Transcript febrile seizures

An 11 month-old male infant was rushed to the
hospital because of first-onset and single episode of
generalized seizure.
The infant was noted to be coughing with nasal
catarrh for the last 5 days. Hours before the seizure
episode, his temperature was taken to be 38.9C.
Perinatal and postnatal histories were
unremarkable.
The father admitted to be having the same episodes
when he was still around 5 years old during the
height of his fever. Neurological examination was
normal.
Salient Features
11 months
old
Male
Recent URI
Spike in body
temp 38.9 °C
(+)Family
history
Normal
Neuro Exam
Missing Data
•Duration of the seizure episode
•If there are other accompanying
symptoms such as vomiting, loss
of consciousness, urinating or
soiling himself.
•Recent vaccination (DTP or MMR)
Clinical Impression
Febrile Seizure
DIFFERENTIAL DIAGNOSIS
DIFFERENTIAL DIAGNOSIS
1. Meningitis
2. Encephalitis
3. Epilepsy
MENINGITIS
• Is an inflammation of the membranes
(meninges) and cerebrospinal fluid
surrounding the brain and spinal cord, usually
due to the spread of an infection
• The swelling associated with meningitis often
triggers the "hallmark" symptoms of this
condition, including headache, fever and a
stiff neck
• Most cases of meningitis are caused by a viral
infection, but bacterial and fungal infections also
can lead to meningitis
– Bacterial infections are the most damaging,
identifying the source of the infection is an important
part of developing a treatment plan
• Depending on the cause of the infection,
meningitis can resolve on its own in a couple of
weeks — or it can be a life-threatening
emergency
• ACUTE BACTERIAL MENINGITIS
– Usually occurs when bacteria enter the
bloodstream and migrate to the brain and spinal
cord
– Can directly invade the meninges, as a result of an
ear or sinus infection or a skull fracture
– Streptococcus pneumoniae (pneumococcus)
• Most common cause of bacterial meningitis in infants
and young children in the United States.
– Neisseria meningitidis (meningococcus)
• Another leading cause of bacterial meningitis
• It commonly occurs when bacteria from an upper
respiratory infection enter your bloodstream.
• Highly contagious and may cause local epidemics in
college dormitories and boarding schools and on
military bases
– Haemophilus influenzae (haemophilus)
• Before the 1990s, Haemophilus influenzae type b (Hib) bacterium
was the leading cause of bacterial meningitis.
• Hib vaccines —routine childhood immunization
– Greatly reduced the number of cases of this type of meningitis
• It tends to follow an upper respiratory infection, ear infection
(otitis media) or sinusitis
– Listeria monocytogenes (listeria)
• These bacteria can be found almost anywhere — in soil, in dust
and in foods that have become contaminated
– Soft cheeses, hot dogs and luncheon meats
• Most healthy people exposed to listeria don't become ill
– Pregnant women, newborns and older adults tend to be more
susceptible.
• Listeria can cross the placental barrier, and infections in late
pregnancy may cause a baby to be stillborn or die shortly after
birth
• Viral meningitis
– Usually mild and often clears on its own within two weeks
– A group of common viruses known as enteroviruses are responsible
for about 90 percent of viral meningitis in the United States
– Most common signs and symptoms: Rash, sore throat, joint aches and
headache
– “Worst headache I've ever had“
• Chronic meningitis
– Ongoing (chronic) forms of meningitis occur when slow-growing
organisms invade the membranes and fluid surrounding the brain
– Although acute meningitis strikes suddenly, chronic meningitis
develops over four weeks or more
– Signs and symptoms: Headaches, fever, vomiting and mental
cloudiness
– This type of meningitis is rare
• Fungal meningitis
– Relatively uncommon
– Cryptococcal meningitis
• Fungal form of the disease that affects people with immune
deficiencies, such as AIDS
– Life-threatening if not treated with an antifungal
medication
• Other meningitis causes
– Meningitis can also result from noninfectious causes, such
as drug allergies, some types of cancer and inflammatory
diseases such as lupus
Harrison’s Principles of Internal Medicine, 17th Edition
CASE
• II month old male infant
• First onset and single episode of
generalized seizure
• coughing with nasal catarrh for the
last 5 days
• T = 38.9C
• Perinatal and postnatal histories
were unremarkable
• The father admitted to be having the
same episodes when he was still
around 5 years old during the height
of his fever
• Neurological examination was
normal
MENINGITIS
• History of infection
• Classic triad of fever, headache, and
nuchal rigidity
• (+) Kernig's sign and Brudzinski's
sign
• Decreased level of consciousness
