0671 Peculiar Age-related Changes of the Periodicity of Leg Movements during Sleep in Restless Legs Syndrome Across the Lifespan

• Published in: Sleep (New York, N.Y.) N.Y.), 2019-04, Vol.42 (Supplement_1), p.A268-A268
• Main Authors: Ferri, Raffaele, DelRosso, Lourdes M, Silvani, Alessandro, Cosentino, Filomena I I, Picchietti, Daniel L, Mogavero, Paola, Manconi, Mauro, Bruni, Oliviero
• Format: Article
• Language: English
• Subjects: Age; Restless legs syndrome; Sleep; Target markets; Teenagers; Young adults
• ISSN: 0161-8105; 1550-9109
• DOI: 10.1093/sleep/zsz067.669

Introduction We aimed to study the age-related changes of periodic leg movements during sleep (PLMS) using the newest international scoring rules, to expand past analyses, including patients in the pediatric age range, and also to analyze the changes of short-interval (SILMS) and isolated (ILMS) leg movements during sleep across the lifespan. Methods 165 patients (84 f) with restless legs syndrome (RLS) were recruited: 16 preschoolers (0-5 years old), 29 school age (6-12), 19 adolescents (13-17), 17 young adults (19-40), 47 adults (41-60) and 37 seniors (>60). Total leg movements during sleep (TLMS), PLMS, SILMS, ILMS, and Periodicity (PLMS/TLMS ratio) indexes were obtained by PSG. Results TLMS index showed (quartic polynomial interpolation) a peculiar age course with a clear decrease before 10 years of age, followed by a steady increase up to the age of 30 years, a relatively stable period until 60 years, and a final increase up to 80 years (preschool 24.5±10.13, school age 21.9±13.17, adolescents 22.2±12.24, young adults 45.9±23.64, adults 43.4±20.96, seniors 70.2±56.82). This course was almost entirely due to changes in PLMS (preschool 4.5±5.42, school age 4.0±3.56, adolescents 5.3±4.95, young adults 23.5±14.21, adults 28.1±18.75, seniors 47.2±42.9). ILMS did not change significantly and SILMS showed only an increase in seniors. Conclusion Our study indicates that, in RLS, TLMS index shows a peculiar and unique course across the lifespan, mainly due to PLMS. The age-related changes in TLMS/PLMS appear to mirror the changes in dendritic spine density in the cortical layer V of the human prefrontal cortex. This layer contains corticostriatal projection neurons and has the highest expression of all dopamine receptor subtypes in primates. It can thus be speculated that the degree of periodicity of leg movements during sleep in RLS might be correlated with the developmental changes in network complexity of these and other dopaminergic structures. These data further confirm the need to better assess the periodicity of leg movements in sleep during the human development period, in order to obtain clinically useful information. Support (If Any) None.