Browsing by Author "Caputo, Domenico (7103299939)"

Purpose: To apply voxelwise analysis of diffusion-tensor (DT) magnetic resonance (MR) tractography and T2-weighted MR lesion measurements to characterize intrinsic damage to the brain white matter (WM) tracts and the relation of this damage to the presence and location of focal lesions among the main clinical phenotypes of multiple sclerosis (MS). Materials and Methods: The study was conducted with institutional review board approval. Written informed consent was obtained from each participant. Brain dual-echo and DT MR images were obtained in 172 patients with MS (22 [13%] with clinically isolated syndromes [CIS] suggestive of MS, 51 [30%] with relapsing-remitting [RR] MS, 44 [26%] with secondary progressive MS, 20 [12%] with benign MS, 35 [20%] with primary progressive MS) and 46 healthy control subjects. Probability maps of the major brain WM tracts were produced. Between-group comparisons were assessed by using analysis of covariance. Results: Compared with the healthy control subjects, the patients with CIS had significantly increased (P<.001) mean diffusivity, axial diffusivity, and radial diffusivity in the majority of WM tracts. The primary progressive MS group showed diffuse increases in mean, axial, and radial diffusivity, with fractional anisotropy (FA) damage involving the majority of WM tracts. No relevant difference in diffusivity measures was found between the CIS and RR-MS groups. Compared with the benign MS group, the RR-MS group had reduced FA values in all WM tracts and decreased axial diffusivity in the majority of tracts. The secondary progressive MS group had pronounced damage to the majority of tracts and, compared with the benign MS group, pronounced FA alteration of the tracts relevant for motor impairment. Conclusion: Voxelwise assessment of DT MR index abnormalities is a rewarding strategy for understanding the heterogeneity of clinical MS phenotypes. © RSNA, 2011.

Purpose: To assess whether a structural disconnection between the cerebellum and the cerebral hemispheres contributes to cerebellar and brainstem symptoms in multiple sclerosis (MS). Materials and Methods: This study was approved by the local ethics committee, and written informed consent was obtained from each participant. Brain T2 lesion load, cerebellar white matter and gray matter volumes, and tract-specific measures of the middle and superior cerebellar peduncles were derived from 172 patients with MS and 46 control subjects. Predictors of clinical impairment, which was determined at ambulation and with cerebellar and brainstem functional system scores, were identified by using random forest analysis. Results: Of the 172 patients, 112 (65%) had middle cerebellar peduncle T2 lesions and 74 (43%) had superior cerebellar peduncle T2 lesions. T2 lesions in the middle and superior cerebellar peduncles were more common in clinically impaired patients than in unimpaired patients (P =.05 to <.0001). Most conventional magnetic resonance imaging metrics were more abnormal in impaired patients than in unimpaired patients (P =.03 to <.0001). Except for axial diffusivity, diffusivity abnormalities of the middle and superior cerebellar peduncles were more severe in clinically impaired patients than in unimpaired patients (P =.04 to <.0001). A minimal overlap was found between diffusivity abnormalities and T2 lesions. Compared with volumetric measures of T2 lesions or cerebellar atrophy, diffusivity measures of middle or superior cerebellar peduncle damage enabled better differentiation between clinically impaired and unimpaired patients (C statistics: 61%-70%). Conclusion: The assessment of middle and superior cerebellar peduncle damage contributes to the explanation of cerebellar and/or brainstem symptoms and ambulatory impairment in MS. © 2014 RSNA.