Seizure (cont.)
What Are the Different Kinds of Epilepsy?
Just as there are many different kinds of seizures, there
are many different kinds of epilepsy. Doctors have identified hundreds of
different epilepsy syndromes -- disorders characterized by a specific set of
symptoms that include epilepsy. Some of these syndromes appear to be hereditary.
For other syndromes, the cause is unknown. Epilepsy syndromes are frequently
described by their symptoms or by where in the brain they originate. People
should discuss the implications of their type of epilepsy with their doctors to
understand the full range of symptoms, the possible treatments, and the
prognosis.
People with absence epilepsy have repeated absence seizures that cause
momentary lapses of consciousness. These seizures almost always begin in
childhood or adolescence, and they tend to run in families, suggesting that they
may be at least partially due to a defective gene or genes. Some people with
absence seizures have purposeless movements during their seizures, such as a
jerking arm or rapidly blinking eyes. Others have no noticeable symptoms except
for brief times when they are "out of it." Immediately after a seizure, the
person can resume whatever he or she was doing. However, these seizures may
occur so frequently that the person cannot concentrate in school or other
situations. Childhood absence epilepsy usually stops when the child reaches
puberty. Absence seizures usually have no lasting effect on intelligence or
other brain functions.
Temporal lobe epilepsy, or TLE, is the most common epilepsy syndrome with focal seizures.
These seizures are often associated with auras. TLE often begins in childhood.
Research has shown that repeated temporal lobe seizures can cause
a brain structure called the hippocampus to shrink
over time. The hippocampus is important for memory and learning. While it may
take years of temporal lobe
seizures for measurable hippocampal damage to occur, this finding underlines the
need to treat TLE early and as effectively as possible.
Neocortical epilepsy is characterized by seizures that
originate from the brain's cortex, or outer layer. The seizures can be either focal or generalized.
They may include strange sensations, visual hallucinations, emotional changes,
muscle spasms, convulsions, and a variety of other symptoms, depending on where
in the brain the seizures originate.
There are many other types of epilepsy, each with its own characteristic set
of symptoms. Many of these, including Lennox-Gastaut syndrome
and Rasmussen's encephalitis, begin in childhood. Children with Lennox-Gastaut
syndrome have severe epilepsy with several different types of seizures,
including atonic seizures, which cause sudden falls and are also called drop
attacks. This severe form of epilepsy can be very difficult to treat
effectively. Rasmussen's encephalitis is a progressive type of epilepsy in which
half of the brain shows continual inflammation. It sometimes is treated with a
radical surgical procedure called hemispherectomy (see the section on Surgery).
Some childhood epilepsy syndromes, such as childhood absence epilepsy, tend to
go into remission or stop entirely during adolescence, whereas other syndromes
such as juvenile myoclonic epilepsy and Lennox-Gastaut syndrome are usually present for
life once they develop. Seizure syndromes do not always appear in childhood,
however.
Epilepsy syndromes that are easily treated, do not seem
to impair cognitive
functions or development, and usually stop spontaneously are often described as
benign. Benign epilepsy syndromes include benign infantile encephalopathy and
benign neonatal convulsions. Other syndromes, such as early myoclonic
encephalopathy, include neurological and developmental problems. However, these
problems may be caused by underlying neurodegenerative processes rather than by
the seizures. Epilepsy syndromes in which the seizures and/or the person's
cognitive abilities get worse over time are called progressive epilepsy.
Several types of epilepsy begin in infancy. The most common type of infantile
epilepsy is infantile spasms,
clusters of seizures that usually begin before the age of 6 months. During these
seizures the infant may bend and cry out. Anticonvulsant drugs often do not work
for infantile spasms, but the seizures can be treated with ACTH
(adrenocorticotropic hormone) or prednisone.
Next: When Are Seizures Not Epilepsy? »
- clonazepam, Klonopin - Explains the medication clonazepam (Klonopin), a drug used for the short-term relief of the symptoms of anxiety.
- CT Scan (Computerized Axial Tomography) - CT Scan (Computerized Axial Tomography, CAT scan) is a procedure that assists in diagnosing tumors, fractures, bony structures, and infections in the organs and tissues of the body.
- Swine Flu - Get the facts on swine flu (swine influenza A H1N1 virus) history, symptoms, how this contagious infection is transmitted, prevention with a vaccine, diagnosis, treatment, news and research.
Latest Medical News
Neurology RSS