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Rapid Plasticity (i) and Rapid Motor Corrections (ii) in movement control| old_uid | 7333 |
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| title | Rapid Plasticity (i) and Rapid Motor Corrections (ii) in movement control |
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| start_date | 2009/09/10 |
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| schedule | 14h30 |
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| online | no |
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| summary | (i) It is now possible to perform resections of slow-growing tumors on awake patients using direct electrical stimulation for functional mapping during the surgical operation. Simple clinical observations made on patients with a resection of slow-growing tumors have demonstrated a substantial recovery within a few days after the awake surgery. The aim of this study was to investigate precisely the kinetic of the recovery following the resection of slow-growing tumors invading the left parietal area. Two patients were assessed on classical line bisection tests and compared with eight healthy individuals. Typically, hemineglect mostly occurs for lesions of the right parietal cortex and recovery is considered to be long and partial. However, results demonstrated clearly that patients recovered rapidly and substantially from a pronounced right neglect, solely 48h after their surgical operation. Recovery was significant for both patients in less than 4h when line bisections were performed in separated sessions during this second day. More strikingly, we observed for patient 2 an ultra fast recovery occurring in less than 7 min within the first session of practice. This substantial recovery occurred when this patient was simply performing the line bisection task. This gain of performance was substantially retained in the following session of testing. The rapidity of this recovery strongly suggests that unmasking processes on redundant networks are at the source of such acute plastic phenomenon. (ii) When subjects are required to point from an upright standing position to a target which randomly jumps forward, some motor corrections can occur in the upper and lower limbs with latencies lower than 100 ms. These rapid motor corrections were revealed by contrasting the electromyographic activities associated with the perturbed and unperturbed trials. The earliest responses were observed especially in the anterior portion of the deltoïdus (shoulder) and the tibialis anterior (leg). It suggests that fast loops with few synaptic relays involve subcortical as well as cortical structures in the on-going movement correction. |
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| oncancel | Horaire inhabituel |
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| responsibles | Marin |
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