Article

Mirrored feedback has potential as a therapeutic intervention to
restore hand function after stroke. However, the functional (effective)
connectivity of neural networks involved in processing mirrored feedback after
stroke is not known. OBJECTIVE: To determine if regions recruited by mirrored
feedback topographically overlap with those involved in control of the paretic
hand and to identify the effective connectivity of activated nodes within the
mirrored feedback network. METHODS: Fifteen patients with chronic stroke
performed a finger flexion task with their unaffected hand during event-related
functional magnetic resonance imaging (fMRI). Real-time hand kinematics was
recorded during fMRI and used to actuate hand models presented in virtual reality
(VR). Visual feedback of the unaffected hand motion was manipulated
pseudorandomly by either actuating the VR hand corresponding to the moving
unaffected side (veridical feedback) or the affected side (mirrored feedback). In
2 control conditions, the VR hands were replaced with moving nonanthropomorphic
shapes. RESULTS: Mirrored feedback was associated with significant activation of
regions within and outside the ipsilesional sensorimotor cortex, overlapping with
areas engaged when patients performed the task with their affected hand.
Effective connectivity analysis showed a significantly interconnected
ipsilesional somatosensory and motor cortex in the mirrored feedback condition.
CONCLUSIONS: Mirrored feedback recruits ipsilesional brain areas relevant for
control of the affected hand. These data provide a neurophysiological basis by
which mirrored feedback may be beneficial as a therapy for restoring function
after stroke.

Langue : ANGLAIS