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Seminar in EpileptologyEpileptic Disord 2018; 20 (2): 77-87

The 2017 ILAE classificationof seizure types and theepilepsies: what do peoplewith epilepsy and theircaregivers need to know?

Martin J. Brodie 1, Sameer M. Zuberi 2, Ingrid E. Scheffer 3,Robert S. Fisher 4

1 Epilepsy Unit, Scottish Epilepsy Initiative, Glasgow, Scotland2 Fraser of Allander Neurosciences Unit, Royal Hospital for Children, Glasgow, Scotland,UK3 Department of Medicine and Paediatrics, University of Melbourne, Melbourne,Australia4 Department of Neurology and Neurological Sciences, Stanford, California, USA

Received October 25, 2017; Accepted January 16, 2018

ABSTRACT – The International League against Epilepsy (ILAE) published inthe April 2017 edition of Epilepsia three companion articles on the classifica-tion of seizures and the epilepsies. These represent a long-awaited updateon the original 1981 and 1989 publications and provide a modern descrip-tive template. The new classification presents three levels of terminology,involving seizure types, epilepsy types, and syndromes. In this fourth paper,we present an interpretation of these new concepts for people with epilepsyand those who care for them, as well as for young medical doctors not spe-

oal in writing this paper is to ensuretanding the same language, which isent of people with epilepsy.

ainst Epilepsy, classification, seizure,epsy, caregiver

classification of seizures and theepilepsies, together with an instruc-tional manual on how to applythe seizure classification (Fisher

cialized in epilepsy and nurses. Our gthat everyone is speaking and undersfundamental to the optimal managem

Key words: International League Agepilepsy, syndrome, people with epil

“If names be not correct, languageis not in accordance with the truthof things. If language be not in accor-dance with the truth of things, affairs

pileptic Disord, Vol. 20, No. 2, April 2018 77

orrespondence:artin J. Brodie

pilepsy Unit,cottish Epilepsy Initiative,1 Somerset Place,lasgow G3 7JT,cotland, [email protected]>

cannot be carried on to success”(Confucius, Analects, 6th centuryBC).

In 2017, the International Leagueagainst Epilepsy (ILAE) pub-lished in two articles an updated

et al., 2017a, 2017b; Scheffer et al.,2017). These were the first newofficial papers on classificationfrom the ILAE since 1989. The newframework is illustrated in figure 1.The first two papers highlightchanges in the revised classification

mailto:[email protected]


7

M.J. Brodie, et al.

Table 1. Glossar

Absence A sudden interruption odeviation of the eyes lasrapid recovery. Atypical

Atonic Sudden loss of muscle tbody, arms and legs

Automatism Coordinated motor, actioften followed by amne

Clonic Symmetrical or asymme

Cognitive Relating to thinking, lan

Comorbidities Conditions associated w

Emotional A focal non-motor seizu

Epilepsy A chronic disorder of thtowards recurrent unproseizures occurring greatabnormal electroencephprobability of a second

Focal Starting with one cerebrmore widely distributed

Generalized Originating at some poi

Generalized tonic-clonic seizure Bilateral convulsion with

Genetics That part of biological scheredity

Hyperkinetic Agitated thrashing or leg

Idiopathic No known or suspected

Metabolic Produced by the processubstances

Motor Involving movement of

Myoclonic Sudden, brief contractioand/or falls

Seizure Transient symptoms andneuronal activity of a po

Spasm Sudden flexion and/or eeye m

res anisab

cle c

(pscr

head nodding, and

Syndrome Characteristic seizutogether in a recog

Tonic An increase in mus

8

Fisher et al., 2017a; Scheffer et al., 2017), while the thirdrovides guidance on how best to use the updatedeizure classification terminology in everyday clini-al practice (Fisher et al., 2017b). One of the maineasons to revise the epilepsy classification was to

ufctw

y of terms.

f activities accompanied by a blank stare with occasionalting a few seconds to half a minute with subsequenttypes with other symptoms can also be found

one lasting a few seconds which can affect the head,

vely accompanied usually by impaired awareness andsia

trical jerking of the same group of muscles

guage, memory, and other similar functions

ith or causing the epilepsy

re that can have elements such as fear and joy

e brain characterised by an enduring dispositionvoked seizures. The diagnosis requires at least 2

er than 24 hours apart or one seizure with a relevantalographic pattern or brain scan suggesting a high

seizure (Fisher et al., 2014)

al hemisphere, either in a specific place in the brain or

nt, but rapidly spreading across both sides of the brain

loss of awareness

ience that is concerned with the study of variation and

pedalling movements

cause other than possible hereditary predisposition

ses in body cells that build up or break down natural

muscles in any way

ns of muscles resulting in dropping or spilling things

/or signs due to abnormal excessive or simultaneouspulation of neuronal cells in the brain

xtension of trunk muscles which can include grimacing,ovements

ssociated with abnormal investigations that occurle pattern

ontraction, lasting from a few seconds to some minutes

Epileptic Disord, Vol. 20, No. 2, April 2018

se more accessible, transparent language suitableor clinicians, scientists, and patients. The aim of thisompanion piece is to present these new conceptso other non-specialist professionals and to peopleith epilepsy and those who care for them. Everyone


