The Epidemiology of Narcolepsy

Abstract

Much has been learned about the pathophysiology of narcolepsy over the last several decades. It is likely that hypocretin-producing cells in the lateral hypothalamus are selectively destroyed in genetically susceptible individuals carrying 1 or more alleles of HLA DQB1*0602. Despite advances, the causes of narcolepsy and how to prevent it remain elusive. Classic epidemiology aims not only to enumerate occurrence of disease in populations, but also to identify etiologic risk factors. This review details what the application of classic epidemiology has taught us so far about narcolepsy and suggests directions for future studies to clarify its etiology. The prevalence of narcolepsy with cataplexy has been examined in many studies and falls between 25 and 50 per 100,000 people. Information on incidence is limited, with 1 study finding the incidence of narcolepsy with cataplexy to be 0.74 per 100,000 person-years. The search for etiologic risk factors has yet to yield important associations. Factors most thoroughly examined include body mass index, immune responses, and stressful life events. Such associations may reflect a consequence rather than a cause of disease. As with other diseases characterized by selective cell loss, such as Parkinson disease or type 1 diabetes mellitus, narcolepsy is likely caused by environmental exposures before the age of onset in genetically susceptible individuals. Matching efforts in these other diseases and using large well-designed epidemiologic studies of narcolepsy, investigators must intensify the search for these exposures, focusing on the first 2 decades of life. Identification of modifiable risk factors will help to prevent this disease.

Sleep Medicine in Saudi Arabia

“…11,12,14 The estimated prevalence of narcolepsy with cataplexy in Saudis is 40 per 100,000 people, 15,16 which is within the range reported in other studies that showed the prevalence of narcolepsy with cataplexy to fall between 25 and 50 per 100,000 people. 17 A national study reported the prevalence of restless leg syndrome among Saudis as 5.2%. 18 This prevalence falls within previously reported ranges of restless leg syndrome prevalence (ie, 3.2% to 12%) in other countries.…”

Diretrizes brasileiras para o diagnóstico de narcolepsia

“…[2][3][4][5][6] The prevalence of narcolepsy with and without cataplexy is estimated at 1.37 per 100,000 people per year, 4 with a peak incidence in the second decade of life. Narcolepsy affects both males and females (1.4-1.8:1).…”

Safety assessment of adjuvanted vaccines: Methodological considerations

“…The incidence of narcolepsy in western countries is estimated at 0.74/100,000 person-years. 57 Narcolepsy is a complex disease and multiple factors may be involved in its development. The etiology of narcolepsy may include a genetic predisposition strongly associated with an HLA II haplotype (DQB1*0602), and environmental risk factors such as streptococcal infection and viral infections, including H1N1 itself.…”