PAEDIATRICS

Febrile convulsions (kids)

September 16, 2023 / No Comments

Definitions

  1. Convulsion – transient disturbance of cerebral function due to an abnormal paroxysmal discharge from the brain
  2. epilepsy denotes any disorder characterised by recurrent seizures
  3. epilepsy generally regarded as a primary idiopathic illness and excludes secondary seizures
  4. 6% of the population will have a non febrile seizure at some stage of their life
    1. -5% of patients with seizures of identifiable cause will have a subsequent seizure
    2. -50% of those without obvious cause have subsequent seizures
    3. -75% of those with a second seizure will have further seizures

Causes: New Onset Secondary Seizure – Causes by age

  1. Age under 10 years
    1. Febrile Seizure (under age 5 years)
    2. Idiopathic
    3. Congenital
    4. Birth Injury
    5. Head Trauma (including due to Child Abuse)
    6. Metabolic disorder
      1. Hypoglycemia
      2. Hyponatremia – secondary to over-dilution of infant formula
      3. Hypocalcemia
      4. Hypomagnesemia
  2. Age 10 to 40 years
    1. Idiopathic
    2. Head Trauma
    3. Pre-existing focal brain disease
    4. Drug Withdrawal
  3. Age 40 to 60 years
    1. Brain Tumor
    2. Head Trauma
  4. Age over 60 years
    1. Prior Cerebrovascular Accident (32%)
    2. Brain Tumors (14%)
    3. Subdural Hematoma
    4. CNS Infection (Meningitis or Encephalitis)
    5. Alzheimer’s Dementia
    6. Metabolic abnormalities
      1. Uremia
      2. Hyperglycemia or Hypoglycemia
      3. Hyponatremia, Alcohol Withdrawal

Causes: Non-Epileptic Causes of Seizure

  1. Pediatric Seizure mimics
    1. Pseudoseizures
    2. Breath holding Spells
    3. Syncope
  2. Miscellaneous
    1. Febrile convulsions
    2. Hyperthermia
    3. Sleep disorder
  3. Idiopathic
    1. usually 5 – 20 years of age at onset
    2. no specific cause found
    3. epilepsy if recurrent
  4. Congenital
    1. congenital abnormalities
    2. perinatal injuries
  5. Metabolic
    1. hypocalcaemia
    2. hypoglycaemia
    3. hypomagnesemia
    4. phenylketonuria
    5. renal failure
  6. Traumatic
    1. usually occur within 2 years of trauma
    2. higher incidence if dura punctured
  7. Space occupying lesions
    1. middle and later life
    2. account for 13% of new seizures in 35-64 year olds
  8. Vascular
    1. cerebral haemorrhages and infarcts
    2. subarachnoid haemorrhage
    3. AV malformations
    4. acute strokes most common cause in > 65 year olds
  9. Degenerative
    1. Alzheimer’s
  10. Infections
    1. meningitis
    2. encephalitis
    3. commonest cause in 5-15 year olds (along with trauma)
  11. Drugs
    1. Toxin induced/overdose
      1. venlafaxine
      2. bupropion
      3. tramadol
      4. stimulants
      5. theophylline
      6. tricyclic antidepressants and other Na channel blocking agents
    2. withdrawal from alcohol, benzodiazepines,cocaine
      1. commonest cause in 35-64 year olds
    3. Metal Toxicity
      1. Hg Poisoning
      2. Pb Poisoning
  12. Seizures in pregnancy

