The causes of epilepsy in childhood vary. In about ⅔ of cases, it is unknown.

- Unknown 67.6%

- Congenital 20%

- Trauma 4.7%

- Infection 4%

- Stroke 1.5%

- Tumor 1.5%

- Degenerative .7%

The mortality rate ranges from 3–7% in a mean follow up period of 8.5 to 9.7 years. Death is often related to accidents.

People with epilepsy are at an increased risk of death. This increase is between 1.6 and 4.1 fold greater than that of the general population and is often related to: the underlying cause of the seizures, status epilepticus, suicide, trauma, and sudden unexpected death in epilepsy (SUDEP). Death from status epilepticus is primarily due to an underlying problem rather than missing doses of medications. The risk of suicide is increased between two and six times in those with epilepsy. The cause of this is unclear. SUDEP appears to be partly related to the frequency of generalized tonic-clonic seizures and accounts for about 15% of epilepsy related deaths. It is unclear how to decrease its risk. The greatest increase in mortality from epilepsy is among the elderly. Those with epilepsy due to an unknown cause have little increased risk. In the United Kingdom, it is estimated that 40–60% of deaths are possibly preventable. In the developing world, many deaths are due to untreated epilepsy leading to falls or status epilepticus.

Dravet syndrome is a severe form of epilepsy. It is a rare genetic disorder that affects an estimated 1 in every 20,000–40,000 births.

Seizures in cats are caused by various onsets. Cats can have reactive, primary (idiopathic) or secondary seizures. Idiopathic seizures are not as common in cats as in dogs however a recent study conducted showed that of 91 feline seizures, 25% were suspected to have idiopathic epilepsy. In the same group of 91 cats, 50% were secondary seizures and 20% reactive.

Idiopathic epilepsy does not have a classification due to the fact there are no known causes of these seizures, however both reactive and symptomatic secondary epilepsy can be placed into classifications.

LGS is seen in approximately 4% of children with epilepsy, and is more common in males than in females. Usual onset is between the ages of three and five. Children can have no neurological problems prior diagnosis, or have other forms of epilepsy. West syndrome is diagnosed in 20% of patients before it evolves into LGS at about 2 years old.

Epilepsy can have both genetic and acquired causes, with interaction of these factors in many cases. Established acquired causes include serious brain trauma, stroke, tumours and problems in the brain as a result of a previous infection. In about 60% of cases the cause is unknown. Epilepsies caused by genetic, congenital, or developmental conditions are more common among younger people, while brain tumors and strokes are more likely in older people.

Seizures may also occur as a consequence of other health problems; if they occur right around a specific cause, such as a stroke, head injury, toxic ingestion or metabolic problem, they are known as acute symptomatic seizures and are in the broader classification of seizure-related disorders rather than epilepsy itself.

Both medication and drug overdoses can result in seizures, as may certain medication and drug withdrawal. Common drugs involved include: antidepressants, antipsychotics, cocaine, insulin, and the local anaesthetic lidocaine. Difficulties with withdrawal seizures commonly occurs after prolonged alcohol or sedative use, a condition known as delirium tremens.

Dehydration can trigger epileptic seizures if it is severe enough. A number of disorders including: low blood sugar, low blood sodium, hyperosmolar nonketotic hyperglycemia, high blood sodium, low blood calcium and high blood urea levels may cause seizures. As may hepatic encephalopathy and the genetic disorder porphyria.

West syndrome is a triad of developmental delay, seizures termed infantile spasms, and EEG demonstrating a pattern termed hypsarrhythmia. Onset occurs between three months and two years, with peak onset between eight and 9 months. West syndrome may arise from idiopathic, symptomatic, or cryptogenic causes. The most common cause is tuberous sclerosis. The prognosis varies with the underlying cause. In general, most surviving patients remain with significant cognitive impairment and continuing seizures and may evolve to another eponymic syndrome, Lennox-Gastaut syndrome. It can be classified as idiopathic, syndromic, or cryptogenic depending on cause and can arise from both focal or generalized epileptic lesions.

The National Institute of Health Office and Rare Disease Research characterizes PCDH19 gene-related epilepsy as a rare disorder. Rare diseases, by definition, are diseases that affect fewer than 200,000 people in the United States. Since the mutation associated with PCDH19 gene-related epilepsy was only recently identified in 2008, the true incidence of the disease is generally unknown.

Although formal epidemiologic data is not available, results from diagnostic screening indicates that approximately 1 out of 10 girls who have seizure onset before five years of age may have PCDH19 gene mutations. Additionally, PCDH19 screening of several large cohorts of females with early onset febrile-related epilepsy has resulted in a rate of approximately 10% of mutation-positive individuals.