occurs in >75% of patients and can
vary from lethargy to coma
• Nausea, vomiting, and photophobia
are also common complaints
• Seizures
• Raised ICP
• Reduced level of consciousness,
papilledema, dilated poorly
reactive pupils
ENCEPHALITIS
• “Inflammation of the brain," it usually refers to
brain inflammation resulting from a viral infection
– Primary encephalitis
• Involves direct viral infection of the brain and spinal cord
– Secondary encephalitis
• A viral infection first occurs elsewhere in the body and then
travels to the brain
• In contrast to viral meningitis, where the
infectious process and associated inflammatory
response are limited largely to the meninges, in
encephalitis the brain parenchyma is also
involved
• It can be caused by:
– Bacterial infection
• Spreads directly to the brain (primary encephalitis)
• Bacterial meningitis
– A complication of a current infectious disease
• Syphilis (secondary encephalitis)
– Parasitic or protozoal infestations
• Can also cause encephalitis in people with compromised immune
systems
• Such as toxoplasmosis, malaria, or primary amoebic
meningoencephalitis
– Lyme disease and/or Bartonella henselae may also cause
encephalitis
CASE
ENCEPHALITIS
• II month old male infant
• First onset and single episode of
generalized seizure
• Coughing with nasal catarrh for the
last 5 days
• T = 38.9C
• Perinatal and postnatal histories
were unremarkable
• The father admitted to be having the
same episodes when he was still
around 5 years old during the height
of his fever
• Neurological examination was
normal
• History of infection
• Fever, headache and nuchal rigidity
• (+) Kernig’s and Brudzinski’s sign
• Photophobia and seizures
• Altered level of consciousness
• Evidence of either focal or diffuse
neurologic signs and symptoms
• Focal findings are aphasia, ataxia,
upper or lower motor neuron
patterns of weakness, involuntary
movements and cranial nerve
deficits
• Hallucinations, agitation, personality
change, behavioral disorders, and, at
times, a frankly psychotic state
EPILEPSY
• Classified as a disorder of at least two
unprovoked recurrent seizures
• More common in young and old, plateau at
2nd – 4th decades of life
• In children (0-14 years old)
congenital> trauma=infection>CVA=tumor
• Genetic Predispostion
– The direct result of a known or presumed genetic
defect in which seizures are the core symptom of
the disorder
• Examples include childhood absence epilepsy,
autosomal dominant nocturnal frontal lobe epilepsy,
and Dravet syndrome
• Epileptic Seizures
– No sexual predisposition, may occur at any age
– Loss of consciousness is common
– Onset is usually abrupt and may have a short aura
– Vocalization is present during automatism
Dravet’s Syndrome
•
•
•
•
Severe myoclonic epilepsy of infancy (SMEI)
Generalized epilepsy syndrome
Onset is in the first year of life
Peaks at about 5 months of age with febrile
hemiclonic or generalized status epilepticus
• Boys are twice as often affected as girls
• Prognosis is poor
• Most cases are sporadic
• Family history of epilepsy and febrile
convulsions is present in around 25 percent of
the cases
• Known causative genes are the sodium
channel α subunit genes SCN1A and SCN2A,
an associated β subunit SCN1B, and a GABAA
receptor γ subunit gene, GABRG2
Pathophysiology
Seizure
Generation
Cellular Level
Na+ channels
Increase Influx of Na+
Increase intracellular Na+
and water
Synaptic Level
Cations
K+ channels
GABA
Ca2+ channels
Decrease intracellular
K+
Decreased
Cell hyperexcitability
Hyperexcitable state
Firing of thalamic and cortical
neurons
Increase Tissue excitability
Glutamate
Increased
CASE
DRAVET’S SYNDROME
• II month old male infant
• First onset and single episode of
generalized seizure
• Coughing with nasal catarrh for
the last 5 days
• T = 38.9C
• Perinatal and postnatal histories
were unremarkable
• The father admitted to be
having the same episodes when
he was still around 5 years old
during the height of his fever
• Neurological examination was
normal
• Onset is in the 1st year of life
• Peaks at about 5 months of
age with febrile hemiclonic or
generalized status epilepticus
• Boys are twice as often affected
as girls
• (+)Family History
FEBRILE SEIZURES
Febrile Seizure
• Most common type of seizure that occurs during childhood that is
associated with a febrile illness not caused by an infection of the central
nervous system (CNS), without previous neonatal seizures or a previous
unprovoked seizure, and not meeting the criteria for other acute
symptomatic seizures (International League Against Epilepsy)
• Rare before 9months and after 5 years of age
• The peak age of onset is 14-18 months
• A strong family history of febrile convulsions in siblings and parents
suggests a genetic predisposition.