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ow has access to medical information via the internethich was not available to previous generations, and

o it is increasingly important that medical conceptsre as clear and unambiguous as possible. This paperay also help doctors to explain epilepsy to affected

ndividuals and their families.ach of the three publications will be discussed sepa-ately. We have not attempted to combine them, sincehis would have added to the risk of inadvertentlyncluding misinterpretations. There is substantialverlap among them and so some repetition is

nevitable. The basic and operational classifications ofeizure types are shown in figures 2 and 3. A revisedlossary of terms is also included (table 1). This paperollows the formats of the three new publicationsnd attempts to provide an interpretation of theontent. The reader may find it helpful to consulthe original papers (which can be freely downloadedrom https://www.ilae.org/guidelines/definition-and-lassification) to obtain a more complete picture ofhe often-complex concepts under discussion.

aper 1: ILAE classification of thepilepsies (Scheffer et al., 2017)

his paper presents a new framework for classifica-ion of the epilepsies with three levels, as well as

major focus on looking for a cause and identify-ng any associated disorders, or co-morbidities, at alltages along the diagnostic process. It begins witheizure type(s) defined by their type of onset (focal;eneralized; unknown), then epilepsy type and thirdly,pilepsy syndrome. Wherever possible, the aim is tolassify a patient’s epilepsy in a way that is recognis-ble across a range of individuals experiencing theame pattern of seizures, age at onset, and electroen-ephalographic (Koutroumanidis et al., 2017a, b) andmaging features, who often share a similar cause forheir epilepsy. When possible, this may allow diagno-is of a specific epilepsy syndrome to be attached tohe collection of symptoms and signs. In some cases,nly the epilepsy type will be diagnosable, and no syn-rome name will apply.he revised classification also emphasizes the impor-ance of considering the cause, or aetiology, ofhe patient’s epilepsy from the initial consultationnwards. It presents six broad headings for the aeti-

pileptic Disord, Vol. 20, No. 2, April 2018

logies (figure 1). Attached to this framework is alsosection for comorbidities, which are conditions

ssociated with epilepsy. These include issues suchs learning problems, intellectual disability, and psy-hiatric features such as depression, psychosis, andutism spectrum disorders; comorbidities will not beiscussed in detail in this paper.

coaijwo

2017 ILAE classification for people with epilepsy and caregivers

his new classification provides a better understand-ng of the types of seizures that the person suffersrom and the likely cause and probable long-term out-ome of the epilepsy. Correct classification can alsoelp with the choice of drug treatment and point to

he possibility of epilepsy surgery, if optimal seizureontrol is not obtained with medication. This pro-ess ideally requires access to specific investigations,uch as a video-EEG (for a detailed educational publi-ation on EEG characteristics see Koutroumanidis etl., 2017a, 2017b) and brain imaging, together with

range of blood studies, including genetic and/oretabolic screening when indicated, aimed at identi-

ying the cause of the epilepsy. The current proposalsre based on the latest scientific information, whichas been reviewed by experts in epilepsy from around

he world.

lassification of the epilepsies

his revised classification attempts to cover theevelopment of epilepsy across a range of global envi-onments. It assumes that the clinician has already

ade a definite diagnosis of an epileptic seizure ands not meant to be a diagnostic algorithm to dis-inguish epileptic from nonepileptic events. Whereossible, the diagnosis should take into consideration

he seizure type or types, epilepsy type, and epilepsyyndrome, as well as the specific cause underlying theroblem (figure 1).eizures can be divided into those with focal onset,eneralised onset, and unknown onset. Some focaleizures can spread quickly to produce a tonic-cloniceizure, previously known as a “grand mal” seizurer convulsion. The epilepsy types can be focal, gen-ralized or both. In some circumstances, this will benclear (“unknown”). Many syndromes include more

han one type of seizure.

eneralized seizuresn these events, the abnormal electrical activity (asudged by behaviour or EEG) apparently originatesimultaneously on both sides of the brain and spreadsapidly via neuronal networks. Most people will recog-ise a generalized tonic-clonic seizure (convulsiveeizure) as a typical sign of epilepsy. However, there isrange of other generalized seizures. These include

bsences, where the affected individual, usually a

79

hild or adolescent, loses awareness for a numberf seconds resulting in a blank stare. This may beccompanied by more subtle signs, such as flicker-ng of the eyelids and mouth movements. Myoclonicerks are also types of generalized seizures and occur

hen there is a sudden rapid contraction of a groupf muscles. They can affect the head, arms, legs or


8

M.J. Brodie, et al.

