Neural Basis of Agitated Behaviors in Patients with Amnestic Mild Cognitive Impairment and Alzheimer’s Disease

Article type: Research Article

Authors: Kashibayashi, Tetsuo^{a; *} | Kanemoto, Hideki^{b; c} | Takahashi, Ryuichi^a | Fujito, Ryoko^d | Chadani, Yoshihiro^d | Tagai, Kenji^e | Shinagawa, Shunichiro^e | Ishii, Kazunari^f | Ikeda, Manabu^b | Kazui, Hiroaki^d

Affiliations: [a] Dementia-related Disease Medical Center, Hyogo Prefectural Rehabilitation Hospital at Nishi-Harima, Tatsuno, Japan | [b] Department of Psychiatry, Graduate School of Medicine, Osaka University, Suita, Japan | [c] Health and Counseling Center, Osaka University, Toyonaka, Japan | [d] Department of Neuropsychiatry, Kochi Medical School, Kochi University, Nankoku, Japan | [e] Department of Psychiatry, School of Medicine, Jikei University, Tokyo, Japan | [f] Department of Radiology, Faculty of Medicine, Kindai University, Osakasayama, Japan

Correspondence: [*] Correspondence to: Tetsuo Kashibayashi, MD, PhD, 1-7-1, Kouto, Shingu-cho, Tatsuno, Hyogo, Japan. Tel.: +81 0791 58 1050; Fax: +81 0791 58 1071; E-mail: t_kashibayashi@hwc.or.jp; ORCID: 0000-0002-0046-4628.

Abstract: Background:Aggression, a common symptom of Alzheimer’s disease (AD), can impose a significant burden on caregivers, necessitating early institutionalization. Objective:The current study examined the neural basis of aggression and its expression mechanism, to advance the development of effective treatment strategies for aggression in patients with AD. Methods:The study sample included 257 patients; 180 were diagnosed with AD and 77 with amnestic mild cognitive impairment (aMCI). Factor analysis of the neuropsychiatric inventory (NPI) aggression scores was performed, and the correlation between each factor and cerebral blood flow (CBF) was examined via diagnosis of AD or aMCI using statistical parametric mapping. Results:Refusal of care was correlated with reduced CBF in the right hippocampus of patients with AD while no specific related regions could be identified in patients with aMCI. Violent behavior was associated with decreased CBF in the right temporal pole and medial frontal lobe of patients with AD and aMCI. Conclusions:These findings suggest that aggression, measured using NPI includes two distinct symptoms, refusal of care and violent behavior, having different underlying neural bases.

Keywords: Aggression, agitation, Alzheimer’s disease, cerebral blood flow, mild cognitive impairment

DOI: 10.3233/JAD-240256

Journal: Journal of Alzheimer's Disease, vol. 100, no. 4, pp. 1399-1406, 2024