Vulnerability of multiple large‐scale brain networks in dementia with Lewy bodies

Aberrations of large‐scale brain networks are found in the majority of neurodegenerative disorders. The brain connectivity alterations underlying dementia with Lewy bodies (DLB) remain, however, still elusive, with contrasting results possibly due to the pathological and clinical heterogeneity characterizing this disorder. Here, we provide a molecular assessment of brain network alterations, based on cerebral metabolic measurements as proxies of synaptic activity and density, in a large cohort of DLB patients (N = 72). We applied a seed‐based interregional correlation analysis approach (p < .01, false discovery rate corrected) to evaluate large‐scale resting‐state networks' integrity and their interactions. We found both local and long‐distance metabolic connectivity alterations, affecting the posterior cortical networks, that is, primary visual and the posterior default mode network, as well as the limbic and attention networks, suggesting a widespread derangement of the brain connectome. Notably, patients with the lowest visual and attention cognitive scores showed the most severe connectivity derangement in regions of the primary visual network. In addition, network‐level alterations were differentially associated with the core clinical manifestations, namely, hallucinations with more severe metabolic dysfunction of the attention and visual networks, and rapid eye movement sleep behavior disorder with alterations of connectivity of attention and subcortical networks. These multiple network‐level vulnerabilities may modulate the core clinical and cognitive features of DLB and suggest that DLB should be considered as a complex multinetwork disorder.     

Effect of Combination Therapy of Hydroxychloroquine and Azithromycin on Mortality in Patients With COVID‐19

Conflicting evidence regarding the use of hydroxychloroquine (HCQ) and azithromycin for the treatment of severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) infection do exist. We performed a retrospective single‐center cohort study including 377 consecutive patients admitted for pneumonia related to coronavirus disease 2019 (COVID‐19). Of these, 297 were in combination treatment, 17 were on HCQ alone, and 63 did not receive either of these 2 drugs because of contraindications. The primary end point was in‐hospital death. Mean age was 71.8 ± 13.4 years and 34.2% were women. We recorded 146 deaths: 35 in no treatment, 7 in HCQ treatment group, and 102 in HCQ + azithromycin treatment group (log rank test for Kaplan–Meier curve P < 0.001). At multivariable Cox proportional hazard regression analysis, age (hazard ratio (HR) 1.057, 95% confidence interval (CI) 1.035–1.079, P < 0.001), mechanical ventilation/continuous positive airway pressure (HR 2.726, 95% CI 1.823–4.074, P < 0.001), and C reactive protein above the median (HR 2.191, 95% CI 1.479–3.246, P < 0.001) were directly associated with death, whereas use of HCQ + azithromycin (vs. no treatment; HR 0.265, 95% CI 0.171–0.412, P < 0.001) was inversely associated. In this study, we found a reduced in‐hospital mortality in patients treated with a combination of HCQ and azithromycin after adjustment for comorbidities. A large randomized trial is necessary to confirm these findings.

The severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) infection is spreading worldwide since December 2019 and still no proven effective therapy has been found. First therapy proposed to treat coronavirus disease 2019 (COVID‐19) has been the association of lopinavir‐ritonavir, a protease inhibitor approved for HIV infection. However, Cao et al. observed no benefit comparing lopinavir‐ritonavir treatment of hospitalized patients with severe COVID‐19, ¹ and this treatment is currently not recommended. Currently, only remdesivir has been approved for COVID‐19 treatment, as it reduced recovery time by 4 days in 1,063 patients randomized to either remdesivir 200 mg loading dose followed by 100 mg daily or placebo for up to 10 days ² with a similar rate of adverse events between the 2 groups. ³ However, no effect on in‐hospital mortality was found.Chloroquine and its derivative hydroxychloroquine (HCQ), based on few preclinical studies, have also been proposed as therapies for COVID‐19. A Chinese randomized trial in patients with mild disease showed a significantly shorter recovery time in the group treated with HCQ vs. the standard of care along with a radiological improvement. ⁴ Differently, a retrospective study performed in the United States Veterans Health Administration medical centers found an increased mortality associated with the treatment with HCQ. ⁵ Moreover, an observational study has shown no significant association between HCQ use and risk of intubation or death. ⁶ Furthermore, a recent randomized controlled trial has found no differences between patients treated with HCQ plus the standard of care vs. the standard of care alone in terms of virus elimination. ⁷ On the basis of a very small nonrandomized study, azithromycin has been proposed as possible treatment in association with HCQ. ⁸ Azithromycin, is an antibiotic belonging to the class of macrolides, with some proven efficacy in acute respiratory distress syndrome. ⁹ , ¹⁰ It is known to have immunomodulatory properties through the polarization of macrophages toward the reparative state ¹¹ and the reduction in the production of pro‐inflammatory cytokines, such as IL‐8, IL‐6, TNF alpha, ¹² and iNOS expression. ¹³ Recently, two large retrospective studies evaluating in‐hospital mortality associated with the use of the combination of HCQ and azithromycin (or another macrolide, such as clarithromycin), have shown no benefits. ¹⁴ Despite the lack of a proven clinical efficacy and some concerns regarding the possible QT prolongations caused by the association of HCQ and azithromycin, ¹⁵ given the low price and the wide availability, the association of these two drugs has become the most used treatment in patients with moderate‐severe COVID‐19.Because of the urgent need to find answers to the many questions posed by the fight to SARS‐CoV2 infection and some negative evidences regarding the use of HCQ, we here propose a retrospective observational study to assess the efficacy of the combination of HCQ plus azithromycin for hospitalized patients with medium‐severe COVID‐19.     

Study of alpha-synuclein fibrillation: state of the art and expectations

Since the discovery of the presence of fibrillary forms ofα-synuclein(α-syn)in Lewy bodies(LB)and Lewy neurites in the brain of patients affected by Parkinson’s disease(PD)and dementia with LB,great effort has been dedicated to study the features ofα-syn fibrillation.In parallel,the pathological relevance of the different toxic forms ofα-syn has been also matter of investigation.In the last twenty years,scientists have been able to single out thatα-syn fibrillation initiates pathological mechanisms that by contributing to or triggering neurodegeneration/neuroinflammation,may lead to PD pathogenesis.This notwithstanding,we still ignore the reasons whyα-syn shifts from its natively unfolded conformation to toxic oligomeric and fibrillary forms.The chameleonic nature of monomericα-syn,and the extremely polymorphic characteristics of aggregated strains,renders it difficult to picture the real nature ofα-syn fibrils,their exact composition and formation dynamics.Recently,sophisticated biophysical methods and microscopy techniques have been exploited to studyα-syn fibrillation.Here,we provide an overview of the most relevant advancement in our understanding ofα-syn fibrils formation and conformation.