title: Neuronal-glial alterations in non-primary motor areas in chronic subcortical stroke.
abstract: 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 un-injured (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.
authors.affiliation: Hoglund Brain Imaging Center, University of Kansas Medical Center, Kansas City 66160, USA. ccirstea@kumc.edu
authors.forename: Carmen M
authors.initials: CM
authors.lastname: Cirstea
authors.forename: Randolph J
authors.initials: RJ
authors.lastname: Nudo
authors.forename: Sorin C
authors.initials: SC
authors.lastname: Craciunas
authors.forename: Elena A
authors.initials: EA
authors.lastname: Popescu
authors.forename: In-Young
authors.initials: IY
authors.lastname: Choi
authors.forename: Phil
authors.initials: P
authors.lastname: Lee
authors.forename: Hung-Wen
authors.initials: HW
authors.lastname: Yeh
authors.forename: Cary R
authors.initials: CR
authors.lastname: Savage
authors.forename: William M
authors.initials: WM
authors.lastname: Brooks
mesh_terms: D000328:Adult; D000368:Aged; D002908:Chronic Disease; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009044:Motor Cortex / Q000378:metabolism* / Q000473:pathology; D009457:Neuroglia / Q000378:metabolism* / Q000473:pathology; D009474:Neurons / Q000378:metabolism* / Q000473:pathology; D020521:Stroke / Q000175:diagnosis / Q000378:metabolism* / Q000473:pathology*