Early Progressive Changes in White Matter Integrity Are Associated with Stroke Recovery

Abstract

Information on microstructural white matter integrity has been shown to explain post-stroke recovery beyond clinical measures and focal brain damage. Especially, knowledge about early white matter changes might improve prediction of outcome. We investigated 42 acute reperfused ischemic stroke patients (mean age 66.5 years, 40% female, median admission NIHSS 9.5) with a symptomatic MRI-confirmed unilateral middle cerebral artery territory infarction 24–72 h post-stroke and after 3 months. All patients underwent neurological examination and brain MRI. Fifteen older healthy controls (mean age 57.3 years) were also scanned twice. We assessed fractional anisotropy (FA), mean diffusivity (MD), axial (AD), and radial diffusivity (RD). Patients showed significantly decreased white matter integrity in the hemisphere affected by the acute infarction 24–72 h post-stroke, which further decreased over 3 months compared with controls. Less decrease in FA of remote white matter tracts was associated with better stroke recovery even after correcting for infarct location and extent. A regression model including baseline information showed that the modified Rankin Scale and mean FA of the genu of the corpus callosum explained 53.5% of the variance of stroke recovery, without contribution of infarct volume. Furthermore, early dynamic FA changes of the corpus callosum within the first 3 months post-stroke independently predicted stroke recovery. Information from advanced MRI measures on white matter integrity at the acute stage, as well as early dynamic white matter degeneration beyond infarct location and extent, improve our understanding of post-stroke reorganization in the affected hemisphere and contribute to an improved prediction of recovery.

Corpus callosal microstructure predicts bimanual motor performance in chronic stroke survivors: A preliminary cross-sectional study

“…Compared to neurologically intact controls, chronic stroke survivors showed significant reduction in FA across the genu (CC1) and body (CC 2, 3, 4) of the corpus callosum, but no difference was found in the splenium (CC5). We extended previous findings of lower callosal FA in acute stroke (Pinter et al, 2020) survivors to the chronic phase, in those with mild to moderate motor impairment (Hayward et al, 2017;Stewart, Dewanjee, et al, 2017), and in pediatric hemiplegia (Hawe et al, 2013). Given that the CC was not directly lesioned (as demonstrated by < 0.05% of overlap between the lesion and the CC), the reduction in FA across the CC is evidence for transcallosal diaschisis.…”

The disrupted topological properties of structural networks showed recovery in ischemic stroke patients: a longitudinal design study

“…The values of nodal efficiency in the right postcentral gyrus and right IPL were also enhanced one month later in stroke patients. Previous studies have found a beneficial role of motor-related areas on the recovery of motor function following stroke [ 7 , 51 , 52 ]. Additionally, the connectivity related to these motor-related areas was improved and tended toward connectivity values of healthy participants after clinical intervention [ 11 , 53 , 54 ].…”

“…Diffusion MRI measures on white matter (WM) integrity in stroke have found that patients showed a significant decrease of WM integrity in the hemisphere at an early stage. The decreased WM integrity showed further reduction over 3 months compared with healthy controls [ 7 ]. Regional variability in stroke patients demonstrated cortical thickness increases particularly in contralesional paracentral, superior frontal and insular regions [ 16 ].…”

“…Disrupted brain functional connectivity between paired cortical motor-related regions showed recovery to nearly normal levels in stroke patients under clinical treatment [ 18 ]. A longitudinal study of WM integrity in stroke also showed that early dynamic changes of fractional anisotropy (FA) in the corpus callosum within the first 3 months after stroke can predict people’s recovery with the correction of infarct location and extent [ 7 ]. Despite these advances in the stroke-related reorganization literatures, little is known concerning how the topological properties of the whole-brain network evolve longitudinally after stroke.…”

The Impact of Voluntary Exercise on Stroke Recovery

“…Therefore, we assessed in vivo DTI as a neuroimaging biomarker for WM and GM integrity 1 week after tMCAO in the same and additional ROI that were used for CBF analysis. WM degeneration after ischemic stroke is associated with reduced fractional anisotropy (FA) and increased mean diffusivity (MD) (Wiesmann et al, 2017(Wiesmann et al, , 2018Pinter et al, 2020).…”