Neuropsychological and Neuroimaging Markers in Early Versus Late-Onset Alzheimer’s Disease

• Published in: American journal of Alzheimer's disease and other dementias Vol. 27; no. 7; pp. 520 - 529
• Main Authors: Kaiser, Natalie C., Melrose, Rebecca J., Liu, Collin, Sultzer, David L., Jimenez, Elvira, Su, Michael, Monserratt, Lorena, Mendez, Mario F.
• Format: Journal Article
• Language: English
• Published: Los Angeles, CA SAGE Publications 01.11.2012
• Subjects: Age of Onset; Aged; Aged, 80 and over; Alzheimer Disease - complications; Alzheimer Disease - diagnostic imaging; Alzheimer Disease - physiopathology; Brain - diagnostic imaging; Brain - physiopathology; Cognition Disorders - diagnostic imaging; Cognition Disorders - etiology; Cognition Disorders - physiopathology; Female; Fluorodeoxyglucose F18; Functional Neuroimaging; Humans; Male; Middle Aged; Neuropsychological Tests; Positron-Emission Tomography; Radiopharmaceuticals; FDG-PET; Alzheimer’s disease; early onset; neuropsychology; dementia; late onset; neuroimaging
• ISSN: 1533-3175; 1938-2731
• DOI: 10.1177/1533317512459798

Background: Early-onset Alzheimer’s disease (EOAD) has been overshadowed by the more common late-onset AD (LOAD). Yet, the literature indicates EOAD may have less hippocampal-memory presentations and more focal neocortical localization early in the disease. Objective: To evaluate these proposed differences between these 2 forms of AD and to explore what they inform about differences in AD pathophysiology. Methods: In all, 21 patients with EOAD and 24 patients with LOAD matched for disease progression and severity were compared on neurocognitive measures and resting state fluorodeoxy-glucose positron–emission tomography (FDG-PET). Results: Patients with EOAD had worse executive functions with greater hypometabolism in the parietal regions; whereas patients with LOAD had worse confrontation naming and verbal recognition memory with greater hypometabolism in inferior frontotemporal regions. Conclusions: In addition to highlighting significant differences between EOAD and LOAD, these results reveal dissociation between executive deficits in AD and frontal hypometabolism, suggesting early disturbances of the parietal–frontal network in EOAD.