Distinguish Pediatric Seizures vs. Pediatric Seizure mimics

  1. Elements that are highly suggestive of true seizure activity include:
    1. Lateralized tongue-biting (high specificity)
    2. Flickering eye-lids
    3. Dilated pupils with blank stare
    4. Lip smacking
    5. Increased heart rate and blood pressure during event
    6. Post-ictal phase
  2. Distinguishing Breath-holding spells from Pediatric Seizure
    • Breath holding spells are most common in the 6-18month age range. 
    • One of the key differentiating factors is that there is usually a clear trigger for a breath holding spells such as emotional distress or pain, whereas seizures typically do not have such precipitants. 
    • This pattern of an initiating trigger, followed by emotional upset, crying, pallor, and occasionally LOC is highly suggestive of a breath holding spell. 
    • The breath holding and LOC can lead to brief seizure activity given the decrease cerebral blood-flow. However, the recovery from a breath-holding spell is rapid and complete without a post-ictal phase.
  3. Distinguishing Pseudo-Seizures from True Seizure
    • seizure activity for secondary gain. 
    • side-to side head, arm or leg movements with eyes closed
    • if the eyes are open, the eye movements are normal as opposed to deviated.
    • A bicycling movement of the legs is highly suggestive of pseudo-seizure.
  4. Distinguishing Syncope from Seizure
    1. may or may not have a clear precipitant but the LOC always precedes any perceived seizure activity. Observers may note some brief twitching episodes as opposed to true tonic-clonic movements. 
    2. The recovery from a syncopal episode is rapid and complete.

Distinguish Simple vs. Complex Febrile Seizure

  1. Simple febrile convulsions:
    • These are generalised, tonic-clonic seizures lasting less than 15 minutes that do not recur within the same febrile illness. 
    • tend to occur early in the illness within 24hrs of onset of fever 
    • if the seizure occurs >24hrs after the onset of fever, the suspicion for a bacterial cause of the fever and a pathologic cause for the seizure should be heightened.
  2. Complex febrile convulsions:
    1. These have one or more of the following
      • focal features at onset or during the seizure 
      • Duration of more than 15 minutes 
      • Recurrence within the same febrile illness 
      • Incomplete recovery within 1 hour.
  3. Febrile status epilepticus
    • This is a febrile convulsion lasting for longer than 30 minutes.

Focal features

Focal Motor Signs:

  • Unilateral (one-sided) jerking or twitching of the limbs (e.g., one arm or one leg).
  • Facial twitching on one side.
  • Asymmetric movements.

Focal Sensory Symptoms:

  • Numbness or tingling in a specific part of the body.
  • Visual disturbances, such as seeing flashing lights or shapes in one part of the visual field.
  • Auditory hallucinations, like hearing sounds that are not present.

Autonomic Symptoms:

  • Pallor, sweating, or changes in heart rate localized to one side.
  • Abnormal sensations in the stomach (epigastric sensations).

Focal Cognitive or Emotional Symptoms:

  • Sudden feelings of fear or anxiety.
  • Déjà vu or jamais vu experiences (feeling that something familiar is new or that something new is familiar).
  • Specific memory disturbances.

Focal Behavioral Symptoms:

  • Repetitive behaviors or automatisms (e.g., lip-smacking, chewing movements) that start on one side.

Note: 

  1. It is now recognized that some children can have a presentation with convulsions and an acute infectious illness (particularly gastroenteritis) without documented fever. 
  2. This is sometimes referred to as “afebrile febrile convulsions”
  3. The management and prognosis is the same as for classical febrile convulsions.
  4. This distinction is important because complex seizures may indicate a more serious disease process and usually require a work-up.

simple vs complex febrile seizure

Assessment

  1. Assessment and management need to occur concurrently if the child is actively convulsing.
  2. Key considerations in assessment include:
    1. Any compromise to ABC?
    2. Duration of seizure including pre-hospital period?
    3. Significant past history including seizures, neurological comorbidity including VP shunts, renal failure (hypertensive encephalopathy), endocrinopathies (electrolyte disturbance)?
    4. Focal features?
    5. Fever? (Febrile convulsion or CNS infection)
    6. Anticonvulsant medications including any acute pre hospital treatment?
    7. Previously successful acute anticonvulsant management?
    8. Evidence of underlying cause that may require additional specific emergency management?
      1. Hypoglycemia
      2. Electrolyte disturbance including hypocalcemia
      3. Meningitis
      4. Drug overdose
      5. Trauma (consider occult head trauma)
      6. Stroke and intracranial haemorrhage

