Epileptic
Seizures
New guidelines for diagnosis.
by James J. Riviello, Jr., MD
PARENTGUIDE NEWS April 2007
Epilepsy is a brain disorder in which seizures recur. A
seizure is caused by a sudden, temporary change in the normal electrical
activity of the brain. It usually results in body movements or behaviors
that are abnormal and beyond a person’s control. A seizure also
changes how a person feels or senses things. Some people may even lose
consciousness during a seizure.
A new guideline developed by the American Academy of Neurology and the
Child Neurology Society aims to help doctors diagnose the causes of status
epilepticus, a state of continuous seizures in children, many of whom
have epilepsy. The guideline was published in the November 14, 2006 issue
of Neurology, the scientific journal of the American Academy of Neurology.
Status epilepticus is the medical term for a seizure, or series of seizures,
that lasts more than 30 minutes. It includes two or more continuous seizures
if there is not full recovery of consciousness in between. Status epilepticus
is a life-threatening emergency that requires hospital evaluation and
treatment for control. The condition annually affects an estimated 31,600
children under the age of 18 in the United States, and it is most common
in infants and toddlers.
The guideline recommends doctors consider anti-epileptic drug (AED) levels
when a child treated with epilepsy develops status epilepticus.
If a child with epilepsy has continuous seizures, it is possible that
AED levels are low because of inadequate dosing, non-compliance or withdrawal
of AED. Data show low AED levels in 32 percent of children who develop
status epilepticus, but this may not necessarily cause the status epilepticus.
The guideline also recommends an electroencephalogram (EEG) be considered
in a child with status epilepticus. An EEG is a test that records the
electrical activity produced by the brain. An EEG may provide more information
about areas of the brain that are abnormal. This may be helpful in determining
whether there are generalized or focal abnormalities or when there is
suspicion that the continuous seizures are non-epileptic. Pseudostatus
epilepticus is an event that looks like status epilepticus. It can occur
in children. Nonconvulsive status epilepticus is another form of status
epilepticus. This occurs in children who also have status epilepticus.
According to the guideline, doctors should also consider infectious, toxicology
and metabolic studies in children with status epilepticus when there are
clinical indicators for concern or when the initial evaluation doesn’t
reveal the cause of the continuous seizures.
When the doctor suspects an infection, blood cultures and lumbar punctures,
or spinal taps, are part of the evaluation. A blood culture will determine
if bacteria or fungus are present in the blood. A lumbar puncture will
evaluate the fluid surrounding the brain and spinal cord for infection.
A toxicology test looks at blood, urine or hair for the presence of drugs.
Metabolic testing will look for inborn errors of metabolism. These are
rare genetic disorders that may cause epilepsy and brain disorders. They
prohibit the body from normally metabolizing or turning nutrients into
energy.
The guideline also states that neuroimaging may be considered, after the
child with status epilepticus is stabilized, if there are clinical indications
or if the cause of the seizures is unknown. Some common imaging techniques
include computed tomography (CT) and magnetic resonance imaging (MRI).
Family members and caretakers of a child with status epilepticus should
talk with a neurologist. Neurologists can provide correct information
about diagnosis and assessment. Ask your neurologist for more information
and available services.
What is epilepsy?
Epilepsy is a brain disorder in which clusters of nerve cells, or neurons,
in the brain sometimes signal abnormally. In epilepsy, the normal pattern
of neuronal activity becomes disturbed, causing strange sensations, emotions
and behavior, such as convulsions, muscle spasms and loss of consciousness.
Epilepsy is a disorder with many possible causes. Anything that disturbs
the normal pattern of neuron activity— from illness to brain damage
to abnormal brain development— can lead to seizures. Epilepsy may
develop because of an abnormality in brain wiring, an imbalance of nerve
signaling chemicals called neurotransmitters, or some combination of these
factors. Having a seizure does not necessarily mean that a person has
epilepsy. Only when a person has had two or more seizures is he or she
considered to have epilepsy. EEGs and brain scans are common diagnostic
tests for epilepsy.
Is there any treatment?
Once epilepsy is diagnosed, it is important to begin treatment as soon
as possible. For about 80 percent of those diagnosed with epilepsy, seizures
can be controlled with modern medicines and surgical techniques. Some
antiepiletic drugs can interfere with the effectiveness of oral contraceptives.
In 1997, the FDA approved the vagus nerve stimulator for use in people
with seizures that are not well-controlled by medication.
What is the prognosis?
Most people with epilepsy lead outwardly normal lives. While epilepsy
cannot currently be cured, for some people it does eventually go away.
Most seizures do not cause brain damage. However, it is not uncommon for
people with epilepsy, especially children, to develop behavioral and emotional
problems as a consequence of embarrassment, frustration, bullying, teasing,
or avoidance in school and other social settings. For many people with
epilepsy, the risk of seizures restricts their independence (some states
refuse drivers licenses to people with epilepsy) and recreational activities.
People with epilepsy are at special risk for two life-threatening conditions:
status epilepticus and sudden unexplained death. Most women with epilepsy
can become pregnant, but they should discuss their epilepsy and the medications
they are taking with their doctors. Women with epilepsy have at least
a 90 percent chance of having a normal, healthy baby.
Source: National Institute of Neurological Disorders and Stroke
The American Academy of Neurology
The American Academy of Neurology is a professional medical association
of more than 20,000 neurologists and neuroscience professionals worldwide
who are dedicated to providing the best possible care for patients with
a neurological condition. For more information about the American Academy
of Neurology, a copy of the guideline or a summary designed for parents
of children with status epilepticus, visit www.aan.com/professionals/practice/guideline/index.cfm.
The Child Neurology Society
The Child Neurology Society is a professional organization representing
more than 1,500 child neurologists. For more information about the Child
Neurology Society, visit www.childneurologysociety.org.
James J. Riviello, Jr., M.D., a member of the American Academy of
Neurology and the Child Neurology Society, is lead author of the guideline
on diagnostic assessment of the child with status epilepticus. He is a
professor of Neurology at Harvard Medical School, a member of the Division
of Epilepsy and Clinical Neurophysiology and co-director of the Critical
Care Neurology Service in the Department of Neurology, at Children’s
Hospital, Boston.
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