TERMINOLOGY AND DEFINITIONS
It is critical to differentiate between epilepsy, epilepsy syndrome, and seizure types and acknowledge that these are different entities.
Seizure: Hughlings Jackson was among the first to outline the distinction between seizures and epilepsy. According to Jackson, “A convulsion is but a symptom, and implies only that there is an occasional, an excessive, and a disorderly discharge of nerve tissue on muscles. This discharge occurs in all degrees; it occurs with all conditions of ill health, at all ages, and under innumerable circumstances” (6). This definition has not changed in the last 150 years. According to the ILAE, an epileptic seizure “is a transient occurrence of signs and/or symptoms due to abnormal excessive or synchronous neuronal activity in the brain.” Defining features include “mode of onset and termination, clinical manifestations, and abnormal enhanced synchrony” (7).
Epilepsy: The term epilepsy initially characterized both the disease and its attacks (8). An operational definition was provided 20 years ago by the ILAE: “A condition characterized by recurrent (two or more) epileptic seizures, unprovoked by any immediate identified cause. Multiple seizures occurring in a 24-h period are considered a single event. An episode of status epilepticus is considered a single event. Individuals who have had only febrile seizures or only neonatal seizures as herein defined are excluded from this category” (9). In 2005, the ILAE attempted to provide a conceptual definition although the report may have overstated this summary in referring to this as an operational definition: “epilepsy is a disorder of the brain characterized by an enduring predisposition to generate epileptic seizures and by the neurobiologic, cognitive, psychological, and social consequences of this condition. The definition of epilepsy requires the occurrence of at least one epileptic seizure. Elements in the definition of epilepsy include history of at least one seizure, enduring alteration in the brain that increases the likelihood of future seizures, and associated neurobiologic, cognitive, psychological, and social disturbances” (7). Most recently in 2014, the epilepsy definition was revised and now includes “(1) At least two unprovoked (or reflex) seizures occurring >24 h apart; (2) one unprovoked (or reflex) seizure and a probability of further seizures similar to the general recurrence risk (at least 60%) after two unprovoked seizures, occurring over the next 10 years; (3) diagnosis of an epilepsy syndrome” (10).
Epilepsy Syndrome: The concept of epilepsy syndromes was introduced over many years and was firmly ensconced in the ILAE report of 1989. An epilepsy syndrome is defined as “a complex of signs and symptoms that define a unique epileptic condition. This must involve more than just a seizure type: thus frontal lobe seizures per se, for instance, do not constitute a syndrome” (11). The ILAE furthermore distinguishes epileptic diseases, which are defined as “a pathologic condition with a single, specific, well-defined etiology. Thus progressive myoclonic epilepsy is a syndrome, but Unverricht-Lundborg is a disease” (11).
EARLY ILAE CLASSIFICATIONS
The first ILAE classification in 1969/1970 (1,2) distinguished primary or secondary epilepsy (based on identification of causes but largely in association with neurodisability) and partial or generalized (based on seizure manifestations). If the cause was not known, the term “primary” was used, whereas “secondary” alluded to a known cause. “Partial” indicated onset from a focal area in the brain, either based on semiologic features or based on clinical evaluation, and generalized included epilepsy with no clear single area of onset in the brain.
The 1981 seizure classification (4) further distinguished seizures into partial or generalized and took into account more than two types of features for a given partial or generalized seizure. Specifically, the classification outlined partial and generalized seizures. Among partial seizures, simple partial, complex partial, and secondary generalized seizures were recognized. Among generalized seizures, absence, myoclonic, atonic, tonic, and tonic–clonic seizures were included.
Partial seizures could be “simple” and “complex” depending on the preservation or loss of consciousness during the events. Secondarily generalized was used, when a partial seizure spreads and involves the whole brain (and both sides of the body simultaneously with loss of consciousness). Generalized epilepsies were characterized by specific seizures in the form of absence (i.e., staring spells), myoclonic (muscle jerks), loss of tone (atonic), increased tone (tonic), and tonic plus clonic movements. Notably, epileptic spasms were excluded from this classification.
