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.

Definitions vary, but currently it is defined as one continuous, unremitting seizure lasting longer than five minutes, or recurrent seizures without regaining consciousness between seizures for greater than five minutes. Previous definitions used a 30-minute time limit.

NCSE is believed to be under-diagnosed.

Between 10 and 30% of people who have status epilepticus die within 30 days. The great majority of these people have an underlying brain condition causing their status seizure such as brain tumor, brain infection, brain trauma, or stroke. However, people with diagnosed epilepsy who have a status seizure also have an increased risk of death if their condition is not stabilized quickly, their medication and sleep regimen adapted and adhered to, and stress and other stimulant (seizure trigger) levels controlled.

However, with optimal neurological care, adherence to the medication regimen, and a good prognosis (no other underlying uncontrolled brain or other organic disease), the person—even people who have been diagnosed with epilepsy—in otherwise good health can survive with minimal or no brain damage, and can decrease risk of death and even avoid future seizures.

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 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 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.

The differential diagnosis of ICOE-G is mainly from symptomatic occipital epilepsy and migraine where misdiagnosis is high. The differential diagnosis from migraine should be easy because elementary visual hallucinations of occipital seizures develop rapidly within seconds, are brief in duration (2–3 minutes) are usually colored and circular. These are fundamentally different from the visual aura of migraine which develops slowly in minutes, is longer lasting ≥5 minutes and mainly achromatic with linear patterns.

Symptomatic occipital epilepsy often imitates ICOE-G; neuroophthalmological examination and brain imaging may be normal. Thus, high resolution MRI is required to detect subtle lesions.

The differentiation of ICOE-G from Panayiotopoulos syndrome is straightforward. The seizures of ICOE-G are purely occipital, brief, frequent and diurnal. Conversely seizures in Panayiotopoulos syndrome manifest with autonomic manifestations, they are lengthy and infrequent; visual symptoms are rare and not the sole manifestation of a seizure.

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.

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 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 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.

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.

Many antiepileptic drugs are used for the management of canine epilepsy. Oral phenobarbital, in particular, and imepitoin are considered to be the most effective antiepileptic drugs and usually used as ‘first line’ treatment. Other anti-epileptics such as zonisamide, primidone, gabapentin, pregabalin, sodium valproate, felbamate and topiramate may also be effective and used in various combinations. A crucial part of the treatment of pets with epilepsy is owner education to ensure compliance and successful management.

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.

There are three types of epilepsy in dogs: reactive, secondary, and primary. Reactive epileptic seizures are caused by metabolic issues, such as low blood sugar or kidney or liver failure. Epilepsy attributed to brain tumor, stroke or other trauma is known as secondary or symptomatic epilepsy.

There is no known cause for primary or idiopathic epilepsy, which is only diagnosed by eliminating other possible causes for the seizures. Dogs with idiopathic epilepsy experience their first seizure between the ages of one and three. However, the age at diagnosis is only one factor in diagnosing canine epilepsy, as one study found cause for seizures in one-third of dogs between the ages of one and three, indicating secondary or reactive rather than primary epilepsy.

A veterinarian's initial work-up for a dog presenting with a history of seizures may include a physical and neurological exam, a complete blood count, serum chemistry profile, urinalysis, bile tests, and thyroid function tests. These tests verify seizures and may determine cause for reactive or secondary epilepsy. Veterinarians may also request that dog owners keep a "seizure log" documenting the timing, length, severity, and recovery of each seizure, as well as dietary or environmental changes.

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.

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.

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.

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).

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”.

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.

There are various reflex epilepsies, including:

- Photosensitive epilepsy

- Eating epilepsy

- Reading epilepsy

- Hot water epilepsy

- Music induced seizures

Generalised seizures, particularly myoclonic and tonic-clonic, are the most common type of reflex seizures, though other types of seizures may occur.

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

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.