Neuropsychological, neuropsychiatric and functional assessments help follow the course of Alzheimer's disease
The cognitive performance of persons with Alzheimer's disease and behavioural and psychological problems are linked to their performance of activities of daily living, according to a recent study completed at the University of Eastern Finland. However, difficulties in cognitive performance were not linked to behavioural and psychological problems, although both deteriorated as the disease progressed. Some persons may have significant problems in memory and other cognitive performance without the presence of behavioural and psychological problems, while others experience behavioural and psychological problems already at the early phase of the disease.
Diseases causing dementia are becoming increasingly common as the population ages and life expectancy increases. Alzheimer's disease (AD) is the most common cause of dementia, leading to progressing problems in memory and other cognitive performance. AD is also associated with deteriorated performance of activities of daily living, and increased need for assistance. Furthermore, AD is often associated with behavioural and psychological problems. Information on the progression of the disease and its evaluation methods is needed for treatment planning and for the evaluation of treatment outcomes..
The PhD thesis of Ilona Hallikainen focuses on the progression of Alzheimer's symptoms after diagnosis, and sheds new light on the usability of the CERAD neuropsychological test battery in the monitoring of the progression of the disease. The study was a three-year follow-up of 236 persons with Alzheimer's disease and their caregivers from three Finnish hospital districts. The study constituted part of the multidisciplinary ALSOVA study coordinated by the Institute of Clinical Medicine (Neurology) at the University of Eastern Finland.
During the follow-up, difficulties in cognitive performance and activities of daily living as well as behavioural and psychological problems and the severity of the disease increased; however, approximately 50% of the study participants were diagnosed with a mild form of Alzheimer's disease after the three-year study period. An interesting observation was that persons who at the onset of the study were diagnosed with a very mild form of Alzheimer's disease and whose treatment had begun at the early phase experienced a slower decline in the performance of activities of daily living and less frequent presence of behavioural problems. The study sheds new light on how the disease progresses in persons under current treatment.
The CERAD neuropsychological test battery is widely used in the early detection of Alzheimer's disease. The study discovered that the test battery's total score was a well-functioning measure in follow-up use. In clinical use, however, the use of the CERAD test battery for the monitoring of AD-related symptoms may be limited due to it requiring plenty of time. In the test battery, tasks assessing global cognition, language, visual perception and executive function were found to be very useful in follow-up use. Although memory problems are first signs of the disease, the role of other cognitive deficits increases as the disease progresses. The results open up new possibilities for the monitoring of the disease both in research and in clinical settings.