Prevalence of periodical leg movements in patients with narcolepsy in an outpatient facility in São Paulo.

Studies have pointed out that approximately 50-60% of narcolepsy patients may demonstrate higher prevalence of periodical leg movements. However, we highlight that the prevalence studies and the effects of periodical leg movements in patients with narcolepsy are limited and with conflicting results. The objective of this study was that of describing and discussing the prevalence of periodical leg movements in patients with narcolepsy in the outpatient facility of diurnal excessive sleepiness of the Federal University of São Paulo, Brazil. We revised 59 files of patients with the clinical and electrophysiological diagnosis of narcolepsy according to the American Academy of Sleep Medicine. Of these 59 cases of patients with narcolepsy, 12 (20.3%) demonstrated periodical leg movements. Thirty five patients (59.3%) had history of cataplexy and 38 patients (64.4%) had the presence of the allele HLA-DQB1⁎0602. There was a higher prevalence of periodical leg movements in patients with cataplexy (p<0.0001) and in patients with the presence of the allele HLA-DQB1⁎0602 (p<0.0001). Our study characterized the higher prevalence of periodical leg movement in patients with narcolepsy, mainly in patients with cataplexy and with the presence of the allele HLA-DQB1⁎0602.