Transcript Seizures in Childhood

Seizures in Childhood
Neurology Chapter of IAP
Reference
• Paediatrics & Child health
Coovadia and Wittenberg
p.477-483
• Lecture on AED
Neurology Chapter of IAP
Introduction
• Convulsion associated with febrile disease
– 2-4% of all children before the age of 5 years
• Symptomatic seizures
– 0.5-1%
• Epilepsy:
– Recurrent unprovoked seizures
• First year of life:
– 1,2/1 000
• Childhood andNeurology
adolescents:
Chapter of IAP
– 0,5-1/10000
Aetiology of Epilepsy
• Specific aetiology
– Identifiable in only
30% of cases
• Idiopathic 67.6%
• Congenital
20%
– Trauma
– HIE
– Congenital brain
anomalies
•
•
•
•
•
Trauma
Infection
Vascular
Neoplastic
Degenerative
Neurology Chapter of IAP
4.7%
4.0%
1.5%
1.5%
0.7%
Seizure type
Partial
(Only a portion
of the brain)
- Simple
(Normal consciousness)
- Complex
(Impaired consciousness)
Generalized
(Both hemispheres are
involved)
Neurology Chapter of IAP
Epilepsy classification
• Clinical presentation is quite variable
– age of onset
– seizure type
– interictal condition
– EEG
– Outcome
• Evaluate the:
– the epileptic syndrome
– Possible aetiology
• The seizure type and syndrome type determine the
– Specific appropriate treatment
– Further evaluation
Neurology Chapter of IAP
International League against Epilepsy:
Classification of epileptic seizures, using both clinical data and
electroencephalography
I. Partial seizures
A. Simple partial seizures (consciousness preserved)

With motor symptoms

focal motor seizures

somato-sensory symptoms

special sensory symptoms

With autonomic symptoms or signs

Flushing

Pallor

epigastric sensations

sweating

With psychic symptoms

deja vu.

illusions and structured hallucinations
B. Complex partial seizures (consciousness impaired)

Simple partial onset followed by impaired consciousness

With impaired consciousness at onset
C. Simple or complex partial seizures evolving into secondary generalized seizures
II. Generalized seizures
A. Absence seizures (petit mal)
B. Myoclonic seizures
C. Clonic seizures
D. Tonic seizures
E.
Atonic seizures
F. Tonic-clonic seizures
III. Unclassified seizures which, due to inadequate data or classification
Neurology Chapter of IAP
International League against Epilepsy
Classification of epilepsies and syndromes
I. Location-related (focal or partial) epilepsies
A.
Idiopathic with an age-related onset.

e.g. benign rolandic epilepsy
B.
Symptomatic

Very rare syndromes e.g. epilepsia partialis continua

Syndromes. which result from seizures arising from a specific part of the
brain but which may have diverse but defined aetiologies

temporal lobe epilepsies

frontal lobe epilepsies

parietal lobe epilepsies
C. Cryptogenic

As above but no aetiology identified
II. Generalised epilepsies
A. Idiopathic

benign neonatal convulsions

childhood and juvenile absence epilepsy

juvenile myoclonic epilepsy
B.
Symptomatic

early myoclonic encephalopathy

Specific syndromes which have epilepsy as the predominant feature. e.g.
Lafora body disease
C. Cryptogenic

Rare with a presumed but undefined aetiology, e.g. Lennox-Gastaut
syndrome
III. Undetermined, whether focal or generalised
IV. Special situations