Epilepsy syndromes

Epilepsy types

Seizure types*Etiology

Structural

Genetic

Infectious

MetabolicFocal

Focal

Generalized

Generalized

CombinedGeneralized

& Focal

Unknown

Unknown

Immune

Unknown

Co

-mo

rbid

itie

s

F

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FIisssas

pihccamsaaftb

(*) Denotes onset of seizure

igure 1. Framework for epilepsy classification.

hole body and can be unilateral or bilateral. Theffected person may drop or spill things and, if theerking is severe or occurs in a young child, theyan fall. Because the jerk can last less than a second,here is no obvious loss of consciousness. Frequent

yoclonic seizures can also occur in some severepilepsies of infancy and early childhood. Other lessommon generalized seizure types include atonic (lossf muscle tone) and tonic (more prolonged increase

n muscle contractions) seizures, both of which canlso result in falls or drop attacks and epilepticpasms.

ocal seizures

0

n these events, the abnormal electrical activity orig-nates on one side of the brain, although in someituations it can spread to the other side later in theeizure. Focal seizures can present with a range ofymptoms, depending on the site of origin of thebnormal electrical discharges and the extent andpeed of their spread in the brain. Awareness may be

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resent, reduced or absent. Sometimes, there is jerk-ng of one arm and/or leg. Epileptic spasms can alsoave a focal origin. The abnormal electrical activityan move quickly from a focal seizure to a tonic-lonic seizure, affecting both sides (bilateral), knowns a focal to bilateral tonic-clonic seizure. The EEGay suggest an area in the brain from where the

eizure is arising, and brain imaging may demonstratestructural cause for the seizures, such as scarring,developmental anatomical abnormality (brain mal-

ormation), an abscess, stroke or tumour. In around ahird of people with focal seizures, brain imaging wille reported as normal.


ocal and generalized seizureshe next group consists of people who have both focalnd generalized seizures. The VEEG (Koutroumanidist al., 2017b) can be helpful in defining this category. Inhe severe epilepsies of infancy and childhood, the EEGs often markedly abnormal. There is often evidence of

ore than one type of seizure.


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ILAE 2017 Classification of Seizure Types Basic Version

Focal to bilateral tonic–clonic

Focal Onset Generalized Onset Unknown Onset

Aware Impaired Awareness

Motor Tonic-clonic Other motor Nonmotor (Absence)

Motor Tonic–clonic Other motor Nonmotor Motor Onset

Nonmotor Onset

Unclassified

Figure 2. Basic operational classification of seizure types.

ILAE 2017 Classification of Seizure Types Expanded Version

Focal Onset Generalized Onset Unknown Onset

Aware Impaired Awareness

Motor Onset Automatisms Atonic Clonic Epileptic spasma Hyerkinetic Myoclonic TonicNonmotor Onset Autonomic Behavior arrest Cognitive Emotional Sensory

Motor Tonic–clonic Clonic Tonic Myoclonic Myoclonic–tonic Myoclonic–atonic Atonic Epileptic spasmsNonmotor (absence) Typical Atypical Myoclonic Eyelid myoclonia

Motor Tonic–clonic Epileptic spasmsNonmotor Behavior arrest

Unclassifed

F

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Ti

aca

Focal to bilateral tonic–clonic

igure 3. Expanded operational classification of seizure types.

nknownccasionally, the doctor cannot be certain whether

he epilepsy is focal or generalized. This is more com-


on where there is limited access to VEEG studies andodern brain imaging such as magnetic resonance

maging (MRI).

pilepsy syndromes

he third level of diagnosis, wherever possible, is thedentification of an epilepsy syndrome. This includes

eaowatd

cluster of features, including seizure types, EEGhanges, brain imaging abnormalities, and geneticnalyses that add up to a recognisable pattern. Differ-

81

nt syndromes can occur at different ages in life, and anccurate diagnosis often provides useful informationn the likely outcome. Some syndromes are associatedith other symptoms, such as intellectual and psychi-

tric problems, which may play an important part inhe overall clinical picture. The recognition of a syn-rome can help to determine the cause, treatment,


8

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.J. Brodie, et al.

nd outcome of the epilepsy. The educational ILAEebsite (www.epilepsydiagnosis.org) and the websitef the ILAE educational journal Epileptic Disorders

www.epilepticdisorders.com) provide descriptions,EGs, and video examples of many seizure types andpilepsy syndromes. New epilepsy syndromes areescribed in the emerging literature fairly often, and

here is currently no “official” ILAE list of all the syn-romes. All this information is readily available toeople with epilepsy and their families.mong the generalized epilepsies are a well-

ecognised group of common epilepsy syndromes:hildhood absence epilepsy, juvenile absencepilepsy, juvenile myoclonic epilepsy, and generalizedonic-clonic seizures alone. They have previouslyeen known collectively as the “idiopathic general-

zed epilepsies”, which means that the exact causes unknown, but the evidence is strongly in favourf a genetic basis. Less frequently, they may have anbvious hereditary component, i.e. run in families.

n the new classification, they can be called “geneticeneralised epilepsies” or “idiopathic generalisedpilepsies” depending on whether the clinician findshe term “genetic” acceptable for their patient andamily.nother group of focal epilepsy syndromes that occur

n childhood have a self-limited course. Often the diag-osis is made by the presence of spikes in a particularattern on the EEG that relate to electrical malfunction-

ng in a particular part of the brain (Koutroumanidis etl., 2017a). These conditions may be treatment respon-ive and self-limiting, and usually affect the temporal,rontal or occipital lobes in the brain. Recognition of aarticular syndrome can provide important informa-

ion on the best approach to management and canhine a light on the likely long-term outcome.

auses of epilepsy

s soon as a person has their first epileptic seizure,veryone involved wants to know the cause. A rangef possibilities can be recognised, which may helpith understanding the problem and point to its opti-al treatment. It should be appreciated that a specific

eason why seizures occur cannot always be identi-ed. As our knowledge improves and the availability ofore sophisticated investigations is becoming moreidespread, this “unknown” group of epilepsies is

2

ecoming smaller. The six recognised causative cate-ories under this heading are highlighted in figure 1. Ithould be appreciated that the patient’s epilepsy mayelong to more than one group of causes. For example,genetic disorder may cause a structural abnormalityf brain development, which leads to the epilepsy. Thisould be termed a “structural” and “genetic” cause.

