What is on the differential diagnosis for a febrile seizure?
CNS infection (meningitis/encephalitis), Idiopathic epilepsy, Ingestion/poisoning, Head trauma
What are the findings from testing with a febrile seizure?
CBC - Normal. CSF - Normal without organisms.
What are some causes of unresponsiveness in a child?
Seizures, Syncope due to breath-holding spells, infection (meningitis/encephalitis), toxic ingestions/poisoning, head trauma with loss of consciousness, intracranial processes (tumor/hemorrhage), intussusception.
Include metabolic disturbances, head trauma, genetic syndromes, developmental abnormalities, fever, idiopathic.
Syncope due to breath-holding spells:
- Common between ages 1 and 3 years
- May be cyanotic or pallid
- Episodes quickly self-resolve; no postictal state
- Up to 20-40 percent of children with meningitis can present with seizure activity
- Children with encephalitis will frequently present with fever and seizure
- Enteroviral and herpes simplex virus infections are typical pathogens for encephalitis.
- Most commonly seen between 9 mo-3 yrs
- Various medications may cause unresponsiveness (eg, opiates, benzodiazepines, clonidine, oral diabetic agents)
- Lethargy with a near-unresponsive state may be seen between episodes of colicky pain
- Dehydration due to vomiting and third-spacing of fluids may lead to mental status changes
Result of excessive neuronal activity in the brain. Types include generalized tonic-clonic seizure, absence epilepsy (petit mal seizures), simple partial seizures, complex partial seizures.
Generalized tonic-clonic seizure:
- Most common type in children
- Begins abruptly with tonic (rigid) stiffening of all extremities and upward deviation of the eyes
- Clonic jerks of all extremities follow the tonic phase
- Finally, child becomes flaccid; urinary incontinence may occur
Absence epilepsy (petit mal seizures):
- Generalized seizure, but consciousness is regained more quickly than seen in a generalized tonic-clonic seizure
- Seen in children starting around age 3
- Characterized by loss of environmental awareness and automatisms
- Not associated with loss of tone
- May be precipitated by hyperventilation or photic stimulation
Simple partial seizures:
- Motor signs in a single extremity or one side of the body
- Focal onset seizure activity may spread to become generalized
Complex partial seizures:
- Alteration of consciousness is hallmark feature
- Signs and symptoms tend to localize around the eyes, the mouth, and the abdomen
- Commonly accompanied by automatisms, quasi-purposeful motor or verbal behaviors that are repeated inappropriately
- Lasts 30 sec to 2 min and are associated with postictal phase
- Secondary generalization can occur
What are conditions that mimic seizures?
Motor tics, myoclonus, gastroesophageal reflux (sandifer’s syndrome), pseudo seizure.
What is the etiology of febrile seizures?
- Typically a benign and self-limited illness like a viral infection causes a fever that triggers a seizure in a susceptible host (young child, positive family history, etc)
- With more serious CNS infection (such as meningitis or encephalitis), the infection itself causes both fever and seizure.
- Prolonged fever prior to the seizure - especially with irritability or inconsolability - is an indication of a more serious CNS condition causing the seizure
What is the epidemiology for febrile seizures?
- One of the most common reasons for seizures in children
- Febrile seizures occur in children ages 6-60 mo at a frequency of 2-4 percent and tend to occur early in the febrile illness (often on the first day)
- Febrile seizures are hereditary, but mode of inheritance is unclear
Classification of febrile seizures:
Simple febrile seizure: More common, last less than 15 min, occur once in a 24 hr period, generalized.
Complex febrile seizure: Less common, last greater than 15 min, occur more than once in 24 hr period, focal
What is the recurrence risk for febrile seizures:
If a child has a first febrile seizure before age 12 mo, the recurrence risk for a second febrile seizure is about 50 percent. If first seizure is after 12 mo of age, the recurrence risk is about 30 percent. Parents should be reassured that recurrent, simple febrile seizures have no long-term effects on child development.
What is the risk of epilepsy in a patient with febrile seizures?
- Risk of developing epilepsy in children with simple febrile seizures is slightly increased above the 0.5-1 percent baseline population risk.
- Epilepsy more common among children with early, recurrent febrile seizures, especially if there is a family history of epilepsy
- Children with complex febrile seizures and those with pre-existing developmental abnormalities are at increased risk
Causes of fever without a source:
Viral infection, Occult bacteremia, UTI, Bacterial meningitis
Many common viral infections (eg enterovirus, adenovirus) may cause significant fever in a young child without any additional clinical signs or symptoms (eg congestion, cough, diarrhea, or rash)
- Occult bacteremia may also cause fever without additional clinical signs or symptoms
- Febrile children ages 3-36 mo without a discernible focus of infection may have an “occult” bacteremia, usually caused by Strep pneumo or Hemophilus influenza type B.
- Since the intro of the protein-polysaccharid conjugate pneumococcal vaccine (PCV-7), the rates of invasive pneumococcal infections have declined. And Hemophilus influenzae, type B - once a feared pathogen- is now uncommon in the US due to universal vaccination.
- Undiagnosed, the child with occult bacteremia is at risk for the development of a more serious bacterial infection, such as meningitis or osteomyelitis, through bacterial seeding of these distant sites.
- Common cause of fever in children
- Because small children cannot complain of dysuria, frequency or costoverterbral angle (CVA) tenderness, UTI must be ruled out by laboratory testing.
- Clinical practice guidelines suggest when it is appropriate to obtain a urine specimen in the workup of a fever without a source.
One of the most potentially serious infections in infants and children.
What is the epidemiology of bacterial meningitis?