Epilepsy is a relatively common disorder, affecting between 0.5-1% of the population, and frontal lobe epilepsy accounts for about 1-2% of all epilepsies. The most common subdivision of epilepsy is symptomatic partial epilepsy, which causes simple partial seizures, and can be further divided into temporal and frontal lobe epilepsy. Although the exact number of cases of frontal lobe epilepsy is not currently known, it is known that FLE is the less common type of partial epilepsy, accounting for 20-30% of operative procedures involving intractable epilepsy. The disorder also has no gender or age bias, affecting males and females of all ages. In a recent study, the mean subject age with frontal lobe epilepsy was 28.5 years old, and the average age of epilepsy onset for left frontal epilepsy was 9.3 years old whereas for right frontal epilepsy it was 11.1 years old.

Cases of epilepsy may be organized into epilepsy syndromes by the specific features that are present. These features include the age at which seizures begin, the seizure types, and EEG findings, among others. Identifying an epilepsy syndrome is useful as it helps determine the underlying causes as well as what anti-seizure medication should be tried.

The ability to categorize a case of epilepsy into a specific syndrome occurs more often with children since the onset of seizures is commonly early. Less serious examples are benign rolandic epilepsy (2.8 per 100,000), childhood absence epilepsy (0.8 per 100,000) and juvenile myoclonic epilepsy (0.7 per 100,000). Severe syndromes with diffuse brain dysfunction caused, at least partly, by some aspect of epilepsy, are also referred to as epileptic encephalopathies. These are associated with frequent seizures that are resistant to treatment and severe cognitive dysfunction, for instance Lennox-Gastaut syndrome and West syndrome.

Epilepsies with onset in childhood are a complex group of diseases with a variety of causes and characteristics. Some people have no obvious underlying neurological problems or metabolic disturbances. They may be associated with variable degrees of intellectual disability, elements of autism, other mental disorders, and motor difficulties. Others have underlying inherited metabolic diseases, chromosomal abnormalities, specific eye, skin and nervous system features, or malformations of cortical development. Some of these epilepsies can be categorized into the traditional epilepsy syndromes. Furthermore, a variety of clinical syndromes exist of which the main feature is not epilepsy but which are associated with a higher risk of epilepsy. For instance between 1 and 10% of those with Down syndrome and 90% of those with Angelman syndrome have epilepsy.

In general, genetics is believed to play an important role in epilepsies by a number of mechanisms. Simple and complex modes of inheritance have been identified for some of them. However, extensive screening has failed to identify many single rare gene variants of large effect. In the epileptic encephalopathies, de novo mutagenesis appear to be an important mechanism. De novo means that a child is affected, but the parents do not have the mutation. De novo mutations occur in eggs and sperms or at a very early stage of embryonic development. In Dravet syndrome a single affected gene was identified.

Syndromes in which causes are not clearly identified are difficult to match with categories of the current classification of epilepsy. Categorization for these cases is made somewhat arbitrarily. The "idiopathic" (unknown cause) category of the 2011 classification includes syndromes in which the general clinical features and/or age specificity strongly point to a presumed genetic cause. Some childhood epilepsy syndromes are included in the unknown cause category in which the cause is presumed genetic, for instance benign rolandic epilepsy. Others are included in "symptomatic" despite a presumed genetic cause (in at least in some cases), for instance Lennox-Gastaut syndrome. Clinical syndromes in which epilepsy is not the main feature (e.g. Angelman syndrome) were categorized "symptomatic" but it was argued to include these within the category "idiopathic". Classification of epilepsies and particularly of epilepsy syndromes will change with advances in research.

Though there is limited evidence, outcomes appear to be relatively poor with a review of outcome studies finding that two thirds of PNES patients continue to experience episodes and more than half are dependent on social security at three-year followup. This outcome data was obtained in a referral-based academic epilepsy center and loss to follow-up was considerable; the authors point out ways in which this may have biased their outcome data. Outcome was shown to be better in patients with higher IQ, social status, greater educational attainments, younger age of onset and diagnosis, attacks with less dramatic features, and fewer additional somatoform complaints.

Most generalized epilepsy starts during childhood. While some patients outgrow their epilepsy during adolescence and no longer need medication, in others, the condition remains for life, thereby requiring lifelong medication and monitoring.

Most children who develop epilepsy are treated conventionally with anticonvulsants. In about 70% of cases of childhood epilepsy, medication can completely control seizures. Unfortunately, medications come with an extensive list of side effects that range from mild discomfort to major cognitive impairment. Usually, the adverse cognitive effects are ablated following dose reduction or cessation of the drug.

Medicating a child is not always easy. Many pills are made only to be swallowed, which can be difficult for a child. For some medications, chewable versions do exist.

