Objectives: To investigate the development of dementia over a five year follow up period in a population of females with Down's syndrome; to examine age at onset and duration of dementia in the population; to document the clinical features of dementia and to highlight scores on functional and cognitive rating scales at diagnosis of dementia and at the onset of complete dependency.
Method: A five year follow-up study of 80 female subjects on prevalence of dementia, early clinical features of dementia and patterns of scoring on rating scales at diagnosis and end-stage dementia was completed. Results: Over the five year study period the number of subjects diagnosed with dementia rose from seven (8.75%) to 35 (43.75%). Age related prevalence figures showed that dementia was more common with increasing age. The earliest recognisable symptoms of dementia were memory loss, spatial disorientation and loss of independence especially in the area of personal hygiene. These findings were confirmed by the rating scales used in the study.
Conclusions: The earliest recognisable clinical features of dementia include memory loss and increased dependency. The results of this study should facilitate earlier diagnosis of dementia in DS.