Clinical meaning
Seizures in children result from abnormal, excessive, synchronous neuronal discharge in the brain. Febrile seizures are the most common seizure type in children, occurring in 2-5% of children aged 6 months to 5 years during febrile illness (temperature typically >38.3C/101F). They are classified as simple (generalized tonic-clonic, <15 minutes, single episode per illness, no focal features) or complex (focal onset, >15 minutes, recurrent within 24 hours, or Todd paralysis). Simple febrile seizures have an excellent prognosis with no increased risk of epilepsy; complex febrile seizures carry a slightly increased risk. The pathophysiology involves immature thermoregulatory mechanisms and increased neuronal excitability during rapid temperature elevation — the RATE of temperature rise matters more than the absolute temperature. Status epilepticus is a neurological emergency defined as continuous seizure activity lasting >5 minutes or two or more seizures without return to baseline consciousness. In children, status epilepticus causes progressive metabolic acidosis, hyperthermia, rhabdomyolysis, and eventually neuronal injury from excitotoxicity (excessive glutamate release causing calcium influx, mitochondrial failure, and cell death). Time is critical: the longer the seizure lasts, the more resistant it becomes to treatment (due to GABA receptor internalization and glutamate receptor upregulation). Developmental considerations are essential — infants may present with subtle seizures (eye deviation, lip smacking, bicycling movements) rather than classic tonic-clonic activity. Neonatal seizures are almost always symptomatic of underlying pathology (hypoxic-ischemic encephalopathy, intracranial hemorrhage, infection, metabolic disturbances).