Poster B85, Sunday, March 26, 8:00 – 10:00 am, Pacific Concourse
Mental-orientation: A novel approach to Alzheimer's disease
Gregory Peters-Founshtein1,2, Michael Peer1,2, Yanai Rein1, Barak Yoresh1,4, Shlomzion Kahana Merhavi2, Zeev Meiner3, Shahar Arzy1,2; 1Neuropsychiatry Lab, Faculty of Medicine, Hadassah Hebrew University Medical School, Jerusalem, Israel, 2Department of Neurology, Hadassah Hebrew University Medical Center, Jerusalem, Israel, 3Departments of Physical Medicine and Rehabilitation, Hadassah University Medical Center, Jerusalem, Israel, 4The Rachel and Selim Benin School of Computer Science and Engineering, Hebrew University, Jerusalem, Israel
Despite the high prevalence of Alzheimer’s disease (AD), and its significant effects on individuals and society, its underlying mechanisms remain poorly understood. Clinical observations propose that a main pathology of AD is disorientation, which is defined as a disruption in the relation between the behaving self and the representations of events, places and people, leading us to hypothesize that disorientation may underlie several manifestations of AD. Recently, we introduced a novel approach to mental-orientation, which requires subjects to determine which of two familiar places, events or people is closer to themselves. Here we first tested this task in 60 patients, evenly distributed among AD, mild cognitively impaired (MCI) and healthy controls (HC). We then compared mental-orientation to standard neuropsychological tests in their diagnostic capacity, and used fMRI to differentiate between the brain regions active in mental-orientation and currently-used tests in young healthy participants. Our results show the mental-orientation task to clearly distinguish between AD, MCI and HCs, unlike currently-used tests. fMRI analysis revealed the mental-orientation task to activate the precuneus, middle temporal lobe and prefrontal cortex bilaterally, significantly overlapping the AD-implicated Default Network. The currently-used tests exhibited sparse activations, mostly at lateral occcipito-temporal cortices. Directly contrasting the two tasks revealed mental-orientation to preferentially activate regions aligned on a parietal-hippocampal axis, known to undergo early AD-related atrophy. Taken together, mental-orientation task was found to surpass currently-used tests in classification of subjects along the AD-spectrum, and its predictions were supported by fMRI, linking it to preferential recruitment of specific AD-implicated brain regions.
Topic Area: LONG-TERM MEMORY: Development & aging