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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.
The prognosis for Rolandic seizures is invariably excellent, with probably less than 2% risk of developing absence seizures and less often GTCS in adult life.
Remission usually occurs within 2–4 years from onset and before the age of 16 years. The total number of seizures is low, the majority of patients having fewer than 10 seizures; 10–20% have just a single seizure. About 10–20% may have frequent seizures, but these also remit with age.
Children with Rolandic seizures may develop usually mild and reversible linguistic, cognitive and behavioural abnormalities during the active phase of the disease. These may be worse in children with onset of seizures before 8 years of age, high rate of occurrence and multifocal EEG spikes.
The development, social adaptation and occupations of adults with a previous history of Rolandic seizures were found normal.
Onset is between 3 and 15 years of age with a mean of around 8. Both sexes are equally affected. The disorder accounts for about 2–7% of benign childhood focal seizures.
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.
The age of onset ranges from 1 to 14 years with 75% starting between 7–10 years. There is a 1.5 male predominance, prevalence is around 15% in children aged 1–15 years with non-febrile seizures and incidence is 10–20/100,000 of children aged 0–15 years
Panayiotopoulos syndrome probably affects 13% of children aged 3 to 6 years who have had 1 or more afebrile seizures and 6% of such children in the 1- to 15-year age group. All races and both sexes are affected.
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.
The prognosis of ICOE-G is unclear, although available data indicate that remission occurs in 50–60% of patients within 2–4 years of onset. Seizures show a dramatically good response to carbamazepine in more than 90% of patients. However, 40–50% of patients may continue to have visual seizures and infrequent secondarily generalized convulsions, particularly if they have not been appropriately treated with antiepileptic drugs.
Panayiotopoulos syndrome is remarkably benign in terms of its evolution. The risk of developing epilepsy in adult life is probably no more than of the general population. Most patients have one or 2-5 seizures. Only a third of patients may have more than 5 seizures, and these may be frequent, but outcome is again favorable. However, one fifth of patients may develop other types of infrequent, usually rolandic seizures during childhood and early teens. These are also age-related and remit before the age of 16 years. Atypical evolutions with absences and drop attacks are exceptional. Children with pre-existing neurobehavioral disorders tend to be pharmacoresistant and have frequent seizures though these also remit with age.
Formal neuropsychological assessment of children with Panayiotopoulos syndrome showed that these children have normal IQ and they are not on any significant risk of developing cognitive and behavioural aberrations, which when they occur they are usually mild and reversible. Prognosis of cognitive function is good even for patients with atypical evolutions.
However, though Panayiotopoulos syndrome is benign in terms of its evolution, autonomic seizures are potentially life-threatening in the rare context of cardiorespiratory arrest.
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.
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.
Consistent risk factors include:
- Severity of seizures, increased refractoriness of epilepsy and presence of generalized tonic-clonic seizures: the most consistent risk factor is an increased frequency of tonic–clonic seizures.
- Poor compliance. Lack of therapeutic levels of anti-epileptic drugs, non-adherence to treatment regimens, and frequent changes in regimens are risk factors for sudden death.
- Young age, and early age of seizures onset.
- Male gender
- Poly-therapy of epilepsy. It remains unclear whether this is an independent risk factor or a surrogate marker for severity of epilepsy.
- Being asleep during a seizure is likely to favour SUDEP occurrence.
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.
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.
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.
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.
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.
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.
The lack of generally recognized clinical recommendations available are a reflection of the dearth of data on the effectiveness of any particular clinical strategy, but on the basis of present evidence, the following may be relevant:
- Epileptic seizure control with the appropriate use of medication and lifestyle counseling is the focus of prevention.
- Reduction of stress, participation in physical exercises, and night supervision might minimize the risk of SUDEP.
- Knowledge of how to perform the appropriate first-aid responses to seizure by persons who live with epileptic people may prevent death.
- People associated with arrhythmias during seizures should be submitted to extensive cardiac investigation with a view to determining the indication for on-demand cardiac pacing.
- Successful epilepsy surgery may reduce the risk of SUDEP, but this depends on the outcome in terms of seizure control.
- The use of anti suffocation pillows have been advocated by some practitioners to improve respiration while sleeping, but their effectiveness remain unproven because experimental studies are lacking.
- Providing information to individuals and relatives about SUDEP is beneficial.
The causes of TLE include mesial temporal sclerosis, traumatic brain injury, brain infections, such as encephalitis and meningitis, hypoxic brain injury, stroke, cerebral tumours, and genetic syndromes. Temporal lobe epilepsy is not the result of psychiatric illness or fragility of the personality.
Studies have found that the incidence of PTE ranges between 1.9 and more than 30% of TBI sufferers, varying by severity of injury and by the amount of time after TBI for which the studies followed subjects.
Brain trauma is one of the strongest predisposing factors for epilepsy development, and is an especially important factor in young adults. Young adults, who are at the highest risk for head injury, also have the highest rate of PTE, which is the largest cause of new-onset epilepsy cases in young people. Children have a lower risk for developing epilepsy; 10% of children with severe TBI and 16–20% of similarly injured adults develop PTE. Being older than 65 is also a predictive factor in the development of epilepsy after brain trauma. One study found PTE to be more common in male TBI survivors than in females.
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.
Prognosis is generally good, and seizures usually respond to classic antiepileptics Resection of pathological tissue has been used successfully to treat occipital lobe epilepsy.
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.