Journal of Alzheimer's Disease Reports · Published 2026-07-01 · DOI 10.1177/25424823261468305
Teruyuki Matsuoka, Ryota Kobayashi, Ayu Imai, Kazutaka Sakamoto, Daichi Morioka, Akihito Suzuki, Noriyuki Kimura, Teruaki Masuda, Takuya Ataka, Jin Narumoto
Background Pineal gland volume reduction in Alzheimer's disease (AD) has been reported. Recent findings also indicate an association between pineal volume reduction and dementia with Lewy bodies (DLB). Objective This study aimed to compare pineal volume between two major neurodegenerative disorders: AD and DLB. Methods This cross-sectional analysis included patients with AD or DLB who underwent brain magnetic resonance imaging (MRI) and Mini-Mental State Examination (MMSE). AD was diagnosed based on the National Institute on Aging-Alzheimer's Association criteria and confirmed by positive amyloid positron emission tomography. DLB was diagnosed per McKeith et al.'s clinical criteria and confirmed by dopamine transporter single-photon emission computed tomography or 123 I-metaiodobenzylguanidine myocardial scintigraphy. Pineal parenchymal volume (PPV) was manually measured using MRI data. The Mann–Whitney U test was used for group comparisons, and analysis of covariance (ANCOVA) was performed with logarithmic transformation since PPV was not normally distributed. Covariates included total intracranial volume, age, sex, MMSE score, use of antidementia drugs, use of psychotropic medications, and MRI magnetic field strength. Results Seventy-five patients (AD, 41; DLB, 34; 35 women) were analyzed. PPV was significantly smaller in the AD group than in the DLB group (74.7 ± 18.8 versus 96.0 ± 31.6 mm 3 , U = 1024, p < 0.001). ANCOVA confirmed a significant diagnostic effect (F = 11.9, p < 0.001). Conclusions Pineal volume was smaller in AD than in DLB; this difference may reflect the neuropathological characteristics specific to AD.
Abstract from DOAJ. Public domain (CC0 1.0).
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Matsuoka, T., Kobayashi, R., Imai, A., et al. (2026). Smaller pineal volume in Alzheimer's disease than in dementia with Lewy bodies. Journal of Alzheimer's Disease Reports. https://doi.org/10.1177/25424823261468305