CAIMS KARIMNAGAR

1. Febrile seizures

2. Definition
Febrile seizures are seizures that occur
between the age of 6 and 60 mon with a
temperature of 38°C (100.4°F) 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.

3. Types
• Simple
• Complex
– Partial onset
– Prolonged duration(>15min)
– Multiple seizures during a single illness

4. • 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-hr
period.
• A complex febrile seizure is more prolonged
(>15 min), is focal, and/or reoccurs within 24
hr.
• Febrile status epilepticus is a febrile seizure
lasting longer than 30 min.

5. • Most patients with simple febrile seizures have
a very short postictal state and usually return
to their baseline normal behavior and
consciousness within minutes of the seizure.
• Febrile seizures recur in approximately 30% of
those experiencing a first episode, in 50% after
2 or more episodes, and in 50% of infants
younger than 1 yr old at febrile seizure onset.
• Although approximately 15% of children with
epilepsy have had febrile seizures, only 2-7% of
children who experience febrile seizures
proceed to develop epilepsy later in life.

6. Incidence
• 3-5% of children below 5yrs experience febrile
seizures.

7. Causes
• May follow fever caused by viral infection like
HHV6.
• Associated with diarrhoeas, respiratory tract
infections, UTI, exanthems, any etiology
especially if fever rises rapidly.
• Can occur following vaccination.
• Recurrence risk is greatest in 1st yr of
diagnosis, in younger patients, with positive
family history.
• Risk of febrile seizures is 10-25% if one parent
has had febrile seizures and 50% if one parent
and one sibling have had febrile seizures.

8. GENETIC FACTORS
• The genetic contribution to the incidence of
febrile seizures is manifested by a positive
family history for febrile seizures in many
patients.
• In some families, the disorder is inherited as
an autosomal dominant trait, and multiple
single genes that cause the disorder have been
identified in such families.
• However, in most cases the disorder appears
to be polygenic, and the genes predisposing to
it remain to be identified.

9. • Identified single genes include FEB 1, 2, 3, 4, 5,
6, 7, 8, 9, and 10 genes on chromosomes 8q13-
q21, 19p13.3, 2q24, 5q14-q15, 6q22-24,
18p11.2, 21q22, 5q34, 3p24.2-p23, and 3q26.2-
q26.33.
• Only the function of FEB 2 is known: it is a
sodium channel gene, SCN1A.

10. • Generalized epilepsy with febrile seizures plus
(GEFS+), severe myoclonic epilepsy of infancy
(also called Dravet syndrome), and, in many
patients, temporal lobe epilepsy secondary to
mesial temporal sclerosis are epilepsy
syndromes associated with febrile seizures.

11. • GEFS+ is an autosomal dominant syndrome
with a highly variable phenotype.
• Onset is usually in early childhood and
remission is usually in mid-childhood.
• It is characterized by multiple febrile seizures
and by several subsequent types of afebrile
generalized seizures, including generalized
tonic–clonic, absence, myoclonic, atonic, or
myoclonic astatic seizures with variable
degrees of severity.
• A focal febrile seizures plus epilepsy variant, in
which the seizures are focal rather than
generalized, has also been described.

12. • Dravet syndrome is the most severe of the
phenotypic spectrum of febrile seizure-
associated epilepsies.
• It constitutes a distinct entity in the onset of
which is in infancy.
• Its onset is characterized by febrile and
afebrile unilateral clonic seizures recurring
every 1 or 2 mon.
• These early seizures are typically induced by
fever, but they differ from the usual febrile
convulsions in that they are more prolonged,
are more frequent, are focal and come in
clusters.

13. • Seizures subsequently start to occur with lower
fevers and then without fever.
• During the 2nd yr of life, myoclonus, atypical
absences, and partial seizures occur frequently
and developmental delay usually follows.
• This syndrome is usually caused by a de novo
mutation, although rarely it is inherited in an
autosomal dominant manner.
• The mutated gene is located on 2q24-31 and
encodes for SCN1A, the same gene mutated in
GEFS+ spectrum.

14. • In Dravet syndrome the mutations lead to loss
of function and thus to a more severe
phenotype.
• There are several milder variants of Dravet
syndrome that manifest some but not all of the
above features and that are referred to as
Dravet syndrome spectrum or Borderland.
• Mutations in other genes may also cause
Dravet syndrome or GEFS+ phenotypes.