A revised epilepsy classification was published in 1985 (5). Because the term secondary generalized epilepsy was sometimes confused with the different concept of “secondary” or “secondarily” generalized tonic–clonic seizures, it was abandoned in the subsequent revision. The terms primary and secondary were replaced with idiopathic (there is no cause except a possible genetic predisposition), symptomatic (the epilepsy is secondary to an underlying disorder of the brain), and cryptogenic (the cause is not known but presumed to be symptomatic). Both terms were applied to partial and generalized epilepsies. Furthermore, the recognition of “benign” rolandic epilepsy necessitated a category of “primary partial” epilepsies. Furthermore, this publication introduced the new concept of epilepsy syndromes as “Epileptic disorder characterized by a cluster of signs and symptoms customarily occurring together.”
THE 1989 ILAE CLASSIFICATION
The 1989 ILAE epilepsy classification is used worldwide and is reproduced in the appendix to this chapter. It was revised from proposals made in 1970 (1,2) and 1985 (5) and, like the 1981 ILAE seizure classification (4), is based primarily on the definition of electroclinical syndromes. In 1969, Henri Gastaut proposed the first classification of epilepsies (2), which was used as the basis of the first ILAE epilepsy classification system that was proposed one year later (1). This classification provided the major division between “partial” (focal) and generalized epilepsies. Each seizure type was grouped according to this dichotomy and associated with interictal and ictal electroencephalographic (EEG) findings, etiology and pathologic findings, and age of manifestation.
About 15 years later, a revision introduced the concept of epilepsy syndromes “defined as an epileptic disorder characterized by a cluster of signs and symptoms customarily occurring together. The signs and symptoms may be clinical (e.g., case history, seizure type, modes of seizure recurrence, and neurologic and psychological findings) or as a result of findings detected by ancillary studies (e.g., EEG, x-ray, CT [computed tomography], and NMR [nuclear magnetic resonance])” (5). This revision divided many specific epilepsy syndromes under the major dichotomy of generalized and “localization-related” (focal) epilepsies and associated them with clinical and EEG findings, etiologies, and disease severity.
The primary dichotomy of these classification systems was set between localization-related (focal) epilepsies, “in which seizure semiology or findings at investigation disclose a localized origin of the seizures” (3), and generalized epilepsies, characterized by “seizures in which the first clinical changes indicate initial involvement of both hemispheres… [and] the ictal encephalographic patterns initially are bilateral” (3). EEG findings are the laboratory results that carry the most weight for defining a focal epilepsy syndrome.
In addition to localizing information, previous epilepsy classifications also contained etiologic information. The 1970 epilepsy classification (1) further divided the generalized epilepsies into primary, those occurring in the setting of normal neurologic status, with seizures that begin in childhood or adolescence and lack any clear cause, and secondary, those involving abnormal neurologic or psychological findings and diffuse or multifocal brain lesions. Because the term secondary generalized epilepsy was sometimes confused with the different concept of “secondary” or “secondarily” generalized tonic–clonic seizures, it was abandoned in the 1985 (5) and 1989 (3) revisions. Primary and secondary were replaced with idiopathic and symptomatic. The 1970 classification (1) applied the etiologic dichotomy only to generalized epilepsies because all focal epilepsies were assumed to be associated with some type of brain lesion. This did not include the idiopathic syndrome of benign epilepsy of childhood with centrotemporal spikes, and therefore, the 1985 (5) and 1989 (3) revisions applied idiopathic and symptomatic to the focal epilepsies as well. The term cryptogenic was added in the 1989 (3) classification to describe epilepsy syndromes that are presumed to be symptomatic but are of unknown cause in specific patients.
