Febrile convulsions

Meest frequente vorm van epilepsie bij kinderen Koortsstuipen = Febriele convulsies Is een vorm van (gegeneraliseerde) epilepsie leeftijdsgebonden genetisch bepaald : ‘genetic susceptibility’

Fetveit A, Assessment of febrile seizures in children, Eur J Paed 2007 Febrile seizures : Frequent !  Simple Self limiting Short duration Generalized (tonic/clonic) No recurrence within the next 24 h No postictal signs  Complex Longer duration New events within following 24 h; series of events Focal seizures Postictal signs

Management of febrile seizures

A febrile seizure is a seizure… Treatment options comparable with epilepsy? 2 seizures or more should be considered as epilepsy and prophylactic treatment should be started Versus Febrile seizures are something special Provoked (fever, infection) Age specificity Benign outcome = no prophylactic treatment necessary

Acute treatment: Benzodiazepines  working 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 seizures Recurrences usually in first year after first seizure Risk factors :  Age at time of first seizure : younger age +++  Familial antecedents of febrile seizures  lower temperature  Complex febrile seizures  Neurodevelopmental abnormalities

2. Neurological sequels  Normal 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 epilepsy  Overall 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 seizures  GEFS +  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: Generalized epilepsy and febrile seizures plus GEFS+

Febrile seizures and MTS  MTS : 30% prolonged febrile seizures  MTS consequence of a prolonged seizure or status epilepticus Hippocampus in childhood vulnerable to excitotoxic damage  But why unilateral MTS? Pre-existing hippocampal abnormality  Hypoxia, cortical malformations

Prevention of recurrences does not prevent epilepsy  Phenobarbital 3mg/kg/day Long 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 1993 Verrotti 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 statements  Royal College of Pediatrics and Child Health 1991  American Academy of Pediatrics Pediatrics 1999, 103:

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.”