Whether
functional changes of the non-primary motor areas, e.g., dorsal
premotor (PMd) and supplementary motor (SMA) areas, after stroke,
reflect reorganization phenomena or recruitment of a pre-existing motor
network remains to be clarified. We hypothesized that cellular changes
in these areas would be consistent with their involvement in post-stroke
reorganization. Specifically, we expected that neuronal and glial
compartments would be altered in radiologically normal-appearing, i.e.,
spared, PMd and SMA in patients with arm paresis.
Twenty survivors of a single ischemic subcortical stroke and 16
age-matched healthy controls were included. At more than six months
after stroke, metabolites related to neuronal and glial compartments:
N-acetylaspartate, myo-inositol, and glutamate/glutamine, were quantified by proton magnetic resonance spectroscopy
in PMd and SMA in both injured (ipsilesional) and uninjured
(contralesional) hemispheres. Correlations between metabolites were also
calculated. Finally, relationships between metabolite concentrations
and arm motor impairment (total and proximal Fugl-Meyer Upper Extremity,
FMUE, scores) were analyzed. Compared to controls, stroke survivors
showed significantly higher ipsilesional PMd myo-inositol
and lower SMA N-acetylaspartate. Significantly lower metabolite
correlations were found between ipsilesional and contralesional SMA.
Ipsilesional N-acetylaspartate was significantly related to proximal
FMUE scores. This study provides evidence of abnormalities in
metabolites, specific to neuronal and glial compartments, across spared
non-primary motor areas. Ipsilesional alterations were related to
proximal arm motor impairment. Our results suggest the involvement of
these areas in post-stroke reorganization.
No comments:
Post a Comment