Febrile convulsions

Meest frequente vorm van epilepsie bij kinderen

Koortsstuipen= Febriele convulsies

Is een vorm van (gegeneraliseerde) epilepsieleeftijdsgebondengenetisch bepaald : genetic susceptibility

Fetveit A, Assessment of febrile seizures in children, Eur J Paed 2007Febrile seizures : Frequent !SimpleSelf limitingShort durationGeneralized (tonic/clonic)No recurrence within the next 24 hNo postictal signs

ComplexLonger durationNew events within following 24 h; series of eventsFocal seizuresPostictal signs

Management of febrile seizures

A febrile seizure is a seizureTreatment options comparable with epilepsy?

2 seizures or more should be considered as epilepsy and prophylactic treatment should be started

Versus

Febrile seizures are something specialProvoked (fever, infection) Age specificityBenign outcome

= no prophylactic treatment necessary

Acute treatment: Benzodiazepinesworking mechanism : + Gaba receptor

Fast acting: fast penetration in the brain

Short half-life

Sedative, hypotensive, respiratory depression

Lorazepam, diazepam, clonazepam

Prophylactic treatment? recurrence risk ? prognostic factors recognizable

(sub)acute sequels of febrile seizures ? Limited

epilepsy after recurrent febrile seizures? only in complex febrile seizures (?) epileptic syndromes including febrile seizures

Prognosis after first febrile seizure

1. Recurrence risk (A.Berg, 2003) 30-40% recurrence Of these children, 50% will have 3 seizuresRecurrences usually in first year after first seizure

Risk factors :Age at time of first seizure : younger age +++Familial antecedents of febrile seizureslower temperature Complex febrile seizuresNeurodevelopmental abnormalities

2. Neurological sequelsNormal developing child with febrile seizures: no increased risk for developmental abnormalities (Ellenberg 1986, Verity 1998)

Secondary brain damage only after 30 minutes of convulsions

Normal/Improved memory functions in children with a history of febrile seizures (Chang et al, 2001)

3. Risk for subsequent epilepsyOverall increased risk :Age 5 : risk of epilepsy 2%Age 25 : risk of epilepsy 7% In children with epilepsy: 13-19% had febrile seizures in the past

Risk factors:

Complex febrile seizures : 4-12% (partial epilepsy syndromes)

simple febrile seizures : 2% (generalized epilepsy syndromes)

Delayed neurodevelopment / brain abnormality : risk + 30%

Family history of epilepsy

Epileptic syndromes with febrile seizuresGEFS +

Severe myoclonic epilepsy of infancy: Dravet syndrome

HHE syndrome

Mesial-temporal sclerosis

Consequence of prolonged complex febrile seizure?Predisposing hippocampal factors? (van Landingham 1998)Genetic predisposition (IL-1 metabolism Kanamoto,2000)

I Scheffer, S Berkovic, Brain 1997, 120:479-490Generalized epilepsy and febrile seizures plusGEFS+

Febrile seizures and MTSMTS : 30% prolonged febrile seizures

MTS consequence of a prolonged seizure or status epilepticusHippocampus in childhood vulnerable to excitotoxic damage

But why unilateral MTS?Pre-existing hippocampal abnormalityHypoxia, cortical malformations

Prevention of recurrences does not prevent epilepsy

Phenobarbital 3mg/kg/dayLong term negative cognitive effects

Sodium valproate 20 mg/kg/day

Not effective : Phenytoin, Carbamazepine

Other anti-epileptic drugs not tested

AED treatment : IS IT NECESSARY?

Oral Diazepam in fever episodes?

Rosman et al NEJM 1993Verrotti et al, EJPN 2004

Oral 0,35 mg/kg every 8 hours for 24 hours or until fever is gone

Side effects can mask or mimic underlying brain infection

Febrile seizure can be the very first sign of a febrile disease

Antipyretics ?Effective in lowering fever: systematic and rigorous antipyretics

Autret 1990 : in febrile episodes:Diazepam + aspirin versus Placebo + aspirin

Results :

overall rate of recurrence lower than in literature (18% versus 30-40%)

no differences between 2 groups (diazepam not effective)

Consensus statementsRoyal College of Pediatrics and Child Health 1991

American Academy of Pediatrics Pediatrics 1999, 103:1307-1309

American Academy of Pediatrics

Based on the risks and benefits of the effective therapies, neither continuous nor intermittent anticonvulsant therapy is recommended for children with one or more febrile seizures.

The American Academy of Pediatrics recognizes that recurrent episodes of febrile seizures can create anxiety in some parents and their children, and, as such, appropriate education and emotional support should be provided.

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