EPILPSY“7”

Presented By:

Dr. Raed Ahmed MBChB , FIBMSNeurologist

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Introduction

Terms seizure and epilepsy are not synonymous

Epilepsy : chronic brain disorder of various aetiologies

characterized by two or more unprovoked seizures

Seizure : a paroxysmal event due to abnormal excessive or

synchronous neuronal activity in the brain.

Convulsion : abnormal movement associated with epileptic

event

‘Sacred illness’

• ‘Sacred illness’: 600 BC

• A seizure (from the Latin sacire , “to take possession of ”)

• Hippocrates 400 BC: It is thus with regard to the disease called

sacred: it appears to me to be in no way more divine nor more

sacred than other diseases [...].

The brain is the cause of this affliction [...].

Alexander the Great Julius Caesar Napoleon

Epidemiology

• Epilepsy is common

• Prevalence of epilepsy: 0.5-1%

• Incidence of epilepsy: 40 - 70/100,000/year

• Lifetime risk of having a single seizure is 5%. , with

the highest incidence occurring in early childhood

and late adulthood.

• Its prevalence is 5 times higher in developing than

developed (0.5%) countries, and the incidence is

doubled.

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Pathophysiological classification of seizures

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• Balance between excitation and inhibition,

• Inhibitory (GABA) acting on ion channels to

enhance chloride inflow and reduce the chances of

action potential formation.

• Excitatory amino acids (glutamate and aspartate)

allow influx of sodium and calcium, producing the

opposite effect.

• Seizures result from an imbalance between this

excitation and Inhibition predisposing to recurrent

action potentials.

Seizures VS Epilepsy

Non-epilepsy

Drug-related

metabolic

Toxic

Febrile

Cardiovascular

Poison

Pseudo-seizures

Epilepsy

(recurrent)

Idiopathic Symptomatic

(primary) (secondary)

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Clinical presentations of epilepsy

• Loss of awareness• Generalized convulsive movements• Drop attacks• Transient focal motor attacks• Transient focal sensory attacks• Facial muscle and eye movements• Psychic experiences• Aggressive or vocal outbursts• Episodic phenomena in sleep• Prolonged confusional or fugue states

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The International League Against Epilepsy (ILAE) Classification of Seizure Type

I. Partial (focal, local) seizures

A. Simple partial seizures

• 1. With motor signs

• 2. With somatosensory or special sensory symptoms

• 3. With autonomic symptoms or signs

• 4. With psychic symptoms

B. Complex partial seizures

• 1. Simple partial onset followed by impairment of consciousness

• 2. With impairment of consciousness at onset11

ILAEC. Partial seizures evolving to secondarily generalized seizures (tonic–clonic, tonic, or clonic)• 1. Simple partial seizures evolving to generalized

seizures• 2. Complex partial seizures evolving to generalized

seizures• 3. Simple partial seizures evolving to complex partial

seizures evolving to generalized seizuresII. Generalized seizures (convulsive and non-convulsive)• A. Absence seizures (typical , atypical )• B. Myoclonic seizures • C. Clonic seizures • D. Tonic seizures• E. Tonic–clonic seizures F. Atonic seizuresIII. Unclassified epileptic seizures 12

Simple partial seizures

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Simple partial seizures

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Complex partial seizures A common seizure type in adulthood

Origin is most often in the temporal lobe

Temporal >> frontal > parietal or occipital

Can be introduced by a simplex partialpsychosensory seizure: olfactory hallucination

déjà vu (familiarity), jamais vu (unfamiliarity)

feeling of alienation

Loss of consciousness: stare, ‘going blank’

Automatisms:involuntary complex motor activity during impaired consciousness .

Examples are gum chewing, nose wiping, drinking from cup, lip smacking .

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Generalised tonic-clonic seizure(grand mal)

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Absence (previously ‘petit mal’)

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Age of onset: 3-10 years

Occurs in genetic (idiopathic)

Seizure types: absence; often in

clusters; …hyperventilation

Cognitive dysfunction with a

sudden onset and end, lasting 5-

10 seconds

Stare, expressionless face; arrest

of ongoing activity; generally no

motor phenomena

No neurological or mental

alterations

EEG: generalised 3 Hz spike and

wave activity

Good response to treatment

Spontaneous remission by puberty

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Myoclonic seizure

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Sudden, quick, arrhythmic

muscle contraction, twitch of a

limb; no loss of consciousness

EEG: generalised polyspike and

wave activity

Occurs in genetic (idiopathic)

epilepsies

Not only an epileptic

phenomenon- it can be the sign

of diffuse encephalopathies

Juvenile myoclonic epilepsy

Most common form of idiopathic

generalised epilepsy

Family history positive in 40%

Age of onset: 15-18 years

Seizure types:

myoclonic

generalised tonic-clonic

absence

EEG: generalised 3-4 Hz spike

and wave, polyspike and wave,

hyperventillation and

fotostimulation are provoking

Good response to treatment, but

needs life-long treatment

• Epileptic Syndromes: grouping of similar epileptic patterns according to sz type, EEG, age of onset, familial episodes, prognosis, other clinical signs.

• Electroclinical epilepsy syndromes ….

