Lesion-to-ventricle distance and other risk factors for the persistence of newly formed black holes in relapsing-remitting multiple sclerosis.

Background: Progenitor cells from the subventricular zone (SVZ) of the lateral ventricles are assumed to contribute to remyelination and resolution of black holes (BHs) in multiple sclerosis (MS). This process may depend on the distance between the lesion and the SVZ. Objective: The objective of this paper is to investigate the relationship between lesion-to-ventricle (LV) distance and persistence of new BHs. Methods: We analysed the magnetic resonance images (MRIs) of 289 relapsing-remitting (RR) MS patients, obtained during a multi-centre, placebo-controlled phase II trial over one year. Results: Overall, 112/289 patients showed 367 new BHs at the beginning of the trial. Of these, 225 were located in 94/112 patients at the level of the lateral ventricles on axial MRIs and included in this analysis. In total, 86/225 (38%) BHs persisted at month 12. LV distance in persistent BHs (PBHs) was not longer than in transient BHs. In fact PBHs tended to be closer to the SVZ than transient BHs. A generalised linear mixed multivariate model adjusted for BHs clustered within a patient and including patient- as well as lesion-specific factors revealed size, ring contrast enhancement, and shorter LV distance as independent predictors for BH persistence. Conclusion: Location of BHs close to the lateral ventricles does not appear to favourably influence the resolution of new BHs in RRMS.