2. Definition of Terms
SEIZURE
Abnormal focal or generalized neuronal
discharge, resulting in abnormal involuntary,
paroxysmal, motor, sensory, or autonomic
activity as a physical manifestations
EPILEPSY
Refers to a condition in which a person
experiences two or more unprovoke seizures
3. Seizure Classification
Partial (focal) Seizures
Abnormal excessive activity limited to parts of one cerebral hemisphere
Focal seizure with no change in consciousness called simple where as
change in consciousness called complex
Generalized Seizures
Arises from both cerebral hemisphere without any focal onset
Approximately 30% of patients who have first afebrile seizure have later
epilepsy
5. Focal Seizures
1.Simple partial seizures
- spontaneous, uncontrolled neuronal discharge from a
focal area of the brain without loss of consciousness
a) Motor - clonic, tonic, automatisms Jacksonian (from
face to arm to leg, adversive head and eye movements to
contralateral sides)
b) Sensory - tingling, a visual sensation, odor, or taste
c) Autonomic – vomiting, asystole, drooling
6. Focal Seizures
2. Complex partial seizures
Spontaneous, uncontrolled neuronal discharge from a
focal area of the brain with loss of consciousness .
Usually least for 1-2 mins and often preceded by Aura,
such as rising abdomenal feeling, a sense of fear,
complex visual hallucination, micropsia or macropsia (
temporal lobe), generalized difficult to characterize
sensations (frontal lobe), focal sensation (parietal lobe),
simple visual experiences (occipital lobe)
7. Focal Seizures
3. Secondary generalized seizure
Most such seizures last 1-2 min. Tonic focal or
secondary generalized seizures often manifest
adversive head deviation to the contralateral side,
or fencing, hemi- or full figure-of-four arm, or
Statue of Liberty postures
EEG in patients with partial seizures usually
shows focal spikes or sharp waves in the lobe
where the seizure originates
8. Generalized Seizures
1. Generalized tonic-clonic seizures (GTC)
Tonic phase: eyes open and roll up, pupils dilate,
elbows flex, arms pronate, incontinence, ictal cry, cyanosis,
apnea, tachycardia least for 10-20 sec
Clonic phase: generalized clonic movements, atonic
between jerks, tongue biting, cyanosis, apnea saliva may
out from mouth, breathing maybe stertorous, least usually
<1 min
Postictal state: drowsy, confused, hypersalivation,
lethargy, regular respiration resumes, headache, muscle
soreness
10. Generalized Seizures
4. Absence seizures
Characterized by sudden loss of consciousness without loss of
postural contron
Typical absence seizures usually start at 5-8 yr of age mostly
gone before adolescence but if persisted then we called it Juvenile
absence seizure
Unlike complex partial seizures they do not have an aura, usually
last for only a few seconds
absence seizures can have simple automatisms like lip-smacking
or picking at clothing and the head can minimally fall forward
Usually occur in children with normal intelligence
Generalized 3-Hz spike-and-slow wave discharge (EEG)
No postictal phase
11. Generalized Seizures
5. Atypical absence seizures
•Longer duration
•Less abrupt onset and offset
•Often loss of postural tone (more pronounced than
mild head drop)
•Associated with other seizure types and mental
retardation
•Slow generalized spike-and-wave (<2.5 Hz)
12. Generalized Seizures
6. Myoclonic seizures
•Shock-like jerk on one part of baody or entire body
•EEG: Diffuse bursts of polyspike and slow waves
7. Atonic seizures
•Drop attacks due to sudden loss of muscle tone for 1-2 sec
•Brief impairment of consciousness
•No post ictal confusion
•Spectrum: from head drop to complete loss of tone in entire body
13. Mechanisms of Seizures
underlying etiologies of epilepsy which include, brain tumors, strokes,
scarring, or mutations of specific genes
repetitive stimulation leads to epilepsy through activation of metabotropic and
ionotropic glutamate receptors
(by glutamate) as well as the tropomyosin-related kinase B (TrkB) receptor
paroxysmal depolarization shift (PDS)
seizure-related neuronal injury
14. Treatment of Seizures and
Epilepsy
After a first seizure, if the risk of recurrence is low then
treatment is usually not started.
