Analysis of regional atrophy on brain imaging compared with cognitive function in the elderly and in patients with dementia – cross-sectional and longitudinal evaluation

Abstract: During aging, brain changes are not homogeneous throughout the entire brain, but are related to changes in the morphology of neurons, as well as to changes in the tissue density, and are specific to each region of the brain. Dementia is a broad category of brain disorders with a set of symptoms including memory, visual-spatial and language problems. Most types of dementia are slowly progressing, and by the time the person shows signs of the disorder, processes in the brain are already advanced. Dementia reduces not only the person’s ability to perform everyday activities, it also increases mortality rates significantly. Because of the increasing incidence of dementia, possible prevention and treatment of dementia as early as possible are essential.The aim of the PhD project is to compare a quantitative and qualitative image analysis of regional cerebral atrophy with cognitive function in the elderly persons.In paper I, 58 persons participated (84–88 years old) from the ULSAM (Uppsala Longitudinal Study of Adult Men) cohort. They underwent CT of the brain, cognitive testing and LP. This study showed that AD biomarkers seem to be less informative in subjects with an advanced age.In papers II–IV, the cohort included subjects from the PIVUS (Prospective Investigation of the Vasculature in Uppsala Seniors) study.Paper II showed that at age 75, gender and education are confounders for MTA rating. Subjects with abnormal right MTA, but normal MMSE scores had developed worse MMSE scores 5 years later.Paper III showed that automated rating of MTA could be used in clinical practice to support the radiological evaluation. Automated rating of PA and F-GCA should be tested in future studies.In paper IV, we found a mild age-associated decrease in regional brain volumes in this healthy cohort with well-preserved cognitive and executive functions.In conclusion, the included studies in this thesis compare regional atrophy grades in the brain on CT and MRI and clinical data and provide knowledge that may be used in future investigations that aim to detect dementia in its early stages.