NICU

Neonatal Seizure

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Neonatal Seizure, Newborn Seizure, Seizure Disorder in Newborns

  • Types (Order of decreasing frequency)
  1. Background
    1. Generalized tonic-clonic Seizures do not typically occur in the immature nervous system of a neonate
    2. Neonatal Seizures typically start focally and then generalize
  2. Subtle findings
    1. Horizontal Eye Deviation
    2. Drooling
    3. Sucking
    4. Lip smacking
    5. Swimming or pedaling motion
  3. Generalized Tonic Seizure (Preterm Infants)
    1. Prolonged limb extension
  4. Multifocal Clonic Seizure (Full-Term infants)
  5. Focal Clonic Seizure (Full-Term more then Preterm)
    1. Focal rhythmic jerking
  6. Myoclonic (Both Preterm and Full-Term)
  7. Infantile Spasms (2-3% of childhood Epilepsy)
    1. Associated with serious underlying conditions (e.g. Tuberous sclerosis, Phenylketonuria, Agenesis of the Corpus Callosum)
  • Causes
  1. Asphyxia or Hypoxic Encephalopathy (12-24 hours after birth)
    1. Consider Induced Therapeutic Hypothermia after Seizure aborted
  2. Interventricular Hemorrhage
  3. Hydrocephalus
  4. Microcephaly
  5. Electrolyte imbalance
    1. Hypoglycemia
    2. Hyponatremia
    3. Hypocalcemia
    4. Hypomagnesemia
  6. Infection (esp. if mother had peripartum infectious symptoms)
    1. TORCH Infection (esp. Toxoplasmosis, CMV, HSV)
    2. Coxsachievirus
    3. Escherichia coli
    4. Group B Streptococcus (GBS Sepsis)
  7. Inborn Errors of Metabolism (including Amino Acid disturbance)
    1. Obtain Serum Ammonia
    2. Obtain serum or Urine Ketones
  8. Drug Withdrawal
  9. Pyridoxine Deficiency (Vitamin B6)
  10. Vitamin K Deficiency
  11. Cardiac Disorder (e.g. channelopathy)
    1. Obtain Electrocardiogram
  12. Dysgenic brain
  13. Neonatal sleep Myoclonus
  14. Benign familial Neonatal Seizures
  15. Benign idiopathic Neonatal Seizures (Fifth Day Fits) or familial
    1. Onset in first 3-5 days of life
    2. Resolves in weeks
  • Imaging
  • Evaluation
  1. Requires broad evaluation (e.g. Neonatal Sepsis, Birth Trauma, inborn error of metabolism)
  • Management
  1. See Status Epilepticus
  2. Seizure abortive measures
    1. See Seizure Emergency Management
    2. Step 1: Diazepam 0.3 mg/kg rectally
    3. Step 2: Phenobarbital 20 mg/kg slow IV push
      1. May repeat dose at 10 mg/kg slow IV push
      2. Risk of apnea, respiratory depression and Hypotension
      3. Phenobarbital much higher efficacy in newborns than Levetiracetam
      4. Sharpe (2020) Pediatrics 145(6) +PMID:32385134 [PubMed]
    4. Step 3: Choose One
      1. Levetiracetam 40 mg/kg IV
        1. May repeat for a second dose at 20 mg/kg
        2. Preferred agent if there is a comorbid cardiac disorder
      2. Phenytoin or Fosphenytoin 18 mg/kg IV over 20 min (10 min for Fosphenytoin)
      3. Midazolam 0.05 to 0.15 mg/kg
  3. Reversible cause management
    1. Hypoglycemia Management
      1. Give D10W 2-4 ml/kg IV
    2. Pyridoxine Dependent Encephalopathy
      1. Pyridoxine 100 mg IV
      2. Observe for apnea
    3. Neonatal Sepsis
      1. Empiric Neonatal Sepsis treatment should include Acyclovir
      2. Evaluation with cultures and Lumbar Puncture
    4. Other measures
      1. Severe Hyponatremia Management (6 ml/kg 3% saline)
      2. Severe Hypocalcemia management (50-100 mg/kg Calcium Gluconate over 10-20 min)
      3. Severe Hypomagnesemia management (2-4 ml 2% MgSO4)
      4. Consider Folate replacement
  • References
  1. (2016) CALS Manual, 14th ed, p. I-210
  2. Claudius (2023) Pediatric Pearls: Neonatal Seizures, EM:Rap, December, accessed 12/1/2023