Pedroza, Claudia

Background ‘Exception from informed consent’ research requires community consultation to ensure that the views of the local population have been considered. Using market research companies to distribute surveys across local populations is attractive because it ensures adequate response rates. It is not known whether individuals who respond to surveys are typical of the targeted communities. The purpose of this study is to compare the demographics of the survey respondents with that of the general population in the same area. Methods This is an analysis of data collected as part of the ‘Trauma Resuscitation with Group O Whole Blood or Products’ (TROOP) trial. The surveys used a commercial market research service to reach the communities of interest and consisted of 18 questions designed to evaluate respondents’ willingness to be enrolled in the TROOP trial and the demographics of survey respondents. Results Catchment populations varied from 0.5 to 9.4 million residents, with a total of 33.5 million. The racial and ethnic composition of the population (and the survey respondents, in brackets) was 44.8% (57.0%) white, 25.7% (13.4%) Hispanic, 12.7% (19.4%) black, 8.0% (2.5%) multiracial, 7.9% (4.4%) Asian, 0.7% (0.9%) Native American, and 0.2% (0.5%) Islanders. Of the male population (and survey respondents, in brackets), 12.2% (15.3%) were aged 18years to 24 years, 20.5% (22.3%) aged 25 years to 34 years, 18.1% (24.9%) aged 35 years to 44 years, 16.3% (18.5%) aged 45 years to 54 years, 15.5% (14.8%) aged 55 years to 64 years, and 17.4% (4.3%) aged 65 years and over. Of the female population (and survey respondents, in brackets), 11.0% (18.5%) were aged 18 years to 24 years, 18.4% (22.6%) aged 25 years to 34 years, 16.4% (23.5%) aged 35 years to 44 years, 15.0% (17.3%) aged 45 years to 54 years, 18.5% (14.1%) aged 55 years to 64 years, and 20.6% (3.9%) aged 65 years and over. Conclusions For this trial, using a market research company to distribute community surveys resulted in respondents that are broadly representative of the geographic areas where the trial will be conducted, except for individuals over the age of 65 years and older. This finding provides reassurance to investigators and institutional review boards that the views expressed by respondents are representative of the population where the trial will be conducted. Level of evidence III

Background Tremor affects up to 45% of patients with Multiple Sclerosis (PwMS). Current understanding is based on insights from other neurological disorders, thus, not fully addressing the distinctive aspects of MS pathology. Objective To characterize the brain white matter (WM) correlates of MS-related tremor using diffusion tensor imaging (DTI). Methods In a prospective case-control study, PwMS with tremor were assessed for tremor severity and underwent MRI scans including DTI. PwMS without tremor served as matched controls. After tract selection and segmentation, the resulting diffusivity measures were used to calculate group differences and correlations with tremor severity. Results This study included 72 PwMS. The tremor group (n = 36) exhibited significant changes in several pathways, notably in the right inferior longitudinal fasciculus (Cohen's d = 1.53, q < 0.001) and left corticospinal tract ( d = 1.32, q < 0.001), compared to controls (n = 36). Furthermore, specific tracts showed a significant correlation with tremor severity, notably in the left medial lemniscus (Spearman's coefficient [ rsp] = −0.56, p < 0.001), and forceps minor of corpus callosum ( rsp = -0.45, p < 0.01). Conclusion MS-related tremor is associated with widespread diffusivity changes in WM pathways and its severity correlates with commissural and sensory projection pathways, which suggests a role for proprioception or involvement of the dentato-rubro-olivary circuit.