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There are three types of febrile seizures.
- A simple febrile seizure is characterized by shorter duration (lasting less than 15 minutes), no focal features (meaning the shaking is general rather than restricted to a part of the body such as an arm or leg), and if they do occur in series, the total duration is less than 15 minutes (classically a generalized tonic-clonic seizure).
- A complex febrile seizure is one in which the seizure lasts longer than 15 minutes or multiple episodes occur within 24 hours and generally does have focal features.
- A febrile status epilepticus is a febrile seizure that lasts for longer than 30 minutes. It can occur in up to 5% of febrile seizure cases.
Long term outcomes are generally good with little risk of neurological problems or epilepsy. Those who have one febrile seizure have an approximately 40% chance of having another one in the next two years, with the risk being greater in those who are younger.
Simple febrile seizures do not tend to recur frequently (children tend to outgrow them) and do not make the development of adult epilepsy significantly more likely (about 3–5%) compared with the general public (1%). Children with febrile convulsions are more likely to have a febrile seizure in the future if they were young at their first seizure (less than 18 months old), have a family history of a febrile convulsions in first-degree relatives (a parent or sibling), have a short time between the onset of fever and the seizure, had a low degree of fever before their seizure, or have a seizure history of abnormal neurological signs or developmental delay. Similarly, the prognosis after a complex febrile seizure is excellent, although an increased risk of death has been shown for complex febrile seizures, partly related to underlying conditions.
An electroencephalography is only recommended in those who likely had an epileptic seizure and may help determine the type of seizure or syndrome present. In children it is typically only needed after a second seizure. It cannot be used to rule out the diagnosis and may be falsely positive in those without the disease. In certain situations it may be useful to prefer the EEG while sleeping or sleep deprived.
Diagnostic imaging by CT scan and MRI is recommended after a first non-febrile seizure to detect structural problems inside the brain. MRI is generally a better imaging test except when intracranial bleeding is suspected. Imaging may be done at a later point in time in those who return to their normal selves while in the emergency room. If a person has a previous diagnosis of epilepsy with previous imaging repeat imaging is not usually needed with subsequent seizures.
In adults, testing electrolytes, blood glucose and calcium levels is important to rule these out as causes, as is an electrocardiogram. A lumbar puncture may be useful to diagnose a central nervous system infection but is not routinely needed. Routine antiseizure medical levels in the blood are not required in adults or children. In children additional tests may be required.
A high blood prolactin level within the first 20 minutes following a seizure may be useful to confirm an epileptic seizure as opposed to psychogenic non-epileptic seizure. Serum prolactin level is less useful for detecting partial seizures. If it is normal an epileptic seizure is still possible and a serum prolactin does not separate epileptic seizures from syncope. It is not recommended as a routine part of diagnosis epilepsy.
Differentiating an epileptic seizure from other conditions such as syncope can be difficult. Other possible conditions that can mimic a seizure include: decerebrate posturing, psychogenic seizures, tetanus, dystonia, migraine headaches, and strychnine poisoning. In addition, 5% of people with a positive tilt table test may have seizure-like activity that seems to be due to cerebral hypoxia. Convulsions may occur due to psychological reasons and this is known as a psychogenic non-epileptic seizure. Non-epileptic seizures may also occur due to a number of other reasons.
Continuous prophylactic antiepileptic drug (AED) treatment may not be needed particularly for children with only 1-2 or brief seizures. This is probably best reserved for children whose seizures are unusually frequent, prolonged, distressing, or otherwise significantly interfering with the child’s life. There is no evidence of superiority of monotherapy with any particular common AED.
Autonomic status epilepticus in the acute stage needs thorough evaluation for proper diagnosis and assessment of the neurologic/autonomic state of the child. "Rescue" benzodiazepines are commonly used to terminate it. Aggressive treatment should be avoided because of the risk of iatrogenic complications, including cardiovascular arrest. There is some concern that intravenous lorazepam and/or diazepam may precipitate cardiovascular arrest. Early parental treatment is more effective than late emergency treatment. Buccal midazolam is probably the first choice medication for out of hospital termination of autonomic status epilepticus which should be administered as soon as the child shows evidence of onset of its habitual autonomic seizures.
