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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.
An electroencephalogram (EEG) can assist in showing brain activity suggestive of an increased risk of seizures. It is only recommended for those who are likely to have had an epileptic seizure on the basis of symptoms. In the diagnosis of epilepsy, electroencephalography may help distinguish 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 perform the EEG while the affected individual is sleeping or sleep deprived.
Diagnostic imaging by CT scan and MRI is recommended after a first non-febrile seizure to detect structural problems in and around the brain. MRI is generally a better imaging test except when bleeding is suspected, for which CT is more sensitive and more easily available. If someone attends the emergency room with a seizure but returns to normal quickly, imaging tests may be done at a later point. If a person has a previous diagnosis of epilepsy with previous imaging, repeating the imaging is usually not needed even if there are subsequent seizures.
For adults, the testing of electrolyte, blood glucose and calcium levels is important to rule out problems with these as causes. An electrocardiogram can rule out problems with the rhythm of the heart. A lumbar puncture may be useful to diagnose a central nervous system infection but is not routinely needed. In children additional tests may be required such as urine biochemistry and blood testing looking for metabolic disorders.
A high blood prolactin level within the first 20 minutes following a seizure may be useful to help confirm an epileptic seizure as opposed to psychogenic non-epileptic seizure. Serum prolactin level is less useful for detecting focal 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 the diagnosis of epilepsy.
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.
Diagnosis of epilepsy can be difficult. A number of other conditions may present very similar signs and symptoms to seizures, including syncope, hyperventilation, migraines, narcolepsy, panic attacks and psychogenic non-epileptic seizures (PNES). In particular a syncope can be accompanied by a short episode of convulsions. Nocturnal frontal lobe epilepsy, often misdiagnosed as nightmares, was considered to be a parasomnia but later identified to be an epilepsy syndrome. Attacks of the movement disorder paroxysmal dyskinesia may be taken for epileptic seizures. The cause of a drop attack can be, among many others, an atonic seizure.
Children may have behaviors that are easily mistaken for epileptic seizures but are not. These include breath-holding spells, bed wetting, night terrors, tics and shudder attacks. Gastroesophageal reflux may cause arching of the back and twisting of the head to the side in infants, which may be mistaken for tonic-clonic seizures.
Misdiagnosis is frequent (occurring in about 5 to 30% of cases). Different studies showed that in many cases seizure-like attacks in apparent treatment-resistant epilepsy have a cardiovascular cause. Approximately 20% of the people seen at epilepsy clinics have PNES and of those who have PNES about 10% also have epilepsy; separating the two based on the seizure episode alone without further testing is often difficult.
Diagnosis is made upon history of absence seizures during early childhood and the observation of ~3 Hz spike-and-wave discharges on an EEG.
The primary diagnostic test for absence seizures is EEG. However, brain scans such as by an MRI can help rule out other diseases, such as a stroke or a brain tumor.
During electroencephalography, hyperventilation can be used to provoke these seizures. Ambulatory EEG monitoring over 24 hours can quantify the number of seizures per day and their most likely times of occurrence.
Absence seizures are brief (usually less than 20 seconds) generalized epileptic seizures of sudden onset and termination. When someone experiences an absence seizure they are often unaware of their episode. Those most susceptible to this are children, and the first episode usually occurs between 4–12 years old. It is very rare that someone older will experience their first absence seizure. Episodes of absence seizures can often be mistaken for inattentiveness when misdiagnosed, and can occur 50-100 times a day. They can be so difficult to detect that some people may go months or years before being given a proper diagnosis. There are no known before or after effects of absence seizures.
Absence seizures have two essential components:
- Clinical - the impairment of consciousness (absence)
- Electroencephalography - an (EEG) shows generalized spike-and-slow wave discharges
Absence seizures are broadly divided into typical and atypical types:
- Typical absence seizures usually occur in the context of idiopathic generalised epilepsies and an EEG shows fast >2.5 Hz generalised spike-wave discharges. The prefix "typical" is to differentiate them from atypical absences rather than to characterise them as "classical" or characteristic of any particular syndrome.
- Atypical absence seizures:
- Occur only in the context of mainly severe symptomatic or cryptogenic epilepsies of children with learning difficulties who also suffer from frequent seizures of other types, such as atonic, tonic and myoclonic.
