170 research outputs found

    Stiff Person Spectrum Disorders—An Update and Outlook on Clinical, Pathophysiological and Treatment Perspectives

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    Stiff person spectrum disorders (SPSD) are paradigm autoimmune movement disorders characterized by stiffness, spasms and hyperekplexia. Though rare, SPSD represent a not-to-miss diagnosis because of the associated disease burden and treatment implications. After decades as an enigmatic orphan disease, major advances in our understanding of the evolving spectrum of diseases have been made along with the identification of multiple associated autoantibodies. However, the most important recent developments relate to the recognition of a wider affection, beyond the classic core motor symptoms, and to further insights into immunomodulatory and symptomatic therapies. In this review, we summarize the recent literature on the clinical and paraclinical spectrum, current pathophysiological understanding, as well as current and possibly future therapeutic strategies

    HACA3: A Unified Approach for Multi-site MR Image Harmonization

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    The lack of standardization is a prominent issue in magnetic resonance (MR) imaging. This often causes undesired contrast variations due to differences in hardware and acquisition parameters. In recent years, MR harmonization using image synthesis with disentanglement has been proposed to compensate for the undesired contrast variations. Despite the success of existing methods, we argue that three major improvements can be made. First, most existing methods are built upon the assumption that multi-contrast MR images of the same subject share the same anatomy. This assumption is questionable since different MR contrasts are specialized to highlight different anatomical features. Second, these methods often require a fixed set of MR contrasts for training (e.g., both Tw-weighted and T2-weighted images must be available), which limits their applicability. Third, existing methods generally are sensitive to imaging artifacts. In this paper, we present a novel approach, Harmonization with Attention-based Contrast, Anatomy, and Artifact Awareness (HACA3), to address these three issues. We first propose an anatomy fusion module that enables HACA3 to respect the anatomical differences between MR contrasts. HACA3 is also robust to imaging artifacts and can be trained and applied to any set of MR contrasts. Experiments show that HACA3 achieves state-of-the-art performance under multiple image quality metrics. We also demonstrate the applicability of HACA3 on downstream tasks with diverse MR datasets acquired from 21 sites with different field strengths, scanner platforms, and acquisition protocols

    Outcomes and risk factors associated with SARS-CoV-2 infection in a North American registry of patients with multiple sclerosis

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    Importance: Emergence of SARS-CoV-2 causing COVID-19 prompted the need to gather information on clinical outcomes and risk factors associated with morbidity and mortality in patients with multiple sclerosis (MS) and concomitant SARS-CoV-2 infections. Objective: To examine outcomes and risk factors associated with COVID-19 clinical severity in a large, diverse cohort of North American patients with MS. Design, Setting, and Participants: This analysis used deidentified, cross-sectional data on patients with MS and SARS-CoV-2 infection reported by health care professionals in North American academic and community practices between April 1, 2020, and December 12, 2020, in the COVID-19 Infections in MS Registry. Health care professionals were asked to report patients after a minimum of 7 days from initial symptom onset and after sufficient time had passed to observe the COVID-19 disease course through resolution of acute illness or death. Data collection began April 1, 2020, and is ongoing. Exposures: Laboratory-positive SARS-CoV-2 infection or highly suspected COVID-19. Main Outcomes and Measures: Clinical outcome with 4 levels of increasing severity: not hospitalized, hospitalization only, admission to the intensive care unit and/or required ventilator support, and death. Results: Of 1626 patients, most had laboratory-positive SARS-CoV-2 infection (1345 [82.7%]), were female (1202 [74.0%]), and had relapsing-remitting MS (1255 [80.4%]). A total of 996 patients (61.5%) were non-Hispanic White, 337 (20.8%) were Black, and 190 (11.7%) were Hispanic/Latinx. The mean (SD) age was 47.7 (13.2) years, and 797 (49.5%) had 1 or more comorbidity. The overall mortality rate was 3.3% (95% CI, 2.5%-4.3%). Ambulatory disability and older age were each independently associated with increased odds of all clinical severity levels compared with those not hospitalized after adjusting for other risk factors (nonambulatory: hospitalization only, odds ratio [OR], 2.8 [95% CI, 1.6-4.8]; intensive care unit/required ventilator support, OR, 3.5 [95% CI, 1.6-7.8]; death, OR, 25.4 [95% CI, 9.3-69.1]; age [every 10 years]: hospitalization only, OR, 1.3 [95% CI, 1.1-1.6]; intensive care unit/required ventilator support, OR, 1.3 [95% CI, 0.99-1.7]; death, OR, 1.8 [95% CI, 1.2-2.6]). Conclusions and Relevance: In this registry-based cross-sectional study, increased disability was independently associated with worse clinical severity including death from COVID-19. Other risk factors for worse outcomes included older age, Black race, cardiovascular comorbidities, and recent treatment with corticosteroids. Knowledge of these risk factors may improve the treatment of patients with MS and COVID-19 by helping clinicians identify patients requiring more intense monitoring or COVID-19 treatment

