Extrapyramidal Signs and Impairment of Cognitive Subdomains in Mild Cognitive Impairment : A Clinical Research Center for Dementia of South Korea (CREDOS) Study

ABSTRACT

OBJECTIVES: This study investigated the association between extrapyramidal signs (EPS) and five cognitive sub-domains in a large number of patients with mild cognitive impairment (MCI). METHODS: Our analyses considered 1,943 patients with MCI drawn from the nationwide Clinical Research of Dementia of South Korea study. EPS were defined as presence in patients with at least 1 of 11 operationally specified features. We assessed five cognitive sub-domains attention, language, visuospatial function, memory, and frontal/executive function using the Seoul Neuropsychological Screening Battery-Dementia version. The associations of EPS with each cognitive sub-domain were analyzed with a multiple linear regression model after controlling for confounding factors sex, age, education years, diabetes, hypertension, severity of global function, depressive symptoms, and white matter hyperintensities (WMH). RESULTS: 138 MCI patients (7.1%%) had EPS. This group had more global cognitive deterioration and severe WMH. MCI patients with EPS showed lower performance compared to those without EPS in 3 cognitive sub-domains attention (p=0.05), visuospatial function (p=0.02), and frontal/executive function (p<0.0001). The language sub-domain and the memory sub-domain did not differ between the EPS positive and the EPS negative groups. CONCLUSION: EPS in MCI are associated with greater cognitive impairment in specific functional sub-domains rather than with global greater cognitive deterioration.