Related Experiment Video
Updated: Jan 2, 2026
Diffusion Tensor Magnetic Resonance Imaging in the Analysis of Neurodegenerative Diseases
Published on: July 28, 2013
Diffusion Properties of Normal-Appearing White Matter Microstructure and Severity of Motor Impairment in Acute
1From the Departments of Neurology (C.I., Y.A.A.) carson.ingo@northwestern.edu.
Background And Purpose:
The effect of white matter hyperintensities as measured by FLAIR MR imaging on functional impairment and recovery after ischemic stroke has been investigated thoroughly. However, there has been growing interest in investigating normal-appearing white matter microstructural integrity following ischemic stroke onset with techniques such as DTI.
Materials And Methods:
Fifty-two patients with acute ischemic stroke and 36 without stroke were evaluated with a DTI and FLAIR imaging protocol and clinically assessed for the severity of motor impairment using the Motricity Index within 72 hours of suspected symptom onset.
Results:
There were widespread decreases in fractional anisotropy and increases in mean diffusivity and radial diffusivity for the acute stroke group compared with the nonstroke group. There was a significant positive association between fractional anisotropy and motor function and a significant negative association between mean diffusivity/radial diffusivity and motor function. The normal-appearing white matter ROIs that were most sensitive to the Motricity Index were the anterior/posterior limb of the internal capsule in the infarcted hemisphere and the splenium of the corpus callosum, external capsule, posterior limb/retrolenticular part of the internal capsule, superior longitudinal fasciculus, and cingulum (hippocampus) of the intrahemisphere/contralateral hemisphere.
Conclusions:
The microstructural integrity of normal-appearing white matter is a significant parameter to identify neural differences not only between those individuals with and without acute ischemic stroke but also correlated with the severity of acute motor impairment.
Insights
Diffusion tensor imaging reveals that normal-appearing white matter integrity is altered in acute ischemic stroke patients, correlating with motor function deficits. These microstructural changes are key indicators of stroke severity.
Area of Science:
- Neuroimaging
- Stroke Research
- White Matter Integrity
Background:
- White matter hyperintensities are well-studied in ischemic stroke.
- Growing interest in normal-appearing white matter (NAWM) microstructural integrity using diffusion tensor imaging (DTI).
Purpose of the Study:
- Investigate NAWM microstructural integrity in acute ischemic stroke.
- Correlate DTI metrics with motor impairment severity.
Main Methods:
- Evaluated 52 acute ischemic stroke patients and 36 controls using DTI and FLAIR MRI.
- Assessed motor impairment with the Motricity Index within 72 hours of symptom onset.
Main Results:
- Stroke group showed decreased fractional anisotropy (FA) and increased diffusivity (MD, RD) in NAWM.
- Significant positive association between FA and motor function.
- Significant negative association between MD/RD and motor function.
- Key sensitive regions included internal capsule, corpus callosum, and superior longitudinal fasciculus.
Conclusions:
- NAWM microstructural integrity is significantly altered in acute ischemic stroke.
- DTI-derived metrics correlate with motor impairment severity.
- NAWM integrity is a crucial parameter for understanding stroke-related neural differences and functional deficits.
