Introduction: The global prevalence of active epilepsy is around 6.38/1,000 persons. In the Arabian region, the median prevalence of active epilepsy is 4.4/1,000 persons. In the Kingdom of Saudi Arabia (KSA), the last prevalence study for active epilepsy cases was conducted in 2001 and showed an estimate of 6.5/1,000 persons. Objectives: The aim of the study was to investigate the prevalence of active epilepsy and etiological factors among Saudi individuals of all ages resident in the Riyadh area, the central province, and the capital of KSA. Method: This is a door-to-door cross-sectional epidemiological study that was conducted between 2012 and 2016. Patients were initially screened at their homes using a questionnaire, and then suspected individuals were interviewed in the clinic by neurologists and epileptologists. Data related to age, age at seizure onset, gender, probable etiology, treatment, family history, duration of epilepsy, and seizure control, as well as images for electroencephalogram and magnetic resonant imaging, were collected and analyzed. Results: Among the 13,873 participants, active epilepsy was evidenced in 55 patients (3.96; 95% CI: [2.99-5.16]/1,000 persons). No significant variation in the prevalence rate was detected between male and female patients (3.99 vs. 3.94/1,000 persons). The age-specific prevalence was the highest among the infants (1-12 months) (14.78/1,000 persons). Of the various seizure types, complex partial seizures were the most common (33%), followed by generalized seizures (29.1%). Concerning etiology, epilepsies with idiopathic and cryptogenic etiologies were the most common in 18 (36.3%) cases. Structural, vascular, and focal abnormalities were the most commonly diagnosed abnormalities (18.2%, 14.5%, and 39.2%, respectively). Conclusion: The prevalence of active epilepsy in KSA has dramatically decreased during the last decades to a rate lower than those reported in most developing countries.
