Action observation and imagery conducted with stroke patients stimulate both hemispheres : the affected and non-affected

Abstract

Objectives: The application of the mirror neuron system (MNS) has<br />extended into the field of stroke rehabilitation through mirror- or video therapy. Current literature has demonstrated that action observation exclusively or predominantly stimulates the non-affected hemisphere [1, 2]. The aim of this study was to use the fMRI (functional magnetic imaging) to investigate whether the affected and non-affected hemispheres are stimulated to the same extent during action observation and imagery conducted in stroke patients.<br />Methods: fMRI in block design applying action observation or action imagery with open eyes. Stimuli consisted of object-related, simple hand actions. Eight right hemispheric and eight left hemispheric stroke patients with incomplete hand pareses participated in the study.<br />Results: Action observation as well as simultaneous action observation and imagery induced activation in a well known network of occipital, superior and inferior parietal and dorsolateral and ventrolateral premotor cortical areas. Cortical activation encompassed a symmetrical bilateral pattern: the affected hemispheres were stimulated to the same degree as the non-affected hemisphere.<br />Conclusion: This study confirms that action observation has facilitatory<br />effects in the affected and non-affected hemispheres, respectively. Data support applicability of video-therapy in stroke patients.<br />1. Kimberley TJ et al (2006) Neurorehabilitation and Neural Repair 20:268 277<br />2. Stinear CM et al (2007) Clin Neurophysiol 118:1794 1801