If the patient has abnormal EEG, MRI, development,
and/or neurologic exam and/or a positive family history of
epilepsy, then the risk is higher and often treatment is
started with AEDs
MECHANISMS OF ACTION OF ANTIEPILEPTIC DRUGS
Current AEDs reduce excitability by interfering with the
sodium or calcium ion channels, by reducing glutamate
induced excitatory function, or by enhancing GABAergic
inhibition
15. CHOICE OF DRUG ACCORDING TO SEIZURE TYPE
AND EPILEPSY SYNDROME
Drug therapy should be based on the type of seizure and the
epilepsy syndrome
drugs of first choice for focal seizures and epilepsies are
oxcarbazepine and carbamazepine
for absence seizures, ethosuximide
for juvenile myoclonic epilepsy, valproate and lamotrigine
for Lennox-Gastaut syndrome, valproate, topiramate,
lamotrigine, and, most recently, as add is rufinamide
for infantile spasms, adrenocorticotropic hormone (ACTH)
Lamotrigine has been shown to be effective for partial
seizures, and valproate has been shown to be effective for
generalized and unclassified epilepsies
West syndrome is best treated with adrenocorticotropic
hormone (ACTH).
17. Febrile Seizures
Febrile seizures are seizures that occur between the age
of 6 and 60 mo with a temperature of 38°C or higher, that
are not the result of central nervous system infection or
any metabolic imbalance, and that occur in the absence of
a history of prior afebrile seizures.
A simple febrile seizure is a primary generalized,
usually tonic-clonic, attack associated with fever, lasting for
a maximum of 15 min, and not recurrent within a 24-hour
period.
A complex febrile seizure is more prolonged (>15
min), is focal, and/or recurs within 24 hr. Febrile status
epilepticus is a febrile seizure lasting >30 min.
20. Epilepsy syndromes typically
start with febrile seizure
Dravet syndrome
severe myoclonic epilepsy of infancy (SMEI)
Most sever phenotype
mutation in the SCN1A gene causes decreased excitability in inhibitory
GABAergic interneurons, leading to increased excitability and epilepsy
Begins within 1 year after birth
No previous brain abnormality
Myoclonic seizures (begin mild, worsen over time)
Often, the first seizure occurs with lower fevers and then without fever
One-fourth of the infants have a family history of seizures
Can also be caused by vaccination but that’s the different entity termed
vaccine encephalopathy
21. Epilepsy syndromes typically
start with febrile seizure
Generalized epilepsy with febrile seizures plus
(GEFS+)
an autosomal dominant syndrome with a highly
variable phenotype. Onset is usually in early childhood
and remission is usually in mid-childhood
characterized by multiple febrile seizures and several
types of afebrile generalized seizures, including
generalized tonic-clonic, absence, myoclonic, atonic, or
myoclonic astatic seizures with variable degrees of
severity.
22. WORK-UP
the cornerstones of the evaluation is detailed history and a thorough
general and neurologic examination of Each child who presents with a
febrile seizure
Lumbar Puncture
Lumbar puncture is recommended in children <12 mo of age after their
first febrile seizure to rule out meningitis
A child between 12 and 18 mo of age should also be considered for
lumbar puncture because the clinical symptoms of meningitis may be
subtle in this age group.
For children >18 mo of age, a lumbar puncture is indicated in the
presence of clinical signs and symptoms of meningitis (e.g., neck stiffness,
Kernig sign, Brudzinski sign) or if the history and/or physical examination
otherwise suggest intracranial infection.
23. Electroencephalogram
If child is presenting with his or her first simple febrile seizure
but neurologically healthy, an EEG need not normally be
performed
EEG would not predict the future recurrence of febrile seizures
or epilepsy even if the result is abnormal.
