Prefrontal theta modulates sensorimotor gamma networks during the reorienting of attention

The ability to execute a motor plan involves spatiotemporally precise oscillatory activity in primary motor (M1) regions, in concert with recruitment of “higher order” attentional mechanisms for orienting toward current task goals. While current evidence implicates gamma oscillatory activity in M1 as central to the execution of a movement, far less is known about top‐down attentional modulation of this response. Herein, we utilized magnetoencephalography (MEG) during a Posner attention‐reorienting task to investigate top‐down modulation of M1 gamma responses by frontal attention networks in 63 healthy adult participants. MEG data were evaluated in the time–frequency domain and significant oscillatory responses were imaged using a beamformer. Robust increases in theta activity were found in bilateral inferior frontal gyri (IFG), with significantly stronger responses evident in trials that required attentional reorienting relative to those that did not. Additionally, strong gamma oscillations (60–80 Hz) were detected in M1 during movement execution, with similar responses elicited irrespective of attentional reorienting. Whole‐brain voxel‐wise correlations between validity difference scores (i.e., attention reorienting trials—nonreorienting trials) in frontal theta activity and movement‐locked gamma oscillations revealed a robust relationship in the contralateral sensorimotor cortex, supplementary motor area, and right cerebellum, suggesting modulation of these sensorimotor network gamma responses by attentional reorienting. Importantly, the validity difference effect in this distributed motor network was predictive of overall motor function measured outside the scanner and further, based on a mediation analysis this relationship was fully mediated by the reallocation response in the right IFG. These data are the first to characterize the top‐down modulation of movement‐related gamma responses during attentional reorienting and movement execution.     

A French survey on the lockdown consequences of COVID-19 pandemic in Parkinson's disease. The ERCOPARK study

BackgroundIn 2020 the coronavirus disease 19 (COVID-19) pandemic imposed a total and sudden lockdown. We aimed to investigate the consequences of the first COVID-19 lockdown (mid-March – mid-April 2020) on motor and non-motor symptoms (NMS) in a cohort of French people with Parkinson's disease (PwP).MethodsPwP were enrolled either by an on-line survey sent from the national France Parkinson association (FP) to reach the French community of PwP or as part of outpatients' telemedicine visits followed by an hospital-based Parkinson Expert Center (PEC). All patients were evaluated using the same standardized questionnaire assessing motor and NMS (including a list of most disabling, new or worsened symptoms and Patient's Global Impression-Improvement scales [PGI-I]) psycho-social queries and quality of life.Results2653 PwP were included: 441 (16.6%) in the PEC group and 2122 (83.4%) in the community-based group. Physiotherapy was interrupted among 88.6% of the patients. 40.9% referred a clinical modification of their symptoms. Based on the questionnaire, pain (9.3%), rigidity (9.1%) and tremor (8.5%) were the three most frequently new or worsened reported symptoms. Based on the PGI-I, the motor symptoms were the most affected domain, followed by pain and psychic state. PwP in community-based group tended to have more frequent worsening for motor symptoms, motor complications, pain and confusion than those of the PEC group.ConclusionsThe first COVID-19 lockdown had a negative impact on motor and NMS of PwP. Efforts should be allocated to avoid interruption of care, including physiotherapy and physical activities and implement telemedicine. .     

Relationship of Hip and Trunk Muscle Function with Single Leg Step-Down Performance: Implications for Return to Play Screening and Rehabilitation

ObjectivesEvaluate the relationship of hip and trunk muscle function with the Single Leg Step-Down test (SLSD).Study designLaboratory study.SettingBiomechanics Laboratory.Participants71 healthy participants with no history of anterior cruciate ligament (ACL) or lower extremity injury in the last 3 months completed this study (38 males, 33 females; mean 25.49 ± 0.62 years).Main outcomesHip abduction (HABD), external rotation (HER), and extension (HEXT) peak isometric force were measured. Trunk endurance was measured with plank (PL) and side plank (SPL) tests. SLSD repetitions in 60-s and dynamic knee valgus (VAL) were recorded.ResultsPL, SPL, HABD, HER, and HEXT were positively correlated with SLSD repetitions. PL (r = 0.598, p < 0.001) was most correlated with SLSD repetitions, and regression demonstrated that PL (p = 0.001, R² = 0.469) was a predictor of SLSD repetitions. VAL trended toward negative correlation with PL and SPL. Sex-specific differences were present, with PL, SPL, HABD, and HER showing stronger relationships with SLSD in females.ConclusionHip and trunk muscle function were positively correlated with SLSD performance, and these relationships were strongest in females. PL predicted performance on the SLSD. Further research is needed to investigate the utility of SLSD as a screening or return-to-play test for lower extremity conditions such as ACL injury and patellofemoral pain.     

