Article

A goal of stroke rehabilitation is to harness the capacity of the
brain to reorganize following neurological damage and enable restoration of
function. OBJECTIVE: To understand how neural oscillatory motor responses change
following a therapeutic intervention and to illuminate whether these
neurophysiological alterations correlate with improvements on behavioral
measurements. METHODS: Magnetoencephalography (MEG) was used to evaluate
plasticity in motor networks following 2 weeks of intensive task-oriented
therapy, which was paired with sham or peripheral nerve stimulation (PNS).
Patients completed unilateral finger tapping before and 3 weeks after therapy as
whole-head MEG data were acquired. MEG data were imaged using beamforming, and
the resulting event-related synchronizations and desynchronizations (ERSs/ERDs)
were subjected to region-of-interest (ROI) analyses. For each ROI, the authors
compared the baseline and postintervention MEG response amplitude, volume, and
peak location for premovement beta ERD, movement-onset gamma ERS, and
postmovement beta ERS. RESULTS: Following therapy, all patients showed reduced
postmovement beta ERS response amplitudes in bilateral precentral gyri and
reduced gamma ERS amplitudes in the precentral gyrus of the affected hemisphere.
This latter response also distinguished treatment groups, as the posttherapy
gamma reduction was greater in patients who received PNS. Finally, both beta and
gamma response amplitudes were significantly correlated with improvement on
several behavioral indices of motor function. DISCUSSION: These case-series data
indicate that oscillatory MEG responses may be useful in gauging plasticity in
motor cortices following therapy in stroke patients.

Langue : ANGLAIS