Epilepsy
Epilepsy
Classification and external resources
ICD-10
G40.-G41.
ICD-9
345
DiseasesDB
4366
MedlinePlus
000694
eMedicine
neuro/415
MeSH
D004827
Epilepsy (from the Greek επιληψία /epili΄p-
sia/ ) is a common chronic neurological dis-
order characterized by recurrent unprovoked
seizures.[1][2] These seizures are transient
signs and/or symptoms of abnormal, excess-
ive or synchronous neuronal activity in the
brain.[3] About 50 million people worldwide
have epilepsy, with almost 90% of these
people being
in developing countries.[4]
Epilepsy is more likely to occur in young chil-
dren, or people over the age of 65 years,
however it can occur at any time.[5] Epilepsy
is usually controlled, but not cured, with
medication, although surgery may be con-
sidered in difficult cases. However, over 30%
of people with epilepsy do not have seizure
control even with the best available medica-
tions.[6][7] Not all epilepsy syndromes are
lifelong – some forms are confined to particu-
lar stages of childhood. Epilepsy should not
be understood as a single disorder, but
rather as a group of syndromes with vastly
divergent symptoms but all involving episodic
abnormal electrical activity in the brain.
Classification
Epilepsies are classified in five ways:
1. By their first cause (or etiology).
2. By the observable manifestations of the
seizures, known as semiology.
3. By the location in the brain where the
seizures originate.
4. As a part of discrete, identifiable medical
syndromes.
5. By the event that triggers the seizures, as
in primary reading epilepsy or
musicogenic epilepsy.
In 1981, the International League Against
Epilepsy (ILAE) proposed a classification
scheme for individual seizures that remains
in common use.[8] This classification is based
on observation (clinical and EEG) rather than
the underlying pathophysiology or anatomy
and is outlined later on in this article. In
1989, the ILAE proposed a classification
scheme for epilepsies and epileptic syn-
dromes.[9] This can be broadly described as a
two-axis scheme havin