Trial Outcomes & Findings for Stimulation of Cingulo-opercular Alertness Network (NCT NCT04817891)

Participants enrolled are those who consented to be in the study. They then underwent a screening process. Three participants did not continue after the screening process.

Stimulation of Cingulo-opercular Alertness Network

Score on a 4-item subscale of the 17-item Dementia Cognitive Fluctuation Scale (DCFS), developed to address limitations in prior scales and has good test-retest and inter-rater reliability; this subscale highly discriminates between dementia with Lewy bodies (DLB) and other dementia groups. The DCFS is a subjective report of cognitive fluctuation, the spontaneous change in cognitive ability which is a core diagnostic feature of DLB. Total subscale scores range from 4 to 20, with higher scores indicating greater cognitive fluctuations. A decrease in score between Baseline and Post-Testing indicates an improvement in cognitive fluctuation.

Functional connectivity measures whether activity in different brain regions show similar patterns of change over time. Graph theory metrics of resting-state fMRI can characterize functional connectivity among nodes (regions) of a brain network, and well as between nodes of different brain networks. Network segregation is the difference of within-network and between-network connectivity as a proportion of within-network connectivity, such that higher numbers reflect more segregation. Given that network segregation typically decreases with normal and pathological aging, higher network segregation is generally considered cognitively beneficial. Network segregation was examined for the ventral attention network (the actual focus of stimulation based on observed cholinergic denervation) and the original cingulo-opercular network, which was predicted at the time of grant proposal (but not supported by the observed cholinergic denervation).

Outcome Measure Description: Interference score in time to complete the Color Word Interference Test version of the Stroop task from the Delis-Kaplan Executive Function System. Participants 1) identify a series of colors, 2) read color words (e.g. blue) all written in black ink, and 3) name the ink color of color words printed in incongruous colored inks (e.g. for the word "green" written in red ink, the correct response is "red"). Tasks are performed as quickly as possible. Time to complete each task is recorded. Interference score is calculated as the time to complete the color-word (interference) test (CWT), less the average of the time to complete the color task (CT) and word-reading task (WT): CWT - ((CT + WT)/2). The score has a theoretical valid range of 0 - 300; a lower score suggests better cognitive control. A negative change (decrease) in score between Baseline and Post-Testing indicates improvement in cognitive control performance.

The n-back test is a working memory task where a participant identify a stimulus that matches the stimulus experienced "n" steps back. Participants performed a 2-back test, in which they were asked to remember and press a button when presented with a stimulus that appeared two steps before the current one (e.g. square, circle, square). The number of correct and incorrect identifications are normalized (z-score). Total score is the z-score of correct button presses minus the z-score of incorrect button presses. Possible scores range from -4.85 to 4.85. A higher score (d') reflects better discrimination between target and non-target stimuli, and therefore better working memory performance. A positive change (increase) in 2-back score (d') between Baseline and Post-Testing indicates an improvement in working memory performance.