In spite of its widespread use, the 1989 proposal has been criticized because of its separation between “partial” and “generalized” epilepsies, and therefore, it does reflect our growing appreciation for the complex manifestations of epilepsy in the brain or how that can change over time, especially in the developing brain. Furthermore, the terms “idiopathic,” “cryptogenic,” and “symptomatic” are based on assumption and lack of knowledge rather than actual evidence. Now that the ability to collect the necessary evidence has developed, those assumptions are being called into question. Additionally, the system accommodates didactic grouping purposes but has limitation when used in clinical practice during the process of data acquisition: A working diagnosis is usually assigned first, and subsequently, etiologies are explored. A final diagnosis and classification is frequently not possible before workup was completed. Furthermore, the systems description of seizure semiology is limited and is thought to mingle seizure semiology and epilepsy type or syndrome and only allows a strict one-to-one relationship between seizure type and epilepsy. In all, the 1989 classification rests on concepts developed over the past century and does not readily incorporate our rapidly expanding knowledge about the causes and manifestations of epilepsy afforded to us by advances in neuroimaging, molecular cell genetics, neuroimmunology, and other fields.
SEMIOLOGIC SEIZURE CLASSIFICATION
A seizure classification based only on clinical semiology, so-called semiologic seizure classification, was proposed by Hans Lüders et al. in the late 1990s (12,13). This considered the following clinical seizure features:
1. Auras: Ictal manifestations having sensory, psychosensory, and experiential symptoms.
2. Autonomic seizures: The main ictal manifestations are objectively documented autonomic alterations.
3. “Dialeptic” seizures: Their main ictal manifestation is an alteration of consciousness independent of ictal EEG manifestations. The term “dialeptic” seizure has been introduced to distinguish this concept from absence seizures (as dialeptic seizures with a generalized ictal EEG) and complex partial seizures (as dialeptic seizures with a focal ictal EEG).
4. Motor seizures: Motor symptoms and are subclassified as simple or complex. Simple motor seizures are characterized by simple, unnatural movements that can be triggered by electrical stimulation of the primary and supplementary motor area (such as myoclonic, tonic, clonic and tonic–clonic, versive seizures). Complex motor seizures are characterized by complex motor movements resembling natural movements but occurring in an inappropriate setting (definition of “automatisms”).
5. Special seizures: Seizures characterized by “negative” features (so named atonic, astatic, hypomotor, akinetic, and aphasic seizures). The semiologic seizure classification identifies in detail the somatotopic distribution of ictal semiology and seizure evolution and paved the way for an ILAE glossary of seizure semiology.
GLOSSARY OF SEIZURE SEMIOLOGY
Terms from the semiologic seizure classification were incorporated in an ILAE glossary of seizure semiology terms in 2001 (11). This glossary delineates descriptive terms that provide additional details on clinical seizure presentation. The glossary contained terms for reference to semiology, as well as terms for indicating seizure timing and duration, severity, prodromes, and postictal phenomena. According to this glossary, seizures can be termed “motor” when they involve musculature in any form. The motor event could consist of an increase (positive) or decrease (negative) in muscle contraction to produce a movement. Seizures can be called “tonic” when consist in a sustained increase in muscle contraction lasting a few seconds to minutes; “atonic” when appearing as a sudden loss or diminution of muscle tone without apparent preceding myoclonic or tonic event lasting 1 to 2 seconds, involving the head, trunk, jaw, or limb musculature; or “myoclonic” if they present with a sudden, brief (usually <100 milliseconds) involuntary single (or multiple) contraction of muscles or muscle groups of variable topography. The term “clonic” was used to refer to myoclonus that is regularly repetitive, involves the same muscle groups at a frequency of about 2 to 3 Hz, and is prolonged. “Tonic–clonic” refers to a sequence consisting of a tonic followed by a clonic phase (14). The glossary also contains details on automatisms