title: Primary motor cortex in stroke: a functional MRI-guided proton MR spectroscopic study.
abstract: OBJECTIVE
  Our goal was to investigate whether certain metabolites, specific to neurons, glial cells, or the neuronal-glial neurotransmission system, in primary motor cortices (M1), are altered and correlated with clinical motor severity in chronic stroke.
  
  
  METHODS
  Fourteen survivors of a single ischemic stroke located outside the M1 and 14 age-matched healthy control subjects were included. At >6 months after stroke, N-acetylaspartate, myo-inositol, and glutamate/glutamine were measured using proton magnetic resonance spectroscopic imaging (in-plane resolution=5×5 mm(2)) in radiologically normal-appearing gray matter of the hand representation area, identified by functional MRI, in each M1. Metabolite concentrations and analyses of metabolite correlations within M1 were determined. Relationships between metabolite concentrations and arm motor impairment were also evaluated.
  
  
  RESULTS
  The stroke survivors showed lower N-acetylaspartate and higher myo-inositol across ipsilesional and contralesional M1 compared with control subjects. Significant correlations between N-acetylaspartate and glutamate/glutamine were found in either M1. Ipsilesional N-acetylaspartate and glutamate/glutamine were positively correlated with arm motor impairment and contralesional N-acetylaspartate with time after stroke.
  
  
  CONCLUSIONS
  Our preliminary data demonstrated significant alterations of neuronal-glial interactions in spared M1 with the ipsilesional alterations related to stroke severity and contralesional alterations to stroke duration. Thus, MR spectroscopy might be a sensitive method to quantify relevant metabolite changes after stroke and consequently increase our knowledge of the factors leading from these changes in spared motor cortex to motor impairment after stroke.
authors.affiliation: Hoglund Brain Imaging Center, University of Kansas Medical Center, 3901 Rainbow Boulevard, Mail Stop 1052, Kansas City, KS 66160, USA. ccirstea@kumc.edu
authors.forename: Carmen M
authors.initials: CM
authors.lastname: Cirstea
authors.forename: William M
authors.initials: WM
authors.lastname: Brooks
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: Ali
authors.initials: A
authors.lastname: Bani-Ahmed
authors.forename: Hung-Wen
authors.initials: HW
authors.lastname: Yeh
authors.forename: Cary R
authors.initials: CR
authors.lastname: Savage
authors.forename: Leonardo G
authors.initials: LG
authors.lastname: Cohen
authors.forename: Randolph J
authors.initials: RJ
authors.lastname: Nudo
mesh_terms: D000368:Aged; D015415:Biomarkers / Q000378:metabolism; D001931:Brain Mapping / Q000379:methods; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009044:Motor Cortex / Q000378:metabolism* / Q000473:pathology; D009457:Neuroglia / Q000378:metabolism* / Q000473:pathology; D009474:Neurons / Q000378:metabolism* / Q000473:pathology; D010291:Paresis / Q000209:etiology / Q000378:metabolism; D011237:Predictive Value of Tests; D012680:Sensitivity and Specificity; D020521:Stroke / Q000378:metabolism* / Q000473:pathology
chemical_list: D015415:Biomarkers