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tructural causestructural causes of epilepsy can be recognised via aange of brain imaging investigations. The anatomicalbnormality needs to relate directly to the symptomsnd signs of the seizures, since many people with-ut epilepsy have abnormal brain imaging. The pastistory may be a useful contributory factor, e.g. a pre-ious head injury, stroke, tumour, birth injury, brainnfection, etc., which may be associated with the par-icular type of seizures under scrutiny. This association

ay take some time to establish. In some cases, aositive brain scan will provide the basis for subse-uent epilepsy surgery, usually after treatment withppropriate antiepileptic drugs has failed. Structuralbnormalities are usually acquired, although on occa-ion the patient may be born with an anatomical defecthat may be part of a genetic syndrome. Recognisinghe cause of the epilepsy can be reassuring to all con-erned and can point the way to the best avenue ofare. The more advanced the available technology, theore likely will a relevant anatomical abnormality be

dentified.

enetic causesenetics can be considered as the part of biological

ciences that is concerned with the study of geneticariation and heredity. Genetic factors are probablyhe most important single causative group for thepilepsies. However, we still cannot find a preciseefect in most people with suspected genetic epilepsy.pilepsies can be called “genetic” if we know thathere is a strong family history, whether an impli-ated gene is discovered in the family or not. Wenow that some common types of epilepsy are largelyaused by genetic factors. For instance, when epilepsyevelops in identical twins, both twins will almostlways be affected. Several hundred genes have noween linked to different epilepsies. The vast majorityf these are associated with rare syndromes, whichost often present in early childhood. Information in

his area is expanding with the development of moreophisticated methodology. Identification of a poten-ial genetic cause for the epilepsy can provide insightsnto what medication to choose and sometimes whatot to choose for treating the seizures. Occasionally, annderlying genetic cause cannot be identified, despite

he fact that a number of people in the family have aimilar type of epilepsy. In addition, a range of differentypes of seizures can occur in some families.


lthough genetic syndromes are most often diagnosedn infancy or childhood, genetic disorders can alsorise in adolescence or even later in adult life. Some-imes, a single gene defect is the culprit, while inther cases, multiple genes are involved in causing the

ndividual’s epilepsy. Interestingly, the same genetic


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bnormality can produce different types of seizures inifferent people, and different gene defects can cause

he same epilepsy syndrome. The same genetic abnor-ality can result in both mild and severe epilepsies.

here must, therefore, be other factors that influenceow the implicated gene affects the individual, e.g.

nteracts with other genes. Often, it is thought thatultiple genes contribute to the clinical picture, espe-

ially in the common situation where there is no familyistory of epilepsy.

t is important to appreciate that a genetic cause doesot necessarily mean the person has an inheritedpilepsy. An affected individual can have a new genebnormality, or mutation, that does not occur in any-ne else in the family. However, this person may have aisk of subsequently passing on the abnormal gene tois or her children. To make matters even more com-licated, although around 50% of the children may

nherit the mutation, this does not necessarily meanhat they will all develop epilepsy, as this can dependn the presence of a range of other, as yet, unidentified

actors. The next decade or two will see an accelera-ion in our understanding of the genetic bases of thepilepsies.

nfectious causesny infection in the brain or its lining, whether acuter chronic, can produce seizures. Much depends on

he part of the world where the infection is contractedn terms of the likely culprit. The commonest infectiveause of epilepsy is neurocysticercosis, a tapewormhat is found commonly in Latin America, Africa andsia. The epilepsy is caused by ingestion of tapewormggs. These hatch in the stomach or intestines andhe worms migrate to the brain, producing characteris-ic cysts. Other potential infective causes include HIV,uberculosis, malaria, bacterial meningitis, and viralncephalitis. Treatment of the infection is an essen-ial component of the therapeutic strategy. The moreidespread the brain damage, the more likely the

eizures will be difficult to control. Sometimes, there isnly a history of a previous infection in infancy or child-ood, which is assumed to be the cause of epilepsy

ater in life.

etabolic causeshere are a number of unusual and complicated dis-rders involving the production or breakdown of


atural substances in body cells that are also associatedith the development of epilepsy. The biochemical

hanges produced can result in seizures as part of theymptoms of the condition. Thus, they may only makep a small part of a more complex clinical picture. Manyf these conditions have a genetic basis. Recognitionf these rare disorders is essential to lead the clinician

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own the correct treatment path, as in certain caseseplacing a missing chemical compound or vitamin

ay be indicated rather than, or in addition to, pro-iding standard antiepileptic drug therapy.

