Objective: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 Neuro-psychological 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, sever-ity 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 pa-tients with EPS showed lower performance compared to those without EPS in 3 cognitive sub-domains: attention (p=0.05), vi-suospatial 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.