and associated features of semiology. The term “automatism” is recommended for a more or less coordinated, repetitive, motor activity mostly occurring when cognition is impaired. Automatisms often resemble a voluntary movement and may consist of an inappropriate continuation of ongoing preictal motor activity. Lip smacking, lip pursing, chewing, licking, teeth grinding, and swallowing are termed “oroalimentary” (14). The term “dyscognitive” refers to events in which [1] disturbance of cognition is the predominant feature, and [2a] two or more of the components of cognition are involved, or [2b] involvement of such components is undetermined. Components of cognition were defined as follows:
1. Perception: symbolic conception of sensory information
2. Attention: appropriate selection of a principal perception or task
3. Emotion: appropriate affective significance of a perception
4. Memory: ability to store and retrieve percepts or concepts
5. Executive function: anticipation, selection, monitoring of consequences, and initiation of motor activity including praxis and/or speech
2001 ILAE PROPOSAL: A SYNDROME-ORIENTED CLASSIFICATION
To resolve these existing controversies surrounding the 1989 epilepsy classification, the ILAE’s Commission on Classification and Terminology published a common terminology for ictal semiology (14) and a revised five-axis classification scheme of epilepsies (11). This proposal (11) was also based on epilepsy syndromes that appeared in previous classifications. The authors defined an epileptic syndrome as “[a] complex of signs and symptoms that define a unique epilepsy condition” (11). However, due to ongoing discussions, this proposal was again revised and another progress report was issued 5 years later (15).
Axes of the 2001 ILAE Proposal
The different axes in the 2001 ILAE proposal included seizure description (axis 1), seizure type (axis 2), epilepsy syndrome (axis 3), etiology (axis 4), and impairment (axis 5).
Axis 1 described ictal seizure semiology through a standardized glossary of descriptive ictal terminology (14). This terminology was independent of pathophysiologic mechanisms, epilepsy focus, or seizure etiology.
Axis 2 was based on a list of accepted epileptic seizure types constructed by the task force. These seizure types were closely related to diagnostic epilepsy entities or indicated underlying mechanisms, pathophysiology, or etiology or implicated related prognosis and therapy.
Axis 3 identified the epilepsy syndrome diagnosis and separated epilepsy syndromes from entities with epileptic seizures. Epilepsy syndromes were divided into “syndromes in development” and fully characterized syndromes (16).
Axis 4 delineated the etiology of epilepsies, which included pathologic and genetic causes as well as diseases frequently associated with epilepsy, and this list was a work in progress at the time of publication.
Axis 5 was incomplete at the time of publication and was intended to include an optional classification of the degree of disability and impairment caused by the epilepsy.
Compared with the 1989 version of epilepsy classification, the diagnostic scheme of the 2001 proposal attempted to overcome shortcomings among EEG features, clinical seizure semiology, and syndromic classification efforts. By dividing the seizure classification into several axes, the ILAE responded to the criticism that a strict one-to-one relationship is lacking between epilepsy syndromes and seizure types. The introduction of a multiaxial diagnostic scheme reflected the recognition of epilepsy as a clinical symptom that can manifest with different semiologic seizure types and be intertwined with different etiologies. It also tried to respond to criticism that seizure semiology was not sufficiently emphasized in previous classifications. Furthermore, it tried to address the more and more confluent borders between generalized and focal epilepsies. The term partial was replaced by focal. Additionally, it attempted to model epilepsy syndromes more flexible by defining “accepted syndromes” versus “syndromes in development.” However, critics highlighted an incomplete and preliminary presentation, lack of inclusion criteria for “accepted” syndromes, redundancy among classification axes, lack of information on age of onset, and inability to use this classification in all patients and lack of applicability (17–20). Due to ongoing discussions, the ILAE core group on classification revised this approach and provided an update in 2006 (15).