    Febrile Convulsion

    1. Definition
      1. Convulsions, in a child between 6 months and 6 years of age
      2. in the setting of an acute febrile illness
      3. without previous afebrile seizures, significant prior neurological abnormality, and no CNS infection.
    2. occur in 3% of health children
    3. are normally associated with simple viral infection, are benign
    4. Greater risk of recurrence if younger at initial
      1. 12 months – 50%
      2. 2 years – 30%
    5. No increased risk of epilepsy – 1%. May be increased if prolonged or complex/focal
    6. If < 6 months consider meningitis/encephalitis

    Acute Management

      1. once the convulsion has terminated, the aim of the assessment is to determine the cause of the fever.
      2. Fever control (RCH guidelines)
        1. Paracetamol has NOT been shown to reduce the risk of further febrile convulsions
        2. It may be used for pain / discomfort associated with febrile illnesses such as otitis media. 
        3. The parents should understand the reasons for its use and be discouraged from using it solely to reduce their child’s fever
      3. Treatment
        1. Treat the seizure when necessary in the same manner as afebrile seizures  – Midazolam etc
        2. Manage the underlying cause of the fever
      1. Which Patients with Febrile Seizures Require a Work-up?
      1. If the child meets the criteria for a simple febrile seizure
        1. no dedicated seizure workup is required and you evaluate the patient as if they solely had a fever.
        2. no greater risk for serious bacterial infection than age-matched controls who have not seized.
        3. should be worked up as if they presented with fever and no seizure. 
        4. measurement of serum electrolytes or glucose in particular has no role in the workup of simple febrile seizures.
        5. A workup beyond a basic febrile workup should be considered if the child appears unwell or meets any of the criteria of a complex febrile seizure.
      1. complex febrile seizures
        1. younger the child 🡪 aggressive the work-up should be. 
        2. In a child less than 6 months of age reconsider your diagnosis, especially the possibility of CNS infection 
        3. 25 % of children with meningitis will present with a new onset febrile seizure.
          1. will almost always display persistent mental status abnormalities along with other signs of meningitis such as nuchal rigidity, focal siezures and petechia.
      1. Counselling Parents about Pediatriac Seizures
        1. Reassurance
        2. Safety – place the child in the recovery position and do not place anything in the child mouth
        3. Risk of recurrence 33% overall with a higher risk in children
          1. temperature < 40.0°C at first convulsion
          2. family history of febrile seizures
        4. Risk of Epilepsy
          1. 2% after a simple febrile seizure
          2. 5 % after a complex febrile seizure
          3. (compared to 1% in the general population)
        5. Discharge when
          1. Return to normal neurological state following simple febrile convulsion 
          2. Serious bacterial infection excluded or adequately treated 
          3. Parental education regarding febrile convulsions
          4. If discharging a patient home following a febrile convulsion, it is important to give the family advice regarding what to do in the event of a future convulsion. 
          5. Verbal advice should be reinforced with written advice

      Non-febrile Pediatric Seizures

      History

      • MOST COMMON <6 MONTHS: Hyponatremia secondary to over-dilution of infant formula
      • Detailed chronological history of events and behaviours before, during and after the seizure
      • History should be taken from the child if possible and obtain bystander account
      • Ask about:
        • aura, focal features
        • level of awareness
        • recent trauma, consider non-accidental injury
        • focality of limb or eye movement
        • post-ictal phase/hemiparesis 
      • Relevant past history
        • Family history of seizures or cardiac disorders/sudden death
        • History suggestive of absence seizures or myoclonic jerks, nocturnal events
        • Developmental history   

      Red Flags

      • Head injury with delayed seizure
      • Developmental delay or regression
      • Headache prior to the seizure
      • Bleeding disorder, anticoagulation therapy
      • Drug/alcohol use
      • Focal signs 

      Examination

      • Skin Look for lesions such as
        • cafe au lait spots (neurofibromatosis)
        • adenoma sebaceum or ash leaf spots (tuberous sclerosis), 
        • port wine stains (Sturge-Weber syndrome)
        • Unexplained bruising should raise the suspicion of a bleeding disorder or child abuse.
      • Head
        • bulging fontanelle
        • microcephaly
        • dysmorphic features
        • signs of trauma
        • presence of a VP shunt.
      • Eyes Examine for
        • papilledema 
        • retinal hemorrhages
      • Neck
        • signs of meningeal irritation.
      • Hepatosplenomegaly
        • May indicate a metabolic or glycogen storage disease