Includes febrile convulsions

seizures due to metabolic upset, e.g. alcohol
Neurology Chapter of IAP
Main Periods according to Age
• Neonates
– Subtle, erratic, non-febrile
• Infancy and early childhood
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–
3 months to 3 years
Febrile seizures
Infantile spasms
Lennox Gastaut
Myoclonic seizures
Status epilepticus
Partial complexNeurology Chapter of IAP
Main Periods according to Age
• Childhood to early adolescence
– Cryptogenic
– Absences
– Benign rolandic epilepsy
• Nine years to adulthood
– Primary generalized epilepsy
– Focal epilepsy with brain injury
Neurology Chapter of IAP
Neonatal seizures
• Subtle seizures
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–
–
–
•
•
•
•
Deviation of the eyes
Eyelids are flickering
Swimming or pedaling movements
Apnoeic spells
Tonic
Clonic
Myoclonic
Seldom tonic clonic seizures
Neurology Chapter of IAP
Aetiology of neonatal seizures
• Perinatal:
• Infections
• Structural
abnormalities
• Drug withdrawal
– HIE
– ICH
• Metabolic
– Hypoglycemia,
hypocalcemia
– hypomagnesemia
– Other
Neurology Chapter of IAP
Treatment of neonatal seizures
• Optimize ventilation, cardiac output, BP,
glucose, electrolytes and pH.
• Treat the underlying disease
• Intravenous line is essential
• Treat the seizures promptly and vigorously
• Phenobarbitone
• Phenytoin
Neurology Chapter of IAP
Non-epileptic paroxysmal events
in childhood
• Syncope
• Breath-holding spells
– Pallid: Vagal asystole
– Cyanotic: Cerebra ischaemia due to a sudden rise in
the intra-thoracic pressure impeding the venous return
to the heart
• Night terrors
• Nightmares
• Masturbation
• Cardiac disorders
Neurology Chapter of IAP
Non-epileptic paroxysmal events
in childhood
• Complicated migraine
• Movement disorders
• Jitteriness
– Absence of abnormal gaze movements
– Provoked by passive flexion or extension
– Seizure jerks tend to be 2-3 Hz, clonus or
jitteriness tend to be 5-6 Hz
– Normal EEG
of IAP
– No increase in Neurology
bloodChapter
pressure
or heart rate
Febrile seizures
• Definition:
– Seizure in children between the age of 6 months
and 3-4(5) years in association with fever but
without evidence of an intracranial infection
• Majority occurs before the age of 3 years
• Average age of onset: 18 months to 22
months
• Boys more than girls
Neurology Chapter of IAP
Febrile seizures
• Recurrence
– 1/3 may have at least one recurrence
– The younger the age of onset the greater the
risk of recurrence
• Risk of developing epilepsy
– 2%
– Risk increases with:
• Complex
• Abnormal neurological state
Chapter of IAP
• Mesial temporalNeurology
sclerosis
Management of febrile seizures
• Identify the underlying disease
– LP?
• CT or MRI is not warranted in the evaluation of febrile
convulsions
• Routine EEG is seldom necessary
• Treatment:
– Long-term use of AED is not indicated
• Phenobarbitone
• Sodium valproate
– Rectal diazepam
– Antipyretics
Neurology Chapter of IAP
Treatment of Epilepsy
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–
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Drug treatment should be regular
Simple as possible
Minimum of side effects
Monotherapy
Changes should be made gradually
High initial dosages increases side effects
Rapid withdrawal carries the risk of provoking
status
– Always calculate the dosage according to the
weight
Neurology Chapter of IAP
Treatment of Epilepsy
•
Drugs commonly used
– Carbamazepine
– Sodium valproate
– ? Clonazepam
– ? Phenobarbitone
– ? Phenytoin
• Newer drugs