The ketogenic diet is used to treat children who have not responded successfully to other treatments. This diet is low in carbohydrates, adequate in protein and high in fat. It has proven successful in two thirds of epilepsy cases.

In some cases, severe epilepsy is treated with the hemispherectomy, a drastic surgical procedure in which part or all of one of the hemispheres of the brain is removed.

Most people with PNES (75%) are women, with onset in the late teens to early twenties being typical.

Some studies have reported an elevated frequency of childhood abuse in people with PNES. However, others that have controlled for other demographic factors have failed to find a higher rate of reported childhood abuse than in a comparable groups with organic disease (usually epilepsy).

A number of studies have also reported a high incidence of abnormal personality traits or personality disorders in people with PNES such as borderline personality. However, again, when an appropriate control group is used, the incidence of such characteristics it not always higher in PNES than in similar illnesses arising due to organic disease (e.g., epilepsy).

Other risk factors for PNES include having a diagnosis of epilepsy, having recently had a head injury or recently undergone neurosurgery.

PME accounts for less than 1% of epilepsy cases at specialist centres. The incidence and prevalence of PME is unknown, but there are considerable geography and ethnic variations amongst the specific genetic disorders. One cause, Unverricht Lundborg Disease, has an incidence of at least 1:20,000 in Finland.

A 2008 study, found a relationship between the PCDH19 gene and early onset female seizures, with subsequent studies confirming the relationship.

PCDH19 gene-related epilepsy can arise as a single case in a family, due to a de novo error in cell replication, or it can be inherited. In a large series of cases in which inheritance was determined, half of the PCDH19 mutations occurred de novo, and half were inherited from fathers in good health, and who had no evidence of seizures or cognitive disorders.

Men and women can transmit the PCDH19 mutation, although females, but not males, usually, but not always, exhibit symptoms, which can be very mild. Females with a mutation have a 50% chance of having children who are carriers. Men have a 100% chance of transmitting the mutation to a daughter and 0% chance to a son.

Although males do not generally exhibit PCDH19 gene-related history such as cluster seizures, in a study involving four families with PCDH19 gene mutations, 5 of the fathers had obsessive and controlling tendencies. The linkage of chromosome Xq22.1 to PCDH19 gene-related epilepsy in females was confirmed in all of the families.

The inheritance pattern is very unusual, in that men that carry the PCDH19 gene mutation on their only X-chromosome are typically unaffected, except in rare instances of somatic mosaicism. Alternatively, approximately 90% of women, who have the mutation on one of their two X-chromosomes, exhibit symptoms. It has been suggested that the greater occurrence of PCDH19-epilepsy in females may relate to X-chromosome inactivation, through a hypothesized mechanism termed ‘‘cellular interference’’.

A 2011 study found instances where patients had PCDH19 mutation, but their parents did not. They found that "gonadal mosaicism” of a PCDH19 mutation in a parent is an important molecular mechanism associated with the inheritance of a mutated PCDH19 gene.

Seven anti-epileptic drugs are approved for use in cases of suspected primary generalized epilepsy:

- Felbamate

- Levetiracetam

- Zonisamide

- Topiramate

- Valproate

- Lamotrigine

- Perampanel

Valproate, a relatively old drug, is often considered the first-line treatment. It is highly effective, but its association with fetal malformations when taken in pregnancy limits its use in young women.

All anti-epileptic drugs (including the above) can be used in cases of partial seizures.

A person who suffers from epilepsy regardless of whether it is nocturnal or not, can be categorized into two different types of epilepsy either being generalized, or partial. A generalized epilepsy syndrome is associated with an overall hyperactivity in the brain, where electrical discharges occur all over the brain at once; this syndrome often has a genetic basis. While generalized epilepsy occurs all over the brain, partial epilepsy consists of a regional or localized hyperactivity, which means that the seizures occur conversely in one part of the brain or several parts at once.

These syndromes are childhood absence epilepsy, epilepsy with myoclonic absences, juvenile absence epilepsy and juvenile myoclonic epilepsy. Other proposed syndromes are Jeavons syndrome (eyelid myoclonia with absences), and genetic generalised epilepsy with phantom absences.

These types of seizures are also known to occur to patients suffering with porphyria and can be triggered by stress or other porphyrin-inducing factors.

Incidence is around 1:3200 to 1:3500 of live births. Statistically, boys are more likely to be affected than girls at a ratio of around 1.3:1. In 9 out of every 10 children affected, the spasms appear for the first time between the third and the twelfth month of age. In rarer cases, spasms may occur in the first two months or during the second to fourth year of age.

Although the theory is controversial, there is a link between febrile seizures (seizures coinciding with episodes of fever in young children) and subsequent temporal lobe epilepsy, at least epidemiologically.