- Onset and termination is not so abrupt and changes in tone are more pronounced.
- Ictal - EEG is of slow (less than 2.5 Hz) spike and slow wave. The discharge is heterogeneous, often asymmetrical and may include irregular spike and slow wave complexes, fast and other paroxysmal activity. Background interictal EEG is usually abnormal.
The diagnosis of Jeavons syndrome is simple because the characteristic eyelid myoclonia, if seen once, will never be forgotten or confused with other conditions. Furthermore, the EEG with the characteristic eye-closure-related discharges and photosensitivity leaves no room for diagnostic error. Nevertheless, eyelid myoclonia is often misdiagnosed as facial tics, sometimes for many years.
The symptom/seizure of eyelid myoclonia alone is not sufficient to characterise Jeavons syndrome, as it may also occur in symptomatic and cryptogenic epilepsies, which are betrayed by developmental delay, learning difficulties, neurological deficits, and abnormal MRI and background EEG.
The diagnosis or suspicion of LGS is often a question of probability rather than certainty. This is because the varied presentations of LGS share features with other disorders, many of which may be said to have overlapping characteristics.
The diagnosis is more obvious when the epilepsy has frequent and manifold attacks, with the classic pattern on the electro-encephalogram (EEG); the latter is a slowed rhythm with Spike-wave-pattern, or with a multifocal and generalizing Sharp-slow-wave-discharges at 1.5–2.5 Hz. During sleep, frequently, tonic patterns can be seen. But variations of these patterns are known in patients with no diagnosis other than LGS, and they can differ bilaterally, and from time to time, within the same patient.
General medical investigation usually reveals developmental delay and cognitive deficiencies in children with true LGS. These may precede development of seizures, or require up to two years after the seizures begin, in order to become apparent.
Exclusion of organic or structural brain lesions is also important in establishing a correct diagnosis of LGS; this may require magnetic resonance imaging (MRI) or computerized tomography (CT). An important differential diagnosis is 'Pseudo-Lennox-Syndrome', which differs from LGS, in that there are no tonic seizures; sleeping EEG provides the best basis for distinguishing between the two.
Intravenous immunoglobulin therapy has been used in Lennox–Gastaut syndrome as early as 1986, when van Rijckevorsel-Harmant and colleagues used it in seven patients with ostensibly idiopathic LGS and saw EEG improvement and decreased seizure frequency in six of them.
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.
Criteria for diagnosis of abdominal epilepsy includes frequent periodic abdominal symptoms, an abnormal electroencephalogram (EEG) and significant improvement of gastrointestinal symptoms after taking anti-seizure medication. Medical testing for diagnosis can be completed using MRI scans of the brain, CT scans and ultrasounds of the abdomen, endoscopy of the gastrointestinal tract, and blood tests.
The trigger needs to be identified before prescribing anti-epileptics. The most commonly prescribed drugs for reflex epilepsy are valproate, carbamazepine and clonazepam, though lamotrigine, levetiracetam are promising.
There is no general treatment for patients with a seizure disorder. Each treatment plan is specifically tailored to the individual patient based on their diagnosis and symptoms. Treatment options may include medical therapy, nerve stimulation, dietary therapy, or surgery, as appropriate. Clinical trials may also be a valuable treatment alternative.
Usually, anticonvulsants are given based on other symptoms and / or associated problems.
Because the areas of the cerebellum which determine increases and decreases in muscular tonus are close together, people experiencing atonic seizures are most likely experiencing myoclonic ones too, at some point. This may play a role in therapy and diagnostic.
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.
Treatment of patients with absence seizures only is mainly with valproic acid or ethosuximide, which are of equal efficacy controlling absences in around 75% of patients. Lamotrigine monotherapy is less effective, with nearly half of the patients becoming seizure free. This view has been recently confirmed by Glauser et al. (2010), who studied the effects of ethosuximide, valproic acid, and lamotrigine in children with newly diagnosed childhood absence epilepsy. Drug dosages were incrementally increased until the child was free of seizures, the maximal allowable dose was reached, or a criterion indicating treatment failure was met. The primary outcome was freedom from treatment failure after 16 weeks of therapy; the secondary outcome was attentional dysfunction. After 16 weeks of therapy, the freedom-from-failure rates for ethosuximide and valproic acid were similar and were higher than the rate for lamotrigine. There were no significant differences between the three drugs with regard to discontinuation because of adverse events. Attentional dysfunction was more common with valproic acid than with ethosuximide.
