Alzheimer’s Disease or Behavioral Variant Frontotemporal Dementia? Review of Key Points Toward an Accurate Clinical and Neuropsychological Diagnosis

Article type: Review Article

Authors: Musa, Gada^{a; b; c} | Slachevsky, Andrea^{a; d; e; f; *} | Muñoz-Neira, Carlos^{e; g} | Méndez-Orellana, Carolina^h | Villagra, Roque^{a; d} | González-Billault, Christian^{d; i; j} | Ibáñez, Agustín^{k; l; m; n; o} | Hornberger, Michael^p | Lillo, Patricia^{d; q; *}

Affiliations: [a] Neuropsychology and Clinical Neuroscience Laboratory (LANNEC), Department of Physiopathology, ICBM, Department of Neurosciences, Department of East Neuroscience, Faculty of Medicine, University of Chile, Providencia, Santiago, Chile | [b] Universidad de los Andes, Santiago, Chile | [c] Capredena, Health and Rehabilitation Center, Santiago, Chile | [d] Gerosciences Center for Brain Health and Metabolism (GERO), Providencia, Santiago, Chile | [e] Memory and Neuropsychiatric Clinic (CMYN) Neurology Department- Hospital del Salvador and University of Chile, Providencia, Santiago, Chile | [f] Departamento de Medicina, Servicio de Neurología, Clínica Alemana-Universidad del Desarrollo, Santiago, Chile | [g] Research into Memory, Brain Sciences and Dementia Group (ReMemBr Group), Bristol Medical School, Faculty of Health Sciences, University of Bristol, Bristol, UK | [h] Carrera de Fonoaudiología, Departamento Ciencias de la Salud, Facultad de Medicina, Universidad Católica de Chile, Santiago, Chile | [i] Department of Biology, Faculty of Sciences, Universidad de Chile, Santiago, Chile | [j] The Buck Institute for Research on Aging, Novato, CA, USA | [k] Institute of Cognitive and Translational Neuroscience (INCyT), INECO Foundation, Favaloro University, Buenos Aires, Argentina | [l] National Scientific and Technical Research Council (CONICET), Buenos Aires, Argentina | [m] Universidad Autónoma del Caribe, Barranquilla, Colombia | [n] Center for Social and Cognitive Neuroscience (CSCN), School of Psychology, Universidad Adolfo Ibáñez, Santiago, Chile | [o] Centre of Excellence in Cognition and its Disorders, Australian Research Council (ACR), Sydney, Australia | [p] Norwich Medical School, University of East Anglia, Norwich, UK | [q] Department of Neurology South, Faculty of Medicine, Universidad de Chile, Santiago, Chile

Correspondence: [*] Correspondence to: Dr. Patricia Lillo, Departamento de Neurología Sur, Facultad de Medicina, Universidad de Chile, Complejo Asistencial Barros Luco, Gran Avenida José Miguel Carrera 3204, San Miguel, Santiago, Chile. Tel.: +562 25763337; E-mail: [email protected]. and Andrea Slachevsky, Geroscience Center for Brain Health and Metabolism (GERO), Faculty of Medicine, University of Chile, Av. Salvador 486, Providencia, Santiago, Chile. Tel.: +56 2 29770530; Fax: +56 2 2 2741628; E-mail: [email protected].

Abstract: Alzheimer’s disease (AD) and frontotemporal dementia (FTD) are the most common neurodegenerative early-onset dementias. Despite the fact that both conditions have a very distinctive clinical pattern, they present with an overlap in their cognitive and behavioral features that may lead to misdiagnosis or delay in diagnosis. The current review intends to summarize briefly the main differences at the clinical, neuropsychological, and behavioral levels, in an attempt to suggest which aspects would facilitate an adequate diagnosis in a clinical setting, especially in Latin American and low- and middle-income countries, where the resources needed for a differential diagnosis (such as MRI or biomarkers) are not always available. A timely diagnosis of AD and FTD have significant implications for the medical management and quality of life of patients and careers.

Keywords: Alzheimer’s disease, neuropsychology, differential diagnosis, frontotemporal dementia, young onset dementia

DOI: 10.3233/JAD-190924

Journal: Journal of Alzheimer's Disease, vol. 73, no. 3, pp. 833-848, 2020