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

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.

[18F]THK5351 PET Imaging in Patients with Mild Cognitive Impairment

“…Previous studies found that the risk of progression to dementia was higher in verbal-aMCI and both-aMCI patients than in visual-aMCI patients. [10][11][12] Our results contrast with cortical thinning studies revealing left medial temporal atrophy in verbal-aMCI patients compared to NC subjects. 39 This difference may have been due to the smallness of the sample in the verbal-aMCI subgroup or nonspecific binding of [ 18 F]THK5351 in the medial temporal regions reducing its resolving power in this area.…”

“…MCI participants were diagnosed according to a modified criteria proposed by Petersen 4,38 for MCI that have been used in previous studies. 12,39 aMCI patients were defined as those with a performance below -1.0 SD of the norm in at least one of the following memory tests: Seoul Verbal Learning Test (SVLT), delayed recall; and Rey Complex Figure Test (RCFT), delayed recall. naMCI patients had task scores worse than -1.0 SD below the norm in at least one of the following tests: neuropsychological tests of language and related functions, visuospatial function, and frontal/executive function.…”

“…[7][8][9] Further differentiation of aMCI according to the presence of verbal and visual memory impairments has revealed that conversion rates to AD are higher in patients with dysfunction of either verbal or both verbal and visual memory, but not visual memory alone. [10][11][12] aMCI patients with cognitive impairment in multiple domains on neuropsychological tests were also found to progress more frequently to dementia compared to single-domain aMCI. [13][14][15] Histologically, neurofibrillary tangles (NFTs) along with amyloid plaques are characteristic features of AD.…”

Neuropsychological test-based risk prediction of conversion to dementia in amnestic mild cognitive impairment patients: a personal view

“…Poor performance in episodic memory tests, cognitive impairment in other domains such as frontal/executive function, and depression are all known to predict the conversion to dementia in aMCI subjects [7][8][9][10]. In fact, even among aMCI subjects, those with more severe https://doi.org/10.23838/pfm.2018.00065 Jun Pyo Kim, et al memory impairment, multi-domain cognitive deficits, or verbal memory impairment have higher dementia conversion rates than those with milder memory impairment, memory involvement only, or visual memory impairment only [3,[11][12][13]. In addition, the results of a recent meta-analysis showed that older age, female gender, hypertension, diabetes, hippocampal and medial temporal lobe atrophy, entorhinal atrophy, lower mini-mental status examination (MMSE) score, higher Alzheimer's Disease Assessment Scale-cognitive subscale (ADAS-cog) score, presence of the apolipoprotein E4 (ApoE4) allele, and abnormal cerebrospinal fluid tau levels are associated with the progression from aMCI to AD dementia [14].…”

“…Patients with verbal-aMCI showed significant cortical thinning in the left anterior and medial temporal regions compared with NC, while visual-aMCI patients did not. Furthermore, the cortical thinning pattern of the both-aMCI group included that found in the verbal-aMCI group, but was more widespread, with involvement in the bilateral temporal regions.In terms of clinical course, we evaluated the longitudinal outcomes of aMCI patients according to the modality of the memory impairment involved[13]. Patients were classified into visual-aMCI, verbal-aMCI, and both-aMCI groups, as de-scribed above.…”