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Temporal lobe epilepsy Most common epilepsy in adulthood;

can be heralded by a few seizures in

childhood, but typical age of onset is

20-22 years

Seizure types:

olfactory hallucination (simplex

partial)

psychosensory seizures (simplex

partial)

complex partial

generalised tonic-clonic

Febrile convulsions in childhood

Hippocampal sclerosis

Often refractory to therapy

Surgical treatment eliminates

seizures in 80%-90% of refractory

cases

West syndrome Age of onset: 3-5 months

Seizure types: infantile spasms

Causes: inborn metabolic, storage

diseases, perinatal hipoxic brain damage

Cryptogenic in 40-50%

Neurological symptoms, mental

retardation; bad prognosis; can transform

into Lennox-Gastaut syndrome

EEG: hypsarrhythmia

Lennox-Gastaut syndrome

Age of onset: 1-8 years

3-10 of childhood epilepsy

Seizure types: atonic, axial tonic,

myoclonic, atypical absence, tonic-

clonic

30%of WS syndrome will have

LGS

Causes: same as in West

syndrome; can develop from West

syndrome

Neurological symptoms, mental

retardation

Unfavourable prognosis, refractory

to treatment

Diagnosis / differential diagnosis

Is it an epileptic

seizure? ?

Yes No

1. Seizure type?

2. Acute symptomatic

seizure or epilepsy?

Epilepsy

Idiopathic or

symptomatic?

Acute symptomatic seizure

Cause?

Symptomatic epilepsy

Cause?

Syncope?

TIA?

Psychogenic?

Diagram shows the common causes of “blackouts”

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DISORDERS RESEMBLING SEIZURES

• Syncope

• Cardiac disorders

• Migraine

• Transient ischemic attack

• Hypoglycemia

• Movement disorders

• Psychogenic nonepileptic seizures

• Malingering27

Syncope• Syncope is the most common cause of episodes of loss of

awareness.

• Simple faints or vasovagal syncopal attacks can usually be related to identifiable precipitants.

Hyperventilation blackouts• young and female; anxious , difficulty in ‘getting her breath’,

distal limb paraesthesiae and/or tetany are mentioned, need reassurance and rebreathing into a paper bag.

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Cardiac syncope

• Potentially serious and often treatable.

• Caused by a sudden drop in cardiac output

• May be provoked by exertion in those with severe aortic stenosis, ischaemia or hypertrophic obstructive cardiomyopathy, or

• Without warning in patients with cardiac arrhythmia (e.g. Stokes–Adams attack).

• Often prodromal features as palpitations, chest pain, shortness of breath or other features of cardiovascular insufficiency.

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Migraine

• A common cause of episodic visual phenomena

• Evolution is usually gradual, over several minutes, with fortification spectra and associated photophobia, nausea and headache.

• Epileptic phenomena are usually much shorter, evolving over seconds & visual hallucinations are more commonly of coloured blobs rather than jagged lines.

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Transient cerebral ischaemia• TIAs usually present with negative phenomena• TIAs are not usually stereotyped or repeated with the

frequency of epileptic seizures• Usually associated features to suggest vascular disease.

Vertebrobasilar ischaemia• Typically, the attacks occur in the elderly, with evidence of

vascular disease • Attacks may be precipitated by head turning or neck extension • Sudden onset, with features of brainstem ischaemia such as

diplopia, vertigo and bilateral facial and limb sensory and motor deficits.

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Hypoglycaemia• Hypoglycaemic attacks esp. in patients with treated

diabetes mellitus.

• Causes attacks of loss of consciousness, sometimes with a convulsion.

• Often warning, with hunger, malaise, shaking and sweating.

• Prompt recovery occurs with i.v. (or oral) glucose, or household sugar.

Hypocalcaemia• may be accompanied by a grand mal fit as seizure

threshold is lowered.33

Other neurological disorders

Movement disorders

• Paroxysmal choreoathetosis may cause drop attacks if there is lower limb involvement

• Tics

Cataplexy

• Cataplexy usually occurs in association with narcolepsy, although it may be the presenting clinical feature.

• There is no loss of consciousness with attacks.

• Attacks may be precipitated by emotion, especially laughter.

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Psychogenic nonepileptic seizures

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Diagnostic steps

History ( 70% of Dx)

EEG

Negative EEG does not exclude epilepsy

Positive EEG without clinical signs does not prove epilepsy

EEG after sleep deprivation or during sleep

Long-term EEG / video monitoring

CT, MRI

Epilepsy is a clinical diagnosis.

EEG Abnormalities

• During a seizure the EEG is almost invariably abnormal

• Background abnormalities

-Significant asymmetries and/or degree of slowing

inappropriate for clinical state

•Transient abnormalities associated with seizures

-Spikes (< 70 m sec)

-Sharp waves (~70 – 200 msec)

-Spike-wave complexes

•May be focal, lateralized or generalized

Indications for brain imaging in epilepsy (either

CT or MRI)

Epilepsy starting after the age of 16 yrs

Seizures having focal features clinically

EEG showing a focal seizure source

Control of seizures difficult or deteriorating

Video of Epilepsy