If monotherapy fails or unacceptable adverse reactions appear, replacement of one by another of the three antiepileptic drugs is the alternative. Adding small doses of lamotrigine to sodium valproate may be the best combination in resistant cases.
While ethosuximide is effective in treating only absence seizures, valproic acid is effective in treating multiple seizure types including tonic-clonic seizure and partial seizure, as such it may be a better choice if a patient is exhibiting multiple types of seizures.
Similarly, lamotrigine treats multiple seizure types including partial seizures and generalized seizures, therefore it is also an option for patients with multiple seizure types. Clonazepam (Klonopin, Rivotril) is effective in the short term but is not generally recommended for treatment of absence seizure because of the rapid development of tolerance and high frequency of side effects.
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.
The most important factor in diagnosing a patient with vertiginous epilepsy is the subject’s detailed description of the episode. However, due to the associated symptoms of the syndrome a subject may have difficulty remembering the specifics of the experience. This makes it difficult for a physician to confirm the diagnosis with absolute certainty. A questionnaire may be used to help patients, especially children, describe their symptoms. Clinicians may also consult family members for assistance in diagnosis, relying on their observations to help understand the episodes. In addition to the description of the event, neurological, physical and hematologic examinations are completed to assist in diagnosis. For proper diagnosis, an otological exam (examination of the ear) should also be completed to rule out disorders of the inner ear, which could also be responsible for manifestations of vertigo. This may include an audiological assessment and vestibular function test. During diagnosis, history-taking is essential in determining possible causes of vertiginous epilepsy as well as tracking the progress of the disorder over time.
Other means used in diagnosis of vertiginous epilepsy include:
- Electroencephalography (EEG)
- Magnetic resonance imaging (MRI)
- Positron emission tomography (PET)
- Neuropsychological testing
The EEG measures electrical activity in the brain, allowing a physician to identify any unusual patterns. While EEGs are good for identifying abnormal brain activity is it not helpful in localizing where the seizure originates because they spread so quickly across the brain. MRIs are used to look for masses or lesions in the temporal lobe of the brain, indicating possible tumors or cancer as the cause of the seizures. When using a PET scan, a physician is looking to detect abnormal blood flow and glucose metabolism in the brain, which is visible between seizures, to indicate the region of origin.
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.
Epilepsy with myoclonic-astatic seizures has a variable course and outcome. Spontaneous remission with normal development has been observed in a few untreated cases. Complete seizure control can be achieved in about half of the cases with antiepileptic drug treatment (Doose and Baier 1987b; Dulac et al. 1990). In the remainder of cases, the level of intelligence deteriorates and the children become severely intellectually disabled. Other neurologic abnormalities such as ataxia, poor motor function, dysarthria, and poor language development may emerge (Doose 1992b). However, this proportion may not be representative because in this series the data were collected in an institution for children with severe epilepsy.
The outcome is unfavorable if generalized tonic-clonic, tonic, or clonic seizures appear at the onset or occur frequently during the course. Generalized tonic-clonic seizures usually occur during the daytime in this disorder, at least in the early stages. Nocturnal generalized tonic-clonic seizures, which may develop later, are another unfavorable sign. If tonic seizures appear, prognosis is poor.
Status epilepticus with myoclonic, astatic, myoclonic-astatic, or absence seizures is another ominous sign, especially when prolonged or appearing early.
Failure to suppress the EEG abnormalities (4- to 7-Hz rhythms and spike-wave discharges) during therapy and absence of occipital alpha-rhythm with therapy also suggest a poor prognosis (Doose 1992a).
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)
Any number of medications may be used to both prevent and treat seizures.
Generally after three medications are tried, different treatment should be considered. It should also be noted that some medications are harmful to those with this syndrome and can increase seizures.
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.
The International League against Epilepsy has not yet recognized Jeavons syndrome despite overwhelming evidence of its existence. Instead, only ‘eyelid myoclonia’ has been accepted as an “absence seizure with special features”.