mmune causesmong the wide range of disorders that can be asso-iated with the production of seizures are immuneonditions, where the body attacks its own tissues byhe production of antibodies. The epilepsy can be aonsequence of inflammation in the brain and man-gement may require specific medication to dampown the immune system, i.e. treat the cause of theeizures rather that the seizures themselves. Theseutoimmune-mediated epilepsies are unusual condi-ions that must be recognised promptly to ensureptimal management.

nknown causesome epilepsies do not have a recognisable cause.uch depends on the availability of routine, and some-

imes more sophisticated, investigations. Thus, theumber of people who have epilepsy for no obviouseason is higher in resource-poor countries. This oftenrings its own problems, since all affected individualsnd their families want to know why they have devel-ped seizures and why their treatment may be lifelong.he situation may be even more stressful for the familyf an affected infant or child in the developing world.

n summary, It is hoped that this updated “Classi-cation of the epilepsies” will help to improve theiagnosis, focus better on the cause, and provide a use-

ul guide to management in as wide a range of peopleith epilepsy as possible. Thus, we can all understandhat is happening in the affected person’s brain andhat is the best course of action to treat the disorder.his new classification is also an important clinical toolor communication among people with epilepsy andheir doctors.

aper 2: Operational classificationf seizure types by the Internationaleague Against EpilepsyFisher et al., 2017a)

his paper presents a revised classification of seizureypes, which depends on how seizures present to

83

eople with epilepsy and their families, carers, andoctors. These terms are largely based on what isbserved during the episodes. The aim is to providecommon language so that everyone involved knowsxactly what is meant by each type of seizure. Pre-ious terms that were unclear to non-specialists andeople with epilepsy have been largely abandoned.


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.J. Brodie, et al.

his new approach does not represent a major changeut makes recognising seizure types more straight-

orward. The major categories include focal onsetnd generalized onset seizures, and also take cogni-ance of situations where the onset of the seizure isnknown. Some seizures involve movement of par-

icular parts of the body and others affect awareness.hese can both be types of focal seizures and the pre-entation depends on where the abnormal electricalctivity arises in the brain and how far and how fast itpreads. Seizures usually involve a network of changesnd are not just symptoms of a local problem.

ethods of classification of epileptic seizures

eizures can be defined as “transient symptoms and/origns due to abnormal and simultaneous neuronalctivity of a population of neuronal cells in the brain”.he first goal of the doctor is to ensure that thepisodes are definitely epileptic seizures. The nexttep is classifying the seizure type, based on its onsetharacteristics. This provides a useful group of clinicalharacterisations that can be used for communicationmong people with epilepsy, their families, and theiroctors. Using this agreed terminology can also helpith teaching and research, since everyone should be

peaking the same language. Correct classification ofhe epilepsy is important too for insurance policies,egulatory agencies, advocacy groups, and medicaleports.

eizure classification

igure 2 shows the basic updated seizure classifica-ion, whereas figure 3 presents an expanded versionhat covers the most common or most importantypes of seizures in greater detail, although not everyeizure type can be represented in a classification,nd in clinical practice a detailed description of theymptoms observed remains essential. All terms thatre likely to be employed by specialist neurologists,aediatricians or psychiatrists have been included in

his latter description. Some relevant terminology isxplained in the attached glossary (table 1). Focalnset seizures may be accompanied by continuedwareness, depending on the site of onset and extentnd speed of the spread of the abnormal electricalctivity. Often, however, the individual will lose aware-ess at some stage during the focal seizure, which

4

s now referred to as a “focal impaired awareness”eizure. Arrest of movement or loss of memory forvents occurring during the seizure can also be partf the seizure pattern. People with atonic or myocloniceizures and epileptic spasms will usually retain aware-ess, or loss of awareness will be so brief as to be hard

o detect. Cognitive seizures refer to problems during

a(ttatt

he seizure such as impaired speech, hallucinations,llusions, or feelings of déjà-vu. Emotional seizures can

anifest as anxiety, fear, joy or any other emotion. Anbsence is atypical when it differs from the usual fastnset and EEG pattern of a 3-4 per second generalizedpike-wave pattern. If seizure patterns are not clearlyecognisable, the episodes will remain unclassified.

tructure

he columns in the classification allow specific seizureescriptions to be included under the general head-

ngs of focal, generalized or unknown onset (figures 2,). Awareness is an optional extra in the focal seizureolumn, but it is so important in influencing the impactf a seizure that it has been given special mention.e employ an operational definition of awareness

s knowledge of self and environment. In this con-ext, awareness refers to perception or knowledgef events occurring during a seizure, not to knowl-dge of whether a seizure has occurred. Level ofwareness may vary among similar seizures in theame individual. Sometimes, loss of awareness is notomplete or always recognised by the person expe-iencing the seizure and by bystanders. Abnormal

ovements may be present. The first prominent signsually determines the seizure classification, because

he first manifestation marks the part of brain wherehe seizure originates. More prominent features maynsue and be worthy of mention, but the first sign orymptom classifies a focal onset seizure. The excep-ion to this rule is awareness, such that a seizure is

