This document provides an overview of the ILAE classification of seizures. It begins with definitions of key terms like seizure, epilepsy, aura, etc. It describes the purpose of the ILAE classification system and how it categorizes seizures as either partial or generalized based on clinical manifestations and EEG findings. The classifications include simple and complex partial seizures as well as generalized seizure types like absence seizures, myoclonic seizures, and tonic-clonic seizures. Electrographic characteristics are also discussed for different seizure types. The document concludes with references for further information.

1. ILAE Classification of
seizures
By: Syed Irshad Murtaza
Technologist
CLINICAL
NEUROPHYSIOLOGY
DEPARTMENT.
13/14-10-2014

2. Study Outlines:-
 Definitions
 Purpose of the International Classification
of Seizures and Epilepsies
 Recommended terminology for etiology
 Recognition of seizures
 Classification of Seizures pictorial division
 Descriptive details of seizures
 References
13-10-2014
Classification of Seizures By IM
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3. Definitions:-
Seizure:-
1- An event of sudden abnormal excessive discharges of
electrical activity within the brain, which leads to a
change in movement, sensation or consciousness.
2- Its is an uncontrolled, synchronized paroxysmal
excitation of cortical neurons in the brain that results in
motor (body movements,) sensory (unusual sensation) &
autonomic (altered perception, hallucination etc)
manifestations.
3- A seizure is the manifestation of an abnormal,
hypersynchronous discharge of a population of cortical
neurons. This discharge may produce subjective
symptoms or objective signs, in which case it is a
clinical seizure, or it may be apparent only on an
electroencephalogram (EEG), in which case it is an
electrographic (or Classification subclinical) of Seizures By: IM
seizure.
3

4. Definitions cont’d . . .
Convulsions:-
Convulsions are violent
involuntary contractions of body
musculature.
In neurology, this term is limited to
contractions produced by cerebral seizure
activity.
Epilepsy:-
Epilepsy is defined as two or more
recurrent seizures unprovoked by systemic
or acute neurologic insults.
Classification of Seizures By: IM
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5. • Aura:- Definitions cont’d . . .
It’s the initial event, signaling the beginning
of seizure and it is part of the seizure.
• Epileptic prodrome:-
Its change in mode or behavior before
the seizure and could be in hours or days before
the seizure event.
Ictus or ictal phase:-
It’s a synonym word for seizure event.
Post-Ictus or Postictal Phase:-
Its Time after a Seizure; may experience
sensory, motor, or autonomic manifestations
and it usually lasts longer than the seizure itself.
Classification of Seizures By: IM
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6. Definitions cont’d . . .
• Interictal period:-
It’s the time period between two
successive seizure events.
• Status Epilepticus:-
1.It is described as the recurrence of seizures by
intervals too short to allow recovery of the
condition that existed before the onset of the
seizures.
2. *An episode of more than 05 minutes of
continuous seizure activity, or
3.*Two or more sequential seizures spanning
this period without full recovery between
seizures.
*American Epilepsy Society “Epilepsia USA”
Classification of Seizures By: IM
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7. Definitions cont’d . . .
• Epilepsia Partialis Continua:-
It is continuous and rather stereotype
repetition of one, fairly constant type of epileptic
activity, usually rhythmical jerking of a limb or of
part of a limb, or lower face etc may be with
mildly reduced alertness. It may be lasted for
weeks, months or years.
• It may be interrupted by discrete partial or
generalized seizures or may become less violent or
more restricted and even disappear intermittently.
Classification of Seizures By: IM
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8. Purpose of the International Classification of Seizures
and Epilepsies
• The seizers classification being most widely used is
proposed by the Commission on classification
and Terminology of the International League
Against Epilepsy(ILAE).
• Classification is necessary for;
 New terms & concepts with internationally
accepted terminology
 Standardization of the seizures types description
 New concepts regarding Focal and generalized
seizures
 Better adaptation of etiological terms
 Electro-clinical diagnosis for seizures etc
Classification of Seizures By: IM
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9. Cont’d. . .
How ILAE Defines/Categorized seizures?
ILAE defines Seizures types only in terms of
clinical manifestations & EEG findings,
▫ It differs from previous classifications
because it is based on the study of
videotape recordings of simultaneously
recorded EEG & clinical epileptic seizures.
Classification of Seizures By: IM
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10. Recommended terminology for etiology
Classification of Seizures By: IM
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11. SEIZURE RECOGNITION:-
• HOW TO RECOGNIZE SEIZURES:-
• Anatomical
(patient history help us to locate the
origin of discharge )
• Pathological
(infections or lesions help us to
reorganization of Sz)
• Clinical
(by self observation during seizure)
• Electro diagnostically
(by the help of EEG+VEEG recording)
Classification of Seizures By: IM
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12. 12
Origin of symptoms and signs in focal seizures - Visual display over the
dominant hemispheres Classification of Seizures By: IM

