- Occurrence of an aura.
- Alteration in or impaired consciousness or behavior.
- Abnormal movement.
- Interictal trauma or incontinence.
- Eyewitness account.
- Presence of fever.
- Postictal confusion, lethargy, or sleepiness.
- Diagnostic electroencephalogram.
- Abnormality on neuroimaging.
Despite an alarming appearance, a single seizure rarely causes injury or permanent sequelae or signals the onset of epilepsy. The lifetime risk for seizure is 10% but only 2% of the population develops epilepsy, defined as usually unprovoked, recurrent seizures. The annual number of new seizures in children and adolescents is 50,000-150,000, only 10,000-30,000 of which constitute epileptic seizures.
Epilepsy has an annual incidence of 50 and a prevalence of 500-1000 per 100,000 population. The incidence is high in childhood, decreases in midlife, and then peaks in the elderly. Generally, epilepsy presents as repetitive seizures, but even a single seizure coupled with a significant abnormality on neuroimaging or a diagnostic electroencephalogram (EEG) can signify epilepsy. During childhood the incidence of partial seizures is 20 per 100,000; generalized tonic-clonic seizures, 15 per 100,000; and absence seizures, 11 per 100,000.
Only about 30% of children get a medical evaluation after a single seizure. In contradistinction, more than 80% of children with a second seizure obtain medical assistance. Recognizable, treatable seizure etiologies; negative family histories; normal physical examinations; lack of head trauma; normal EEG findings; and normal neuroimaging results indicate low risk for seizure recurrence. Each year about 3% of 6-month-old to 6-year-old children have a febrile seizure, the most common seizure entity. The likelihood of these children developing epilepsy is extremely low.
Jana LA, Shu J: Heading home with your newborn. 2nd Ed. Elk Grove Village. AAP. 2011:1-372.
Shelov SP, Altmann TR, eds: Caring for your baby and young child birth to age 5. 5th Ed. Bantam Books. AAP. 2009:1-892.
A seizure results from an abnormal, transient outburst of involuntary neuronal activity. Anoxic degeneration, focal neuron loss, hippocampal sclerosis (common in temporal lobe epilepsy), and neoplasia are examples of pathologic central nervous system (CNS) changes that can produce seizures. Why a seizure spontaneously erupts is unclear, but abnormal ion flow in damaged neurons initiates the event.
Seizures are either generalized (a simultaneous discharge from the entire cortex) or partial (focal, a discharge from a focal point within the brain). Generalized seizures impair consciousness and, with the exception of some petite mal (absence) spells, cause abnormal movement, usually intense muscle contractions termed convulsions. Because generalized convulsions occur most commonly in the absence of a focal defect, the initiating mechanism of a generalized seizure is less well understood than that of a partial seizure from a focal CNS lesion. Partial seizures may either impair consciousness (complex) or not (simple) and can start with almost any neurologic complaint, the aura, ...