Epilepsy (from the Ancient Greek verb meaning "to seize, possess, or afflict")[1] is a group of neurological disorders characterized by epileptic seizures.[2]

HYPERLINK "http://en.wikipedia.org/wiki/Epilepsy" \l "cite_note-Fisher2014-3" [3] Epileptic seizures are episodes that can vary from brief and nearly undetectable to long periods of vigorous shaking.[4] In epilepsy, seizures tend to recur, and have no immediate underlying cause[2] while seizures that occur due to a specific cause are not deemed to represent epilepsy.[5]The cause of most cases of epilepsy is unknown, although some people develop epilepsy as the result of brain injury, stroke, brain tumor, and drug and alcohol misuse. Genetic mutations are linked to a small proportion of the disease.[6] Epileptic seizures are the result of excessive and abnormal cortical nerve cell activity in the brain.[5] The diagnosis typically involves ruling out other conditions that might cause similar symptoms such as fainting. Additionally, making the diagnosis involves determining if any other cause of seizures is present such as alcohol withdrawal or electrolyte problems.[6] This may be done by imaging the brain and performing blood tests.[6] Epilepsy can often be confirmed with an electroencephalogram (EEG) but a normal test does not rule out the condition.[6]Seizures are controllable with medication in about 70% of cases.[7] In those whose seizures do not respond to medication, surgery, neurostimulation or dietary changes may be considered. Not all cases of epilepsy are lifelong, and many people improve to the point that medication is no longer needed.

About 1% of people worldwide (65million) have epilepsy,[8] and nearly 80% of cases occur in developing countries.[4] In 2013 it resulted in 116,000 deaths up from 111,000 deaths in 1990.[9] Epilepsy becomes more common as people age.[10]

HYPERLINK "http://en.wikipedia.org/wiki/Epilepsy" \l "cite_note-Holmes2008-11" [11] In the developed world, onset of new cases occurs most frequently in infants and the elderly;[12] in the developing world this is in older children and young adults,[13] due to differences in the frequency of the underlying causes. About 510% of all people will have an unprovoked seizure by the age of 80,[14] and the chance of experiencing a second seizure is between 40 and 50%.[15] In many areas of the world those with epilepsy either have restrictions placed on their ability to drive or are not permitted to drive,[16] but most are able to return to driving after a period of time without seizures.

Contents

1 Signs and symptoms

1.1 Seizures 1.2 Postictal 1.3 Psychosocial 2 Causes

2.1 Genetics 2.2 Acquired 3 Pathophysiology

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 Other 6.5 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 linksSigns and symptoms

Play mediaAn instructional video about epileptic seizures

A bite to the tip of the tongue due to a seizure

Epilepsy is characterized by a long-term risk of recurrent seizures.[17] These seizures may present in several ways depending on the part of the brain involved and the person's age.[17]

HYPERLINK "http://en.wikipedia.org/wiki/Epilepsy" \l "cite_note-FOOTNOTENational_Clinical_Guideline_Centre201221.E2.80.9328-18" [18]Seizures

The most common type (60%) of seizures are convulsive.[18] Of these, one-third begin as generalized seizures from the start, affecting both hemispheres of the brain.[18] Two-thirds begin as partial seizures (which affect one hemisphere of the brain) which may then progress to generalized seizures.[18] 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.[19]

HYPERLINK "http://en.wikipedia.org/wiki/Epilepsy" \l "cite_note-20" [20]Partial seizures are often preceded by certain experiences, known as an aura.[21] These may include sensory (visual, hearing or smell), psychic, autonomic, or motor phenomena.[19] 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.[22] Automatisms may occur; these are non-consciously generated activities and mostly simple repetitive movements like smacking of the lips or more complex activities such as attempts to pick something up.[22]There are six main types of generalized seizures: tonic-clonic, tonic, clonic, myoclonic, absence, and atonic seizures.[23] They all involve loss of consciousness and typically happen without warning.

Tonic-clonic seizures present with a contraction of the limbs followed by their extension along with arching of the back which lasts 1030seconds (the tonic phase). A cry may be heard due to contraction of the chest muscles. This is then 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 1030minutes 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.[4] The tongue may be bitten at either the tip or on the sides during a seizure.[24] In tonic-clonic seizure, bites to the sides are more common.[24] Tongue bites are also relatively common in psychogenic non-epileptic seizures.[24]Myoclonic seizures involve spasms of muscles in either a few areas or all over.[25] Absence seizures can be subtle with only a slight turn of the head or eye blinking.[19] The person does not fall over and returns to normal right after it ends.[19] Atonic seizures involve the loss of muscle activity for greater than one second.[22] This typically occurs on both sides of the body.[22]About 6% of those with epilepsy have seizures that are often triggered by specific events and are known as reflex seizures.[26] Those with reflex epilepsy have seizures that are only triggered by specific stimuli.[27] Common triggers include flashing lights and sudden noises.[26] In certain types of epilepsy, seizures happen more often during sleep,[28] and in other types they occur almost only when sleeping.[29]Postictal

After the active portion of a seizure, there is typically a period of confusion referred to as the postictal period before a normal level of consciousness returns.[21] This usually lasts 3 to 15 minutes[30] but may last for hours.[31] Other common symptoms include feeling tired, headache, difficulty speaking, and abnormal behavior.[31] Psychosis after a seizure is relatively common, occurring in 610% of people.[32] Often people do not remember what happened during this time.[31] Localized weakness, known as Todd's paralysis, may also occur after a partial seizure. When it occurs it typically lasts for seconds to minutes but may rarely last for a day or two.[33]Psychosocial

Epilepsy can have adverse effects on social and psychological well-being.[18] These effects may include social isolation, stigmatization, or disability.[18] They may result in lower educational achievement and worse employment outcomes.[18] Learning difficulties are common in those with the condition, and especially among children with epilepsy.[18] The stigma of epilepsy can also affect the families of those with the disease.[4]Certain disorders occur more often in people with epilepsy, depending partly on the epilepsy syndrome present. These include depression, anxiety disorders, and migraines.[34] Attention deficit hyperactivity disorder affects three to five times more children with epilepsy than children in the general population.[35] ADHD and epilepsy have significant consequences on a child's behavioral, learning, and social development.[36] Epilepsy is also more common in autistic people.[37]