      Work-up

      1. Consider ordering laboratory studies on pediatric patients who:
        1. Have prolonged seizures
        2. < 6 months of age (specifically for hyponatremia)
        3. History of diabetes, metabolic disorder, dehydration, or excess free water intake
        4. Altered LOC
        5. Suspect formula over-dilution in under 6 month olds (Hyponatremia, treated with 3ml/kg of hypertonic (3%) normal saline)
      2. Neuroimaging(CT) if:
      1. Focal seizure or persistent seizure activity
      2. Focal neurologic deficit
      3. VP shunt
      4. Neurocutaneous disorder
      5. Signs of elevated ICP and history of trauma or travel to an area endemic for cysticercosis
      6. Patients who have immunocompromising diseases (malignancy or HIV),
      7. Hypercoagulable states (sickle cell disease), or bleeding disorders

      Disposition 

      1. depends on age, serial physical examinations, initial work-up and follow-up capabilities
      2. Under 6months of age 
      1. generally require a full workup and are usually admitted for observation
      2. emergency management of pediatric seizures
      3. 6 months and 2 years of age
      1. disposition will depend on blood work
      2. reassessment and the ability to have close follow-up.
      3. Over 2 years of age
      1. those who have returned to baseline
      2. have a normal neurological exam with normal workup are often safe to be discharged to close outpatient follow-up
      3. Otherwise, admit.

      Emergency Management 

        • Aim to identify reversible cause and manage accordingly.
        • Seizures lasting more than 5 minutes should be treated.
        • EEG should not be routinely performed after a first afebrile seizure.
        • Ensure parental education regarding safety and future seizures.
        • Initial support
          • In most situations, observation for 5 minutes is appropriate whilst waiting for seizure to stop spontaneously
          • Treat the child the way the parents will at home – keep safe and observe
          • At this stage there is no need to check oximetry or apply oxygen 

        Parental Education: Safety and Management of Future Seizures

        Reassurance

        • Benign Nature: Explain that febrile seizures are generally benign and do not cause brain damage or long-term health issues.
        • Low Risk of Epilepsy: Emphasize that the risk of developing epilepsy after a simple febrile seizure is very low, around 1% (only slightly higher if complex seizures).

        Safety Measures During a Seizure

        • Recovery Position: Place the child on their side in the recovery position to prevent choking and ensure an open airway.
        • Avoid Restraint: Do not try to hold or restrain the child during the seizure; this can cause injury.
        • Mouth Safety: Do not put anything in the child’s mouth; it is a myth that they can swallow their tongue, and putting objects in the mouth can cause choking or dental injuries.
        • Clear the Area: Remove any nearby objects that could cause injury during the seizure.
        • Time the Seizure: Note the duration of the seizure. If it lasts more than 5 minutes, seek immediate medical help.

        After the Seizure

        • Post-Ictal Phase: The child may be confused, drowsy, or irritable after the seizure. This is normal and typically lasts a few minutes to an hour.
        • Monitoring: Stay with the child until they have fully recovered. Ensure they are breathing normally and are responsive.

        Risk of Recurrence

        • Recurrence Rate: Inform parents that about one-third of children who have a febrile seizure will experience another one.
        • High-Risk Factors: Recurrence is more likely if the first seizure occurred at a younger age (especially under 12 months) or if there is a family history of febrile seizures.

        Managing Fever

        • Fever Control: While controlling fever does not prevent febrile seizures, it can help with the child’s comfort.
          • Use paracetamol or ibuprofen for fever management according to the recommended dosages.
          • Encourage fluids to prevent dehydration.
          • Dress the child in light clothing to avoid overheating.