EEG generally be restricted to special cases in which epilepsy
is highly suspected
EEG should be performed for at least 30 min in wakefulness and
in sleep according to international guidelines to avoid
misinterpretation and drawing of erroneous conclusions.
24. Blood Studies
serum electrolytes, calcium, phosphorus, magnesium, and CBC are
not routinely done in child with a first simple febrile seizure
Serum electrolytes maybe imbalanced during fever do only used to
ruleout if there is dehydration
Blood glucose should be determined only in children with poor oral
intake (prolonged fasting).
Neuroimaging
CT or MRI should not be routinely requested in children with first
simple febrile seizure
Patients with febrile status epilepticus have been reported to have
swelling of their hippocampus acutely and subsequent long-term
hippocampal atrophy. These patients may be candidates for
neuroimaging
25. TREATMENT
In general, antiepileptic therapy, continuous or
intermittent, is not recommended for children with one or
more simple febrile seizures.
Parents should counseled about recurrences and
educated on how to handle seizure accurately and given
emotional support
If the seizure lasts for >5 min, then diazepam, lorazepam,
or midazolam is needed for acute management of seizures
and status epilepticus mostly given rectally
27. Neonatal Seizures
Seizures are the most important and common indicator of significant
neurologic dysfunction in the neonatal period.
Seizure incidence is higher during this period than in any other period
in life: 57.5/1,000 in infants with birth weights <1,500 g and 2.8/1,000
in infants weighing between 2,500 and 3,999 g have seizures.
PATHOPHYSIOLOGY
In limbic and neocortical region , excitatory synapses develop before
inhibitory (NMDA receptor)
Deficient development of substantia nigra for inhibiton of seizure
Delay in development of inhibitory GABAergic transmission.
In fact, GABA in the immature brain has an excitatory function as the
chloride gradient is reversed relative to the mature brain, with higher
concentrations of chloride being present intracellularly than
extracellularly
31. Neonatal Seizures
1. Benign neonatal seizures
Also called “fifth-day fits”
Clinical presentation:
1) Clonic or myoclonic seizures and apneic events during first few weeks
after birth
2) Seizures usually stop by 6 weeks after birth, no long- term sequelae
3) Normal development
4) Later, some of the children have epilepsy (10%-15%) or febrile seizures
(33%)
5) Treatment is often unnecessary, may prescribe phenobarbital for 1
month, then taper
32. Neonatal Seizures
Mutations in two genes have been identified:
KCNQ2 on chromosome 20
KCNQ3 on chromosome 8
impair potassium-dependent repolarization, thus
causing hyperexcitability
33. Neonatal Seizures
2. Early myoclonic encephalopathy (EME)
Clinical presentation
1) Erratic, focal myoclonus: migrates randomly to different body parts
2) Occurs within first few hours after birth
Multiple causes, a nonspecific diagnosis
a) Metabolic (nonketotic hyperglycemia)
b) Inherited (autosomalrecessive)
c) Various developmental malformations
EEG: burst-suppression pattern
Poor prognosis
More than 50% die, others have profound psychomotor delay
34. Neonatal Seizures
3. Ohtahara syndrome
Clinical presentation
1) Frequent tonic spasms ± partial seizures (not myoclonus)
2) Onset is usually within first 10 days after birth (otherwise, <3
months)
3) Difficult-to-control seizures
4) Clinical course is marked by neurologic deterioration
Often progresses to West’s syndrome or Lennox-Gastaut syndrome
phenotypes
35. Neonatal Seizures
4. Migrating partial seizures of infancy
Clinical presentation
1) Onset less than 6 months after birth (average, first seizure at 3
months)
2) Progresses over weeks
3) Multifocal seizures, shift from hemisphere to hemisphere
4) Seizures are nearly continuous at times, occur in clusters
5) Progressive microcephaly and severe psychomotor
