Progression of Korean Mini-Mental Status Examination (K-MMSE) score in Korean patients with Alzheimer's disease

Abstract

Progression of Alzheimers Disease (AD) is well known from studies regarding the natural courses, while only few studies have shown in patients on medications. Previous clinical trials addressed that cholinesterase inhibitors (ChEIs) and N-methyl-D-aspartate (NMDA) receptor blockers in Alzheimers disease(AD) alter the rate of cognitive decline, but their long-term effects need further investigation. In this study, we aimed to demonstrate the long-term cognitive changes on Korean AD patients in clinical settings receiving pharmacological treatments and identify the associated variables affecting the rate of cognitive decline. This was a retrospective cohort study from patients whom visited Seoul National University Bundang Hospital, between 2003 to 2013. From medical records of AD patients using ChEIs and/or NMDA receptor blockers, we determined the progression of Korean Mini-Mental Status Exam (K-MMSE) by calculating the rate of change in years from each pairs of consecutive K-MMSE assessments. The mixed random/fixed coefficient method was used for modeling predictions of K-MMSE progressions and verifying the rate modifying risk factors. Total number of 366 patients and their 1337 assessments were included in analysis. Mean rate of K-MMSE change calculated from 971 pairs of K-MMSE per year was 1.31 points (95% CI -1.47 to -1.14) in all score ranges. From the mixed model analyses, earlier-onset disease, presence of APOE ε4 allele, higher level of education, and lower initial K-MMSE scores were associated with faster cognitive decline rates. Compared to previous studies, rate of K-MMSE changes has decelerated. The effects of rate modifying factors from analyses lined with our current knowledge. This was the first study in Korean AD patients on pharmacological treatments demonstrating the long-term progression course in clinical settings. We were able to predict the rate of decline and verify the risk variable effects. The model acquired from our study may be of use to clinicians who encounter AD patients in long-term follow-up, by giving information on progression rate and aiding clinical decisions.