THE 2006 REPORT OF THE ILAE CLASSIFICATION CORE GROUP
This proposal aimed to outline “scientifically rigorous criteria for identification of specific epileptic seizure types and specific epilepsy syndromes as unique diagnostic entities” (15). Criteria included epileptic seizure types, age of onset, progressive nature, interictal EEG, associated interictal signs and symptoms, pathophysiologic mechanisms, anatomical substrate, and etiologic categories, as well as genetic basis. Subsequently, the group scored epilepsy syndromes listed in the 2001 proposal on a scale from 1 to 3, with 3 being the most clearly and reproducibly defined. The proposal mentioned that this was a very preliminary method and intended to ignite further research and category suggestions or possible cluster analysis of signs and symptoms (15). Based on this proposal, epilepsy syndromes could be assigned in up to 70% of cases in a first comparison (21). However, persistent inter- and intra-axial discordance was noted necessitating further revision in 2010.
THE 2010 REVISED TERMINOLOGY AND CONCEPTS FOR ORGANIZATION OF SEIZURES AND EPILEPSIES
This additional update is an “interim organization” and tries to address ongoing criticisms to concepts and terminology (22). Classification is not treated as a rigid doctrine but a guide to summarize our current understanding about seizures and epilepsies in a useful manner. This revision includes the concept of electroclinical syndromes and essentially leaves the suggested syndrome list from 2006 unchanged although it incorporated additional, well-documented syndromes (22). It also addresses the variable degrees of precision of diagnosis and attempts to include the natural evolution. Epilepsies are now organized by specificity into three major divisions of electroclinical syndromes, nonsyndromic epilepsies with structural–metabolic causes, and epilepsies of unknown cause. This organization allows further description within divisions by dimensions as previously suggested (17). These may include cause, seizure types, age at onset, and others. Furthermore, it emphasizes the descriptive seizure terminology from 2001 (14) within these dimensions, specifically for focal epilepsies. Seizures are now recognized as “occurring in and rapidly engaging bilaterally distributed networks (generalized) and within networks limited to one hemisphere and either discretely localized or more widely distributed (focal)” and terms such as complex partial and simple partial have been abandoned. It also rekindles the terminology “focal” and differentiates from “generalized” seizures, while recognizing that generalized epileptic seizures do not necessarily include the entire cortex. Suggested etiologic concepts within the causal dimension include genetic, structural–metabolic, and unknown replacing idiopathic, symptomatic, and cryptogenic. Further changes in terminology and classification remain work in progress.
DO NOT CLASSIFY—DIAGNOSE!
While the ILAE efforts still continue to revise this epilepsy classification, clinicians continue to take care of epilepsy patients and make clinical epilepsy diagnoses, largely unaffected by the Ivory Tower, theoretical discussions, and deliberations on epilepsy classification. Like any other neurologic condition, the general neurologic diagnostic approach to diagnosis of characterizing the clinical presentation (namely, the seizures), followed by localization in the CNS, and investigating underlying etiologies and comorbidities can also be applied to epilepsy. The diagnostic approach to seizures and epilepsy involves five independent steps:
1. How old is the patient?
2. Is it epilepsy?
3. What is the clinical presentation? (What are the seizure symptoms/the neurologic exam findings/cognitive or developmental status?)
4. What are the results of investigational tests?
5. Can you localize the source of the seizures, can you identify one or several epilepsy causes, or can you identify an epilepsy syndrome? (Is there a functional or structural lesion and if so, where is it? Is there a genetic factor? A vascular, infectious, toxic, autoimmune, metabolic, idiopathic/unknown, neoplastic, congenital, degenerative, and endocrine component (mnemonic: VITAMIN CDE)? This process requires comparison of all collected evidence in the setting of previously described findings and literature categories. Interpretation of above collected clinical findings and test results may allow localization or syndrome diagnosis. Also, are there other related features that may assist with diagnosis making or fit with known syndromes? Ongoing synopses of independent investigational techniques include synthesis and integration of all results into a working and ultimately final diagnosis during the process of collection of a detailed history and clinical course, seizure semiology analysis either by history or video review, physical examination, electrophysiologic studies, structural neuroimaging and functional and metabolic neuroimaging, and laboratory testing including genetic and histopathologic studies, and these studies aid in answering the questions outlined above.
