
Simple partial seizures do not affect consciousness or
awareness.
- Complex partial seizures. Complex
partial seizures do affect level of consciousness. You may become
unresponsive or may lose consciousness completely.
- Partial seizures with secondary
generalization. Partial seizures with secondary generalization begin as
simple or complex
partial seizures but then spread (generalize) to the
rest of the brain and look like
generalized tonic-clonic seizures. These two types can
easily be confused, but they are treated differently. Most tonic-clonic
seizures in adults begin as partial seizures and are caused by partial
epilepsy. Generalized tonic-clonic seizures are more common in children.
Generalized seizures
Seizures that begin over the
entire surface of the brain are called
generalized seizures. The main types of generalized
seizures are:
- Generalized tonic-clonic seizures
(grand mal seizures), during which the person falls to the ground, the entire
body stiffens, and the person's muscles begin to jerk or spasm
(convulse).
- Absence seizures (petit mal seizures),
which make a person stare into space for a few seconds and then “wake up”
without knowing that anything has happened.
- Myoclonic seizures,
which make the body jerk like it is being shocked.
- Atonic
seizures, in which a sudden loss of muscle tone makes the person fall
down without warning.
- Tonic seizures, in which the muscles
suddenly contract and stiffen, often causing the person to fall down.
People may refer to seizures as convulsions, fits, or
spells—but seizure is the correct term. Convulsions, during which the muscles
twitch or jerk, are just one characteristic of seizures. Some seizures cause
convulsions, but many do not.
Epileptic seizures are sometimes
confused with
psychogenic seizures, which are not due to abnormal
electrical function. A psychogenic seizure may be a psychological response to
stress, injury, emotional trauma, or other factors.
Types of epilepsy
There are many types of
epilepsy. All types cause seizures. It can be difficult to determine what type
of epilepsy you have because of the numerous possible causes, because different
types of seizures can occur in the same person, and because the types may
affect each person differently.
Some specific types of epilepsy
are:
- Benign focal childhood
epilepsy, which causes muscles all over the body to stiffen and jerk.
These usually occur at night.
- Childhood and juvenile
absence epilepsy, which causes staring into space, eye fluttering, and
slight muscle jerks.
- Infantile spasms (West syndrome), which
causes muscle spasms that affect a child's head, torso, and limbs. Infantile
spasms usually begin before the age of 6 months.
- Juvenile
myoclonic epilepsy, which causes jerking in the shoulders or
arms.
- Lennox-Gastaut syndrome, which causes frequent and
several different types of seizures to occur at the same time. This syndrome
can lead to falls during a seizure, which can cause an
injury.
- Temporal lobe epilepsy (the most common type of
epilepsy in adults), which causes smacking of the lips or rubbing the hands
together, emotional or thought disturbances, and hallucinations of sounds,
smells, or tastes.
Epilepsy is not a form of mental retardation or mental
illness. Although a few forms of childhood epilepsy are associated with
below-average intelligence and problems with physical and mental development,
epilepsy does not cause these problems. Seizures may look scary or strange, but
they do not make a person crazy, violent, or dangerous.
Not
everyone who has a seizure has epilepsy. Seizures that are not epileptic may
result from several different medical conditions—poisoning, fever, fainting, or
alcohol or drug withdrawal, among others. Seizures that occur at the time of a
disease, injury, or illness and stop when the condition improves are not
related to epilepsy. But if seizures occur repeatedly (become chronic),
occurring weeks, months, or even years after the injury or illness, you have
developed epilepsy as a result of the condition.
There are several
other conditions with similar symptoms, such as
fainting or seizures caused by high fevers.