Therapeutic plasma exchange in MS refractory relapses: Long-term outcome.

INTRODUCTION: Therapeutic plasma exchange (TPE) is considered a treatment option for steroid-refractory multiple sclerosis (MS) relapses. Our objective was to assess long-term clinical response to TPE in MS steroid-refractory exacerbations. METHODS: Retrospective study of relapsing remitting MS (RRMS) patients presenting intravenous methylprednisolone (IVMPS)-refractory relapses, who underwent TPE. Response to TPE was assessed at 1, 3, 6, 12 and 24-months post-treatment, and compared to a second group of RRMS patients with similar demographic and clinical characteristics presenting, IVMPS-refractory relapses but not treated with TPE. Multivariate regression analysis was used to assess potential predictors of significant clinical response. RESULTS: Between 2011 to 2020, a total of 23 RRMS patients were treated with TPE. Twenty-one patients not receiving the treatment served as controls. No differences in demographic or clinical characteristics, or predictors of clinical improvement after TPE were detected between groups. Seventy-eight percent of patients treated with TPE presented clinical improvement at 24 months. TPE-treated patients presented lower EDSS scores at 6 and at 24 months. Younger age, presence of gadolinium-enhancing lesions and TPE treatment were associated with better clinical outcomes. No life-threatening side effects were reported. CONCLUSIONS: TPE is a safe and well tolerated procedure that decreases long-term disability in RRMS patients with IVMPS-refractory relapses.

The effects of land use and topographic changes on sediment connectivity in mountain catchments.

Understanding the evolution of sediment connectivity associated with different land use and topographic changes is a prerequisite for a better understanding of sediment budgets and sediment transport processes. We used the Index of Sediment Connectivity (IC) developed by Cavalli et al. (2013) based on the original approach by Borselli et al. (2008) to study the effects of decadal-scale land use and topographic changes on sediment connectivity in mountain catchments. The input variables of the IC (i.e. land cover and topography) were derived from historical aerial photos using Structure from Motion-Multi View Stereo algorithms (SfM-MVS). The method was applied in different sub-catchments of the Upper River Cinca Catchment (Central Pyrenees), representative of three scenarios: (a) Land cover changes; (b) Topographic changes in agricultural fields (terracing); and (c) Topographic changes associated with infrastructure (road construction). In terms of land cover changes, results show that although connectivity is increased in some areas due to the establishment of new field crops, for most of the study area connectivity decreased due to afforestation caused by rural abandonment. Topographic changes due to the establishment of agricultural terraces affected connectivity to a larger degree than land cover changes. Terracing generally reduced connectivity due to the formation of flat areas in step-slopes, but in certain points, an increase in connectivity caused by the topographic convergence produced by terraces was observed. Finally, topographic changes associated with road construction greatly modified surface flow directions and the drainage network, resulting in changes in connectivity that may affect erosional processes nearby. The methodology used in this paper allows to study the effects of real decadal-scale land use and topographic changes on sediment connectivity and also evaluating and disentangling those changes. Furthermore, this approach can be a useful tool to identify potential risks associated with morphological and land use changes, involving road infrastructures.

Basin-scale analysis of the geomorphic effectiveness of flash floods: A study in the northern Apennines (Italy).

Large floods may produce remarkable channel changes, which determine damages and casualties in inhabited areas. However, our knowledge of such processes remains poor, as is our capability to predict them. This study analyses the geomorphic response of the Nure River (northern Italy) and nine tributaries to a high-magnitude flood that occurred in September 2015. The adopted multi-disciplinary approach encompassed: (i) hydrological and hydraulic analysis; (ii) analysis of sediment delivery to the stream network by means of landslides mapping; (iii) assessment of morphological modifications of the channels, including both channel width and bed elevation changes. The spatial distribution of rainfall showed that the largest rainfall amounts occur in the upper portions of the catchment, with cumulative rainfall reaching 300 mm in 12 h, and recurrence intervals exceeding 100-150 years. The unit peak discharge ranged between 5.2 and 25 m3 s-1 km-2. Channel widening was the most evident effect. In the tributaries, the ratio between post-flood and pre-flood channel width averaged 3.3, with a maximum approaching 20. Widening was associated with channel aggradation up to 1.5 m and removal of riparian vegetation. New islands formed due to the fragmentation of the former floodplain. In the Nure River, the average width ratio was 1.7, and here widening occurred mainly at the expenses of islands. Bed level dynamics in the Nure were varied, including aggradation, incision, and overall stability. The flood geomorphic effectiveness was more pronounced in the middle-higher portions of the basin. Planimetric and elevation changes were well correlated. Regression analysis of the relationship between widening and morphological/ hydraulic controlling factors indicated that unit stream power and confinement index were the most relevant variables. The study provides useful insights for river management, especially with regard to the proportion of the valley floor subject to erosion and/or deposition during large events.