        When to Seek Medical Help

        • Prolonged Seizures: Seek immediate medical help if a seizure lasts more than 5 minutes.
        • Repeated Seizures: If the child has more than one seizure during the same illness, medical evaluation is necessary.
        • Post-Seizure Concerns: If the child does not return to their usual state after the seizure, or if they have difficulty breathing, seek medical attention.

        Emergency Plan

        • Contact Information: Keep contact details for the family doctor or pediatrician readily available.
        • Emergency Medication: In some cases, a doctor may prescribe emergency medication like rectal diazepam or intranasal midazolam to be used if a seizure lasts too long.

        Written Instructions

        • Provide parents with written instructions and resources on how to handle future seizures. This can include:
          • Steps to take during a seizure.
          • Signs that require emergency medical attention.
          • Tips for managing fever and preventing overheating.

        Long-Term Outlook

        • Regular Follow-ups: Schedule regular follow-ups with the pediatrician to monitor the child’s development and address any concerns.
        • Educational Resources: Provide parents with access to reliable sources of information about febrile seizures (e.g., pamphlets, websites).

        By educating parents on these aspects, you help them feel more prepared and less anxious about managing febrile seizures, ensuring the safety and well-being of their child.

        Status Epilepticus 

        Seizure lasting > 5 minutes, OR Consecutive seizures without a return to baseline in between

        afebrile seizure

        Start with ABCs

        1. A, B: evaluating the airway and provide supplemental oxygen
        2. C: establish cardiac monitoring + Access (IV/ IO – may be difficult and time ocnsuming)
        3. Check BGL
        4. focus on terminating the seizure and the goal is to terminate all seizure activity within 60 seconds.

        1st line

        1. Benzodiazepines – Administration of EARLY benzodiazepines is a priority!
          1. The choice of benzodiazepine and the choice of route is not the major determinant of efficacy. 
        Midazolam 0.15   mg/kg IV/IM (max 10 mg)0.3 mg/kg buccal/IN (max 10 mg)
        Diazepam 0.3 mg/kg IV/IO (max 10 mg)
        0.5 mg/kg PR (max 10 mg)         		IV dose preferableDo not give IM
        1. Clinical Pearl: Once you have started giving your antiepileptic medications start drawing up the next dose of medication so that it is ready to administer if seizure activity continues to persists

        2nd line

        1. Phenytoin
          1. Loading dose: 20 mg/kg IV/IO 
          2. less effective for the treatment of seizures due to toxins or drugs and may intensify

        seizures caused by cocaine, other local anesthetics, theophylline, or lindane.

        1. Levetiracetam 
          1. 40 mg/kg IV/IO (max 3g)
          2. Dilute to 50 mg/mL and infuse over 5 mins 
        2. Phenobarbitone
          1. 20 mg/kg IV/IO (Max 1g)
          2. Dilute to 20 mg/mL or weaker and infuse over 20 mins (max rate 30 mg/min) in a monitored patient.
          3. Stop infusion when seizure ceases

        3rd  line 

        Failing this:

        1. Phenobarbitone (popular in paeds, if available)
        2. Intubation with propofol induction (usually no ongoing  paralysis to assess for persistent seizure activity but EEG may be the only way to properly ascertain this
        1. Refractory Status Epilepticus
          1. initiate continuous IV infusions of:
            1. Midazolam
              1. 1 – 5 micrograms/kg/min
            2. Pentobarbital
            3. Pyridoxine (100mg IV)
              1. Consider it for intractable seizures in the prenatal and neonatal period (Pyridoxine-dependent epilepsy)
          2. Anticipate need to support respiration. 
          3. Thiopentone or Propofol and rapid sequence induction (RSI) may be required for seizure control.
            1. Propofol
              1.  2.5mg/kg stat followed by infusion at 1-3mg/kg/hr for no longer than 48 hours 
              2. contraindicated with ketogenic diet
            2. Thiopentone
              1. 2-5 mg/kg slowly stat followed by IV infusion at 1-4 mg/kg/hr 
            3. Ketamine
              1. 63.5% cessation rates in seizures in pediatric refractory status epilepticus, however our experts do not recommend it as a first line agent in this setting

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