    Benefits of early treatment with natalizumab: A real-world study

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    BACKGROUND: The impact of early versus later high-efficacy disease-modifying therapy (DMT) in patients with multiple sclerosis (MS) is uncertain. This study reported the association of early versus later natalizumab treatment with real-world clinical outcomes in MS patients. METHODS: The study included 661 participants diagnosed with MS in 1994 or later from 7 US centers participating in the MS Partners Advancing Technology for Health Solutions (MS PATHS) network. Time to natalizumab treatment between diagnosis and first infusion (TTNT) was determined from the Tysabri Outreach: Unified Commitment to Health (TOUCH) registry. Clinical outcomes were defined using neuroperformance tests included in the Multiple Sclerosis Performance Test. Associations were tested using TTNT as a categorical and continuous variable. Linear mixed models addressed within-subject and within-site clustering. RESULTS: TTNT varied from 0.1 to 19.8 years (median [interquartile range] 4.2 [1.8, 9.0] years). A significant association between later natalizumab use and worse outcomes was demonstrated for walking speed (p \u3c 0.001), processing speed (p \u3c 0.001), manual dexterity (p \u3c 0.001), brain atrophy (p = 0.001), and T2 lesion volume (p = 0.02). Covariate-adjusted modelling of a sensitivity population diagnosed with MS in 2006 or later (n = 424) demonstrated significant associations between longer TTNT and worse walking speed (p \u3c 0.05), processing speed (p \u3c 0.001), and manual dexterity (p \u3c 0.001). CONCLUSION: Later initiation of natalizumab was associated with worse clinical and radiologic imaging outcomes. Thus, high-efficacy DMT may have greater benefit when started earlier in MS patients. These results provide a rationale for randomized controlled trials to further assess the impact of early highly-effective DMT use versus later escalation of therapy

    The many faces of gastrointestinal dysfunction in stiff person syndrome spectrum disorders

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    IntroductionThe effect of stiff person syndrome spectrum disorders (SPSD) on the gastrointestinal tract (GIT) is unknown. This case series aims to characterize the prevalence and types of GI dysfunction in individuals with SPSD.MethodsA retrospective chart review included individuals diagnosed with SPSD with descriptors of GI symptoms in their medical records. SPSD phenotypes, type of motility test performed, and dysmotility pattern (upper, lower, or diffuse) were assessed. Descriptive statistics and univariate chi-square analyses were utilized.ResultsOf 240 individuals with SPSD, 32% reported GI symptoms, most were female (83.1%), and white (74%), with a median age at time of GI symptom onset of 50 ± 13 years. Most common symptoms reported were dysphagia (45%), constipation (40%), and nausea/vomiting (23%). Most individuals had classic SPS (47%) followed by SPS-plus (29%) and 82.9% were positive for serum antiGAD65 antibodies. Of 36 patients that underwent at least one GI motility test, 26 had evidence of upper, lower, or diffuse GI dysmotility (44.4%, 17%, and 4%, respectively). The group who did not undergo testing had a higher proportion of patients with DM.DiscussionThere is a high prevalence of GI symptoms and transit abnormalities in patients with SPSD. Future prospective, longitudinal studies are warranted to further assess GI symptoms in the context of SPSD and to determine if individuals with GI symptoms differ in prognosis or treatment response from those without GI symptoms. In the meantime, there should be a low threshold for motility testing in patients with SPSD

