Effect of Simultaneous Dual-Task Training on Regional Cerebral Blood Flow in Older Adults with Amnestic Mild Cognitive Impairment.

BACKGROUND: No previous study has examined the effect of dual-task training using changes in regional cerebral blood flow (rCBF) using single-photon emission computed tomography (SPECT) as an outcome. OBJECTIVE: This study aimed to examine the effects of simultaneous dual-task training of exercise and cognitive tasks on rCBF using SPECT in older adults with amnestic mild cognitive impairment (aMCI). METHODS: In this non-randomized control trial, 40 older adults with aMCI participated from May 2016 to April 2018. Outpatients in the intervention group (n = 22) underwent 24 sessions (12 months) of dualtask training twice a month for 60 mins per session. Participants in the control group (n = 18) continued to have regular outpatient visits. The primary outcome was rCBF at baseline and after 12 months, which was compared in each group using the two-sample t-test. The secondary outcomes were the rate of reversion and conversion from aMCI after 12 months. RESULTS: Of the 22 participants in the intervention group, six dropped out; therefore, 16 were included in the analysis. The intervention group showed more significant increases in rCBF in multiple regions, including the bilateral frontal lobes, compared with the control group. However, the rates of reversion or conversion from mild cognitive impairment (MCI) were not significantly different. CONCLUSION: Dual-task training for older adults with aMCI increased rCBF in the frontal gyrus but did not promote reversion from MCI to normal cognition. Future intervention studies, such as follow-up examinations after the intervention, are warranted to consider long-term prognosis.

Characteristics of Regional Cerebral Blood Flow in Alzheimer Disease and Amnestic Mild Cognitive Impairment by Single-Photon Emission Computerized Tomography: A Cross-Sectional Study.

INTRODUCTION: The regional cerebral blood flow (rCBF) distribution can affect brain functioning, leading to amnestic mild cognitive impairment (aMCI) and mild Alzheimer disease (AD). This study aimed to clarify the detailed characteristics of rCBF distribution in patients with mild AD and aMCI. METHODS: This cross-sectional study from April 2015 to March 2018 included 103 older adults (mean age 78.9 years; 60% females), out of a total of 302 adults, and categorized them into 3 groups according to cognitive symptoms. The normal control (NC), aMCI, and mild AD groups included 20, 50, and 33 participants, respectively. The primary outcome was rCBF, which was compared among the 3 groups using a 2-sample t test without correction for multiple comparisons. RESULTS: In the aMCI group, the rCBF decreased in the bilateral parietal and left frontal association cortex and the bilateral premotor cortex (p < 0.01) but increased in the bilateral cerebellum (p < 0.01). In the mild AD group, the rCBF decreased in the bilateral parietal and occipital association cortex, the bilateral premotor cortex, the left temporal and frontal association cortex, and the left limbic lobe (p < 0.01). Conversely, the rCBF increased in some parts of the cerebellum, the bilateral frontal and temporal association cortex, the left occipital association cortex, and the right premotor cortex (p < 0.01). CONCLUSION: Based on the analysis of the values obtained, it was inferred that the rCBF undergoes reduction and elevation in aMCI and AD patients.