Article

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. CONCLUSION: 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.

Langue : ANGLAIS