Affiliations: MEDIAN Klinik Berlin-Kladow, Berlin, Germany | Centre for Stroke Research Berlin, Charité – University Medicine Berlin, Berlin, Germany | Department of Neurology, Charité – University Medicine Berlin, Berlin, Germany | Centre of Rehabilitation, the Second Affiliated Hospital of Jiaxing University, Jiaxing, China | Centre for Rehabilitation Science, University Potsdam, Potsdam, Germany
Note: [] Both authors contributed equally to this work.
Note: [] Both authors contributed equally to this work.
Note: [] Corresponding author: Dr. Christian Dohle, M. Phil., MEDIAN Klinik Berlin-Kladow, Kladower Damm 223, 14089 Berlin, Germany. Tel.: +49 30 36503 101; Fax: +49 30 36503 123; E-mail: christian.dohle@median-kliniken.de
Abstract: Purpose: Mirror therapy can improve motor and sensory functions, but effects of the mirror illusion on primary motor and somatosensory cortex could not be established consistently. Methods: Fifteen right handed healthy volunteers performed or observed a finger-thumb opposition task. Cerebral activations during normal movement (NOR), mirrored movement (MIR) and movement observation (OBS) by means of a video chain were recorded with functional magnetic resonance imaging (fMRI). Activation sizes in movement > static conditions were identified using SPM8 (p < 0.001, unc.) and attributed to predefined areas employing the Anatomy toolbox 1.8. Laterality indices for the responsive areas were calculated on the basis of the number of activated voxels. Results: Relevant bilateral BOLD responses were found in primary motor (M1) and somatosensory (S1 – BA 2, 3b and 3a) cortex, premotor and parietal areas and V5. When comparing MIR to NOR, no significant change of contralateral activation in M1 was found, but clearly at S1 with differences between hands. Conclusion: The mirror illusion does not elicit immediate changes in motor areas, yet there is a direct effect on somatosensory areas, especially for left hand movements. These results suggest different effects of mirror therapy on processing and rehabilitation of motor and sensory function.