deterioration
6) Poor response to anticonvulsants
36. Neonatal Seizures
5. Pyridoxine (vitamin B6)-dependent
seizures (congenital dependency on
pyridoxine)
Autosomal recessive disorder
Age at onset: usually neonatal period but may appear up
to 1 year of age
Diagnosis: established by response (remission of
seizures) to treatment with IV pyridoxine and relapse
without ongoing treatment
Treatmen is usually by life-long administration of pyridoxine oral
supplements daily
38. Infantile spasms
a. This is not an epilepsy syndrome but a seizure type
b. poor developmental outcome:mild to no mental
retardation in 40%
c. Associated with West’s syndrome
Clinical presentation
1) Occurs within first year after birth
2) Sudden tonic extension or flexion of limbs and axial body
3) Spasms occur in clusters, often after awakening
EEG
hypsarrhythmia (high-amplitude, chaotic slow waves with
multifocal spikes and sharp waves), which diminishes during
REM sleep
Treatment: ACTH, vigabatrin
39. 1. West’s syndrome
onset: 3 months to 3 years
Triad:
infantile spasms
hypsarrhythmia
developmental arrest
Etiology: tuberous sclerosis and chromosomal
abnormalities
Treatment: ACTH, corticosteroids, and
vigabatrin the latter is drug of choice for
infantile spasms associated with tuberous
sclerosis
40. 2. Aicardi’s syndrome
Triad:
Infantile spasms
agenesis of the corpus callosum
retinal malformations
X-linked: occurs predominantly in girls, lethal in boys
3. Benign myoclonic epilepsy of infancy
Normal infant or toddler
If treated, excellent developmental outcome
Easily controlled with valproate
41. 4. Benign infantile seizures
Partial seizures in first 1 to 2 years after birth
Often occur in clusters 1 to 3/day, <10/day
Seizures last a maximum of a few minutes
No postictal stupor or status
Normal psychomotor development
43. 1. Benign childhood epilepsy with centrotemporal
spikes
“benign rolandic epilepsy of childhood”
Most common accounts for one-fourth of
childhood seizures
Onset in childhood, age 4 to 12 years, resolves
by middle teens
Motor, sensory simple seizures
Can have secondary generalization, usually nocturnal
Seizures increase with sleep: 70% of patients have seizures only
during sleep
Normal development and neurologic examination
44. Treatment
Easily controlled with anticonvulsants
Often not necessary to treat (physicians often wait until
the second seizure)
Treatment can be stopped after adolescence (only 10%
of patients continue to have seizures 5 years after
onset)
45. 2. Early-onset benign childhood occipital
epilepsy
“Panayiotopoulos syndrome”
Most common in children 3 to 6 years old
ictal vomiting
Infrequent seizures: most patients, 1 to 3 seizures total
Treatment
1) Not needed if only one seizure or a few brief
seizures 2) Carbamazepine is usually the first-line
treatment
46. 3. Late-onset childhood occipital epilepsy (Gastaut
type)
Children 4 to 8 years old
Visual seizures: Hallucinations, blindness
Frequent: weekly to several per day
Often followed by migraine
Often induced by photic stimulation
Treatment is recommended because seizures are frequent
4. Epilepsy with myoclonic absences
Rare
3 Hz spike and slow waves
High-dose ethosuximide and valproate usually control the seizures
47. 5. Myoclonic-astatic epilepsy of childhood
the first seizure usually occurs in a developmentally normal child 2 to
5 years old
mild or early form of Lennox-Gastaut syndrome
6. Lennox-Gastaut syndrome
Clinical triad:
1. mental retardation
2. slow spike-and-wave (2 Hz) EEG
3. multiple seizure types
age at onset is 2 to 8 years; Boys affected more often than girls
The first seizure type is usually drop attacks or atonic seizure
Prognosis is usually poor, especially if symptomatic
Treatment
Valproate: all seizure types
48. 7. Landau-Kleffner syndrome
Acquired aphasia (word deafness): the main feature
of the syndrome
Treatment:
Antiepileptic drugs (valproate and lamotrigine)
may help decrease seizure frequency and improve
