Age-related cognitive decline and vision impairment affecting the detection of dementia syndrome in old age

Background Currently the Mini Mental State Examination (MMSE) is widely used as a screening instrument for dementia syndrome. Diagnostic validity may be lowered in old age by normal age-related cognitive decline. Furthermore, visual impairment, occurring frequently in old age, leads to missing values which prevent an interpretation of the test result. Method In the Berlin Ageing Study (n=516, age range 70-103 years) MMSE and clinical dementia diagnosis, made by a psychiatrist investigating ail subjects by the Geriatric Mental State-A and History and Aetiology Schedule interviews, were investigated independently. The MM blind was analysed, an MMSE version for vision impairment in which all items requiring image processing are omitted. The study sample is population-based; dementia cases (DSM-III-R) were excluded on the basis of the clinical diagnosis. Results Norms are reported for very old age regarding MMSE as well as MM blind. There is a considerable age effect on MMSE scores, in contrast to MMSE, sensitivity and specificity of the shorter MM blind version are not reduced. Conclusions The considerable age effect requires the adaptation of cut-off values for old age. The blind version of the MMSE seems to be a valid instrument improving the applicability of the MMSE in old age.