Gabelle A, et al. - In elderly patients with narcolepsy type 1 (NT1), researchers assessed whether brain amyloid burden is lower than in controls as well as the relationships between amyloid burden, cerebral spinal fluid (CSF) markers of Alzheimer disease (AD), CSF orexin-A, and cognitive profile in patients with NT1. In patients with NT1 aged ≥ 65 years (n = 23) and in age- and sex-matched controls free of clinical dementia selected from the Alzheimer's Disease Neuroimaging Initiative (n = 69) and the Multi-Domain Intervention Alzheimer's Prevention Trial (n = 23) cohorts, data from cognitive and 18F-florbetapir positron emission tomography (PET) were compared. According to findings, lower brain amyloid burden, evaluated by ¹⁸F-florbetapir PET, in patients with NT1 suggests that appearance of amyloid plaques appear delayed.