focal impaired awareness seizure if awareness ismpaired at any time during the seizure. The begin-ing of the seizure is, therefore, important in helpingith its classification. The greater the observed detailf each episode, the more likely will the seizure clas-ification be correct.eizure activity progresses through brain networksnd can arise from different anatomical sources. Thebnormal electrical activity spreads, bringing with it aariety of symptoms and signs. Some people will haveore than one type of seizure. Generalized seizures

an be divided into motor and absence seizures.ther types include myoclonic, atonic, tonic or a

ombination that can allow a specific pattern to beecognised, leading to the diagnosis of an epilepsy syn-rome. Seizures of unknown origin can be regardeds “unclassified” with or without other features, such


s motor, nocturnal, tonic-clonic, epileptic spasmswhich can be called “infantile spasms” in children lesshan a year of age), and behavioural arrest. These addi-ional terms allow better description of the episodesnd can be useful to the doctor in narrowing downhe epilepsy type, with implications for causation andreatment.


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here is an overlap between focal and generalizedeizures, since both have to start somewhere, and itay not be possible with limited investigational tools

o be certain exactly what is happening in the braint the onset of the abnormal electrical activity. Thepisode may only be recognised when it is alreadyffecting both sides of the brain. In some instances, thexact sequence of events can only be determined byareful study of a video-EEG, which is unusual even inountries with the most sophisticated healthcare sys-ems. Focal onset can often, however, be obvious withn aura of déjà-vu, a strange taste or smell, or a risingensation in the stomach, followed by loss of aware-ess, lip-smacking, and hand rubbing. The term “aura”as been retained since, if presenting alone, is a focalware seizure. Unwitnessed seizures or those occur-ing during sleep are common. If they are infrequent,t may not be possible to be certain of the seizureype, or even to discern whether the episode has aocal or generalized onset. Thus, “unknown onset”an be regarded as an acceptable description in somenstances until more useful information becomes avail-ble. “Unclassified” should be regarded as a term ofast resort, where the clinician is confident that thevents represent epileptic seizures, but cannot furtherlassify them.

hether a person retains or loses consciousnessuring a seizure can be a complicated issue. Thisan matter greatly since episodes accompanied bympaired consciousness are often considered differ-ntly, e.g. with respect to driving, impaired learningapacity, and poor memory and recall. Consciousness,herefore, is an important concept in classifying focaleizures. However, different levels of impairment ofonsciousness can occur in the same person and itan be difficult to be certain that some seizures are notssociated with some reduction in awareness or mem-ry. The affected individual may not be certain whether

ull consciousness is retained during every episode. Aerson may be conscious during the seizure, but notecessarily fully aware of everything going on around

hem i.e. unaware is not the same as unconscious. Onepproach is to define the episode as a focal awarer focal impaired awareness seizure. From a practicalerspective, the affected individual should be able toecall and relate all aspects of the event, even if unableo respond during the seizure; otherwise, impairedwareness must be assumed. Responsiveness, aware-ess, and consciousness are not usually present during


eneralized seizures, so these features are not used tolassify generalized seizures.nowledge of the cause of the epilepsy can greatlyelp with seizure classification. Thus, evidence of annatomical abnormality in the brain, which matcheshe symptoms and signs of the seizures, usuallyupports their focal onset. With improved brain

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maging, this scenario is being increasingly recognisedn everyday clinical practice. A clear history from theffected person, accompanied by an eyewitness to thettack, provides the most useful diagnostic informa-ion. Videos from a smart phone brought to the clinicy the family, EEG patterns, brain imaging, and lab-ratory tests, including those for antibodies or geneutations, can also help to confirm the seizure clas-

ification and aid in making an epilepsy syndromeiagnosis. Supportive information, however, may be

ess available in resource-poor countries, although thishould not prevent the neurologist from trying to iden-ify the correct seizure type and attempting to make theiagnosis of an epilepsy syndrome.number of terms have been discarded in this new

lassification, including “simple partial seizure”,complex partial seizure,” “psychic seizure,” anddyscognitive seizure.” Reorganisation of someeizure types has taken place to keep up with newnowledge. Terms like “epileptic (infantile) spasms”,tonic-clonic”, “atonic” and “myoclonic seizures”an now appear under the headings of seizures ofocal, generalized and unknown onset. A number ofew seizure descriptions have been included, suchs automatism, cognitive, emotional, hyperkinetic,nd behavioural arrest. A few unusual seizure typesre now regarded as generalized, such as absenceeizures with eyelid myoclonia and myoclonicbsences. Thus, certain seizure types now appear inultiple categories. The new approach provides a

etailed descriptive template for seizures.

aper 3: Instruction manual for the ILAE017 operational classification of seizureypes (Fisher et al., 2017b)

his third article contains substantial overlap with thether two papers. The goal here is to provide guidancen how best to use the new classification of seizure

ypes. A glossary of terms has been included, whichas been amended in this paper to make the termi-ology more accessible to people with epilepsy and

heir families (table 1). Key symptoms and signs pro-ide the basis for the classification of the seizures.ocal seizures can progress to bilateral tonic-clonicpisodes. Generalized seizures involve both sides ofhe brain from the outset. As discussed previously,ocal onset seizures can be further designated accord-

