Assessment of cognitive impairment in patients with Parkinson's disease: prevalence and risk factors

Abstract

BackgroundAlthough Parkinson’s disease (PD) is clinically characterized by motor symptoms, cognitive impairment is one of the most disabling non-motor symptoms. Despite it attracting increasing attention worldwide, less is known about its prevalence in the Chinese population. The objective of this study was to assess cognitive impairment and related risk factors in Chinese PD patients.MethodsWe collected the demographic, diagnostic, and treatment information of 901 PD patients from 42 centers throughout the People’s Republic of China, then administered a battery of neuropsychological tests, to assess motor, cognitive, and neuropsychiatric symptoms.ResultsOverall, 193 of 901 (21.4%) PD patients met the criteria for dementia (PD-D), and 206 (22.8%) met the criteria for mild cognitive impairment (PD-MCI). Visuospatial dysfunction and attention/executive impairment predominated. Increased severity of cognitive impairment was associated with greater motor impairment. Patients with psychiatric symptoms, such as depression and hallucinations, were more likely to have dementia. Potentially, the younger-aged and more educated are shown less cognitive impairment, but age at onset, and levodopa equivalent dose, were not associated with the presence of cognitive dysfunction.ConclusionThe prevalence and profile of cognitive impairment in Chinese PD patients, as well as the risk factors, are similar as those reported for other races, but the frequency of nonamnestic cognitive domains differs.

Clinical Characterization of Parkinson's Disease Patients With Cognitive Impairment

“…The global severity of PD, measured by HY stage, and motor symptoms in PD were strongly associated with the presence of any type of cognitive impairment. Previous studies and reviews have shown that motor impairment is related to the overall presence of cognitive impairment (70,71) and specifically to PD-MCI (72) and PDD (73,74). In line with these previous studies, we found that the presence of cognitive impairment was associated with a more severe HY stage of PD.…”

The impact of cognitive performance on quality of life in individuals with Parkinson's disease

“…In addition to age and educational level, other risk factors have been found for cognitive dysfunction in PD, including lower scores on performance tests, rigidity, postural instability, increased daytime sleepiness and white matter disease. 3 , 6 , 27 , 28 …”

Initial cognitive changes in Parkinson's disease

“…Not surprisingly, poorer cognitive performance and older age are associated with a higher risk of developing PD-MCI 36, 42, 47 . In particular, poorer performance on language, short-term recall and working memory tasks predicted future development of PD-MCI 47 .…”

“…Studies not using the IPMDS criteria have used various criteria to define PD-MCI (Table 1) and reported a lower, but still broad range, of prevalence estimates among newly diagnosed individuals: 9-24% 36-39 . Cross-sectional cohorts of patients with PD, enrolling patients with no restriction on disease duration, report a higher prevalence of PD-MCI, up to 55% 40-42, 44 . A large study incorporating data on 1346 patients without dementia of highly variable disease duration from 8 different centers found a prevalence of PD-MCI of 26% 45 .…”

“…In particular, poorer performance on language, short-term recall and working memory tasks predicted future development of PD-MCI 47 . Other clinical features that have been associated with a higher risk of developing cognitive impairment include poorer olfactory performance, RBD, depression and greater motor impairment 42, 46 . Biomarkers have been found to have added predictive value, in particular APOE genotype, low CSF Abeta:total tau ratio, and lower putaminal DAT asymmetry 46 .…”