– Clobazam
– Oxcarbazepine
– Gabapentin
– Vigabatrin
– Lamotrigine
NB. You are referred to the lecture on AED and the side effects should be
studied!
Neurology Chapter of IAP
Treatment of Epilepsy
• AED can cause convulsions
– Benzodiazepines can induce TC seizures in
LGS
– Carbamazepine may exacerbate absence
seizures
• What is used as first line treatment.
– Absence:
• Sodium valproate
– Focal and Generalized TC:
Neurology Chapter of IAP
• Carbamazepine
Table 1: Anticonvulsants used
Dose
mg/kg/day
Daily schedule
(T1/2 in hours)
Valproate
(Epilim, Convulex)
Carbamazepine
(Tegretol)
Oxcarbazepine
(Trileptal)
Phenytoin
(Epanutin)
Lamotrigine
(Lamictan)
20-30
2-4
(7-15)
2-3
(8-24)
2-3
Ethosuximide
(Zarontin)
20-25
20-30
5-8
Therapeutic
levels
 g/ml
50-100
Indications
Mechanism of action
Broad spectrum
Effect on Ca current
6-12
Partial
T/C
Partial
T/C
T/C
Partial
Partial
Generalised
Lennox Gastaut
Absence
Myoclonic
Absences
Blocks Na channels
13-31
1-2
(9-40)
1-2
(60 if on
valproate)
5-20
20-30
1-2
(20-40)
40-60
Clonazepam
(Rivotril)
Clobazam
(Urbanol)
Phenobarbitone
(Lethyl)
Gabapentin
(Neurontin)
Vigabatrin
(Sabril)
0.2-0.3
2-4
(20-30 min)
1-2
NA
1-2
(37-73)
3-4
(6)
1-2
(4-5 days)
15-45
Topiramate
(Topamax)
3-9
1-2
(12-24)
NA
5-10
(Less in
combination
with valproate)
0.5-2
3-5
10-25
40-100
1.5-4
NA
Not available
NA
Myoclonic
T/C
Adjunct in myoclonic ,
T/C and Lennox Gastaut
T/C
Partial
Generalised
Partial
Generalised
West syndrome
Broad spectrum
*T: Tonic; C: Clonic; T/C: Tonic-Clonic; A: Atonic,
Neurology Chapter of IAP
Blocks Na channels
Blocks Na channels
Inhibits release of
excitatory amino acids
like glutamate
Reduction of the T type Ca current in the
thalamic relay
neurones
Enhances GABA
mediated inhibition
Enhances GABA
mediated inhibition
Enhances GABA
mediated inhibition
Irreversible blocking of
GABA transaminase
Unknown
NA channel blocker
Enhances GABA
mediated transmission
Inhibition on AMPA
glutamate receptors
Carbonic anhydrase
inhibitor
Status Epilpeticus
• Medical emergency
• Management
– Abort the seizures
• See figure 1
– Resuscitate the brain
• ABC of resuscitation
• Cerebral oedema
– Mannitol
• Metabolic and biochemical abnormalities
• Hyperpyrexia Neurology Chapter of IAP
Step wise treatment of seizure control in Status Epilepsy (Excluding Neonates)
Step I:
Benzodiazepine
-
Lorazepam: 0.1 mg/kg IVI at 2 mg/min
NB: Lorazepam, if available, is the drug of choice because
the anticonvulsant effect last up to 24 hours
OR
-
Valium: 0.25-0.5 mg/kg IVI
Followed by

Step II:
Phenytoin
20 mg/kg IVI slowly not faster than 25-50 mg/min
Seizures continuing

Step III:
Phenytoin
Additional 5 mg/kg
Seizures continuing

Step IV:
Has to be done in ICU as ventilatory support is usually necessary
1. Thiopentone
Starting infusion dose is 1-3 mg/kg/hour and one may need to
go as high as 5-7 mg/kg/hour
OR
2. Midazolam
Start with a loading dose of 0.2 mg/kg IVI bolus, then at a dose
of 0.75 – 10 microgram/kg/min
OR
3. Propofol
1-2 mg/kg IVI, followed by 2-10 mg/kg/hour.
Its use in children is limited and should be used with caution.
Neurology Chapter of IAP
Status epilepticus
– Treat the cause of the seizures
•
•
•
•
? LP
CT/MRI
Drug levels
Toxic screen
Neurology Chapter of IAP
Status epilepticus
– Correct the metabolic and systemic effects
•
•
•
•
•
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Drop in blood pressure
Impaired brain perfusion
 Liver enzymes
Clotting defects
Hyperkalaemia
Hypoglycaemia
Inappropriate ADH
Renal failure
Neurology Chapter of IAP