– In a child with febrile seizure, the risk of febrile seizure is 10% for the
sibling and almost 50% for the sibling if a parent has febrile seizures as
well
Reference: Nelson’s Pediatrics 18th ed. and eMedicine.medscape.com
Febrile Seizure
• Febrile seizures are not associated with reduction in
later intellectual performance, and most children
with febrile seizures have only a slightly greater risk
of later epilepsy than the general population.
• Usually it takes the form of a single, generalized
motor seizure occurring as the temperature rises or
reaches its peak.
• Seldom does the seizure last longer than a few
minutes;
• By the time an EEG can be obtained, there is usually
no abnormality.
• Recovery is complete
Reference: Nelson’s Pediatrics 18th ed. and eMedicine.medscape.com
Risk Factors
•
•
•
•
Family history of febrile seizures
High temperature
Parental report of developmental delay
Neonatal discharge at an age greater than 28 days
(suggesting perinatal illness requiring hospitalization)
• Daycare attendance
• Presence of 2 of these risk factors increases the
probability of a first febrile seizure to about 30%.
• Maternal alcohol intake and smoking during
pregnancy has a 2-fold increased risk.
Reference: Nelson’s Pediatrics 18th ed. and eMedicine.medscape.com
Types of febrile seizure
• Simple
– associated with a core temperature that increases rapidly
to ≥39°C.
– It is initially generalized and tonic-clonic in nature
– lasts a few seconds and rarely <15 min
– followed by a brief postictal period of drowsiness
– occurs only once in 24 hr.
• Complex
– Duration is >15 min
– Focal seizure activity or focal findings are present during
the postictal period.
– Repeated convulsions occur within 24 hr
Reference: Nelson’s Pediatrics 18th ed. and eMedicine.medscape.com
Recurrent Seizures
• Approximately 30–50% of children have recurrent seizures with
later episodes of fever and a small minority has numerous recurrent
febrile seizures.
• Risk factors for recurrent febrile seizures include the following:
– Young age at time of first febrile seizure <12 mon.
– Relatively low fever at time of first seizure
– Family history of a febrile seizure in a first-degree relative
– Brief duration between fever onset and initial seizure
– Multiple initial febrile seizures during same episode
• Patients with all 4 risk factors have greater than 70% chance of
recurrence. Patients with no risk factors have less than a 20%
chance of recurrence.
Reference: Nelson’s Pediatrics 18th ed. and eMedicine.medscape.com
Pathophysiology
•Febrile seizures occur in young
children at a time in their
development when the seizure
threshold is low.
•This is a time when young children
are
susceptible
to
frequent
childhood infections such as upper
respiratory infection, otitis media,
viral syndrome, and they respond
with
comparably
higher
temperatures.
•Animal studies suggest a possible
role of endogenous pyrogens, such
as interleukin 1beta, that, by
increasing neuronal excitability, may
link fever and seizure activity.
•Preliminary studies in children
appear to support the hypothesis
Reference: Nelson’s Pediatrics 18th ed. and eMedicine.medscape.com
History
• The type of seizure (generalized or focal) and its duration should be described
to help differentiate between simple and complex febrile seizures.
• Focus on the history of fever, duration of fever, and potential exposures to
illness.
• A history of the cause of fever (eg, viral illnesses, gastroenteritis) should be
elucidated.
• Recent antibiotic use is particularly important because partially
treated meningitis must be considered.
• A history of seizures, neurologic problems, developmental delay, or other
potential causes of seizure (eg, trauma, ingestion) should be sought.
Physical Examination
•
•
•
•
The underlying cause for the fever should be sought.
A careful physical examination often reveals otitis media, pharyngitis, or a viral
exanthem.
Serial evaluations of the patient's neurologic status are essential.
Check for meningeal signs as well as for signs of trauma or toxic ingestion.
