Clinical Characteristics of Non-Amnestic Mild Cognitive Impairment: A Single-Center Experience

Abstract

Background To evaluate the clinical characteristics of patients with non-amnestic mild cognitive impairment (naMCI) in a memory disorder clinic at a single center. Methods A retrospective study was conducted involving 312 patients with naMCI from May 2011 to July 2018. Brain magnetic resonance imaging and detailed neuropsychological tests were performed in all patients. We used the proposed criteria for naMCI to classify the patients into single- and multiple-domain groups. We compared the baseline clinical characteristics, neuroimaging findings, and the rate of progression to dementia between these two groups. Results The 312 patients comprised 210 in the single-domain group (67.3%) and 102 in the multiple-domain group (32.7%). The mean age was significantly higher in the multiple-domain group than in the single-domain group. The years of education, mean Mini Mental State Examination score, and mean Clinical Dementia Rating Scale Sum of Boxes score were significantly lower in the multiple-domain group than in the single-domain group. The Z-scores of neuropsychological tests in most cognitive domains were significantly lower in the multiple-domain group than in the single-domain group. Compared to the single-domain group, the multiple-domain group showed more-severe medial temporal atrophy and contained a higher proportion of patients with moderate white-matter hyperintensities. Thirteen (8.4%) patients with naMCI progressed to dementia, most of who were diagnosed with Alzheimer’s disease. Conclusions We present a single-center experience of clinical characteristics in patients with naMCI. Close observation of the clinical profiles of patients with naMCI may help identify individuals at the greatest risk of dementia. Key Words: Cognitive dysfunction, Dementia, Alzheimer disease