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.

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.

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.

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.

Following a first seizure, the risk of more seizures in the next two years is 40%–50%. The greatest predictors of more seizures are problems either on the electroencephalogram or on imaging of the brain. In adults, after 6 months of being seizure-free after a first seizure, the risk of a subsequent seizure in the next year is less than 20% regardless of treatment. Up to 7% of seizures that present to the emergency department (ER) are in status epilepticus. In those with a status epilepticus, mortality is between 10% and 40%. Those who have a seizure that is provoked (occurring close in time to an acute brain event or toxic exposure) have a low risk of re-occurrence, but have a higher risk of death compared to those with epilepsy.

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.

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 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.

Like many other types of seizures, gelastic seizures are hard to control for an extended period of time. The best outlook is for children suffering the seizures due to a benign tumor in their hypothalamus. The removal of these tumors can be effective not only for the frequency of the seizures, but also the behavioral and cognitive symptoms that come along with the syndrome. Cases have also been described where that antiepileptic drugs have stopped seizures fully.

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.

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 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.

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

Absence seizures are one of several kinds of seizures. These seizures are sometimes referred to as petit mal seizures (from the French for "little illness", a term dating from the late 18th century). Absence seizures are characterized by a brief loss and return of consciousness, generally not followed by a period of lethargy (i.e. without a notable postictal state).

The main sign of a gelastic seizure is a sudden outburst of laughter or crying with no apparent cause. The laughter may sound unpleasant and sardonic rather than joyful. The outburst usually lasts for less than a minute. During or shortly after a seizure, an individual might display some twitching, strange eye movements, lip smacking, fidgeting or mumbling. If a person who suffers from the seizures is hooked up to an electroencephalogram it will reveal interictal epileptic discharges. This syndrome usually manifests itself before the individual reaches the age of three or four. The temporal lobes, and the hypothalamus are the areas of the brain with the most involvement with these seizures. This may cause learning disabilities, and faulted cognitive function as well. It is not uncommon for children to have tonic-clonic seizures, and atonic seizures directly following the seizure. Those that are associated with hypothalamic hamartomas may occur as often as several times hourly and typically begin during infancy. Seizures that occur in infancy may include bursts of cooing, respirations, giggling, and smiling. Due to early hypothalamic-pituitary-gonadal axis activation in girls who suffer from the seizures, it is not uncommon for them to display secondary sex characteristics before the age of eight.

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.

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.

Deep brain stimulation of the anterior nuclei of the thalamus is approved for DRE in some countries in Europe, but has been and continues to only be used in a very few patients. After 5 years of DBS a seizure reduction of 69% and a 50%-responder rate of 68% was reported in a randomized-double blinded trial. The rate of serious device related events was 34% in this study.

Responsive neurostimulation (RNS) is approved for DRE in the USA and involves stimulation directly to 1 or 2 seizure foci when abnormal electrocorticographic activity is detected by the devices software. After 2 years of RNS a seizure reduction of 53% was reported in a randomized-double blinded trial as well as a rate of serious device related events of 2.5%.

Transcutaneous vagus nerve stimulation (tVNS) is approved for DRE in some European countries and involves externally stimulating the auricular branch of the vagus nerve in the ear. tVNS failed to demonstrate efficacy in a first randomized-double blinded trial: responder rates did not differ between active and control groups potentially indicating a placebo effect behind the 34% seizure reduction seen in the patients who completed the full follow-up period.

In Europe the ketogenic diet is the diet that is most commonly recommended by doctors for patients with epilepsy. In this diet the ratio of fat to carbohydrates and proteins is 4:1. That means that the fat content of the consumed food must be around 80%, the protein content must be around 15%, and the carbohydrate content must be around 5%. For comparison the average western diet consists of a carbohydrate content of over 50%. After one year on the ketogenic diet the success rate (seizure reduction over 50%) is between 30 and 50% and the dropout rate is around 45%. Although the ketogenic diet can be very effective some families report that it's not compatible with daily life on the long run because it's too restrictive as bread pasta and sweets are forbidden in the ketogenic diet. In puberty with increasing autonomy it can be difficult for adolescents to follow the diet strictly. For this reason a fat ratio of 3: 1 instead of 4: 1 can be recommended to make meals more palatable. Side effects of the ketogenic diet can be constipation, tiredness and after a long term diet, in one out of 20 patients, kidney stones.

Musicogenic epilepsy is a form of reflex epilepsy with seizures elicited by special stimuli.

