Temporal Change of Cognitive Decline in Alzheimer’s Disease: The Results of Turquoise Alzheimer’s Working Group

Abstract

OBJECTIVE: The aim of the present study was to evaluate the temporal change of the cognitive decline in Alzheimer's Disease (AD). For this reason, the factorial analysis of Mini-Mental State Examination (MMSE) Test was used in first visit and six months later.

METHODS: In this multicenter, longitudinal study, data of 268 (n: 152 mild, n: 116 moderate) cases, obtained from the ‘Turquoise Alzheimer Working Group’ in Turkey, were evaluated. The patients who were diagnosed with probable AD according to the DSM-IV criteria were included in the study. Disability was assessed by means of global deterioration scale. The MMSE, which has 7 components (time orientation, spatial orientation, immediate memory, attention/concentration, delayed recall, language, and constructional praxis), was applied to all patients at the baseline visit and 6 months later.

RESULTS: The baseline evaluation revealed a significant correlation between orientation and attention subscales in the mild AD group. At the second evaluation of mild AD group and at both evaluations of moderate AD group, there were stronger correlations among all subscales.

Subscales of time orientation, attention/concentration and immediate memory had higher factorial load in the first evaluation in mild AD group. Subscales of delayed recall and language were more significant in second evaluation. Subscale of spatial orientation was added in moderate AD group in both evaluation periods.

CONCLUSION: Factor analysis of MMSE subscales varied according to the stage and duration of the disease. Generally, disturbances in attention and orientation might be the first findings in AD groups. When assessing AD cases, the properties of subscales in MMSE should be considered.