Article

Mirror therapy is a new form of stroke rehabilitation
that uses the mirror reflection of the unaffected hand in place of the affected
hand to augment movement training. The mechanism of mirror therapy is not known
but is thought to involve changes in cerebral organization. We used
magnetoencephalography (MEG) to measure changes in cortical activity during
mirror training after stroke. In particular, we examined movement-related changes
in the power of cortical oscillations in the beta (15-30 Hz) frequency range,
known to be involved in movement. METHODS: Ten stroke patients with upper limb
paresis and 13 healthy controls were recorded using MEG while performing bimanual
hand movements in 2 different conditions. In one, subjects looked directly at
their affected hand (or dominant hand in controls), and in the other, they looked
at a mirror reflection of their unaffected hand in place of their affected hand.
The movement-related beta desynchronization was calculated in both primary motor
cortices. RESULTS: Movement-related beta desynchronization was symmetrical during
bilateral movement and unaltered by the mirror condition in controls. In the
patients, movement-related beta desynchronization was generally smaller than in
controls, but greater in contralesional compared to ipsilesional motor cortex.
This initial asymmetry in movement-related beta desynchronization between
hemispheres was made more symmetrical by the presence of the mirror. CONCLUSIONS:
Mirror therapy could potentially aid stroke rehabilitation by normalizing an
asymmetrical pattern of movement-related beta desynchronization in primary motor
cortices during bilateral movement.
CI - (c) The Author(s) 2014.

Langue : ANGLAIS