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Updated: Feb 18, 2026
Magnetic Resonance Imaging of Multiple Sclerosis at 7.0 Tesla
Published on: February 19, 2021
Imaging patterns of gray and white matter abnormalities associated with PASAT and SDMT performance in
Gianna C Riccitelli1, Elisabetta Pagani1, Mariaemma Rodegher2
1Neuroimaging Research Unit, Institute of Experimental Neurology, Division of Neuroscience, San Raffaele Scientific Institute, Vita-Salute San Raffaele University, Milan, Italy.
Objectives:
To map the regional patterns of white matter (WM) microstructural abnormalities and gray matter (GM) atrophy exclusively associated with reduced performance in the Symbol Digit Modalities Test (SDMT) and Paced Auditory Serial Addition Test (PASAT) in relapsing-remitting (RR) multiple sclerosis (MS) patients.
Methods:
In all, 177 RRMS patients and 80 healthy controls (HC) were studied. WM microstructural abnormalities were investigated on diffusion tensor images using tract-based spatial statistics analysis, and regional GM atrophy was estimated on three-dimensional (3D) T1-weighted images using voxel-based morphometry.
Results:
Compared to HC, RRMS patients showed the expected pattern of cortical-subcortical GM atrophy and WM microstructural abnormalities. In patients, diffusivity abnormalities of supratentorial WM tracts correlated with both SDMT and PASAT scores. Lower SDMT performance was also associated with WM damage in several infratentorial WM tracts. Lower SDMT scores correlated with atrophy of the right anterior cingulate cortex, left postcentral gyrus, and right middle temporal gyrus, whereas lower PASAT scores correlated with atrophy of the deep GM nuclei, bilaterally, and several fronto-temporo-occipital regions.
Conclusion:
In RRMS patients, regional damage of different neural systems helps explaining reduced performance in SDMT and PASAT. WM microstructural damage typified reduced SDMT performance, whereas atrophy of several GM regions distinguished reduced PASAT performance.
Insights
White matter damage in multiple sclerosis (MS) patients is linked to lower Symbol Digit Modalities Test (SDMT) scores. Gray matter atrophy is associated with reduced Paced Auditory Serial Addition Test (PASAT) performance in these patients.
Area of Science:
- Neuroimaging
- Neurology
- Multiple Sclerosis Research
Background:
- Relapsing-remitting multiple sclerosis (RRMS) is characterized by neurological deficits.
- Cognitive impairments, particularly in processing speed and attention, are common in RRMS.
- Understanding the neuroanatomical correlates of these deficits is crucial for patient management.
Purpose of the Study:
- To identify specific white matter (WM) and gray matter (GM) abnormalities associated with reduced performance on the Symbol Digit Modalities Test (SDMT) and Paced Auditory Serial Addition Test (PASAT) in RRMS patients.
- To differentiate the neuroanatomical underpinnings of SDMT versus PASAT performance decrements.
Main Methods:
- Tract-based spatial statistics (TBSS) analysis of diffusion tensor images (DTI) to assess WM microstructural integrity.
- Voxel-based morphometry (VBM) of 3D T1-weighted MRI to quantify regional GM atrophy.
- Correlation analysis between neuroimaging metrics and SDMT/PASAT scores in 177 RRMS patients and 80 healthy controls (HC).
Main Results:
- RRMS patients exhibited widespread GM atrophy and WM microstructural abnormalities compared to HC.
- WM diffusivity abnormalities in supratentorial tracts correlated with both SDMT and PASAT scores.
- Lower SDMT scores were linked to WM damage in infratentorial tracts and atrophy in specific cortical regions (anterior cingulate, postcentral gyrus, middle temporal gyrus).
- Lower PASAT scores correlated with deep GM atrophy and fronto-temporo-occipital region atrophy.
Conclusions:
- Regional neural system damage explains cognitive deficits in RRMS patients.
- WM microstructural damage is a key factor in reduced SDMT performance.
- GM atrophy in specific regions is associated with reduced PASAT performance.
