Efficacy of Rehabilitation Using Action Observation and Muscle Stimulation in Post-stroke Patients.

The ARAT test assess upper limb functioning through the execution of 19 tasks, divided in 4 sub-tests (grasp, grip, pinch, and gross arm movement). Each movement is scored on a 4-point ordinal scale (0=no movement, 1=movement partially performed, 2=movement completed but takes abnormally long; 3=movement performed normally). Total possible score is 57 points, with higher scores associated to best motor functioning.

WHODAS 2.0 is an instrument assessing the level of health and disability across all diseases, directly linked to the concepts of the International Classification of Functioning, Disability and Health (ICF). WHODAS 2.0 covers 6 domains (Cognition, Mobility, Self-care, Getting along, Life activities, Participation) and scores range for each item from 0 to 4 (higher scores, higher disability). The 36-items version will be administered. Summary score (possible total score: 144) and domain-specific scores (score 0-24 for each domain) will be considered as outcome measures.

The Stroke Impact Scale 3.0 specifically measures quality of life in stroke survivors, considering multiple dimensions (strength, hand function, mobility, activities of daily living (ADL)/instrumental activities of daily living (IADL), memory, communication, emotion, social participation). Each of the 59 items can be rated on a 5-point Likert scale (from 1 to 5), with higher values corresponding to better quality of life. Each subscale of the SIS 3.0 may have a score from 0 to 100.

The EQ-5D-5L is an instrument measuring health status, yet applied in different populations and settings. The EQ-5D-5L considers five dimensions (5D: mobility, self-care, usual activities, pain/discomfort and anxiety/depression) each of them measured with a single item scored on 5 levels (5L: no problems, slight problems, moderate problems, severe problems and extreme problems).

The selected level for each dimension is represented by a single digit (from 1: no problems to 5: extreme problems) and the digits of the five levels are combined in a 5-digits number describing the patient's health state, raging from 11111 (no problems in all dimensions) to 5555 (extreme problems in all dimensions).

The MoCA test is a screening tool assessing global cognitive functioning across eight domains (orientation, visuospatial abilities, executive function, naming, memory, attention, language, abstraction). The possible maximun total score is 30, with higher values indicating a more preserved cognitive functioning.

Surface Electromyography (EMGs) is a non-invasive tool able to assess muscular electrical activity during the execution of active movements using electrodes applied on the skin surface. Muscular contraction amplitude will be recorded from 24 sensors placed on upper limbs (12 sensors/limb), during the execution of motor acts. Then, the difference between patient's and observed model's temporal dynamic of muscular contraction will be chosen as EMG outcome.

Motor evoked potentials (MEPs) can indicate the level of corticospinal excitability and the integrity of motor pathways. Motor potentials in first digital interosseus muscle will be evoked via Transcranial Magnetic Stimulation (TMS, single pulse) and peak-to-peak amplitudes will be recorded as indices of cortico-spinal excitability (i.e. integrity of motor pathways).

The H/M ratio is an index of motorneuron reflex excitability. The H/M ratio amplitude will be recorded over the Flexor Carpi Radialis muscle, evoked through the stimulation of the median nerve and eliciting H-reflex in extensor carpi radialis longus (ECRL) and flexor carpi radialis (FCR)

Kinematics of the upper limb and trunk will be recorded using a 9 camera optoelectronic system during 3D motor acts. The system will measure the 3D coordinates of spherical markers attached to body landmarks to compute trunk, shoulder, elbow and wrist angles.

Data processing will provide measures of deviations from physiological movement.

Muscle synergies will be extracted from the EMG envelope of each subject using the Non Negative Matrix Factorization algorithm.

Short- and long-term changes induced by treatment in the similarities of muscle synergies with respect to physiological pattern will be evaluated. The module similarity will be measured by the maximum scalar product of the muscle weightings of each module between each participant and the normative reference, while the activation profile similarity by the Pearson's correlation coefficient of the activation profile of each module.

High-resolution structural sequences will be collected using Magnetic Resonance Imaging at 3.0 Tesla. Data on gray matter will be acquired using MPRAGE (T1w MPRAGE, at least 1x1x1 mm resolution) and FLAIR (1x1x1 mm resolution) sequences. White matter microstructure images will be collected using a DWI protocol (2x2x2 mm resolution, 5 b0 images, 50 directions). Data processing will provide measures of brain integrity, with higher integrity corresponding to more preserved brains.

Sensory-motor brain networks will be assessed using advanced functional Magnetic Resonance Imaging (fMRI) protocols. Data will be acquired on a 3.0T scanner and will provide insights about spared/recovered neural correlates of sensory-motor function.