1. How Old Is the Patient?
Perhaps the single most important overriding factor in the diagnosis of a patient with epilepsy is the age at onset. This is because different types of epilepsies, seizures, and causes of epilepsy manifest at different ages. If one begins with age, the field of diagnostic possibilities rapidly simplifies and one can focus on a relatively restricted range of possibilities. That said, there are fundamental principles to guide diagnosis at any age.
2. Is It Epilepsy?
Any given patient may present with nonepileptic seizures. Therefore, it is always crucial to consider the option that events may be nonepileptic. The differentiation between epileptic and nonepileptic events is often challenging. Video–EEG monitoring can help capture clinical semiology and an EEG correlate—or lack thereof. In infants and children, overdiagnosis of epilepsy is often seen in the context of breath-holding spells, gastroesophageal reflex, excessive startling, or parasomnias among others. In older adolescents and adults, a phenomenon known as nonepileptic (sometimes psychogenic) seizures is seen. This is a conversion disorder and ideally should result in the involvement of a psychiatrist.
Diagnosis is recognized as an ongoing interactive and iterative process. Once further evidence and results become available, patients can be diagnosed with an increasing degree of precision or results may inform further, more targeted testing. If it is uncertain whether the patient has epilepsy or nonepileptic seizures, we prefer the term paroxysmal event. As further information becomes available through the steps outlined previously (e.g., an electroencephalogram [EEG] demonstrating left mesial temporal sharp waves, left temporal EEG seizures, and an MRI showing left hippocampal atrophy), the diagnosis becomes more precise (left mesial temporal lobe epilepsy). Therefore, it is helpful to document progress in diagnostic workup and diagnosis as well as a revised diagnostic hypothesis with every patient encounter. Additional details on localizing and lateralizing evidence of clinical seizures as well as diagnostic syndromic features are also outlined in several other chapters in this book.
3. What Is the Clinical Presentation?
A detailed account of the episodes in question is crucial. Specific questions may focus on who witnessed the event, when and where events occur, whether they are triggered by external stimuli, how they begin, how they evolve, and how they end, which are essential to determining the type of seizure.
The seizure setting includes a reliable witness who can provide a detailed account of the event in question. Alternatively, a video recording of the event may also be extremely helpful, especially in circumstances if the patient cannot recall the event or parts of the event. Emphasis should also be placed on the immediate period prior to the seizure, as a detailed account of that time period may reveal potential seizure triggers or prodrome. Examples may include the patient’s baseline activity, changes in the setting or patient behavior immediately before the event (i.e., occurrence out of sleep), or clinical symptoms that the patient experienced prior to seizure onset, such as a headache or fever.
Onset: Detailed reconstruction of the seizure onset may divulge further information about potential auras, although auras do not necessarily need to be present. However, the first clinical symptom often provides most information regarding the ictal onset zone and epileptogenic zone as the initial symptomatogenic zone is usually closest to the actual seizure onset (23).
Evolution: Further clinical seizure features and evolution may present with a variety of different presentations, including motor, language, automatisms, autonomic manifestations, and alteration of consciousness among others. The clinical signs and symptoms are the most important pieces of information for localizing a lesion in the central nervous system (23). Seizures and seizure semiology are the clinical manifestation of epilepsy. The ILAE epilepsy terminology from 2001 (14), based on clinical seizure descriptions (12,13,24–29), provides a helpful framework for this description. This glossary uses only the clinical semiology and does not require any additional diagnostic techniques other than analysis of an observed or videotaped seizure. Of note, data from other investigational techniques, such as EEG, MEG, MRI, or nuclear imaging, are not necessary to utilize the glossary.
Postictal: Events that happen after the seizure may also provide additional information. Lateralizing signs, such as postictal hemiparesis (Todd palsy) or postictal nose wiping, may continue to provide additional clinical information.
