title: White matter integrity is a stronger predictor of motor function than BOLD response in patients with stroke.
abstract: OBJECTIVE
  Neuroimaging techniques, such as diffusion tensor imaging (DTI) and blood oxygenation level-dependent (BOLD) functional magnetic resonance imaging (fMRI), provide insights into the functional reorganization of the cortical motor system after stroke. This study explores the relationship between upper extremity motor function, white matter integrity, and BOLD response of cortical motor areas.
  
  
  METHODS
  Seventeen patients met study inclusion criteria; of these 12 completed DTI assessment of white matter integrity and 9 completed fMRI assessment of motor-related activation. Primary clinical outcome measures were the Wolf Motor Function Test (WMFT) and the upper limb portion of the Fugl-Meyer (FM) motor assessment. Structural integrity of the posterior limb of the internal capsule was assessed by examining the fractional anisotropy (FA) asymmetry in the PLIC. Laterality index of motor cortical areas was measured as the BOLD response in each patient during a finger pinch task. Linear regression analyses were performed to determine whether clinical outcome was associated with structural or functional MRI measures.
  
  
  RESULTS
  There were strong relationships between clinical outcome measures and FA asymmetry (eg, FM score [R(2) = .655, P = .001] and WMFT asymmetry score [R(2) = .651, P < .002]) but relationships with fMRI measures were weaker.
  
  
  CONCLUSIONS
  Clinical motor function is more closely related to the white matter integrity of the internal capsule than to BOLD response of motor areas in patients 3 to 9 months after stroke. Thus, use of DTI to assess white matter integrity in the internal capsule may provide more useful information than fMRI to interpret motor deficits following supratentorial brain injury.
authors.affiliation: Third Military Medical University, Chongqing, China.
authors.forename: Mingguo
authors.initials: M
authors.lastname: Qiu
authors.forename: Warren G
authors.initials: WG
authors.lastname: Darling
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Morecraft
authors.forename: Chun Chun
authors.initials: CC
authors.lastname: Ni
authors.forename: Justin
authors.initials: J
authors.lastname: Rajendra
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Butler
mesh_terms: D000328:Adult; D000368:Aged; D002560:Cerebrovascular Circulation / Q000502:physiology*; D005260:Female; D006429:Hemiplegia / Q000473:pathology* / Q000503:physiopathology; D006801:Humans; D020772:Internal Capsule / Q000098:blood supply / Q000473:pathology* / Q000503:physiopathology; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009413:Nerve Fibers, Myelinated / Q000473:pathology*; D011237:Predictive Value of Tests; D011379:Prognosis; D020127:Recovery of Function / Q000502:physiology; D020521:Stroke / Q000473:pathology* / Q000503:physiopathology