Reference: Nelson’s Pediatrics 18th ed. and eMedicine.medscape.com
CASE
• II month old male infant
• First onset and single episode of
generalized seizure
• Coughing with nasal catarrh for
the last 5 days
• T = 38.9C
• Perinatal and postnatal histories
were unremarkable
• The father admitted to be
having the same episodes when
he was still around 5 years old
during the height of his fever
• Neurological examination was
normal
FEBRILE SEIZURES
• History of infection
• Ages of 3 months and 5 years
• Twice more common in boys
than girls
• Fever and seizures
MANAGEMENT
Diagnostics
• To determine the cause of the fever
• To rule out meningitis or encephalitis
Lumbar Puncture with CSF examination
• cerebrospinal fluid
(CSF) is essential in
confirming the
diagnosis of
meningitis,
encephalitis, and
subarachnoid
hemorrhage
Lumbar Puncture with CSF examination
• Contraindications:
– elevated ICP owing to a suspected mass lesion of
the brain or spinal cord
– symptoms and signs of pending cerebral
herniation in a child with probable meningitis
– critical illness
– skin infection at the site of the LP
– thrombocytopenia
Lumbar Puncture with CSF examination
WBC
Protein
Normal
0-5
lymphocyte
15-45
Acute
bacterial
High
neutrophil
→
(after 5 days)
lymphocytes
High
Others
Low
Turbid
N or slight
increase
Viral
TB
Sugar
50-75
>50% of
blood
sugar
High
lymphocytes
High
Clear
Clear
Low <40
Xanthochromic
EEG
• Not recommended after an initial simple
febrile seizure in children with a normal
neurologic examination
• Typically does not identify specific
abnormalities or help predict recurrent
seizures
• Consideration of EEG if febrile seizures are
complex or recurrent
http://www.merck.com/mmpe/sec19/ch283/ch283c.html
TREATMENT
Treatment for Nasal catarrh
• Pseudoephedrine/Dextromethorphan
can be given for the cough and
decongesting the airways of the infant.
• It works by constricting blood vessels
and reducing swelling in the nasal
passages, which helps you to breathe
more easily. The cough suppressant
works in the brain to help decrease the
cough reflex.
• However, you should not use
decongestants for more than 5-7 days
at a time. This is because they can only
provide short-term relief for catarrh,
and using them for any longer can
make your symptoms worse.
Medical Treatment
• Treatment of infants
with seizures is different
than treatment for
adults. Unless a specific
cause is found, most
infant with first-time
seizures will not be
placed on medications.
Medical Treatment
• Phenobarbital
- enhances the inhibitory
actions of gammaaminobutyric acid (GABA)
on neurons.
- decreases the
occurrence of subsequent
febrile seizures.
- Oral Dosage (as
recommended by the
American Academy of
Pediatrics): 1 to 3 mg/kg.
Medical Treatment
Benzodiazepine
• Centrally acting muscle
relaxant.
• Gel, rectal 2.5 mg (pediatric)
• Anticonvulsant properties
may be in part or entirely due
to binding to voltagedependent sodium channels.
• It can reduce the risk of
subsequent febrile seizures.
• Because it is given
intermittently, this therapy
probably has the fewest
adverse effects. If preventing
subsequent febrile seizures is
essential, this would be the
treatment of choice.
Medical Treatment
• Paracetamol(Acetaminop
hen)
- inhibits prostaglandins
in CNS, but lacks antiinflammatory effects in
periphery; reduces fever
through direct action on
hypothalamic heatregulating center.
-15 mg per kilogram of
weight; taken once every
4 hours, up to 4 times per
day if needed
PREVENTION
Prevention
• Most seizures cannot be
prevented.
• There are some exceptions, but
these are very difficult to control,
such as head trauma and
infections during pregnancy.
• Children who are known to have
febrile seizures should have their
fevers well controlled when sick.
Prevention
• The best way to prevent
fevers is to reduce the
infant's exposure to
infectious diseases.
• Hand-washing is the
single most important
prevention measure for
people of all ages.
Prevention
If another seizure ensues:
• The initial efforts should be
directed first at protecting the
infant from additionally
injuring himself.
• Lie down the infant.
• Remove glasses or other
harmful objects in the area.
• Do not try to put anything in
mouth. In doing so, it may
injure the infant.
• Immediately check if the infant
is breathing. Call a doctor or
proceed to the nearest hosp.