Where can I learn more about epilepsy?
Epilepsy is a group of neurological disorders characterized by epileptic seizures.[10][11] Epileptic seizures are episodes that can vary from brief and nearly undetectable to long periods of vigorous shaking.[1] These episodes can result in physical injuries including occasionally broken bones.[1] In epilepsy, seizures tend to recur and as a rule, have no immediate underlying cause.[10] Isolated seizures that are provoked by a specific cause such as poisoning are not deemed to represent epilepsy.[12] People with epilepsy in some areas of the world experience stigma due to the condition.[1]
The cause of most cases of epilepsy is unknown.[1] Some cases occur as the result of brain injury, stroke, brain tumors, infections of the brain, and birth defects, through a process known as epileptogenesis.[1][2][3] Known genetic mutations are directly linked to a small proportion of cases.[4][13] Epileptic seizures are the result of excessive and abnormal nerve cell activity in the cortex of the brain.[12] The diagnosis involves ruling out other conditions that might cause similar symptoms such as fainting and determining if another cause of seizures is present such as alcohol withdrawal or electrolyte problems.[4] This may be partly done by imaging the brain and performing blood tests.[4] Epilepsy can often be confirmed with an electroencephalogram (EEG), but a normal test does not rule out the condition.[4]
Epilepsy that occurs as a result of other issues may be preventable.[1] Seizures are controllable with medication in about 70% of cases.[7] Inexpensive options are often available.[1] In those whose seizures do not respond to medication, then surgery, neurostimulation, or dietary changes may be considered.[5][6] Not all cases of epilepsy are lifelong, and many people improve to the point that treatment is no longer needed.[1]
As of 2015 about 39 million people have epilepsy.[8] Nearly 80% of cases occur in the developing world.[1] In 2015 it resulted in 125,000 deaths up from 112,000 deaths in 1990.[9][14] Epilepsy is more common in older people.[15][16] In the developed world, onset of new cases occurs most frequently in babies and the elderly.[17] In the developing world onset is more common in older children and young adults, due to differences in the frequency of the underlying causes.[18] About 5–10% of people will have an unprovoked seizure by the age of 80,[19] and the chance of experiencing a second seizure is between 40 and 50%.[20] In many areas of the world those with epilepsy either have restrictions placed on their ability to drive or are not permitted to drive until they are free of seizures for a specific length of time.[21] The word epilepsy is from Ancient Greek: ἐπιλαμβάνειν "to seize, possess, or afflict".[22]
File:Epilepsy video.webmPlay media
Video explanation
Contents
1 Signs and symptoms
1.1 Seizures
1.2 Postictal
1.3 Psychosocial
2 Causes
2.1 Genetics
2.2 Acquired
3 Mechanism
3.1 Epilepsy
3.2 Seizures
4 Diagnosis
4.1 Definition
4.2 Classification
4.3 Syndromes
4.4 Tests
4.5 Differential diagnosis
5 Prevention
6 Management
6.1 First aid
6.2 Medications
6.3 Surgery
6.4 Diet
6.5 Other
6.6 Alternative medicine
7 Prognosis
7.1 Mortality
8 Epidemiology
9 History
10 Society and culture
10.1 Stigma
10.2 Economics
10.3 Vehicles
10.4 Support organizations
11 Research
12 Other animals
13 References
14 Further reading
15 External links
Signs and symptoms
File:Epilpesia.ogvPlay media
An instructional video about epileptic seizures
A still image of a generalized seizure
A bite to the tip of the tongue due to a seizure
Epilepsy is characterized by a long-term risk of recurrent seizures.[23] These seizures may present in several ways depending on the part of the brain involved and the person's age.[23][24]
Seizures
Main article: Epileptic seizure
The most common type (60%) of seizures are convulsive.[24] Of these, one-third begin as generalized seizures from the start, affecting both hemispheres of the brain.[24] Two-thirds begin as focal seizures (which affect one hemisphere of the brain) which may then progress to generalized seizures.[24] The remaining 40% of seizures are non-convulsive. An example of this type is the absence seizure, which presents as a decreased level of consciousness and usually lasts about 10 seconds.[2][25]
Focal seizures are often preceded by certain experiences, known as auras.[26] They include sensory (visual, hearing, or smell), psychic, autonomic, and motor phenomena.[2] Jerking activity may start in a specific muscle group and spread to surrounding muscle groups in which case it is known as a Jacksonian march.[27] Automatisms may occur, which are non-consciously-generated activities and mostly simple repetitive movements like smacking of the lips or more complex activities such as attempts to pick up something.[27]
There are six main types of generalized seizures: tonic-clonic, tonic, clonic, myoclonic, absence, and atonic seizures.[28] They all involve loss of consciousness and typically happen without warning.
Tonic-clonic seizures occur with a contraction of the limbs followed by their extension along with arching of the back which lasts 10–30 seconds (the tonic phase). A cry may be heard due to contraction of the chest muscles, followed by a shaking of the limbs in unison (clonic phase). Tonic seizures produce constant contractions of the muscles. A person often turns blue as breathing is stopped. In clonic seizures there is shaking of the limbs in unison. After the shaking has stopped it may take 10–30 minutes for the person to return to normal; this period is called the "postictal state" or "postictal phase." Loss of bowel or bladder control may occur during a seizure.[29] The tongue may be bitten at either the tip or on the sides during a seizure.[30] In tonic-clonic seizure, bites to the sides are more common.[30] Tongue bites are also relatively common in psychogenic non-epileptic seizures.[30]
Myoclonic seizures involve spasms of muscles in either a few areas or all over.[31] Absence seizures can be subtle with only a slight turn of the head or eye blinking.[2] The person does not fall over and returns to normal right after it ends.[2] Atonic seizures involve the loss of muscle activity for greater than one second.[27] This typically occurs on both sides of the body.[27]
About 6% of those with epilepsy have seizures that are often triggered by specific events and are known as reflex seizures.[32] Those with reflex epilepsy have seizures that are only triggered by specific stimuli.[33] Common triggers include flashing lights and sudden noises.[32] In certain types of epilepsy, seizures happen more often during sleep,[34] and in other types they occur almost only when sleeping.[35]
Postictal
After the active portion of a seizure (the ictal state) there is typically a period of recovery during which there is confusion, referred to as the postictal period before a normal level of consciousness returns.[26] It usually lasts 3 to 15 minutes[36] but may last for hours.[37] Other common symptoms include feeling tired, headache, difficulty speaking, and abnormal behavior.[37] Psychosis after a seizure is relatively common, occurring in 6–10% of people.[38] Often people do not remember what happened during this time.[37] Localized weakness, known as Todd's paralysis, may also occur after a focal seizure. When it occurs it typically lasts for seconds to minutes but may rarely last for a day or two.[39]
Psychosocial
Epilepsy can have adverse effects on social and psychological well-being.[24] These effects may include social isolation, stigmatization, or disability.[24] They may result in lower educational achievement and worse employment outcomes.[24] Learning disabilities are common in those with the condition, and especially among children with epilepsy.[24] The stigma of epilepsy can also affect the families of those with the disorder.[29]