Increasingly uncommon due to immunization (and herd immunity), but potentially devastating.
What is the etiology of bacterial meningitis?
- Bacterial meningitis in immunized children 2 mo to 12 years of age is usually due to Step pneumo or Neisseria meningitides.
- In younger infants, gram negative organisms, such as Escherichia coli, and organisms like Group B strep (strep agalactiae) need to be considered
How does bacterial meningitis present?
- May present with increasing lethargy and irritability, as well as signs of meningeal irritation (nuchal rigidity or meningismus).
- Alternatively, non-specific findings, including fever (in 90-95 percent of cases), anorexia, poor feeding, symptoms of an upper respiratory infection, myalgia, and tachycardia may predominate.
How do you treat bacterial meningitis?
- In cases in which meningitis is highly suspected, antibiotics are generally given empirically as soon as the CSF culture is obtained (and in severe cases, even beforehand).
- Start with high-dose IV antibiotics directed at the most likely organisms (usually a 3rd ben cephalosporin and vancomycin). Then tailor antibiotics based on sensitivities.
- Treatment duration: 7-14 days
What are complications of bacterial meningitis?
- Stroke, subdural effusions, and syndrome of inappropriate anti-diuretic hormone (SIADH) secretion
- Developmental delay, seizures, and hearing loss
- Unusual for treated meningitis to be fatal
What are the bacterial meningitis findings in CSF?
Decreased CSF glucose. Decreased CSF glucose: blood glucose ratio. Increased CSF protein. Increased WBC count. Increased percentage of polymorphonuclear cells in CSF WBCs.
What are the viral meningitis findings in CSF?
Increased CSF WBC count. Variable percentage of polymorphonuclear cells in CSF WBCs. Protein and glucose normal.
What types of questions should be asked when obtaining a seizure history?
- Why did you suspect something was wrong?
- What was the first thing you noticed?
- Did you notice any movements in his arms and legs? How would you describe them?
- Establish a clear timeline of events including how child recovered.
What is supportive evidence of a true seizure (as opposed to a pseudo seizure)?
- History of alteration or loss of consciousness
- Deviation of eyes
- Rhythmic motor movements that cannot be stopped by touching or holding the child
- Postictal state
What is on the differential diagnosis for febrile seizure?
Infection (meningitis/encephalitis), Epilepsy, Ingestion/poisoning, Post-traumatic seizure.
Usually occur on the first day of the illness. Fever greater than 38 deg C is typically seen. Children with febrile seizures are developmentally normal and often have a positive family history for other first-degree relatives with febrile seizures as children.
Approx. 30 percent of infants with meningitis present with a seizure. However, they typically have other signs of illness (vomiting, persistent lethargy, behavior change). Because clinical signs and symptoms of meningitis can be subtle in children, a febrile child with irritability and a seizure (esp. if he has not recovered to normal activity and behavior after a period of observation) should have meningitis including in the differential diagnosis, even when the physical exam does not demonstrate a stiff neck.
A fever often triggers the first seizure in a child with epilepsy. Although some children with epilepsy also have developmental delay due to genetic, congenital or acquired disorders (symptomatic epilepsy), many children with epilepsy are developmentally normal (idiopathic epilepsy).
A poisoning (accidental ingestion) may lead to a generalized seizure. Examples include hypoglycemia due to a diabetic medication, lead poisoning, and acute alcohol poisoning.
Diagnostic studies for fever without a source with CNS symptoms:
WBC count and differential, CBC and blood culture, Urinalysis, Urine culture, lumbar puncture.
White blood cell count and differential:
A low or high white blood cell count, as well as a left shift, are sensitive indicator of a possible bacterial infection.
CBC and blood culture:
In many cases occult bacteremia resolves on its own without sequelae; however, there is the possibility that untreated occult bacteremia may go on to seed other sites, such as the meninges or a bone or joint. Risk of disease is low but burden of disease may be high (eg, missed bacteremia progressing to bacterial meningitis). Especially important to obtain a CBC and blood culture when immunization status is unclear.
A urinalysis, looking for evidence of pyuria and bacteria, should be checked routinely in males less than 6 mo old (less than 12 mo old if uncircumcised) and females less than 12 mo old.
A positive culture is the gold standard for diagnosing infection. A urine culture should be obtained from males less than 6 mo old (less than 12 mo old if uncircumcised) and females less than 12 mo old. Cultures are only as good as the sample, so most pediatricians will catheterize infants and toddlers to obtain the specimen.
The younger the child, the more subtle the signs of meningitis may be. Very young infants (less than 3 mo to under 6 mo) with bacterial meningitis may not show signs of nuchal rigidity and should undergo lumbar puncture for spinal fluid. Strongly consider lumbar puncture after the first seizure in a child less than 12 months. Potentially consider lumbar puncture in children 12 to 18 months. A LP should also be a strong consideration in children older than 6-12 months with atypical seizures, children whose immunization status is incomplete or unknown, or if there is persistent irritability in children slow to return to baseline behavior.
How do you best manage a fever?
- If child is uncomfortable, may give NSAID medicines (acetaminophen, ibuprofen)
- However, studies show that this does not prevent recurrence of febrile seizure
How do you best manage a seizure?
- A child experiencing seizure should be placed on his side to avoid choking on stomach contents or saliva
- Keep child in safe setting to minimize risk of injury while seizing
- Do not put anything in his mouth
- Do not restrain movements
- Call 911 if seizure lasts greater than 5 minutes
What is anti-seizure prophylaxis?
Should not be used for children with simple febrile seizures due to serious side effects!