Causes of Seizures in Pediatric Patients
The most common causes of seizures in pediatric patients include hypoxic-ischemic encephalopathy, intracranial hemorrhage, infections, genetic disorders, and malformations of cortical development, with etiology varying significantly by age group. 1, 2
Age-Specific Etiologies
Neonatal Period (Birth to 28 days)
- Hypoxic-ischemic encephalopathy (HIE): Most common cause (46-65%) 2
- Intracranial hemorrhage and perinatal ischemic stroke: 10-12% of cases 1, 2
- Infections: Meningitis, encephalitis
- Genetic/metabolic disorders: May present with treatment-resistant seizures
- Timing significance:
Infancy (29 days to 1 year)
- Febrile seizures: Begin at 6 months, common cause 1
- Developmental brain abnormalities: Malformations of cortical development
- Genetic epilepsy syndromes: Infantile spasms, Dravet syndrome
- Metabolic disorders: Inborn errors of metabolism
- Infections: Meningitis, encephalitis
Early Childhood (1-5 years)
- Febrile seizures: Peak incidence, affecting 2-5% of children 1
- Genetic epilepsy syndromes
- Post-traumatic seizures
- Infections: Viral encephalitis, bacterial meningitis 1
- Brain tumors
School Age and Adolescence (6-18 years)
- Idiopathic/genetic epilepsy syndromes
- Trauma: Head injuries
- Infections: Encephalitis, meningitis
- Vascular abnormalities: Arteriovenous malformations
- Brain tumors
- Autoimmune encephalitis: Often with antibody-mediated disease 1
Specific Causes by Category
Structural Causes
- Traumatic brain injury: Post-traumatic seizures 1
- Vascular disorders: Stroke, hemorrhage, arteriovenous malformations
- Intracerebral hemorrhage: Associated with acute symptomatic seizures in 48% of cases 3
- Brain malformations: Cortical dysplasia, heterotopias
- Tumors: Primary brain tumors, metastatic lesions
Infectious Causes
- Bacterial: Meningitis, brain abscess
- Viral: Encephalitis (HSV, Japanese encephalitis) 1
- Parasitic: Neurocysticercosis, cerebral malaria
- Fungal: Cryptococcal meningitis
Genetic/Metabolic Causes
- Genetic epilepsy syndromes: Dravet syndrome, KCNQ2-related epilepsy
- Inborn errors of metabolism: Mitochondrial disorders, amino acid disorders
- Neurocutaneous syndromes: Tuberous sclerosis, neurofibromatosis
Immune-Mediated Causes
- Autoimmune encephalitis: Anti-NMDA receptor encephalitis
- Acute disseminated encephalomyelitis (ADEM): Often mistaken for viral encephalitis 1
- Rasmussen's encephalitis: Rare, progressive epileptic disorder 1
Systemic Causes
- Fever: Febrile seizures (not prevented by antipyretics) 1
- Electrolyte disturbances: Hyponatremia, hypocalcemia
- Hypoglycemia: Can lead to seizures and unconsciousness 1
- Toxic exposures: Medications, recreational drugs, environmental toxins
Clinical Pearls and Pitfalls
Important Considerations
- Simple febrile seizures (generalized, <15 minutes, no recurrence within 24 hours) do not require neuroimaging 1
- Seizures can be subtle in neonates and may not present with classic tonic-clonic movements 2
- Epilepsy comorbidities are common, including intellectual disability (25%), learning disabilities, and ADHD 4
- Drug-resistant epilepsy develops in approximately 25% of children with epilepsy 4
Diagnostic Pitfalls
- Seizure mimics must be considered for accurate diagnosis 4
- Non-convulsive status epilepticus can only be diagnosed with EEG and should be considered in patients with unexplained encephalopathy 1
- Paradoxical excitation can occur in 10-30% of children under 8 years when treated with benzodiazepines 5
- Autoimmune causes are increasingly recognized and may present with both seizures and movement disorders 1
Warning Signs Requiring Immediate Attention
- Seizure lasting >5 minutes
- Multiple seizures without return to baseline between episodes
- Failure to return to baseline within 5-10 minutes after seizure stops
- Seizures with respiratory distress or traumatic injuries
- Seizures occurring in water or associated with choking 1
Understanding the diverse etiologies of pediatric seizures is crucial for appropriate diagnostic workup, treatment selection, and prognosis determination.