Related Experiment Videos
Cognitive dysfunction in patients with mildly disabling relapsing-remitting multiple sclerosis: an exploratory study
Marco Rovaris1, Giuseppe Iannucci, Monica Falautano
1Neuroimaging Research Unit, Department of Neuroscience, Scientific Institute and University Ospedale San Raffaele, via Olgettina 60, 20132, Milan, Italy.
Abstract:
Previous studies assessing the magnetic resonance imaging (MRI) correlates of cognitive dysfunction in multiple sclerosis (MS) achieved conflicting results. Diffusion tensor (DT)-MRI provides metrics that are sensitive to the macro- and microscopic MS lesion load with increased specificity to the more destructive aspects of MS pathology than conventional imaging. We performed an exploratory study to assess the magnitude of the correlation between quantities derived from DT-MRI and measures of cognitive impairment in patients with relapsing-remitting (RR) MS.T2, T1, DT-MRI scans of the brain and an extensive battery of neuropsychological tests (exploring language, complex reasoning, attention and memory) were obtained from 34 RRMS patients. We measured T2 and T1 lesion volumes (LV) and brain volume. Average lesion mean diffusivity (D) and fractional anisotropy (FA) were calculated. D and FA histograms from the brain tissue (BT), the normal-appearing brain tissue (NABT), the normal-appearing white matter (NAWM) and the normal-appearing gray matter (NAGM) were also obtained. Nine patients (26.5%) were found to be cognitively impaired. Moderate correlations were found between symbol digit modalities test, verbal fluency test and 10/36 spatial recall test scores and T2 LV, T1 LV and average lesion, WBT, NABT, NAWM and NAGM values (r values ranging from -0.30 to -0.53). No correlations were found between any of the neuropsychological test scores and brain volume, average lesion FA and WBT FA.DT-MRI provides quantitative metrics that seem to reflect the severity of language, attention and memory deficits in patients with RRMS. This study also suggests that the extent and the intrinsic nature of the macroscopic lesions as well as the damage of the NAWM and NAGM all contribute to the neuropsychological deficits of RRMS patients.
Insights
Diffusion tensor magnetic resonance imaging (DT-MRI) metrics correlate with cognitive impairment in relapsing-remitting multiple sclerosis (RRMS). DT-MRI may reflect the severity of attention, language, and memory deficits in RRMS patients.
Area of Science:
- Neuroimaging
- Neurology
- Cognitive Science
Background:
- Previous studies on magnetic resonance imaging (MRI) and cognitive dysfunction in multiple sclerosis (MS) yielded inconsistent findings.
- Diffusion tensor (DT)-MRI offers metrics sensitive to MS lesion load, with greater specificity to destructive pathology than conventional imaging.
Purpose of the Study:
- To explore the correlation between DT-MRI-derived quantities and cognitive impairment measures in relapsing-remitting MS (RRMS) patients.
- To investigate the contribution of lesion characteristics and normal-appearing tissue integrity to neuropsychological deficits.
Main Methods:
- Acquired T2, T1, and DT-MRI brain scans from 34 RRMS patients.
- Administered a comprehensive neuropsychological test battery assessing language, reasoning, attention, and memory.
- Calculated lesion volumes, brain volume, and histogram-derived metrics (mean diffusivity, fractional anisotropy) for various brain tissues.
Main Results:
- Nine patients (26.5%) exhibited cognitive impairment.
- Moderate correlations (r = -0.30 to -0.53) were observed between cognitive test scores and T2/T1 lesion volumes, and DT-MRI metrics of brain tissue, normal-appearing brain tissue, white matter, and gray matter.
- No significant correlations were found between cognitive scores and overall brain volume or average lesion fractional anisotropy.
Conclusions:
- DT-MRI provides quantitative metrics that appear to reflect the severity of language, attention, and memory deficits in RRMS.
- Both the extent/nature of macroscopic lesions and damage in normal-appearing white and gray matter contribute to neuropsychological deficits in RRMS.