15. • The majority of patients who had prolonged
febrile seizures and encephalopathy after
vaccination and who had been presumed to
have suffered from vaccine encephalopathy
(seizures and psychomotor regression
occurring after vaccination and presumed to
be caused by it) turn out to have Dravet
syndrome mutations, indicating that their
disease is caused by the mutation and not
secondary to the vaccine.

16. Risk Factors for Recurrence of Febrile Seizures
MAJOR
• Age <1 yr
• Duration of fever <24 hr
• Fever 38-39°C (100.4-102.2°F)
MINOR
• Family history of febrile seizures
• Family history of epilepsy
• Complex febrile seizure
• Daycare
• Male gender
• Lower serum sodium at time of presentation

17. Clinical diagnosis
• Brief, bilateral, clonic or tonic events during
fever.
• Postictal manifestations and neurological
deficits are unknown
• The seizures are generally single within each
episode
• Generally occur in initial stage of fever
• Exclusion of early meningitis is important in
1st yr of life, more in first episode.

18. Evaluation
History and clinical examination:
History aims to :
• Rule out possible CNS infections
• Determine cause of fever
• Describe seizure semiology
• Asertain family/risk factors
• Determine neurodevelopment of the child

19. Clinical examination aims to:
• Exclude CNS infections – meningitis etc
• To identify raised ICP, full, bulging, non
pulsatile fontanelle in an infant.
• Examine for neurological abnormality
• Observation of postictal phase

20. Investigations
Blood Studies
• Blood studies (electrolytes, calcium,
phosphorus, magnesium, and CBP) are not
routinely recommended in the work-up of a
child with a first simple febrile seizure.
• Blood glucose should be determined in
children with prolonged postictal obtundation
or with poor oral intake (prolonged fasting).

21. • Serum electrolyte values may be abnormal in
children after a febrile seizure, but this should
be suggested by precipitating or predisposing
conditions elicited in the history and reflected
in abnormalities of the physical examination.
• If clinically indicated (eg: in a history or
physical examination suggesting dehydration),
these tests should be performed.
• A low sodium level is associated with higher
risk of recurrence of the febrile seizure within
the following 24 hr.

22. Lumbar puncture- Indications are:
• All infants younger than 6 mon of age who
present with fever and seizure, or if the child is
ill appearing or at any age if there are clinical
signs or symptoms of concern.
• Child 6-12 mo of age who is deficient in
Haemophilus influenzae type b and
Streptococcus pneumoniae immunizations or
for whom immunization status is unknown
• First febrile seizure does not require LP unless
clinical signs of CNS infection are present.

23. • In patients presenting with febrile status
epilepticus in the absence of a central nervous
system infection, a nontraumatic lumbar
puncture rarely shows cerebrospinal fluid
(CSF) pleocytosis (96% have <3 nucleated cells
in the CSF) and the CSF protein and glucose
are usually normal.

24. EEG:
• If the child is presenting with the first simple
febrile seizure and is otherwise neurologically
healthy, an EEG need not normally be
performed as part of the evaluation.
• An EEG would not predict the future
recurrence of febrile seizures or epilepsy even
if the result is abnormal.
• Spikes during drowsiness are often seen in
children with febrile seizures, particularly
those older than age 4 yr, and these do not
predict later epilepsy.

25. • EEGs performed within 2 wk of a febrile
seizure often have nonspecific slowing, usually
posteriorly.
• Thus, in many cases, if an EEG is indicated, it
is delayed until or repeated after more than 2
wk have passed.
• An EEG should, therefore, generally be
restricted to special cases in which epilepsy is
highly suspected, and, generally, it should be
used to delineate the type of epilepsy rather
than to predict its occurrence.

26. • If an EEG is done, it should be performed for
at least 20 min in wakefulness and in sleep
according to international guidelines to avoid
misinterpretation and drawing of erroneous
conclusions.
• At times, if the patient does not recover
immediately from a seizure, then an EEG can
help distinguish between ongoing seizure
activity and a prolonged postictal period,
sometimes termed a nonepileptic twilight
state.

