Definition of Epilepsy
Epilepsy is a brain disorder defined by recurrent unprovoked seizures, specifically requiring either: (1) at least two unprovoked seizures occurring more than 24 hours apart, (2) one unprovoked seizure with ≥60% probability of recurrence over the next 10 years, or (3) diagnosis of an epilepsy syndrome. 1, 2, 3
Core Conceptual Framework
Epilepsy represents more than just recurrent seizures—it is characterized by an enduring predisposition of the brain to generate abnormal electrical activity. 3, 4 This distinguishes it from isolated or provoked seizures that occur in response to acute insults (such as metabolic disturbances, trauma, or infections), which do not constitute epilepsy. 5, 6
What Constitutes a Seizure
A seizure is defined as a transient occurrence of signs and/or symptoms resulting from abnormal excessive or synchronous neuronal activity in the brain. 7, 1 These events are self-limited clinical manifestations that can range from subtle behavioral changes to dramatic convulsions. 8
Critical Distinction: Provoked vs. Unprovoked Seizures
Provoked (acute symptomatic) seizures occur at the time of or within 7 days of an acute neurologic, systemic, metabolic, or toxic insult—these do NOT define epilepsy. 5
Unprovoked seizures occur without acute precipitating factors and indicate an enduring predisposition to generate seizures—these ARE the hallmark of epilepsy. 5, 2
Common provoking factors include electrolyte abnormalities (hyponatremia, hypocalcemia), medication non-compliance, certain drugs (tramadol), and metabolic derangements. 5
When Epilepsy is Considered "Resolved"
Epilepsy can be considered resolved when: (1) the patient had an age-dependent epilepsy syndrome but is now past the applicable age, OR (2) the patient has remained seizure-free for the last 10 years AND off antiseizure medications for at least the last 5 years. 3, 4 This "resolved" status does not necessarily mean cured, but indicates the condition is no longer active. 3
Epidemiologic Impact
Approximately 10% of the population will experience at least one seizure during their lifetime. 1
Active epilepsy affects approximately 1.2% of the US population (3.4 million people) and 50 million people worldwide. 1
In children under 17 years, approximately 470,000 (0.6%) suffer from epilepsy, with 50,000 new cases diagnosed annually in this age group. 7
Occupational Definition
For occupational purposes, epilepsy is considered "active" when an individual has doctor-diagnosed epilepsy or seizure disorder AND is currently taking medication for control OR has had one or more seizures in the past year. 2 A single seizure does not constitute epilepsy in the occupational context unless there is high recurrence risk (≥60% over 10 years). 2