    Age-dependent white matter disruptions after military traumatic brain injury: Multivariate analysis results from ENIGMA brain injury

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    Mild Traumatic brain injury (mTBI) is a signature wound in military personnel, and repetitive mTBI has been linked to age-related neurogenerative disorders that affect white matter (WM) in the brain. However, findings of injury to specific WM tracts have been variable and inconsistent. This may be due to the heterogeneity of mechanisms, etiology, and comorbid disorders related to mTBI. Non-negative matrix factorization (NMF) is a data-driven approach that detects covarying patterns (components) within high-dimensional data. We applied NMF to diffusion imaging data from military Veterans with and without a self-reported TBI history. NMF identified 12 independent components derived from fractional anisotropy (FA) in a large dataset (n = 1,475) gathered through the ENIGMA (Enhancing Neuroimaging Genetics through Meta-Analysis) Military Brain Injury working group. Regressions were used to examine TBI- and mTBI-related associations in NMF-derived components while adjusting for age, sex, post-traumatic stress disorder, depression, and data acquisition site/scanner. We found significantly stronger age-dependent effects of lower FA in Veterans with TBI than Veterans without in four components (q \u3c 0.05), which are spatially unconstrained by traditionally defined WM tracts. One component, occupying the most peripheral location, exhibited significantly stronger age-dependent differences in Veterans with mTBI. We found NMF to be powerful and effective in detecting covarying patterns of FA associated with mTBI by applying standard parametric regression modeling. Our results highlight patterns of WM alteration that are differentially affected by TBI and mTBI in younger compared to older military Veterans

    Tracing Carbon Sources through Aquatic and Terrestrial Food Webs Using Amino Acid Stable Isotope Fingerprinting

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    Tracing the origin of nutrients is a fundamental goal of food web research but methodological issues associated with current research techniques such as using stable isotope ratios of bulk tissue can lead to confounding results. We investigated whether naturally occurring delta C-13 patterns among amino acids (delta C-13(AA)) could distinguish between multiple aquatic and terrestrial primary production sources. We found that delta C-13(AA) patterns in contrast to bulk delta C-13 values distinguished between carbon derived from algae, seagrass, terrestrial plants, bacteria and fungi. Furthermore, we showed for two aquatic producers that their delta C-13(AA) patterns were largely unaffected by different environmental conditions despite substantial shifts in bulk delta C-13 values. The potential of assessing the major carbon sources at the base of the food web was demonstrated for freshwater, pelagic, and estuarine consumers; consumer delta C-13 patterns of essential amino acids largely matched those of the dominant primary producers in each system. Since amino acids make up about half of organismal carbon, source diagnostic isotope fingerprints can be used as a new complementary approach to overcome some of the limitations of variable source bulk isotope values commonly encountered in estuarine areas and other complex environments with mixed aquatic and terrestrial inputs

    Effect of lutein and antioxidant dietary supplementation on contrast sensitivity in age-related macular disease:A randomized controlled trial

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    Objective: The aim of the study is to determine the effect of lutein combined with vitamin and mineral supplementation on contrast sensitivity in people with age-related macular disease (ARMD). Design: A prospective, 9-month, double-masked randomized controlled trial. Setting: Aston University, Birmingham, UK and a UK optometric clinical practice. Subjects: Age-related maculopathy (ARM) and atrophic age-related macular degeneration (AMD) participants were randomized (using a random number generator) to either placebo (n = 10) or active (n=15) groups. Three of the placebo group and two of the active group dropped out. Interventions: The active group supplemented daily with 6 mg lutein combined with vitamins and minerals. The outcome measure was contrast sensitivity (CS) measured using the Pelli-Robson chart, for which the study had 80% power at the 5% significance level to detect a change of 0.3log units. Results: The CS score increased by 0.07 ± 0.07 and decreased by 0.02 ± 0.18 log units for the placebo and active groups, respectively. The difference between these values is not statistically significant (z = 0.903, P = 0.376). Conclusion: The results suggest that 6 mg of lutein supplementation in combination with other antioxidants is not beneficial for this group. Further work is required to establish optimum dosage levels
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