Motor function-related maladaptive plasticity in stroke: a review

Brain plasticity can be classified as adaptive and maladaptive. Maladaptive plasticity indicates hindered functional recovery or the development of an unwanted symptom. Although a considerable amount is known about adaptive plasticity in stroke, relatively little is known of maladaptive plasticity. In the current study, previous studies on motor function-related maladaptive plasticity in stroke are reviewed in terms of compensatory movement pattern (CMP), delayed-onset involuntary abnormal movements (IAMs), and the ipsilateral motor pathway as a motor recovery mechanism. For successful stroke rehabilitation, it is important that the characteristics of maladaptive plasticity are accurately recognized. However, there is a lack of definitive evidence regarding the recognition of motor function-related maladaptive plasticity, although it seems that each of the three above-mentioned topics are involved. As for CMP, patients with a good neurological state as much as having a normal movement pattern, should be considered to have maladaptive plasticity, and in terms of the ipsilateral motor pathway, patients with bilateral innervations can be considered to have maladaptive plasticity. On the other hand, IAMs due to delayed neuronal degeneration should be ruled out in patients with delayed-onset IAMs. Therefore, for the accurate recognition of motor function-related maladaptive plasticity in stroke, a thorough evaluation of neurological state using brain mapping techniques is necessary, and subsequently, the prevention or intensive management of maladaptive plasticity is needed.