BackgroundParkinson’s disease (PD) is a common neurodegenerative disorder in older people, and half of the world’s older population lives in Asia. However, the epidemiology of PD in Asian countries is poorly understood. This review assembles evidence on the prevalence and incidence of PD in Asian countries and identifies gaps in our present knowledge.MethodsA systematic search of studies published from 1965 to October 2008 was conducted using MEDLINE and EMBASE. The selection criteria were defined a priori. Prevalence and incidence were standardized to the WHO World Standard Population 2000. Twenty-one original studies were selected for the review. Two studies that described the ethnic origin of participants and contained Asian populations were also included in the analysis.ResultsExcluding one study with questionably low prevalence and incidence, the remaining studies reported a standardized all-age prevalence of 51.3 to 176.9 per 100 000 in door-to-door surveys; prevalence in record-based studies ranged from 35.8 to 68.3 per 100 000. The standardized incidence rates were 8.7 per 100 000 person-years in door-to-door surveys and 6.7 to 8.3 per 100 000 person-years in record-based surveys.ConclusionsThe prevalence of PD in Asian countries was slightly lower than that in Western countries. However, comparison of incidence was difficult because of the small number of studies. Varying methodologies, diagnostic criteria, and case-finding strategies contributed to the considerable variation in the reported prevalence and incidence of PD.

MCI is associated with significant neuropsychiatric symptoms which caused caregiver distress. In this study, the pattern of neuropsychiatric symptoms in a Thai MCI population was similar to those reported in western countries. Age, sex, educational level and financial status influenced the neuropsychiatric symptoms of MCI patients.

The MCI patients had poorer psychological QOL than normal subjects. Low education, poor financial status, living alone and depressive symptoms had an influence on the quality of life.