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 [R2 = .655, P = .001] and WMFT asymmetry score [R2 = .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.

Microstructure of the superior longitudinal fasciculus predicts stimulation-induced interference with on-line motor control

“…This finding is consistent with prior studies that reported a negative relationship between the TMS-induced modulation of visual sensitivity and the fronto-tectal WM connectivity (Quentin et al, 2013(Quentin et al, , 2014. Considering the 'virtual-lesion' model, in which inhibitory rTMS might act as a breakdown of the function associated to the targeted area, these results are also in line with previous clinical studies in traumatic brain injury (TBI) (Strangman et al, 2012) and stroke patients (Qiu et al, 2011). In these studies, FA predicts their prognosis, that is to say, FA is considered as a biomarker that might anticipate which of these patients will recover their functional deficit and which not.…”

Mechanisms of arm paresis in middle cerebral artery distribution stroke: Pilot study

“…Our lesion maps are consistent with this localization. More generally, our study is consistent with the results of studies that show that UL motor function after stroke correlates better with axonal integrity in the posterior limb of the internal capsule (as determined by diffusion tensor imaging) than it does with engagement of the ahPCG, as determined by blood oxygen-level dependent fMRI [26].…”

Structural and Resting-State Brain Connectivity of Motor Networks After Stroke

“…[5][6][7][8][9] Tractography in those chronic cases indeed demonstrates a reduction of the tract volume, which may be interpreted as atrophy secondary to anterograde degeneration. 10,11 These metrics of PT integrity also seem to better correlate with motor impairment than lesion size alone 12 or task-based fMRI motor network activity 13 but are highly correlated with functional resting-state connectivity.…”