Introduction
Stroke, stroke, hand motor function, upper-limb deficits, poststroke
STROKE, PATHOLOGY, CEREBROVASCULAR ACCIDENT, STROKE
Stroke is a leading cause of long-lasting disability. As many as 41.5 million new cases occur yearly in Europe, and 3.7 million survivors experience long-lasting impairments, whereas less than 15% of patients achieve full poststroke recovery [It is estimated that 80% of stroke patients have upper-limb deficits and have decreased activity and use of the paretic hand in daily life [Most of the functional recovery after diagnosis occurs in the first three months, although neural repair processes and behavioral improvements continue to show slight plasticity in later phases of the rehabilitation process [Rehabilitative treatment of the upper limb is recognized by consensus among survivors, caregivers and health professionals as one of the top ten research priorities for poststroke recovery [During poststroke hand treatment, special attention must be paid to restoring the different biomechanical movements and curvature of the hand in order to provide a stable base and correct alignment as a prerequisite for dexterity training and modulation of reaching movements [Various therapies based on a conventional approach have been demonstrated to be useful, achieving good results in terms of hand rehabilitation: motor imagery training seems to improve the precision and accuracy of movement, as well as the reception of sensory signals, by fostering activation of dormant synapses and accelerating reperfusion of the ischemic penumbra [Another important aspect of hand-focused therapy programs is the use of a generous dose of intense repetition [Recent years have witnessed an increased use of technology-based and especially virtual reality–based neurorehabilitation approaches, which have allowed the creation of effective simulated environments and provided multimodal, controllable and customizable stimulation [There are two major types of virtual reality-based systems used in neurorehabilitation: nonspecific virtual reality (N-SVR) systems and specific virtual reality (SVR) systems. These two classes differ in that systems of the former type use game consoles and video games designed by the entertainment industry. Such consoles (Wii, Xbox, PlayStation, etc.) run games that are not designed for adults suffering from a neurological pathology and do not allow monitoring of movement or other motor or functional variables of the affected body segments. Thus, N-SVR systems are not designed for the neurophysiological recovery of the brain, and they do not focus on the neuronal connections necessary for the recovery of hand function after stroke. In contrast, SVR systems are specifically designed to promote motor learning and recovery, optimizing the acquisition, retention and generalization of motor skills. SVR systems incorporate key features of virtual reality and add objective, quantitative movement monitoring and exergames to facilitate the motor recovery of the hand (regular voluntary movement, arches of hand curvature, grasping, pinch grips and gross manipulation). In addition, SVR systems comply with the principles of neurorehabilitation: mass practice (repetitive training), high dosing (intensive training), structured practice, task-specific practice (ADL-relevant skills training), variable practice, multisensory stimulation (training in which the feedback is not limited to the visual modality), increasing difficulty (individualized training), explicit feedback (training that provides knowledge about the results), implicit feedback (training that provides task-relevant implicit signals), avatar representation (immersive training) and encouragement of the use of the paretic limb (training that counteracts compensation) [In this sense, neurorehabilitation SVR systems allow rehabilitation work to proceed in a functional way and with specific intervention objectives, and these systems can easily evaluate and document progress during sessions [In this regard, Laver et al. [Choosing the appropriate neurorehabilitation strategies to maximize clinical results in stroke patients takes priority. In this sense, a combination of more traditional neurophysiological approaches and motion-based therapies, delivered at a high intensity and in a large dose in motivating game-related environments where motion can be made, offers an important advantage in restoring the motor function of the upper limb [Our clinical trial differs from the studies included in the review as follows: (1) it adds SVR technology (HandTutorIkbali and collaborators [The Kinect sensor, independent of any specific software for rehabilitation after stroke, is able to capture gross movement of the upper limb, but it cannot identify hand motion and does not include exergames designed for hand motor rehabilitation.Programs incorporating SVR technology to train distal motor function after cerebrovascular accident remain little known [It was hypothesized that, compared to control group (CG) participants, adults randomized to the experimental group (EG) would achieve an increased degree of hand motor function improvement and have superior results on the Fugl-Meyer Assessment, Ashworth Scale, and Action Research Arm Test.