Article

The aim of the study was to examine whether neural state of spared
motor and premotor cortices captured before a therapy predicts therapy-related
motor gains in chronic subcortical stroke. DESIGN:
Ten survivors, presenting
chronic moderate upper limb impairment, underwent proton magnetic resonance
spectroscopy, magnetic resonance imaging, clinical, and kinematics assessments
before a 4-wk impairment-oriented training. Clinical/kinematics assessments were repeated after therapy,
and motor gain was defined as positive values of clinical
upper limb/elbow motion changes and negative values of trunk motion changes.
Candidate predictors were N-acetylaspartate-neuronal marker,
glutamate-glutamine-indicator of glutamatergic neurotransmission, and
myo-inositol-glial marker, measured bilaterally within the upper limb territory
in motor and premotor (premotor cortex, supplementary motor area) cortices.
Traditional predictors (age, stroke length, pre-therapy upper limb clinical
impairment, infarct volume) were also investigated. RESULTS: Poor motor gain was
associated with lower glutamate-glutamine levels in ipsilesional primary motor
cortex and premotor cortex (r = 0.77, P = 0.01 and r = 0.78, P = 0.008,
respectively), lower N-acetylaspartate in ipsilesional premotor cortex (r = 0.69,
P = 0.02), higher glutamate-glutamine in contralesional primary motor cortex (r =
-0.68, P = 0.03), and lower glutamate-glutamine in contralesional supplementary
motor area (r = 0.64, P = 0.04). These predictors outperformed myo-inositol
metrics and traditional predictors (P approximately 0.05-1.0). CONCLUSIONS:
Glutamatergic state of bilateral motor and premotor cortices and neuronal state
of ipsilesional premotor cortex may be important for predicting motor outcome in
the context of a restorative therapy.

Langue : ANGLAIS