The Impact TDCS-linked Motor and Cognitive Training Gains in Parkinson's Disease

The Wisconsin Card Sorting Test (WCST) is a neuropsychological test of "set-shifting", i.e. the ability to display flexibility in the face of changing schedules of reinforcement. A number of stimulus cards are presented to the participant. The participant is told to match the cards, but not how to match; however, they are told whether a particular match is right or wrong. The original WCST used paper cards and was carried out with the experimenter on one side of the desk facing the participant on the other. The test takes approximately 12-20 minutes to carry out and generates a number of psychometric scores, including numbers, percentages, and percentiles of: categories achieved, trials, errors, and perseverative errors.

The Trail Making Test (TMT) is a neuropsychological test of visual attention and task switching. It consists of two parts in which the subject is instructed to connect a set of 25 dots as quickly as possible while still maintaining accuracy.The test can provide information about visual search speed, scanning, speed of processing, mental flexibility, as well as executive functioning

The Verbal Fluency Test are a kind of psychological test in which participants have to produce as many words as possible from a category in a given time (usually 60 seconds). This category can be semantic, including objects such as animals or fruits, or phonemic, including words beginning with a specified letter, such as p, for example

The Montreal Cognitive Assessment (MoCA) is a cognitive screening tool. MoCA is composed of eight cognitive domains, which are scored within a range of 0 to 30 points (higher scores indicate better function): short-term memory; visuospatial skills; executive function; verbal fluency; attention, concentration and working memory; language; sentence repetition; and spatiotemporal orientation.

The Dynamic Gait Index (DGI) assess gait, balance and fall risk. It evaluates not only usual steady-state walking, but also walking during more challenging tasks. A four-point ordinal scale, ranging from 0-3. "0" indicates the lowest level of function and "3" the highest level of function (total score = 24).

The 10-meter walk test to estimate gait speed by recording the average time the patient takes to cover a distance of 10m in three attempts

The Timed Up and Go (TUG) test to stand up from a chair at the command, walk 3 meters walk along a demarcated course, turn around and walk back to the chair, then sit down.

To analyze movement using the Qualisys Motion Capture System (Qualisys Medical AB, 411 13, Gothenburg, Sweden);

For this outcome, the Unified Parkinson's Disease Rating Scale - Part III will be used. Section III provides an overall score for movement-related functions and activities (tremor, stiffness, gait, alternating movements, among others). This section is made up of 33 items, which can range from zero (normal) to four (severe), with responses that are linked to commonly accepted clinical terms. The higher the score, the greater the impairment of motor function.

For this outcome, Activities-specific balance confidence (ABC) scale to measure the level of confidence in performing daily activities, in addition to identifying fear of falling and possible social isolation

The PDSS is a scale specifically designed to assess sleep quality in individuals with Parkinson's. The PDSS-2 consists of 15 questions rated according to five categories ranging from 0 (never) to 4 (very frequent). Its total score ranges from 0 (no disturbance) to 60 (maximum nighttime disturbance).

The Pittsburgh Sleep Quality Index (PSQI) is a widely used self-report questionnaire that assesses sleep quality over a one-month time interval. Each component score of the PSQI ranges from 0 to 3, with 3 indicating the greatest dysfunction or disturbance. The seven component scores are then summed to obtain a global PSQI score, which ranges from 0 to 21. Higher scores indicate poorer sleep quality, with a score greater than 5 suggesting significant sleep difficulties.

The ESS is a self-administered questionnaire with 8 questions. Respondents are asked to rate, on a 4-point scale (0-3), their usual chances of dozing off or falling asleep while engaged in eight different activities. The ESS score (the sum of 8 item scores, 0-3) can range from 0 to 24. The higher the ESS score, the higher that person's average sleep propensity in daily life (ASP), or their 'daytime sleepiness'.