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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.
Clinical Impression Febrile Seizure
DIFFERENTIAL DIAGNOSIS • Meningitis • Encephalitis • 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. • Neisseriameningitidis (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
Haemophilusinfluenzae (haemophilus) • Before the 1990s, Haemophilusinfluenzae 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 • Listeriamonocytogenes (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
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 Bartonellahenselae may also cause encephalitis
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
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
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
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 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 gamma-aminobutyric 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 voltage-dependent 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(Acetaminophen) - inhibits prostaglandins in CNS, but lacks anti-inflammatory effects in periphery; reduces fever through direct action on hypothalamic heat-regulating center. -15 mg per kilogram of weight; taken once every 4 hours, up to 4 times per day if needed
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.
