[Motor and non-motor symptoms of Parkinson's disease in the elderly population].

Non-motor symptoms in the very elderly Parkinson's disease (PD) population are poorly described. Our study (PPMI cohort and literature review), in two possible situations (late-onset PD (MPDT, > 70 years), and classic onset PD (MPDC, < 70 years) focused on (1) a cross-sectional comparison of patients seen > 70 years and (2) a longitudinal comparison based on duration of progression (< 3 years, 3-6 years, ≥ 6 years). A total of 1,188 PD patients were included (950 MPDC, 238 MPDT). MPDT patients showed faster progression, with greater motor severity (UPDRS III) and daily functional impairments (UPDRS I-II) at all stages, greater involvement of axial signs, gait disorders and postural instability. Non-motor disorders are more common, including earlier and more marked cognitive decline and more frequent daytime sleepiness. Dysautonomic symptoms (urinary disorders, constipation, hypotension, hypersalivation) are also more frequent. These results highlight the need for close cognitive monitoring and individualized management of these late-onset forms and may reflect different underlying pathophysiological mechanisms depending on age.