Parental education about Panayiotopoulos syndrome is the cornerstone of correct management. The traumatizing, sometimes long-lasting effect on parents is significant particularly because autonomic seizures may last for many hours compounded by physicians’ uncertainty regarding diagnosis, management, and prognosis.
The diagnosis can be confirmed when the characteristic centrotemporal spikes are seen on electroencephalography (EEG). Typically, high-voltage spikes followed by slow waves are seen. Given the nocturnal activity, a sleep EEG can often be helpful. Technically, the label "benign" can only be confirmed if the child's development continues to be normal during follow-up. Neuroimaging, usually with an MRI scan, is only advised for cases with atypical presentation or atypical findings on clinical examination or EEG.
The disorder should be differentiated from several other conditions, especially centrotemporal spikes without seizures, centrotemporal spikes with local brain pathology, central spikes in Rett syndrome and fragile X syndrome, malignant Rolandic epilepsy, temporal lobe epilepsy and Landau-Kleffner syndrome.
The distinctive clinical features particularly lengthy seizures and ictus emeticus means that the diagnosis of Panayiotopoulos syndrome is easy. However, these are frequently mistaken as nonepileptic conditions such as acute encephalitis, syncope, migraine, cyclic vomiting syndrome, motion sickness, sleep disorder, or gastroenteritis. The consequence is avoidable misdiagnosis, high morbidity, and costly mismanagement.
Autonomic seizures and autonomic status epilepticus as occur in Panayiotopoulos syndrome have not been described in other epileptic syndromes in that sequence though 10–20 per cent of children with the same seizure semiology may have cerebral pathology. The major problem is to recognize emetic and other autonomic manifestations as seizure events and not to dismiss them or erroneously to consider them as unrelated to the ictus and a feature of encephalitis, migraine, syncope or gastro-enteritis.
Diagnosis is made upon history of absence seizures during early childhood and the observation of ~3 Hz spike-and-wave discharges on an EEG.
There is no treatment for Todd's paralysis. Individuals must rest as comfortably as possible until the paralysis disappears.
An occurrence of Todd's paralysis indicates that a seizure has occurred. The prognosis for the patient depends upon the effects of the seizure, not the occurrence of the paralysis.
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.
A wide array of phenomena may resemble epileptic seizures, which may lead to people who do not have epilepsy being misdiagnosed. Indeed, a significant percentage of people initially diagnosed with epilepsy will later have this revised. In one study, the majority of children referred to a secondary clinic with "fits, faints and funny turns" did not have epilepsy, with syncope (fainting) as the most common alternative. In another study, 39% of children referred to a tertiary epilepsy centre did not have epilepsy, with staring episodes in mentally challenged children as the most common alternative. In adults, the figures are similar, with one study reporting a 26% rate of misdiagnosis.
Differentiation of a non-epileptic attack from an epileptic seizure includes the patient keeping their eyes closed and rarely causing themselves harm (both more common in non-epileptic attacks)
The International League Against Epilepsy (ILAE) define an epileptic seizure as "a transient occurrence of signs and/or symptoms due to abnormal excessive or synchronous neuronal activity in the brain." Epileptic seizures can occur in someone who does not have epilepsy – as a consequence of head injury, drug overdose, toxins, eclampsia or febrile convulsions, for example.
Medically, when used on its own, the term seizure implies an epileptic seizure. The lay use of this word can also include sudden attacks of illness, loss of control, spasm or stroke. Where the physician is uncertain as to the diagnosis, the medical term paroxysmal event and the lay terms spells, funny turns or attacks may be used.
Childhood absence epilepsy is a fairly common disorder with a prevalence of 1 in 1000 people. Few of these people will likely have mutations in CACNA1H or GABRG2 as the prevalence of those in the studies presented is 10% or less.
