2. 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
3. ‘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
4. 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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5. 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.
11. 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 onset
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12. ILAE
C. 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 seizures
II. 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 seizures
III. Unclassified epileptic seizures 12
15. 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 partial
psychosensory 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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17. 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
19. 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
20. 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
21. • 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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22. 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
23. 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
24. 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
25. 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?
28. 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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29. 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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31. 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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32. 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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33. 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.
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34. 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. 34
36. 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.
37. 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
38. 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