27. • EEG can also be helpful in patients who
present with febrile status epilepticus because
the presence of focal slowing present on the
EEG obtained within 72 hr of the status has
been shown to be highly associated with MRI
evidence of acute hippocampal injury.

28. Neuroimaging
• A CT or MRI is not recommended in
evaluating the child after a first simple febrile
seizure.
• The work-up of children with complex febrile
seizures needs to be individualized.
• This can include an EEG and neuroimaging,
particularly if the child is neurologically
abnormal.

29. • Approximately 11% of children with febrile
status epilepticus are reported to have
(usually) unilateral swelling of their
hippocampus acutely, which is followed by
subsequent long-term hippocampal atrophy.

30. TREATMENT

31. Home management
Reduction of body temperature:
• Antipyretics:
– Should be started early at home.
– Oral paracetamol 15mg/kg/dose every 6th
hrly/oral Nimesulide 5mg/kg/day in 2
divided doses/oral Ibuprofen 20mg/kg/day
in 3 divided doses.
– Can be used alternately for better response
• Tepid sponging if temperature remains high
even after antipyretic therapy (cold water may
induce shivering and may be counter
productive)

32. • Antipyretics can decrease the discomfort of the
child but do not reduce the risk of having a
recurrent febrile seizure, probably because the
seizure often occurs as the temperature is
rising or falling.

33. Control of seizure:
• Per rectal, buccal Diazepam or midazolam is
preferred.
• Diazepam 0.33 mg/kg every 8 hrly oral
diazepam and 0.5 mg/kg/per rectal every 8th
hrly. For acute attack suppositories are not
preferred.
• Midazolam 0.2 mg/kg on buccal mucosa or
instilled intranasally is safe and equally
effective.

34. Seizure prophylaxis
• They reccur in 30-70% cases
• Prophylaxis aims to prevent recurrences
• Risk of recurrence is high if
– The first seizure occured in infancy
– Family history of febrile seizures
– Developmentally abnormal child
• Prophylaxis is advised in the above risk
factors.

35. Intermittent prophylaxis
• It is preferred mode of therapy
• Benzodiazepenes are agents of choice
• Diazepam oral/rectal and oral clobazam are
used
• Diazepam:
– Reduces risk in almost 80% children
– Per rectal is more efficacious than oral
– Dose is 0.33 mg/kg oral or 0.5 mg/kg per
rectal repeated every 8th hourly at onset of
fever for 48 to 72 hrs (seizure recurrence is
more in first 48hrs)

36. • Clobazam : oral intermittent use, 1mg/kg
single dose/day reduces risk to almost 80%
• Duration: 2yrs seizure free period or 5yrs of
age whichever is earlier.

37. Continuous prophylaxis
• Phenobarbitone and valproate are used.
• Limited indications like frequent complex
febrile seizures, failed intermittent therapy,
febrile seizures with neurological deficits.
• Phenobarbitone 4-5 mg/kg/day in 1 or 2
divided doses reduces febrile seizures by 80%.
• Sodium valproate 20-30 mg/kg/day in 2 or 3
divided doses.
• They are efficacious in preventing recurrences
• Not recommended in intermittent prophylaxis
except when it has failed to prevent
recurrences.

38. • In general, antiepileptic therapy, continuous
or intermittent, is not recommended for
children with 1 or more simple febrile seizures.
• In majority of cases, it is not justified to use
continuous therapy owing to the risk of side
effects and lack of demonstrated long term
benefits, even if the recurrence rate of febrile
seizures is expected to be decreased by these
drugs.

39. • Chronic antiepileptic therapy may be
considered for children with a high risk for
later epilepsy.
• Iron deficiency is associated with an increased
risk of febrile seizures, and thus screening for
it is required.

40. Counseling
• Parents should be counselled about the
relative risks of recurrence of febrile seizures
and recurrence of epilepsy, educated on how to
handle a seizure acutely, and given emotional
support.

41. Prognosis and outcome
• Incidence of epilepsy is 9%
• Risk of epilepsy in simple febrile without risk
factors is only 2 times higher than general
population.
• Prophylaxis does not alter the risk of epilepsy.
• Risk of temporal lobe epilepsy(mesial
temporal sclerosis) after atypical febrile
seizures is high.

42. THANKYOU!!!