Determinants of Deep Gray Matter Atrophy in Multiple Sclerosis: A Multimodal MRI Study.

BACKGROUND AND PURPOSE: Deep gray matter involvement is a consistent feature in multiple sclerosis. The aim of this study was to evaluate the relationship between different deep gray matter alterations and the development of subcortical atrophy, as well as to investigate the possible different substrates of volume loss between phenotypes. MATERIALS AND METHODS: Seventy-seven patients with MS (52 with relapsing-remitting and 25 with progressive MS) and 41 healthy controls were enrolled in this cross-sectional study. MR imaging investigation included volumetric, DTI, PWI and Quantitative Susceptibility Mapping analyses. Deep gray matter structures were automatically segmented to obtain volumes and mean values for each MR imaging metric in the thalamus, caudate, putamen, and globus pallidus. Between-group differences were probed by ANCOVA analyses, while the contribution of different MR imaging metrics to deep gray matter atrophy was investigated via hierarchic multiple linear regression models. RESULTS: Patients with MS showed a multifaceted involvement of the thalamus and basal ganglia, with significant atrophy of all deep gray matter structures (P < .001). In the relapsing-remitting MS group, WM lesion burden proved to be the main contributor to volume loss for all deep gray matter structures (P ≤ .006), with a minor role of local microstructural damage, which, in turn, was the main determinant of deep gray matter atrophy in patients with progressive MS (P ≤ .01), coupled with thalamic susceptibility changes (P = .05). CONCLUSIONS: Our study confirms the diffuse involvement of deep gray matter in MS, demonstrating a different behavior between MS phenotypes, with subcortical GM atrophy mainly determined by global WM lesion burden in patients with relapsing-remitting MS, while local microstructural damage and susceptibility changes mainly accounted for the development of deep gray matter volume loss in patients with progressive MS.

Use of ultrasound shear wave to measure muscle stiffness in children with cerebral palsy.

PURPOSE: Cerebral palsy (CP) is a disorder characterized by an increased muscle stiffness that can be contingent on both neurological and biomechanical factors. The neurological aspects are related to hyper-excitability of the stretch reflex, while the biomechanical factors are related to modifications in muscle structure. We used smart-shear wave elastography (S-SWE) to analyze muscle properties and to compare shear wave speed in soleus muscles of patients affected by CP and typically developing children. METHODS: We enrolled 21 children (15 males and 6 females; age range 3-16) with spastic hemiplegia CP and 21 healthy children (11 males and 10 females; age range 3-14). Measurements of soleus S-SWE were performed using a Samsung RS80A ultrasound scanner with Prestige equipment (Samsung Medison Co. Ltd., Seoul, Korea), with a convex array transducer (CA1-7; Samsung Medison Co. Ltd., Seoul, Korea). For each CP child clinical assessment included Modified Ashworth Scale (MAS) score. RESULTS: Children with CP showed greater S-SWE values than the healthy ones (p < 0.001). Our data suggest a significant correlation between the S-SWE values and the MAS scores (Spearman correlation coefficient 0.74; p < 0.001 at Kruskal-Wallis test) in children with CP. CONCLUSIONS: Measuring muscle properties with SWE, a non-invasive and real-time technique, may integrate the physical exam. SWE may be a reliable clinical tool for diagnosis and longitudinal monitoring of muscle stiffness, as well as particularly suitable for grading and for assessing the response to treatments.