Prevalence of acute repetitive seizures (ARS) in the United Kingdom.

INTRODUCTION: "Acute repetitive seizures" (ARS) is a term to describe a condition manifest by multiple seizures occurring over a relatively brief period of time -generally 24 hours- in patients with epilepsy. There is limited information regarding the epidemiology of ARS in the general population.
METHODS: We performed a historical cohort study using data from the United Kingdom General Practice Research Database (GPRD) to identify all incident and prevalent cases of active epilepsy in 2005. From among this group, we identified individuals at risk for ARS. This included those with "catastrophic epilepsy syndromes of childhood" (CE), and those with a history of seizure clustering in the context of other epilepsy syndromes.
RESULTS: We identified 21,010 people with active epilepsy in the GPRD in 2005; prevalence 7.2/1000; age adjusted to the European Standard Population, 6.7; incidence 50/100,000 per year, age-adjusted 48/100,000. We identified 665 people at risk for ARS. The prevalence of CE in the general population was 1.2/10,000 and that of cluster seizures was 1.1/10,000. We estimated the crude prevalence of ARS in the general population to be 2.3/10,000; age adjusted 2.5 (CI, 2.3-2.7. The prevalence of ARS was highest in those 0-4 years of age (5.9/10,000) and fell with advancing age to 0.5/10,000 in those age 70 and older).
CONCLUSIONS: This is the first population-based study to provide information on the prevalence of ARS. ARS affects about 3% of the population with epilepsy and 0.02% of the general population. More studies are needed to further evaluate this serious epilepsy phenomenon.