It has probably been described for the first time in 1605 by the French philosopher and scholar Joseph Justus Scaliger (1540-1609). Later publications were, in the eighteenth century, among others, by the German physician Samuel Schaarschmidt, in the nineteenth century 1823 by the British physician John C. Cooke, 1881 by the British neurologist and epileptologist William Richard Gowers, as well as in 1913 by the Russian neurologist, clinical neurophysiologist and psychiatrist Vladimir Mikhailovich Bekhterev. In 1937 the British neurologist Macdonald Critchley coined the term for the first time and classified it as a form of reflex epilepsy.

Most patients have temporal lobe epilepsy. Listening, probably also thinking or playing, of usually very specific music with an emotional content triggers focal seizures with or without loss of awareness, occasionally also evolving to bilateral tonic-clonic seizures.

Although musicality is at least in non-musicians predominantly located in the right temporal lobe, the seizure onset may also be left-hemispherical. Of the approximately 100 patients reported in the literature so far, about 75% had temporal lobe epilepsy, women were slightly more affected, and the mean age of onset was about 28 years. Ictal EEG and SPECT findings as well as functional MRI studies localized the epileptogenic area predominantly in the right temporal lobe. Treatment with epilepsy surgery leading to complete seizure freedom has been reported.

Although a specific cause has not been identified to always induce vertiginous epilepsy there have been a number of supported hypotheses to how these seizures come about, the most common being traumatic injury to the head. Other causes include tumor or cancers in the brain, stroke with loss of blood flow to the brain, and infection. A less tested hypothesis that some believe may play a larger role in determining who is affected by this disease is a genetic mutation that predisposes the subject for vertiginous epilepsy. This hypothesis is supported by occurrences of vertiginous epilepsy in those with a family history of epilepsy.

Vertiginous epilepsies are included in the category of the partial epilepsy in which abnormal electrical activity in the brain is localized. With current research, it is presumed that the most likely cause to produce vertigo are epilepsies occurring in the lateral temporal lobe. These abnormal electrical activities can either originate from within the temporal lobe or may propagate from an epilepsy in a neighboring region of the brain. Epilepsies in the parietal and occipital lobes commonly propagate into the temporal lobe inducing a vertiginous state. This electrical propagation across the brain explains why so many different symptoms may be associated with the vertiginous seizure. The strength of the electrical signal and its direction of propagation in the brain will also determine which associated symptoms are noticeable.

Ictal refers to a physiologic state or event such as a seizure, stroke, or headache. The word originates from the Latin "ictus", meaning a blow or a stroke. In electroencephalography (EEG), the recording during a seizure is said to be "ictal". The following definitions refer to the temporal relation with seizures.

Pre-ictal refers to the state immediately before the actual seizure, stroke, or headache, though it has recently come to light that some characteristics of this stage (such as visual auras) are actually the beginnings of the ictal state.

Post-ictal refers to the state shortly after the event.

Interictal refers to the period between seizures, or convulsions, that are characteristic of an epilepsy disorder. For most people with epilepsy, the interictal state corresponds to more than 99% of their life. The interictal period is often used by neurologists when diagnosing epilepsy since an EEG trace will often show small interictal spiking and other abnormalities known by neurologists as subclinical seizures. Interictal EEG discharges are those abnormal waveforms not associated with seizure symptoms.

Peri-ictal encompasses pre-ictal, ictal and post-ictal.

Ictal asystole is a rare occurrence for patients that have temporal lobe epilepsy. It can often be identified by loss of muscle tone or the presence of bilateral asymmetric jerky limb movements during a seizure, although ECG monitoring is necessary to provide a firm result. Ictal asystole and Ictal bradycardia can cause an epileptic patient to die suddenly.

There have been early and consistent strategies for measurement to better understand vertiginous epilepsy including caloric reflex test, posture and gait, or rotational experimentation.

In Japan, Kaga et al prepared a longitudinal study of rotation tests comparing congenital deafness and children with delayed acquisition of motor system skills. They were able to demonstrate the development of post-rotation nystagmus response from the frequency of beat and duration period from birth to six years to compare to adult values. Overall, the study demonstrated that some infants from the deaf population had impaired vestibular responses related to head control and walking age. A side interpretation included the evaluation of the vestibular system in reference to matching data with age.

Research in this area of medicine is limited due to its lacking need for urgent attention. But, the American Hearing Research Foundation (AHRF) conducts studies in which they hope to make new discoveries to help advance treatment of the disease and possibly one day prevent vertiginous seizures altogether.

The cause of Todd's paresis been attributed to the affected cortex being ‘exhausted’ or silenced due to increased inhibition, but these conjectures are not supported. It has been observed that the impairments that follow seizures are similar to those that follow strokes, where for a period of time blood flow to certain areas of the brain is restricted and these areas are starved of oxygen.