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Heterogeneous pathological processes account for thalamic degeneration in multiple sclerosis: Insights from 7 T imaging

2017; SAGE Publishing; Volume: 24; Issue: 11 Linguagem: Inglês

10.1177/1352458517726382

1477-0970

Céline Louapre, Sindhuja Tirumalai Govindarajan, Costanza Giannì, Nancy Madigan, Jacob A. Sloane, Constantina A. Treaba, Elena Herranz, Revere P. Kinkel, Caterina Mainero,

Neurogenesis and neuroplasticity mechanisms

Background: Thalamic degeneration impacts multiple sclerosis (MS) prognosis. Objective: To investigate heterogeneous thalamic pathology, its correlation with white matter (WM), cortical lesions and thickness, and as function of distance from cerebrospinal fluid (CSF). Methods: In 41 MS subjects and 17 controls, using 3 and 7 T imaging, we tested for (1) differences in thalamic volume and quantitative T 2 * (q-T 2 *) (2) globally and (3) within concentric bands originating from the CSF/thalamus interface; (4) the relation between thalamic, cortical, and WM metrics; and (5) the contribution of magnetic resonance imaging (MRI) metrics to clinical scores. We also assessed MS thalamic lesion distribution as a function of distance from CSF. Results: Thalamic lesions were mainly located next to the ventricles. Thalamic volume was decreased in MS versus controls ( p < 10 −2 ); global q-T 2 * was longer in secondary progressive multiple sclerosis (SPMS) only ( p < 10 −2 ), indicating myelin and/or iron loss. Thalamic atrophy and longer q-T 2 * correlated with WM lesion volume ( p < 0.01). In relapsing-remitting MS, q-T 2 * thalamic abnormalities were located next to the WM ( p < 0.01 (uncorrected), p = 0.09 (corrected)), while they were homogeneously distributed in SPMS. Cortical MRI metrics were the strongest predictors of clinical outcome. Conclusion: Heterogeneous pathological processes affect the thalamus in MS. While focal lesions are likely mainly driven by CSF-mediated factors, overall thalamic degeneration develops in association with WM lesions.