13. ILAE Classification of Seizures
13

14. Classification of Seizures 11-06-2012
By: ML/CK
14
Classification of Seizures By: IM
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15. • Partial Seizures:-
• Involve only part
of one cerebral
region or
hemisphere and
produce symptoms
in corresponding
parts of body or
some related
mental functions.
11-06-2012
15
Classification of Seizures
By: IM
Seizures
Partial Generalized
Simple Partial
Complex Partial
Secondarily
Generalized

16. Localization of Partial Seizure Focus
11-06-2012
2200%%
Classification of Seizures By: IM
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7700%% 1100%%
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17. Simple partial Seizures:-
• With somatosensory
or special sensory
symptoms
• Convulsion confine to
single limb ,
• Autonomic
manifestations
• Psychic or experiential
symptoms
• Symptoms with out
LOC
Classification of Seizure1s B7y: IM
Seizures
Partial Generalized
Simple Partial
With somatosensory
or special sensory symptoms
With motor signs
With autonomic
symptoms or signs
With psychic or
experiential symptoms

18. Classification 18 of Seizures By: IM

19. 19
Psychic auras often originate from the temporal lobe,
associated with simple partial seizures:
Psychic Aura Definition
Déjà vu: An illusion of a familiar memory
Jamais vu: When what should be a familiar visual experience becomes
unfamiliar
Déjà entendu: An auditory illusion of something familiar
Jamais entendu: When what should be a familiar auditory experience
becomes unfamiliar
Autoscopy: Seeing oneself in external space, as if the mind has left the
body
Derealization: A feeling of unreality of the outside world; the world seems
strange and unreal.
Depersonalization: A feeling of unreality in one’s sense of self; feeling as
if in a dream or watching oneself act
Macro-/Micropsia: Objects appear larger or smaller than usual
Macr-/Micracusia: Sounds are louder or softer than usual

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An epileptic disorder can be symptomatic, idiopathic, or
cryptogenic.
Symptomatic is a term that means the etiology is
known—usually a structural lesion within the brain.
Idiopathic is a term that refers to an epilepsy of
presumed genetic etiology without a structural brain
lesion or other neurological signs or symptoms. The
term has been replace by “genetic”
Cryptogenic is a term that refers to an
epilepsy that is presumed to be symptomatic but the
etiology is unknown (1989). The term
cryptogenic has been replaced by “probably
symptomatic”
The observable manifestation of the seizures, is known
as semiology.

21. Classification of Seizures By: IM
simple partial.wmv
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22. Complex Partial Seizures:-
• Complex partial seizure
• Often called temporal lobe
seizures.
• LOC
• Patient have no recollection
or incomplete memory of
events that occurred during
seizures
Partial Sz with secondary
generalization.
• When a seizure start focally
and spread to the whole
limb or become generalized,
it is called Jacksonian
march or partial seizure
with secondary
generalization.
11-06-2012
Classification of Seizures
By: IM
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Seizures
Partial Generalized
Complex Partial
Secondarily
Generalized

23. Classification of Seizures
By: IM
nwU_gFrO3uo.wmv
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24. Generalized Seizures
• GENERALIZED SEIZURES.
• • Seizures that occur on bilateral limbs and with out
focal onset are grouped as generalized seizures.
TYPES OF GENERALIZED SEIZURE.
1.Absence (Petit mal Seizures)
• Usually occur in childhood and rarely persist
into adult hood
• Impairment of consciousness
• With mild clonic component
• With also atonic and tonic component
• With automatisms
Classification of Seizures By: IM
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25. Absence Sz’s Cont’d. . .
• Absence seizures:-
Simple (typical) absence or typical seizure
Complex (atypical) absence or atypical seizure
Simple absence or Typical seizures
 Impairment of consciousness
 Some patient retain awareness during the attacks
but cannot respond with movement or speech.
 Attacks are triggered by hyperventilation and photic
stimulation
 Seizures lasted in seconds
 Background usually normal during interictal phase.
 Typical EEG findings 3 Hz spike & waves discharges
with abrupt onset and off set & clinically consistent
with unresponsiveness and eyes staring or blinking.
 Findings are bilaterally symmetrical
Classification of Seizures By: IM
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26. Classification of Seizures By: IM 26

27. 27

28. Absence Sz’s Cont’d. . .
Complex absence or Atypical seizures:-
28
• Brief episodes of LOC
• Including mild clonic component
• Reduction in body tone
• Seizures durations are in minutes
• EEG background usually abnormal during interictal
phase.
• EEG findings are more heterogeneous, may include
irregular spike-&-slow-wave complexes (2-4Hz), fast
activity or other paroxysmal activity.
• Abnormalities are bilateral but often irregular and
asymmetrical .
Classification of Seizures By: IM

29. Classification of Seizures By: IM
absence.wmv
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30. 3.Myoclonous seizures:-
• In Myoclonic seizures clinically single or multiple
repetitive jerks are noted
• It mainly occur during sleep and when patient
wake up from sleep early in morning.
• It consists of isolated or Gen. body jerks for few
seconds
• EEG findings include spikes, polyspikes, sharp-&-
slow waves complexes are seen.
• Absence component may be present in the seizures
manifestation
• Generally hyperventilation & especially photic
stimulation activation maneuvers are provoking
measures of ictal or interictal abnormalities .
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Classification of Seizures By: IM

