DTI Evidence of Microstructural Damage to the Striatum in Subjects with Multiple Sclerosis (P06.107)

OBJECTIVE: To assess microstructural damage to deep gray matter (GM) nuclei in subjects with multiple sclerosis (MS) by means of brain diffusion tensor imaging (DTI). BACKGROUND: GM damage is an established, clinically relevant feature of MS. DTI is a sensitive tool to disclose deep GM degeneration, as fractional anisotropy (FA) of the caudate and thalamus has been shown to be increased in subjects with MS. Clinical relevance of such changes has been argued following observed correlations with disease duration, disability scores and cerebral white matter (WM) lesion burden in T2-weighted images. Here we report on DTI changes in the deep GM in MS patients, including the putamen, a structure of interest that has not yet been investigated with DTI in MS. We also addressed the impact of these changes on motor performance. DESIGN/METHODS: We compared DTI-derived FA and mean diffusivity of the caudate, putamen and thalamus between 30 MS patients (25 relapsing-remitting and 5 secondary progressive) and 10 controls. Correlation analyses between DTI metrics of the structures of interest and clinical data, including disability (EDSS) and mobility indexes (ambulation index and 25-ft walk time), were investigated in the subjects with MS. RESULTS: FA of both the caudate (p=0.007) and the putamen (p=0.04) was higher in MS patients compared to controls. Caudate FA was positively correlated with EDSS (r=0.42, p=0.02) and ambulation index (r=0.38, p=0.04) in MS patients, controlling for age and gender. Putamen FA, but not caudate FA, correlated with FLAIR white matter lesion burden (r=0.40, p=0.03) in the patients. No other associations between DTI metrics of the structures of interest and clinical parameters were found. CONCLUSIONS: Increased FA in the striatum may represent a marker of microstructural damage to the deep GM in subjects with MS. Disclosure: Dr. Cavallari has nothing to disclose. Dr. Ceccarelli has nothing to disclose. Dr. Wang has nothing to disclose. Dr. Neema has nothing to disclose. Dr. Bakshi has received personal compensation for activities with Biogen Idec, Novartis, Questcor, and Teva Neuroscience. Dr. Bakshi has received personal compensation in an editorial capacity for Neurotherapeutics. Dr. Bakshi has received research support from Biogen Idec, EMD Serono, and Teva Neuroscience. Dr. Guttmann has nothing to disclose.