A Study of Cerebral Perfusion With tDCS in Chronic Hypoperfusion

Cerebral blood flow imaging assessed by MRI to measure blood flow through the blood vessels reported in millimeters of mercury (mmHg)

Assessed using the Montreal Cognitive Assessment (MoCA), which is a 30-item questionnaire that includes tests of orientation, attention, memory, language and visual-spatial skills. Possible total scores range from 0 to 30, with higher scores indicating higher cognitive function. A final total score of 26 and above is consider normal.

Assessed using the Fatigue Severity Scale (FFS) 9-item questionnaire that contains statements that rate fatigue symptoms on a scale of 1 to 7 where a low value (e.g., 1) indicates strong disagreement with the statement and a high value (e.g., 7) indicates strong agreement. Possible total scores range from 9 to 63, with higher scores indicating greater fatigue severity.

Assessed using the Visual Analogue Scale to Evaluate Fatigue Severity (VAS-F) 18-item questionnaire that rates how a subject is currently feeling in regards to fatigue symptoms on a scale of 0 to 10 where a low value (e.g., 0) indicates "not at all/no effort at all" and a high value (e.g., 10) indicates "extremely/tremendous chore". Possible total scores range from 0 to 180, with higher scores indicating greater fatigue severity.

Assessed using the Stroke Specific Quality of Life (SS-QOL) 49-item questionnaire assessing quality of life with regards to energy, family roles, language, mobility, mood, personality, self-care, social roles, thinking, upper extremity function, vision, and work/productivity on a scale of 1 to 5 where a low value (e.g., 1) indicates "total help/couldn't do it at all/strongly agree" and a high value (e.g., 5) indicates "no help needed/no trouble at all/strongly disagree". Possible total scores range from 49 to 245, with higher scores indicating better quality of life.

Assessed using the Patient Health Questionnaire 9-item (PHQ-9) scale to assess severity of depression. Scoring is calculated by assigning scores of 0, 1, 2, and 3 to the response categories, respectively, of "not at all," "several days," "more than half the days," and "nearly every day." Total score for the nine items ranges from 0 to 27 where 0 is no depression, 1-4 is minimal depression, 5-9 is mild depression, 10-14 is moderate depression, and 15-19 is moderately severe depression and 20-27 severe depression.

Assessed using the Epworth sleepiness scale (ESS) 8-item questionnaire that measures daytime sleepiness in participants. Possible scores range from 0-24, with higher scores indicating a higher average sleep propensity in daily life, and a worse outcome.

The Trail Making Test is a two part assessment of cognitive functions, principally attention and working memory. Subjects connect a set of 25 dots as quickly as possible, connect 13 dots labeled alphabetically, and 12 dots that are numbered in an alternating pattern as quickly as possible without lifting the pen. Results are reported as the number of seconds required to complete the task with higher scores indicating greater impairment.

Assessed using the Consortium to Establish a Registry for Alzheimer's Disease (CERAD) wordlist memory test (WLT). This is a memory task for assessing word list recall. A list of 10 words are read 3 times and subjects are asked to recall the list of words. The more words recalled indicates less cognitive impairment.