Characterization of Alzheimer’s Disease Subtypes Based on Magnetic Resonance Imaging and Perfusion Single-Photon Emission Computed Tomography

Article type: Research Article

Authors: Hanyu, Haruo^{a; d; *} | Koyama, Yumi^b | Horita, Haruka^b | Aoki, Toshinori^c | Sato, Tomohiko^d | Takenoshita, Naoto^d | Kanetaka, Hidekazu^d | Shimizu, Soichiro^d | Hirao, Kentaro^d | Watanabe, Sadayoshi^e

Affiliations: [a] Dementia Research Center, Tokyo General Hospital, Tokyo, Japan | [b] Department of Rehabilitation, Tokyo General Hospital, Tokyo, Japan | [c] Department of Radiology, Tokyo General Hospital, Tokyo, Japan | [d] Department of Geriatric Medicine, Tokyo Medical University, Tokyo, Japan | [e] Department of Neurosurgery, Tokyo General Hospital, Tokyo, Japan

Correspondence: [*] Correspondence to: Haruo Hanyu, MD, PhD, Dementia Research Center, Tokyo General Hospital, 3-15-2 Egota, Nakano-ku, Tokyo 165-8906, Japan. Tel.: +81 3 3387 5421; Fax: +81 3 3387 5659; E-mail: haruohanyu0212@gmail.com.

Abstract: Background:Alzheimer’s disease (AD) is a biologically heterogenous disease. Previous studies have reported the existence of various AD subtypes, and the various clinical features of the subtypes. However, inconsistent results have been obtained. Objective:To clarify the clinical characteristics of the various AD subtypes, by classifying probable AD into subtypes based on magnetic resonance imaging (MRI) and single-photon emission computed tomography (SPECT) findings. Methods:A total of 245 patients with probable AD were classified into the typical AD (TAD) subtype, limbic-predominant (LP) subtype, hippocampal-sparing (HS) subtype, and minimal-change (MC) subtype, based on the presence of medial temporal lobe atrophy on MRI and posterior cerebral hypoperfusion on SPECT. Demographics, including age, sex, body mass index, disease duration, education years, comorbidities, frailty, leisure activity, and neuropsychological findings were compared between the AD subtypes. Results:he frequency of TAD, LP, HS, and MC subtypes was 49%, 20%, 18%, and 13%, respectively. Patients with the LP subtype were older and characterized by fewer major comorbidities, higher frailty, and slower progression of disease. Patients with the HS subtype were younger and characterized by shorter disease duration, lower frailty, and preserved memory, but had prominent constructional dysfunction. Patients of the MC subtype were characterized by shorter disease duration, lower education level, less leisure activity, less impaired memory and orientation, and slower progression. Conclusion:Patients with different AD subtypes differed in their demographic and clinical features. The characterization of patients’ AD subtypes may provide effective support for the diagnosis, treatment, and care of AD patients.

Keywords: Alzheimer’s disease, atrophy, hypoperfusion, magnetic resonance imaging, neuropsychology, single-photon emission computed tomography

DOI: 10.3233/JAD-215674

Journal: Journal of Alzheimer's Disease, vol. 87, no. 2, pp. 781-789, 2022