Browsing by Author "Gallo, Antonio (56421492900)"

Purpose: To study the concomitant use of structural and functional magnetic resonance (MR) imaging correlates to explain information processing speed (IPS) and executive function (EF) in multiple sclerosis (MS). Materials and Methods: Local ethics committee approval was obtained at all sites for this prospective, multicenter study. All subjects provided written informed consent. Twenty-six patients with relapsing-remitting MS and 32 healthy control subjects from four centers underwent structural and functional MR imaging, including a go/no-go task and neuropsychological assessment. Subtests of the Brief Repeatable Battery of Neuropsychological Tests, the Wisconsin Card Sorting Test, and the performance with the functional MR imaging paradigm were used as estimates of IPS and EF. Activation of the thalamus and the inferior frontal gyrus (pars triangularis), thalamic volume, T2 lesion load, and age were used to explain IPS and EF in regression models. Results: Compared with control subjects, patients showed increased activation in a frontoparietal network, including both thalami, during the execution of the go/no-go task. Patients had decreased thalamic volume (P , .001). Among tested variables, thalamic volume (b = 0.606, P = .001), together with thalamic activation (b = 20.410, P = .022), were the best predictors of IPS and EF and helped explain 52.7% of the variance in IPS and EF. Conclusion: This study highlights the potential of the combined use of functional and morphologic parameters to explain IPS and EF in patients with relapsing-remitting MS and confirms the central role of the thalamus as a relay station in executive functioning. © RSNA, 2016.

Objectives To evaluate white matter and grey matter T1-weighted (w)/T2w ratio (T1w/T2w ratio) in healthy controls and patients with multiple sclerosis, and its association with clinical disability. Methods In this cross-sectional study, 270 healthy controls and 434 patients with multiple sclerosis were retrospectively selected from 7 European sites. T1w/T2w ratio was obtained from brain T2w and T1w scans after intensity calibration using eyes and temporal muscle. Results In healthy controls, T1w/T2w ratio increased until 50-60 years both in white and grey matter. Compared with healthy controls, T1w/T2w ratio was significantly lower in white matter lesions of all multiple sclerosis phenotypes, and in normal-appearing white matter and cortex of patients with relapsing-remitting and secondary progressive multiple sclerosis (p≤0.026), but it was significantly higher in the striatum and pallidum of patients with relapsing-remitting, secondary progressive and primary progressive multiple sclerosis (p≤0.042). In relapse-onset multiple sclerosis, T1w/T2w ratio was significantly lower in white matter lesions and normal-appearing white matter already at Expanded Disability Status Scale (EDSS) <3.0 and in the cortex only for EDSS ≥3.0 (p≤0.023). Conversely, T1w/T2w ratio was significantly higher in the striatum and pallidum for EDSS ≥4.0 (p≤0.005). In primary progressive multiple sclerosis, striatum and pallidum showed significantly higher T1w/T2w ratio beyond EDSS=6.0 (p≤0.001). In multiple sclerosis, longer disease duration, higher EDSS, higher brain lesional volume and lower normalised brain volume were associated with lower lesional and cortical T1w/T2w ratio and a higher T1w/T2w ratio in the striatum and pallidum (β from-1.168 to 0.286, p≤0.040). Conclusions T1w/T2w ratio may represent a clinically relevant marker sensitive to demyelination, neurodegeneration and iron accumulation occurring at the different multiple sclerosis phases. ©