Neural Substrates for Motor Imagery in Severe Hemiparesis
- 1 June 2006
- journal article
- research article
- Published by SAGE Publications in Neurorehabilitation and Neural Repair
- Vol. 20 (2), 268-277
- https://doi.org/10.1177/1545968306286958
Abstract
Background. The beneficial effects of imagined movements on motor learning and performance suggest that motor imagery is functionally close to preparatory and executive motor processes. Objective. The purpose of this study was to examine the cortical processes associated with imagery of movement of the wrist in subjects with severe hemiparesis. Methods. During fMRI, subjects with stroke performed alternating blocks of imagining wrist-tracking movements with the hemiparetic hand, active wrist-tracking movements with the unaffected hand, and resting. Control subjects performed the same tasks using an assigned hand. Cortical activation in the primary motor (M1), primary sensory (S1), supplementary motor area (SMA), and pre-SMA regions was determined through a laterality index of active voxels and signal intensity. Ability to imagine was assessed with an Imagery Rating Scale. Results.All subjects displayed primarily contralateral control during the track condition. Healthy subjects demonstrated contralateral control in all areas during the imagine condition, whereas subjects with stroke displayed primarily contralateral activation in S1 but ipsilateral in M1 and SMA. The percentage change in signal intensity was greater in the ipsilateral hemisphere in subjects with stroke than in the ipsilateral hemisphere in healthy subjects during the imagine condition. Additionally, subjects with self-reported low ability to imagine displayed no difference in activation compared to those with high imagery ability. Conclusions. These findings are consistent with other works demonstrating primarily ipsilateral control of the hemiparetic hand in subjects with functional movement and lay the groundwork for further investigation into the ability of mental imagery to affect functionally relevant cortical control in subjects recovering from stroke.Keywords
This publication has 55 references indexed in Scilit:
- From mental power to muscle power—gaining strength by using the mindNeuropsychologia, 2004
- Stimulation through simulation? Motor imagery and functional reorganization in hemiplegic stroke patientsBrain and Cognition, 2004
- Training Mobility Tasks after Stroke with Combined Mental and Physical Practice: A Feasibility StudyNeurorehabilitation and Neural Repair, 2004
- Is the human primary motor cortex involved in motor imagery?Cognitive Brain Research, 2004
- Lesion location alters brain activation in chronically impaired stroke survivorsNeuroImage, 2004
- Intact Motor Imagery in Chronic Upper Limb Hemiplegics: Evidence for Activity-Independent Action RepresentationsJournal of Cognitive Neuroscience, 2002
- The Effect of Stimulus–Response Compatibility on Cortical Motor ActivationNeuroImage, 2001
- Pilot Study of Functional MRI to Assess Cerebral Activation of Motor Function After Poststroke HemiparesisStroke, 1998
- Contralateral and ipsilateral EMG responses to transcranial magnetic stimulation during recovery of arm and hand function after strokeElectroencephalography and Clinical Neurophysiology/Electromyography and Motor Control, 1996
- Electric and magnetic fields of the brain accompanying internal simulation of movementCognitive Brain Research, 1996