Association between Cognitive Subdomains and Extrapyramidal Signs in Alzheimer Disease: A Clinical Research Center for Dementia of South Korea (CREDOS) Study

ABSTRACT

OBJECTIVES: We aimed to investigate the prevalence of Extrapyramidal signs (EPS) and the associations between EPS and cognitive subdomains in patients with Alzheimer disease (AD). METHODS: We recruited 1,324 patients with AD from the Clinical Research of Dementia of South Korea (CREDOS), a hospital based cohort study with fifty-six participating hospitals. We estimated cognitive subdomain using the Seoul Neuropsychological Screening Battery-Dementia version (SNSB-D). Dementia severity was measured by Clinical Dementia Rating Sum of Boxes (CDR-SB) and Korean version of Mini-Mental Status Examination (K-MMSE). The EPS group was defined by the presence of at least one EPS based on a focused neurologic examination. RESULTS: The prevalence of patients with EPS was 11%. These had higher CDR-SB scores than non-EPS group. After controlling for demographic, radiological, and dementia severity (CDR-SB) factors, EPS group showed lower cognitive ability in the subdomains for visuospatial and frontal-executive function than non-EPS group. The patients with EPS were showed significantly higher scores in the subdomain for memory function. CONCLUSION: The presence of EPSs in patients with AD was associated with lower visuospatial, frontal-executive function and higher memory function.