cognitive function
8. Epilepsy with continuous spike-and-wave pattern
during slow wave sleep
“electrical status epilepticus during sleep”
EEG: Continuous spike-and-wave pattern during NREM Sleep
First seizure occurs in childhood (peak age at onset: 5 years)
49. 9. Childhood absence epilepsy
Clinical presentation
1) Children (girls, 70%), peak age at onset: 6 years
2) Neurologically and developmentally normal
3) Multiple daily spells usually lasting a few seconds
10. Progressive myoclonic epilepsies
Encompasses several progressive disorders, most are lysosomal and
mitochondrial disorders
Clinical Presentation:
1) Progressive cognitive deterioration
2) Myoclonus (nonepileptic)
3) Seizures: tonic-clonic, tonic, or myoclonic
4) With or without ataxia, movement disorders
Treatment of seizures
First-line treatment: valproate
51. Juvenile
1. Juvenile absence epilepsy
Clinical presentation
1) Onset at age 10 to 17 years
2) Developmentally normal children
3) Boys and girls affected equally
4) Initially, infrequent absence seizures: usually not
daily
5) Later, tonic-clonic seizures in 75% of patients upon
awakening: more common
52. Juvenile
2. Juvenile myoclonic epilepsy (JME)
Clinical Presentation:
Age at onset is 8 to 24 years (peak, in teens)
Developmentally normal
Most common seizure induced by photic stimulation, alcohol,and sleep
deprivation
Myoclonic seizures: the most frequent seizure type
a) Usually predominantly on awakening (early morning or nap)
b) Large-amplitude, bilateral, simultaneous:
c) May be repetitive
d) No loss of awareness
53. 2. Juvenile myoclonic epilepsy (JME)
Treatment
1) First-line: valproate
2) Second-line: lamotrigine, levetiracetam, topiramate,
and zonisamide
3) Avoid carbamazepine and phenytoin, which are
useful in focal seizures but may worsen some primary
generalized seizures (myoclonic and absence seizures)
Prognosis: it is a lifelong seizure disorder typically requiring lifelong treatment
and avoidance of triggers
54. Status Epilepticus
Classic definition
30 minutes of continuous seizure activity or two or
more seizures in 30 minutes without recovery of
consciousness
Controversial new definition
more than 5 minutes of seizure activity or two or more
seizures without recovery of consciousness
55. Status Epilepticus
Types of Status Epilepticus
1. Generalized convulsive status
a. High mortality (20%)
b. Mortality varies depending on the underlying cause
2. Non-convulsive status
Typically evolves from prolonged seizures
Often requires EEG to differentiate it from other causes of
unresponsiveness (postictal state, underlying neurologic disease)
3. Subtle nonconvulsive status
a. Similar to nonconvulsive status
b. There is subtle face, eyelid, or eye twitching
4. Focal status (simple or complex)
Complex focal status has significant morbidity and mortality
It merits aggressive treatment
56. Status Epilepticus
Types of Status Epilepticus
5. Absence status
a. Benign
b. Brain damage is unlikely
c. Responds to low-dose benzodiazepines
6. Myoclonic status
Usually indicates severe neurologic injury (e.g., anoxic, degenerative)
Thus, treatment response and prognosis are poor
57. Status Epilepticus
Causes:
Any acute or chronic brain lesion or toxic-metabolic
disturbance
A. acute vascular event (stroke)
B. withdrawal or low levels of AED
C. tumors
D. CNS infections: meningitis, encephalitis,
E. metabolic derangements (hyponatremia)
F. head trauma
Notes de l'éditeur
paroxysmal depolarization shift (PDS) that consists of a sudden depolarization phase, resulting from glutamate and calcium channel activation, with a series of action potentials at its peak followed by an afterhyperpolarization phase, resulting from activation of potassium channels and GABA receptors. When the afterhyperpolarization is disrupted in a sufficient number of GABAergic interneurons, the inhibitory surround is lost and a population of neurons fires at the same rate and time, resulting in a seizure focus.