Classification of Seizures (ILAE) By Syed Irshad Murtaza

ILAE Classification of seizures

By: Syed Irshad Murtaza

Technologist

CLINICAL NEUROPHYSIOLOGY

DEPARTMENT.14/15-10-2014

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

1410-2014Classification of Seizures By IM

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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 subclinical) seizure.

Classification of Seizures By: IM

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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.


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1410-2014

Definitions cont’d . . . • Aura:- 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.


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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”


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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.


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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

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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.


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Recommended terminology for etiology


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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)


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Origin of symptoms and signs in focal seizures - Visual display over the dominant hemispheres Classification of Seizures By: IM

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ILAE Classification of Seizures

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11-06-2012Classification of Seizures By: ML/CK

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• 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


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Seizures

Partial Generalized

Simple Partial

Complex Partial

Secondarily

Generalized

Localization of Partial Seizure Focus

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70%70%10%10%

20%20%

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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 Seizures By: IM17

Seizures

Partial Generalized

Simple Partial

With somatosensory

or special sensory symptoms

With motor signs

With autonomic

symptoms or signs

With psychic or

experiential symptoms


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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.

simple partial.wmv


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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


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Seizures

Partial Generalized

Complex Partial

Secondarily

Generalized

nwU_gFrO3uo.wmv


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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


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Absence Sz’s Cont’d. . .

• Absence seizures:- Simple (typical) absence or typical seizureComplex (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


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Absence Sz’s Cont’d. . .

Complex absence or Atypical seizures:-

• 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 .


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absence.wmv


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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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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.


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Hypsarrhythmia with increased inter-hemispheric synchrony

infantile.wmv


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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.


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gtc.wmv


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Tonic seizures:-

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.


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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.


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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 seizuresPossible 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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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.


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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.

•


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Semiology:

By the observable manifestations of the seizures, known as semiology.

OrThe 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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10-second EEGs: Seizure Evolution


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Normal Pre-Seizure

Seizure Onset Post-Seizure

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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• Thanks for the patience

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Health & Medicine

Classification of Seizures (ILAE) By Syed Irshad Murtaza