We investigated the intervention effect of training using a feedback-type tactile discrimination system on sensorimotor dysfunction of the hand after a stroke. A human male subject with sensorimotor dysfunction in his left hand after a stroke was asked to perform peg manipulation practice, a building block stacking task, and a material identification task for 10 min each for six weeks. During the activities, a tactile discrimination feedback system was used. The system is a device that detects the vibration information generated when touching an object with a hand and that feeds back the captured information in real time as vibration information. After the intervention, in addition to the reorganization of the sensorimotor areas, the deep sensation, sense of agency, numbness, amount of use, and quality of the left-hand movement improved. Our results suggest that training with the use of a feedback system could be a new form of rehabilitation for sensorimotor dysfunction of the hand.

The sensory dysfunction after the stroke also greatly affects motor function. In particular, it is known that the presence of sensory dysfunction in the fingers causes loss of somatosensory muscle reflex control and excessive muscle output when grasping objects. These are called sensorimotor dysfunction and have been shown to have a significant impact on prognosis. One element to improve this dysfunction is to reconstruct the “Sense of Agency (SOA) subject feeling” and it has become clear that SOA is enhanced by matching the collation information related to motor intention and sensory feedback in time. In order to reconstruct the SOA associated with the movement of the fingers of patients with sensorimotor dysfunction, it is important to match motor intentions while using visual information as compensation for tactile sensory information. Furthermore, considering the functional characteristics of the fingers, it is also important to adjust the fine muscle output from feedback information synchronously discriminating and recognizing somatosensory information generated by resistance, friction, etc., when an object is actively touched. This chapter outlines the importance of rehabilitation of sensory feedback for poststroke sensorimotor dysfunction and investigates the usefulness of intervention with a real-time sensory compensation feedback system that can input tactile sensory information via vibratory stimulation (deep sensation) to other body parts where sensory function is preserved.