85

ng to whether awareness is retained or impaired.eizures with a motor onset may have other features,hich can be described as atonic, automatism, clonic,pileptic spasms or have hyperkinetic, myoclonic oronic activity. Non-motor seizures can display a rangef elements including autonomic, behavioural, cogni-

ive, emotional, and sensory dysfunction. The earliest


8

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.J. Brodie, et al.

ymptoms or signs usually define the seizure type.eneralized motor seizures can be characterised as

tonic, clonic, epileptic spasm, myoclonic, myoclonic-tonic, myoclonic-tonic-clonic, tonic, and tonic-clonic.on-motor seizures are typical or atypical absencesr seizures that present myoclonic activity or eye-

id myoclonia. Seizures of unknown onset can haveomponents that are classified as motor, non-motor,onic-clonic, epileptic spasm, or behavioural arrest.eizure classification can be followed by a descrip-ion of other features of the seizure. Although suchdescription does not change the seizure type, it maye very helpful in portraying the manifestations of aeizure. The more detail included in the description,he more likely can a cause be inferred or identified,nd a specific syndrome recognised. A range of old-ashioned terms has been discarded in favour of a moreescriptive approach. This paper also provides a “useranual” for the new classification aimed at encour-

ging the adoption of the new system by all doctorsnd the wider community of health professionals. Peo-le with epilepsy are also required to understand anddopt this modified language, although perhaps not inoo much detail.

pplication

n accurate classification of seizure types requiresareful observation of the episodes with a degree ofonsistency that supports the appropriate terminol-gy. This relies on a good history and a witnessedescription. A home video of the episodes can provide

nvaluable information. There is some overlap regard-ng the different types of seizures. Taking time to gethings right is essential, since the likely cause and the

ost effective treatment can vary. Outcomes too cane different, depending on the seizure and syndromelassification. An understanding of the sequence ofvents may contribute to their correct interpretation.s discussed throughout this paper, EEG and brain

maging are often essential to help the doctor reachhe correct conclusion regarding the type of epilepsynd its cause. One of the major problems is our lackf understanding of the processes that underlie theroduction of different types of seizures and so were usually treating the symptoms and not the causef the problem. Nevertheless, if we are to eventuallynderstand these processes, we will all need to speak

he same language, e.g. identify correctly the seizure

6

ypes and epilepsy syndromes, wherever the affectederson comes from around the world.e have included in this discussion paper both the

asic and extended versions of the classification ingures 2 and 3 (Fisher et al., 2017a). Focal onset seizurestart in a particular part of the brain and general-zed seizures are usually bilateral at onset. In some

uAlipts

ircumstances, the site of origin of the episodes cannote accurately identified. On other occasions, the clas-ification may be unclear, particularly if sophisticatedodern investigations are not available. Helpful infor-ation can include lack of awareness, symptoms or

igns affecting a particular part of the body, responsive-ess during an episode, and progression of the seizure

n a consistent pattern. Sometimes, coordinated motorctivity can occur, which can be complicated, e.g. walk-ng in circles. The affected person is usually unawaref what is happening around them. This is known asautomatism”, meaning semi-automatic movements.bsence seizures can present, usually in children or

eenagers, with sudden cessation of activity, accompa-ied by loss of awareness. An EEG is often essential toake a correct diagnosis (Koutroumanidis et al., 2017a,

017b). Seizures of uncertain onset can be motor,on-motor or unclassified. Some description of thepisodes is better than none, even if it is incomplete.he expanded classification provides a more detailedreakdown of the seizure types, and is particularly use-

ul for neurologists and will be critical for researchurposes. This detailed approach will have evenreater interest for epilepsy specialists and may note as relevant to paediatricians or general practition-rs. The wide range of descriptions allows a clearernderstanding of the seizures, which is of particu-

ar importance for some of the complex epilepsiesn infants and young children. Again, the presencer absence of awareness, motor signs, and a goodescription of the episodes can provide a more accu-ate picture of what is happening in the brain. Thisnformation may have little discriminatory value to theerson with epilepsy and their family, but can be veryelpful to their doctor in understanding better thenderlying disorder and choosing the most appropri-te approach to treatment.he terminology used in these three papers will bef value in explaining what is happening before, dur-

ng, and after a seizure, and so should be accessible toveryone involved in epilepsy care. How much of thishould be discussed with the affected person and theiramily depends on the specific requirements of all con-erned. These descriptive terms are more scientificallyeaningful than the previous discarded terminol-

gy, such as “grand mal” and “petit mal”. There areany symptoms associated with seizures and these

hould be accurately described so that everyone ispeaking the same language. This detail may be partic-


larly valuable if epilepsy surgery is being considered.ccordingly, the content of this third contribution has

ess relevance to people with epilepsy and their fam-lies than the information contained in the other twoapers. Nevertheless, the doctor can expect to have

o respond to questions about these symptoms andigns, and will be required to explain how they relate to


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he seizures, their cause, their investigation, and theirreatment.

