Communication Orale

Représentation cinématique corticale: valeur ajoutée de la prise en compte de la performance motrice dans l'analyse de l'IRMf

Dr Liesjet VAN DOKKUMa, Pr Denis MOTTETb, Pr Isabelle LAFFONTc, Pr Alain BONAFÉa, Dr Nicolas MENJOT DE CHAMPFLEURa, Dr Jerome FROGERd, Dr Emmanuelle LE BARSa

a CHU Montpellier, Gui de Chauliac, b Montpellier University, Movement 2 Health - Euromov, c CHU Montpellier, Lapeyronie, d CHU Nimes, le Grau du Roi

Objective: To evaluate the additional value of adding movement kinematics into the design matrix in order to gain fine grained insight in motor control strategies.
Methods: 10 healthy volunteers (age 41.8 ±14.5, 5 male) performed a continuous elbow flexion/extension within a 1.5 MRI system. Movement kinematics were registered with the Zebris, a MRI compatible 3D motion capture system.
Results: Without taking the movement kinematics into consideration we found the expected systematic activation of the primary sensorimotor network, thought to generate movement execution (1). By adding the kinematics to the fMRI design matrix we unmasked the involvement of fronto-cerebellar circuits and of the sensory cortex, as a function of both the irregularity and the frequency of movement, highlighting underlying processes of error-control to ensure optimal execution (2).
Discussion: Our results reveal the modular and hierarchical structure of rhythmic motor control within brain networks: rhythmical movement generation relies on the activation of the primary sensorimotor network and error control of that movement results from the trade-off between automatically driven intermittent control involving cerebellar-frontal loops and continuous feedback involving the sensory cortex. Motor planning and error-control are important process involved in recovery post-stroke, and the detailed kinematic analysis during fMRI measurements seems to have an additional value possibly contributing to further understanding motor learning post-stroke.
1 Schaal S, Sternad D, Osu R, Kwato M (2004) Rhythmic arm movement is not discrete. Nat Neurosci, 7:1136-1143
2 Penhune VB, Steel CJ (2012) Parallel contributions of cerebellar, striatal and M1 mechanisms to motor sequence learning. Behav Brain Res 226:579-591

Mots clés : Stroke, kinematics, upper arm movements, functional MRI, rehabilitation