According to the Dravet Syndrome Foundation, the diagnostic criteria for DS requires the patient to present with several of the following symptoms:
- Onset of seizures in the first year of life in an otherwise healthy infant
- Initial seizures are typically prolonged and are generalized or unilateral
- Presence of other seizure types (i.e. myoclonic seizures)
- Seizures associated with fever due to illness or vaccinations
- Seizures induced by prolonged exposure to warm temperatures
- Seizures in response to strong lighting or certain visual patterns
- Initially normal EEGs and later EEGs with slowing and severe generalized polyspikes
- Normal initial development followed by slow development during the first few years of life
- Some degree of hypotonia
- Unstable gait and balance issues
- Ankle pronation and flat feet and/or development of a crouched gait with age
The test is particularly indicated in children who have had cluster seizures in series. It is also recommended for patients who are diagnosed GEFS+ and when the seizures are associated with fever, infection, experienced regression, delayed cognitive growth or behavioral problems. The test is typically ordered by neurologists. The diagnostic test can be done by drawing blood or saliva of the patient and their immediate family. It is analyzed in laboratories that specialize in genetic testing. Genetic testing can aid in a firmer diagnosis and understanding of the disorder, may aid in identifying the optimal treatment plan and if positive, testing of the parents can determine if they are carriers. (See Genetic Counseling)
Seizures in Dravet syndrome can be difficult to manage but may be reduced by anticonvulsant medications such as clobazam, stiripentol, topiramate and valproate. Because the course of the disorder varies from individual to individual, treatment protocols may vary. A diet high in fats and low in carbohydrates may also be beneficial, known as a ketogenic diet. Although diet adjustment can help, it does not eliminate the symptoms. Until a better form of treatment or cure is discovered, those with this disease will have myoclonic epilepsy for the rest of their lives.
Certain anticonvulsant drugs that are classed as Sodium Channel Blockers are now known to make seizures worse in most Dravet patients. These drugs include carbamazepine, gabapentin, lamotrigine, and phenytoin.
Treatments include cognitive rehabilitation through psychomotor and speech therapy. In addition, valproate is often administered to prevent recurrence of febrile seizures and benzodiazapine is used for long lasting seizures, but these treatments are usually insufficient.
Stiripentol was the only drug for which a double-blind placebo trial was performed and this drug showed efficacy in trials. It acts as a GABAergic agent and as a positive allosteric modulator of GABA receptor. Stiripentol, can improve focal refractory epilepsy, as well as Dravet's syndrome, supplemented with clobazam and valproate was approved in Europe in 2007 as a therapy for Dravet syndrome and has been found to reduce overall seizure rate by 70%. In cases with more drug resistant seizures, topiramate and the ketogenic diet are used as alternative treatments.
Cannabidiol (CBD) has received orphan drug status in the United States, for treatment of Dravet syndrome which will allow it to be studied.
PCDH19 gene-related epilepsy is clinically based on patient and family seizure history, cognitive and behavioral neuropsychological evaluation, neurological examination, electroencephalogram (EEG) studies, and long term observation. Diagnosis is confirmed using molecular testing for PCDH19 mutations.
Epilepsy surgery has been performed since the 1860s and doctors have observed that it is highly effective in producing freedom from seizures. However, it was not until 2001 that a scientifically sound study was carried out to examine the effectiveness of temporal lobectomy.
Temporal lobe surgery can be complicated by decreased cognitive function. However, after temporal lobectomy, memory function is supported by the opposite temporal lobe; and recruitment of the frontal lobe. Cognitive rehabilitation may also help.
The diagnosis of temporal lobe epilepsy can include the following methods: Magnetic resonance imaging (MRI), CT scans, positron emission tomography (PET), EEG, and magnetoencephalography.
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.
The cause of FIRES is not known. It does not happen twice in the same family, but the medical community does not know if it is genetic. It happens in boys more than girls. After the initial status, life expectancy is not affected directly. Issues such as overdose of medications or infections at a food tube site are examples of things that would be secondary to the status.
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.
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.
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%