The Change of Cognitive Function and Prognostic Factor in Alzheimer's Disease: 1-Year Follow-up Study

ABSTRACT

BACKGROUND: The rate of cognitive change and prognostic factor in Alzheimer's disease are important for clinical management, but little is known in Korea. We report a one year follow-up study of comprehensive evaluation including cognitive functions, behavioral and psychological symptoms of dementia (BPSD) and activity of daily living (ADL). METHODS: 43 patients with Alzheimer's disease were enrolled. All subjects received the Korean version of Mini-Mental State Examination (K-MMSE), the Severe Dementia Scale (SDS), the extended version of Korean Clinical Dementia Rating Scale (CDR) and Sum of Box (CDR-SB), the Barthel index of Activity of Daily Living (B-ADL), the Korean Instrumental Activity of Daily Living (K-IADL) and the Korean version of the Neuropsychiatric Inventory (K-NPI). We retested each scale after 1 year and evaluated the changes. RESULTS: The mean change rates of K-MMSE, SDS, CDR, CDR-SB and B-ADL scores were 2.0 +/- 3.2 (-7~8) mean +/- SD (range), 3.5 +/- 4.9 (-7~14), -0.4 +/- 0.7 (-2~1), -0.8 +/- 4.4 (-10~9) and 1.5 +/- 3.7 (-7~9). The change of K-MMSE and B-ADLscore according to CDR were significantly different. The annual rates of changes of scores on K-MMSE, B-ADL and CDR were largest in CDR 1 group (K-MMSE: 4.0 +/- 2.7, B-ADL: 3.4 +/- 2.8, CDR: -1 +/- 0.7). The change rate of SDS was largest in CDR 4 (7.2 +/- 4.3). There were not any significant factors that affected the change of K-MMSE, SDS, B-ADL or CDR. CONCLUSIONS: These results suggest that K-MMSE is sensitive to the early stage and SDS is sensitive to the later stage. The deterioration rate of cognitive function in Alzheimer's disease is large at middle stage.