Neurology Chapter of IAP Seizures in Childhood. Neurology Chapter of IAP Reference Paediatrics &...

Neurology Chapter of IAP

Seizures in Childhood


Reference

• Paediatrics & Child healthCoovadia and Wittenberg

p.477-483

• Lecture on AED


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 and adolescents:– 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

• Trauma4.7%

• Infection4.0%

• Vascular1.5%

• Neoplastic 1.5%• Degenerative

0.7%


Seizure type

Partial (Only a portionof the brain)

- Simple(Normal consciousness)- Complex(Impaired consciousness)

Generalized(Both hemispheres areinvolved)


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


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

Ø focal motor seizures

Ø somato-sensory symptoms

Ø special sensory symptoms• With autonomic symptoms or signs

Ø Flushing

Ø Pallor

Ø epigastric sensations

Ø sweating

• With psychic symptoms

Ø deja vu.

Ø 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


International League against EpilepsyClassification 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 thebrain but which may have diverse but defined aetiologies

Ø temporal lobe epilepsies

Ø frontal lobe epilepsies

Ø 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-Gastautsyndrome

III. Undetermined, whether focal or generalised

IV. Special situations

• Includes febrile convulsions

• seizures due to metabolic upset, e.g. alcohol


Main Periods according to Age• Neonates

– Subtle, erratic, non-febrile

• Infancy and early childhood– 3 months to 3 years– Febrile seizures– Infantile spasms– Lennox Gastaut– Myoclonic seizures– Status epilepticus– Partial complex


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


Neonatal seizures• Subtle seizures

– Deviation of the eyes

– Eyelids are flickering

– Swimming or pedaling movements

– Apnoeic spells

• Tonic

• Clonic

• Myoclonic

• Seldom tonic clonic seizures


Aetiology of neonatal seizures

• Perinatal:– HIE

– ICH

• Metabolic– Hypoglycemia,

hypocalcemia

– hypomagnesemia

– Other

• Infections• Structural

abnormalities• Drug withdrawal


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


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


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– No increase in blood 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


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

• Mesial temporal 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


Treatment of Epilepsy

– 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


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!


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:• Carbamazepine


Table 1: Anticonvulsants used

Dosemg/kg/day

Daily schedule(T1/2 in hours)

Therapeuticlevelsμg/ml

Indications Mechanism of action

Valproate(Epilim, Convulex)

20-30 2-4(7-15)

50-100 Broad spectrum Effect on Ca current

Carbamazepine(Tegretol)

20-25 2-3(8-24)

6-12 PartialT/C

Blocks Na channels

Oxcarbazepine(Trileptal)

20-30 2-3 13-31 PartialT/C

Blocks Na channels

Phenytoin(Epanutin)

5-8 1-2(9-40)

5-20 T/CPartial

Blocks Na channels

Lamotrigine(Lamictan)

5-10(Less incombinationwith valproate)

1-2(60 if onvalproate)

1.5-4 PartialGeneralisedLennox GastautAbsenceMyoclonic

Inhibits release ofexcitatory amino acidslike glutamate

Ethosuximide(Zarontin)

20-30 1-2(20-40)

40-60 Absences Reduction of the T-type Ca current in thethalamic relayneurones

Clonazepam(Rivotril)

0.2-0.3 2-4(20-30 min)

NA MyoclonicT/C

Enhances GABAmediated inhibition

Clobazam(Urbanol)

0.5-2 1-2 NA Adjunct in myoclonic ,T/C and Lennox Gastaut

Enhances GABAmediated inhibition

Phenobarbitone(Lethyl)

3-5 1-2(37-73)

15-45 T/C Enhances GABAmediated inhibition

Gabapentin(Neurontin)

10-25 3-4(6)

Not available PartialGeneralised

Irreversible blocking ofGABA transaminase

Vigabatrin(Sabril)

40-100 1-2(4-5 days)

NA PartialGeneralisedWest syndrome

Unknown

Topiramate(Topamax)

3-9 1-2(12-24)

NA Broad spectrum NA channel blockerEnhances GABAmediated transmissionInhibition on AMPAglutamate receptorsCarbonic anhydraseinhibitor

*T: Tonic; C: Clonic; T/C: Tonic-Clonic; A: Atonic,


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


Step wise treatment of seizure control in Status Epilepsy (Excluding Neonates)

Step I: Benzodiazepine - Lorazepam: 0.1 mg/kg IVI at 2 mg/minNB: 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

ê

Step II: Phenytoin 20 mg/kg IVI slowly not faster than 25-50 mg/min

Seizures continuing

ê

Step III: Phenytoin Additional 5 mg/kg

Seizures continuing

ê

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 togo 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 doseof 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.


Status epilepticus

– Treat the cause of the seizures• ? LP

• CT/MRI

• Drug levels

• Toxic screen


Status epilepticus

– Correct the metabolic and systemic effects• Drop in blood pressure

• Impaired brain perfusion Liver enzymes

• Clotting defects

• Hyperkalaemia

• Hypoglycaemia

• Inappropriate ADH

• Renal failure

Neurology Chapter of IAP Seizures in Childhood. Neurology Chapter of IAP Reference Paediatrics &...

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