The Heterogeneity and Natural History of Mild Cognitive Impairment of Visual Memory Predominant Type

Article type: Research Article

Authors: Ye, Byoung Seok^a | Chin, Juhee^b | Kim, Seong Yoon^c | Lee, Jung-Sun^c | Kim, Eun-Joo^d | Lee, Yunhwan^e | Hong, Chang Hyung^f | Choi, Seong Hye^g | Park, Kyung Won^h | Ku, Bon D.ⁱ | Moon, So Young^j | Kim, SangYun^k | Han, Seol-Hee^l | Lee, Jae-Hong^m | Cheong, Hae-Kwanⁿ | Park, Sun Ah^o | Jeong, Jee Hyang^p | Na, Duk L.^b | Seo, Sang Won^{b; *}

Affiliations: [a] Department of Neurology, Yonsei University College of Medicine, Seoul, Korea | [b] Department of Neurology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea | [c] Department of Psychiatry, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Korea | [d] Department of Neurology, Pusan National University School of Medicine, Pusan, Korea | [e] Department of Preventive Medicine and Public Health, Ajou University School of Medicine, Suwon, Korea | [f] Department of Psychiatry, Ajou University School of Medicine, Suwon, Korea | [g] Department of Neurology, Inha University School of Medicine, Incheon, Korea | [h] Department of Neurology, Dona-A University College of Medicine, Pusan, Korea | [i] Department of Neurology, Kwandong University College of Medicine, Gyeonggi-do, Korea | [j] Department of Neurology, Ajou University School of Medicine, Suwon, Korea | [k] Department of Neurology, Seoul National University Bundang Hospital, Seongnam, Korea | [l] Department of Neurology, Konkuk University College of Medicine, Seoul, Korea | [m] Department of Neurology, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Korea | [n] Department of Social and Preventive Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea | [o] Department of Neurology, Soonchunhyang University Bucheon Hospital, Bucheon, Korea | [p] Department of Neurology, Ewha Womans University School of Medicine and Ewha Medical Research Institute, Seoul, Korea

Correspondence: [*] Correspondence to: Sang Won Seo, MD, PhD, Department of Neurology, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Ilwon-dong, Kangnam-ku, Seoul 135-710, Republic of Korea. Tel.: +82 2 3410 1233; Fax: +82 2 3410 0052; E-mail: sangwonseo@empal.com.

Abstract: We evaluate the longitudinal outcomes of amnestic mild cognitive impairment (aMCI) according to the modality of memory impairment involved. We recruited 788 aMCI patients and followed them up. aMCI patients were categorized into three groups according to the modality of memory impairment: Visual-aMCI, only visual memory impaired; Verbal-aMCI, only verbal memory impaired; and Both-aMCI, both visual and verbal memory impaired. Each aMCI group was further categorized according to the presence or absence of recognition failure. Risk of progression to dementia was compared with pooled logistic regression analyses while controlling for age, gender, education, and interval from baseline. Of the sample, 219 (27.8%) aMCI patients progressed to dementia. Compared to the Visual-aMCI group, Verbal-aMCI (OR = 1.98, 95% CI = 1.19–3.28, p = 0.009) and Both-aMCI (OR = 3.05, 95% CI = 1.97–4.71, p < 0.001) groups exhibited higher risks of progression to dementia. Memory recognition failure was associated with increased risk of progression to dementia only in the Visual-aMCI group, but not in the Verbal-aMCI and Both-aMCI groups. The Visual-aMCI without recognition failure group were subcategorized into aMCI with depression, small vessel disease, or accelerated aging, and these subgroups showed a variety of progression rates. Our findings underlined the importance of heterogeneous longitudinal outcomes of aMCI, especially Visual-aMCI, for designing and interpreting future treatment trials in aMCI.

Keywords: Alzheimer's disease, amnesia, mild cognitive impairment, neuropsychology

DOI: 10.3233/JAD-140318

Journal: Journal of Alzheimer's Disease, vol. 43, no. 1, pp. 143-152, 2015