Associations between path integration, cognitive performances, and brain atrophy in the elderly population

Details

Supervisors

Hanseeuw, Bernard

Faculty

Faculté de pharmacie et des sciences biomédicales

Degree label

Master [120] en sciences biomédicales, à finalité approfondie

Abstract

Alzheimer's disease (AD) is a disorder affecting multiple cognitive functions, such as memory, reasoning, and spatial disorientation. This progressive neurological disease is characterized by the early dysfunction of brain regions, which are necessary for the formation of memory and spatial navigation. Those areas are mainly the entorhinal cortex and the hippocampus. Therefore, in order to slow down disease’s progression, early detection techniques and intervention measures are urgently needed. There is a broad list of risk factors for this disease, but the main ones are: advanced age, genetical predispositions (the presence of the ApoE4 allele for instance), and some lifestyle variables. The current population is living longer and consequently aging, exposing itself to the disease, and according to predictions, the number of people diagnosed with AD is expected to increase consequently in the upcoming decade. Spatial disorientation is one of the earliest and most overlook symptoms of AD, which manifests as difficulties in navigating familiar environments. This cognitive ability is underlined by the entorhinal cortex, which is the earliest brain region affected by AD tau pathology. In this study 100 participants aged between 55 and 86 were divided into three age groups. With the knowledge of the higher vulnerability of older participants to cognitive decline, this study focused on older participants in order to understand in a better way the early manifestations of path integration impairments. They completed a spatial orientation task (path integration) using a video game, underwent blood tests, neuropsychological assessments, and magnetic resonance imaging (MRI) scans while doing the task. Notably, only some participants performed the path integration task during the MRI scans, the one who clearly understood the rules, and which did not need to be guided during the entire task. This study highlights the need for heightened awareness of early symptoms like spatial disorientation, by showing the interplay between neuropsychological assessments, MRI findings, and path integration task performance in individuals with MCI and older individuals. Through the establishment of clear correlations between cognitive impairment, structural brain changes, and functional task outcomes, this research provides insights into the progression of neurodegeneration.