Somite and neurite density imaging is a novel high-grade MRI approach that is effective for determining cellular changes occurring in the gray matter and cortex in brain tissue of multiple sclerosis patients compared to brain tissue of healthy individuals, which can help identify disability status in multiple sclerosis patients.
Multiple sclerosis (MS) is associated with early gray matter changes, which may culminate in diffuse atrophy. The primary objective of this cross-sectional study was to assess the sensitivity of a newly developed methodology for detecting microstructural modifications within the gray matter. When comparing brain tissue from people with multiple sclerosis (MS) to brain tissue from healthy people, the results of the study showed that high-gradient diffusion MRI was able to detect changes in cortical and gray matter cells in MS patients. The findings are published in the journal Brain Communications.
Clinical Characteristics and Demographics of Participants
This cross-sectional study recruited 41 MS patients and 37 healthy volunteers. The MS patients predominantly comprised patients diagnosed with relapsing–remitting multiple sclerosis (RRMS). MS patients demonstrated a significant loss in deep gray matter and cortical volume compared to healthy volunteers.
Altered Signal Fractions in MS Patients Compared to Healthy Volunteers
Compared to healthy volunteers, MS patients had a significant decrease in the intra-soma signal fractions of the cortex and deep gray matter and a significant increase in the extracellular signal fractions of the deep gray matter. The MS patients also demonstrated a significant reduction and elevation in the thalamus and caudate’s intra-soma and extracellular signal fractions, respectively. There was a significant increase in the extracellular signal fraction and a significant decrease in the intracellular and intraneurite signal fractions of normal-appearing white matter in MS patients compared to healthy controls.
Thalamus Volume Loss and MS Cortical Neurodegeneration
There was a significant association between the volume and cortical extracellular signal fractions in the deep gray matter. Volume loss in the thalamus was associated with the net accumulation of neurodegenerative damage in the cortex of MS patients. Somite and neurite density imaging (SANDI) metrics indicated similar patterns in white and gray matter in RRMS and progressive MS. There were significant differences in disability and clinical measures across MS patients and healthy controls. Based on gray matter volume, there was an association between cortical microstructure and thalamic atrophy.
A novel high-grade diffusion MRI, SANDI, is found to be sensitive to the cellular changes occurring in the gray matter and the cortex in MS brain tissue compared to healthy brain tissue. This is representative of the disability status of MS patients.
Source
Krijnen, E. A., Russo, A. W., Karam, E. S., Lee, H., Chiang, F. L., Schoonheim, M. M., Huang, S. Y., & Klawiter, E. C. (2023). Detection of grey matter microstructural substrates of neurodegeneration in multiple sclerosis. Brain Communications, 5(3). https://doi.org/10.1093/braincomms/fcad153
