Mechanisms of recovery in stroke patients with hemiparesis or aphasia: new insights, old questions and the meaning of therapies

Purpose of review The mechanisms responsible for recovery after stroke in patients with hemiparesis or aphasia are under intense study, since knowledge of these mechanisms is a prerequisite for choosing which therapy a patient receives and when to apply it. Recent findings Most of the recent insights are obtained with longitudinal studies using functional imaging and direct cortical stimulation during the process of recovery. They reveal that reorganization is a highly dynamic process, involving the establishment of new communications in the remaining system and showing similarities to learning processes in healthy individuals. Lesion localization is a major determinant for recovery and the pattern of reorganization. Neurobiological hypotheses lead to clinical studies, which in turn are now used to confirm or reject these hypotheses. Summary Although our understanding of the mechanisms responsible for recovery is increasing, the application of this knowledge in daily praxis is still limited. A better understanding of the underlying mechanisms, however, can lead to appropriate therapies for individual patients.