uch of the information in these papers refers par-icularly to focal seizures. Generalized seizures areften more obvious and tend to have fewer nuances.eneralized tonic-clonic seizures, for instance, begin,rogress, and end with jerking of the arms and legs onoth sides of the body, together with the head, neck,

ace, and body on most occasions. These are descrip-ions about what exactly happens during the episodend can contribute to making an accurate diagnosis ofsyndrome. Non-motor episodes comprise a range ofifferent types of absence seizures. Rapid eyelid jerk-

ng with upward deviation of the eyes is a rarer type ofbsence seizure with eyelid myoclonia, often triggeredy photic stimuli, such as bright sun. If all the neces-ary information is not available, a decision to call theeizure “unclassified” may be taken.

ules for classifying seizures

he first step is to decide whether the episode cane classified as focal or generalized and then con-ider whether awareness is affected or not. The startingoint for focal onset seizures should be identified,s well as whether the person stops doing what theyere doing before the episode started. Motor andon-motor features should be carefully documented.or generalized tonic-clonic seizures, any symptomsr signs at onset should be explored to provide a clueegarding the anatomical site of origin for the episode,hich can often later be confirmed by EEG and brain

maging. Specific features can be helpful in differ-ntiating the various types of non-motor seizures,articularly in infants and young children.

onclusions

hese three papers have reworked the 1981, 1985 and989 classifications of seizures and epilepsy syndromeso provide a modern descriptive template (Fisher etl., 2017a, 2017b; Scheffer et al., 2017). Their contentverlaps and so some repetition is inevitable. The aim


f this companion piece is to make this new thinkingvailable to people with epilepsy and those who careor them. This provides them with a description of theerminology used by their doctors so that everyonenderstands the types of seizures that the person suf-

ers from and sometimes also the epilepsy syndrome.his information can influence decisions regarding

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nvestigations, treatment options, and long-term out-omes. Old-fashioned terms such as “grand mal”,petit mal” and “simple and complex partial seizures”ave been discarded. This new terminology is avail-ble on the internet and increasingly people are awarehat they can explore the latest thinking on causesnd treatment of any form of epilepsy for themselves.ll the necessary clinical details may not be avail-ble for every affected individual and so some doubtbout the classification will sometimes remain. A care-ul accurate description of the episodes is an essentialomponent for the correct interpretation of the symp-oms and signs. Our goal in writing this manuscript is tonsure that, wherever possible, people with epilepsynd their doctors speak the same language. �

isclosures.artin Brodie has no conflicts of interest to disclose in relation to

his paper except for his position as President of the Internationalureau for Epilepsy. Sameer Zuberi has no conflict of interest

o disclose in relation to this paper except for his position ashair of the ILAE Commission for Classification and Terminology.

ngrid Scheffer has no conflict of interest to disclose in relationo this paper except for her position as former Chair of the ILAEommission for Classification and Terminology and recent Chairf the Task Force for Classification. Robert Fisher has no conflictsf interest to disclose other than serving as Chair of the ILAE Taskorce on Seizure Classification.

eferences

outroumanidis M, Arzimanoglou A, Caraballo R, et al. Theole of EEG in the diagnosis and classification of the epilepsyyndromes: a tool for clinical practice by the ILAE Neurophys-ology Task Force (Part 1). Epileptic Disord 2017a; 19(3): 233-98.

outroumanidis M, Arzimanoglou A, Caraballo R, et al.he role of EEG in the diagnosis and classification of thepilepsy syndromes: a tool for clinical practice by theLAE Neurophysiology Task Force (Part 1). Epileptic Disord017b; 19(4): 385-437.

isher RS, Acevedo C, Arzimanoglou A, et al. ILAE officialeport: a practical clinical definition of epilepsy. Epilepsia014; 55(4): 475-82.

isher RS, Cross JH, French JA, et al. Operational classificationf seizure types by the International League against Epilepsy.pilepsia 2017a; 58: 522-30.

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isher RS, Cross JH, D’Souza C, et al. Instruction manualor the ILAE 2017 operational classification of seizure types.pilepsia 2017b; 58: 431-542.

cheffer IE, Berkovic S, Capovilla G, et al. ILAE classificationf the epilepsies: Position paper of the ILAE Commission forlassification and Terminology. Epilepsia 2017; 58: 512-21.

http://www.ncbi.nlm.nih.gov/pubmed?term=The role of EEG in the diagnosis and classification of the epilepsy syndromes: a tool for clinical practice by the ILAE Neurophysiology Task Force (Part 1)

http://www.ncbi.nlm.nih.gov/pubmed?term=The role of EEG in the diagnosis and classification of the epilepsy syndromes: a tool for clinical practice by the ILAE Neurophysiology Task Force (Part 1)

http://www.ncbi.nlm.nih.gov/pubmed?term=ILAE official report: a practical clinical definition of epilepsy

http://www.ncbi.nlm.nih.gov/pubmed?term=Operational classification of seizure types by the International League against Epilepsy

http://www.ncbi.nlm.nih.gov/pubmed?term=Instruction manual for the ILAE 2017 operational classification of seizure types

http://www.ncbi.nlm.nih.gov/pubmed?term=ILAE classification of the epilepsies: Position paper of the ILAE Commission for Classification and Terminology

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