High-frequency tRNS for Sleep Disturbances in Neurocognitive Disorders Due to Vascular Disease

Pittsburg Sleep Quality Index (PSQI)

The PSQI is a 19-item questionnaire that includes seven areas of subjective sleep quality and patterns in adults over the last month including the following components: subjective sleep quality, sleep latency, sleep duration, habitual sleep efficiency, SDs, use of sleeping medications, and daytime dysfunction (Buysse et al., 1988). Each item in the scale is scored from 0 to 3 scale (0 = no difficulty; 3 = severe difficulty). The scores are added to yield a global score ranging from 0 to 21 (0 = no difficulty; 21 = severe difficulties in all areas). This scale has good reliability and validity psychometrics and is widely used in research: Cronbach's alpha (0.77 to 0.83), sensitivity (89.6%), specificity (86.5%)(Buysse et al., 1988). Greater score of PSQI indicates worse sleep quality.

Time frame: 12 weeks

Attentional function

Complex attention is measured by attention network test (ANT). The ANT paradigm is run by E-Prime 3.0 software. Within ANT paradigm, there are four types of cue: no cue, center cue, double cue, and spatial cue; and three types of flanker: neutral, congruent, and incongruent. The reaction time (RT) under different types of flanker indicates the efficacy of attention. Greater score indicates lower efficacy of attentional components.

Time frame: 12 weeks

Executive function

Executive function is measured by the category verbal fluency test (CVFT). On each trial, the participants will be asked to overtly generate words in the animal category, fruit category and vegetable category as many as possible within 60 seconds. The total number of correct words is used to measure executive function.

Time frame: 12 weeks