31. 31
Classification of Seizures By: IM

32. Classification of Seizures By: IM
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33. SALAAM ATTACKS:-
• 4.Infantile spasm/ salaam spells
• Sudden flexor spasm of trunk, Extension of arm,
Drawing up of legs, quick nodding or jack-knife
movements of the body are noted.
• Usually occur in the age of 3-9months
• Last up till the age of 3yrs
• After that patient became mentally retarded.
• EEG findings showed chaotic background, with
multifocal, independent and burst suppression like
epileptic form complexes.
• West syndrome is the classical triad of infantile
spasms, hypsarrythmia (a typical EEG Pattern) and
mental retardation.
Classification of Seizures By: IM
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34. 34
Classification of Seizures By: IM
Hypsarrhythmia with increased inter-hemispheric
synchrony

35. Classification of Seizures
By: IM
infantile.wmv
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36. 36
Classification of Seizures
CLONIC SIZURES:-
5.Clonic seizures
• Clonic seizures consist of generalized
rhythmical myoclonic movements which
usually last for 1 min or more and are
associated with loss of consciousness.
• These seizures commonly occur as febrile
Seizures in childhood
• EEG findings may include spikes, polyspikes-&-
wave complexes in ictal or interictal period.
By: IM

37. Classification of Seizures By: IM
gtc.wmv
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38. Tonic seizures:-
Classification of Seizures By: IM
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6.Tonic seizures
• Tonic means stiffening
• Tonic seizures consist of contractions of the axial
musculature of the entire body and produce
flexor positions. They usually last up to 1 min &
are associated with loss of consciousness.
• EEG background is often abnormal for age.
Rhythmic discharges are seen in ictal or interictal
phase.

39. 39
Tonic clonic seizures (grand mal seizures):-
7.Tonic clonic seizures (grand mal seizures)
• Tonic clonic seizures are the most severe form of
Generalized seizure in adults
• They begin suddenly with loss of consciousness
• & sometime preceded by shrill cry
• Frothing, up rolling of eyes, jerking of limbs,
urinary & fecal incontinence may occur in these
seizures.
• EEG findings may include rhythmic decreasing in
frequency and increasing in amplitude during
tonic phase, interrupted by slow waves during
clonic phase.
Classification of Seizures By: IM

40. Atonic seizures:-
8. Atonic seizures;-
 Consists of sudden loss of muscle tone.
 Sudden droop or fall attack
 May be associated with Myoclonic jerks to
form Myoclonic atonic seizures
Possible EEG findings:-
• Generalized spikes, polyspikes, sharp and
slow waves complexes.
• Epileptic burst suppression pattern could be
found in EEG recording during , between or after
seizure event.
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Classification of Seizures By: IM

41. Classification of Seizures
By: IM
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42. UNCLASSIFIED EPILEPTIC SEIZURES
• This category includes all seizures that cannot
be classified because of inadequate or
incomplete data and some that defy
classification in hitherto (Until now) categories.
• This includes some neonatal seizures e,g
rhythmic eye movements, chewing and
swimming movements.
Classification of Seizures By: IM
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43. ADDENDUM:-
• Repeated epileptic seizures occur under a variety of
circumstances.
• As fortuitous (Accidental) attacks coming unexpectedly
and without any apparent provocation.
• As cyclic attacks at more or less regular intervals
• As attacks provoked by non sensory factors or sensory
factors sometimes referred to as reflex seizures.
• Prolonged or repetitive seizures. The term status
epilepticus is used whenever a seizure persists for a
sufficient length of time or is repeated frequently
enough that recovery between attacks does not occur.
Status epilepticus may be divided into partial or
generalized. When much localized motor status occurs
it is referred to as epilepsia patialis continua.
•
Classification of Seizures By: IM
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44. Semiology:
By the observable manifestations of the seizures,
known as semiology.
Or
The appearance/morphology and
clinical/electrographical activity which can be
determined/categorized in a specific/organized
way, would be termed as semiology.
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45. 10-second EEGs: Seizure Evolution
Classification of Seizures By: IM
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Normal Pre-Seizure
Seizure Onset Post-Seizure

46. References:-
• Fisch & Spehlmann’s EEG Primer By Bruce J.Fisch, M.D
• ILAE Classification of Seizures Journal “Epilepsia”.
• A Clinical Approach to the Classification of seizures &
the epileptics Syndromes by Luder & R.Lesser (Eds).
• Primer of EEG With a Mini-Atlas By James Rowan M.D
• Ernst Niedermeyer (Basics of Electroencephalography)
4th edi
• Abu Khalil (EEG atlas)
• Practical Guide for Clinical Neurophysiologic
Testing: EEG by Thoru Yamada & Elizabeth Meng
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Classification of Seizures By: IM

47. • Thanks for the patience
Classification of Seizures By: IM
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