Temporal Variation in Disease Onset and Clinical Features of Lewy Body Disease in China

Lewy body dementia is the second most common neurodegenerative dementia, but data concerning the onset age and clinical features in the prodromal stage remain limited in China.To investigate the associations between onset age and clinical manifestations of cognitive impairment with Lewy bodies in a large-sample cohort.We included 74 patients with mild cognitive impairment with Lewy bodies (MCI-LB), 533 patients with dementia with Lewy bodies (DLB), 118 patients with Parkinson's disease with MCI (PD-MCI), and 313 patients with Parkinson's disease dementia (PDD) in this multicenter cohort from 22 memory clinics of China from 1 January 2018 to 31 March 2022. The onset age, clinical manifestations, and neuropsychological assessments were recorded and analyzed after reviewing the medical records.The average onset age of memory loss was 68.28 (±7.00) years, and parkinsonism happened 2.00 (±1.24) years later for patients with MCI-LB. The average onset age of parkinsonism was 60.56 (±8.96) years, and the memory loss happened 3.49 (±3.02) years later for patients with PD-MCI. Rapid eye movement sleep behavior disorder and visual hallucinations were frequently reported in MCI-LB, DLB, and PDD, while visual hallucinations were least frequently reported in PD-MCI. Lower scores of MMSE and depression, and higher scores of activities of daily living and delusions, were independently associated with older onset age in DLB.The onset of PD-MCI precedes MCI-LB, and memory loss occurs 3 years after parkinsonism. The onset age is associated with cognition and neuropsychiatric symptoms in process.