Author(s)

Gianfranco Spalletta, Vincenzo De Luca, Alessandro Padovani, Luca Rozzini, Roberta Perri, Amalia Bruni, Vincenzo Canonico, Alberto Trequattrini, Giuseppe Bellelli, Carla Pettenati, Floriana Pazzelli, Carlo Caltagirone, Maria Donata Orfei

Azienda Sanitaria Locale Città di Castello, Perugia, Italy.
Centro Regionale Alzheimer, Azienda Ospedaliera Guido Salvini, Passirana, Italy.
Centro Regionale Di Neurogenetica, Azienda Sanitaria Provinciale Catanzaro, Lamezia Terme, Italy.
Department of Clinical and Behavioral Neurology, IRCCS Santa Lucia Foundation, Rome, Italy.
Department of Geriatrics, University of Naples, Naples, Italy.
Department of Neurology, University of Brescia, Brescia, Italy.
Department of Neuroscience, Tor Vergata University of Rome, Rome, Italy.
Department of Prevention and Clinical Medicine, University of Milano-Bicocca, Monza, Italy.
Department of Psychiatry, University of Toronto, Toronto, Canada.
NESMOS Department, Sapienza University of Rome, Rome, Italy.

Objective: As the literature on conventional criteria for discriminating early-onset (EO) from late-onset (LO) Alzheimer’s disease (AD) is sparse and controversial, the aim of this study was to establish a precise age at onset (AAO) criterion, by using a specific statistical procedure, and to describe the clinical characteristics of the two sub-groups. Methods: Admixture analysis was performed to establish the AAO cut-off in a multi-center study including 2000 AD patients consecutively recruited in eight Italian Memory Clinics. None of the patients were taking acetylcholinesterase inhibitors, antipsychoticor anti-depressant drugs. At the first diagnosticvisit, they were administered the Mini Mental StateExamination, the Basic and Instrumental Activities of Daily Living and the Neuropsychiatric Inventorytoassess clinical phenomenology. Results: Using a specific statistical procedure, we established that AAO that discriminated EO-from LO-AD was 66. Compared with the LO-AD group, the EO-AD group showed longer duration of illness and a higher educational level as well as less severe functional impairment and delusions. Conclusions: Differences in sociodemographic and clinical characteristics, such as duration of illness, education and delusion severity, suggested the involvement of different pathogenic processes. Additional studies are needed to further investigate the mechanisms underlying the disorder in the two sub-groups of AD patients.

Alzheimer’s Disease; Onset; Neuropsychiatric Symptoms; Admixture Analysis; Pathogenesis; Cognitive Reserve

Spalletta, G., Luca, V., Padovani, A., Rozzini, L., Perri, R., Bruni, A., Canonico, V., Trequattrini, A., Bellelli, G., Pettenati, C., Pazzelli, F., Caltagirone, C. and Orfei, M. (2013) Early onset versus late onset in Alzheimer’s disease: What is the reliable cut-off?. Advances in Alzheimer's Disease, 2, 40-47. doi: 10.4236/aad.2013.21005.