In between and after seizures, the physical examination can add information regarding etiology, type of epilepsy, and epilepsy syndrome (i.e., a hemiparesis may point toward a large hemispheric lesion; progressive hemiparesis over time may implicate a tumor or Rasmussen encephalitis in the appropriate clinical setting) (23).
Frequency, patterns, and seizure clusters: It may also be crucial to inquire about seizure frequency; seizure patterns, such as predominant occurrence at night; or seizure occurrence in clusters, as seen during epileptic spasms.
4. What Are the Results of Investigational Tests?
An EEG helps in the evaluation of seizure type and localization and possible diagnosis of an epilepsy syndrome and aids in the estimation of seizure recurrence risk. Activation procedures (hyperventilation, photic stimulation, sleep/sleep deprivation) can be performed to provoke epileptiform abnormalities (23).
Neuroimaging, including MRI, can investigate a possible cause of seizures, such as the identification of a structural abnormality. In general, as a practical guideline, persistent postictal focal deficits and the lack of return to baseline within a few hours after a seizure should suggest the need of neuroimaging to rule out additional neurologic structural lesions.
Further investigations to determine the etiology of seizures including genetic testing through laboratory blood tests may also be considered if clinically indicated.
5. Do the Presentation and Investigational Findings Fit with a Specific Epilepsy Localization, Known Genetic Cause, or Well-Described Epilepsy Syndrome?
Seizures are caused by the co-occurrence of multiple triggering factors. On the basis of investigational methods used to determine the cause of the epilepsy (e.g., histopathology, metabolic testing, MRI imaging, genetic testing) or localization to a certain area in the brain, factors responsible for the generation of seizures can be found simultaneously at different diagnostic levels. To account for multiple coexisting etiologic factors, the etiology dimension permits the classification of several factors in one patient. Other diagnostic techniques, such as genetics, have led to the identification of other coexisting causes and, with the results from further research in newer fields, will gain in importance in the future. A large proportion of children with epilepsy and a smaller proportion of adults have epilepsies that may fit criteria for specific electroclinical syndromic diagnoses. Such diagnoses are not independent of any of the other features discussed above, but they do provide a clinical gestalt that allows some confidence regarding the preferred treatments, likely neurologic consequences, and long-term outcomes for the patient. These syndromes are addressed in several different chapters in this text.
CONCLUSION
The classification of epilepsies is an ongoing process. While the terminology of the 1989 ILAE proposal (3) is in widespread use (and is reproduced here as an Appendix), it does not reflect the current approach, terminology, and concepts used in the contemporary diagnosis and treatment of patients with epilepsy. Newer proposals attempt to provide adjust for scientific progress and implement language that directly applies the advances from neuroimaging, genetics, and other areas of neuroscience to the patient and—in doing so—provide a transparent translation of discoveries to patient care. While the classification of epilepsy continues to be revised, we urge the readers not to waste time with classification, but to diagnose their patients, to be able to provide the most appropriate treatment. The general neurologic approach of seizure description, localization and etiology, and comorbidity confirmation works also well in epilepsy, in particular when approaching and diagnosing a new epilepsy patient.
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CHAPTER 9 APPENDIX PROPOSAL FOR REVISED CLASSIFICATION OF EPILEPSIES AND EPILEPTIC SYNDROMES
(COMMISSION ON CLASSIFICATION AND TERMINOLOGY OF THE INTERNATIONAL LEAGUE AGAINST EPILEPSY 1989). REPRODUCED WITH PERMISSION FROM EPILEPSIA. 1989;30:389–399.
PART I: INTERNATIONAL CLASSIFICATION OF EPILEPSIES AND EPILEPTIC SYNDROMES
1. Localization-related (focal, local, partial) epilepsies and syndromes
1.1 Idiopathic (with age-related onset)At present, the following syndromes are established, but more may be identified in the future:
- Benign childhood epilepsy with centrotemporal spike
- Childhood epilepsy with occipital paroxysms
- Primary reading epilepsy
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