Amyotrophic lateral sclerosis leads to the progressive loss of upper and lower motor neurons, which advances to the degeneration of lateral and ventral corticospinal tracts.
In this study, the researchers used 9.4-tesla diffusion-tensor MR imaging (DTI-MRI) and echo-planar spectroscopic imaging to view a postmortem ALS spinal cord. Both modalities have shown sensitivity for microstructural tissue changes, which could serve as biomarkers of ALS.
The researchers found increased radial diffusivity values in the left and right lateral corticospinal tracts and in the ventral corticospinal tracts, indicating neuronal loss related to ALS.
"With the use of proton spectroscopy-based imaging, we are potentially teasing out microstructural information from white matter due to associated microstructurally dependent magnetic susceptibility variations," wrote study co-author Sean Foxley, PhD, a research assistant professor at the University of Chicago. "This allows us an avenue toward spectral biomarkers that are specific to particular microstructural changes due to disease."
Given the data, radial diffusivity and asymmetry values potentially could serve as biomarkers for upper motor neurons affected by ALS, according to the researchers.