Warning signals for eruptive events in spreading fires

Spreading fires are noisy (and potentially chaotic) systems in which transitions in dynamics are notoriously difficult to predict. As flames move through spatially heterogeneous environments, sudden shifts in temperature, wind, or topography can generate combustion instabilities, or trigger self-stabilizing feedback loops, that dramatically amplify the intensities and rates with which fires propagate. Such transitions are rarely captured by predictive models of fire behavior and, thus, complicate efforts in fire suppression. This paper describes a simple, remarkably instructive physical model for examining the eruption of small flames into intense, rapidly moving flames stabilized by feedback between wind and fire (i.e., “wind–fire coupling”—a mechanism of feedback particularly relevant to forest fires), and it presents evidence that characteristic patterns in the dynamics of spreading flames indicate when such transitions are likely to occur. In this model system, flames propagate along strips of nitrocellulose with one of two possible modes of propagation: a slow, structured mode, and a fast, unstructured mode sustained by wind–fire coupling. Experimental examination of patterns in dynamics that emerge near bifurcation points suggests that symptoms of critical slowing down (i.e., the slowed recovery of the system from perturbations as it approaches tipping points) warn of impending transitions to the unstructured mode. Findings suggest that slowing responses of spreading flames to sudden changes in environment (e.g., wind, terrain, temperature) may anticipate the onset of intense, feedback-stabilized modes of propagation (e.g., “blowup fires” in forests).Multistable systems can, when sufficiently perturbed, undergo “critical transitions” in which they shift abruptly between dynamically distinct states. Such transitions represent important steps in the progression of many natural processes [e.g., the sudden demise of ecosystems or populations (1, 2), the onset of climatic shifts (3, 4), the crash of financial markets (5, 6), the collapse of power grids or of Internet communication networks (7, 8), transitions from life to death (9, 10)], and the identification of phenomena that trigger or presage their onset remains an intellectually challenging and practically important goal of research on the dynamics of complex systems.Recent evidence suggests that a set of generic statistical indicators may warn of impending transitions in a wide range of systems (11, 12). Briefly, as systems approach catastrophic bifurcations, they exhibit slower rates of recovery from perturbations (13), a phenomenon referred to as “critical slowing down;” as the duration of influence associated with those perturbations increases, the fluctuations to which they give rise can become larger (increased variance) (14), more correlated (increased autocorrelation) (15), and/or more asymmetric (increased skewness) (16). Many studies of critical transitions in natural systems have identified corresponding trends in individual variables of state [e.g., increased variance in electrical signals before an epileptic seizure (17)] (2–4, 18), but similar patterns have proven difficult to detect in systems for which variables of state are noisy, interdependent, or poorly defined (as in interconnected, cyclic, or chaotic systems) (11, 12). Warning signals—or, more generally, transitions between alternative stable states—in such systems have, as a result, eluded experimental examination.Spreading fires are noisy [and potentially chaotic (19)] systems for which warning signals of transitions in dynamics could aid in the development of improved practices for control and suppression. In large-scale natural fires (i.e., wildfires), for example, slowly moving flames can spontaneously erupt into blowup fires—large, rapidly moving fires stabilized by feedback between wind and spreading flames (i.e., wind–fire coupling) (20, 21). Such events, which are not captured by operative models of fire behavior, pose enormous risks to fire response teams, and complicate efforts in fire suppression (22–24).To examine patterns in dynamics associated with the onset of intense, feedback-stabilized modes of propagation, we built a simple physical model for blowup-like fires based on a bistable combustion system. In this system, flames propagate along strips of nitrocellulose either as slow, structured flames (characterized by well-defined heights and shapes) or as fast, unstructured flames (marked by aperiodic oscillations in size and shape) in which a form of wind–fire coupling sustains 5- to 10-fold faster rates of propagation. Transitions between these modes can be induced by topographical features of the strip: structured flames can, upon encountering folds in the strip become unstructured; similarly, unstructured flames can, upon encountering the same folds (hereafter referred to as “bumps”), become structured and slow. By using this model system to examine (i) conditions that influence the likelihood of perturbation-initiated transitions between modes of propagation and (ii) patterns in dynamics that emerge as these transitions become more likely, we addressed this question: “Do slowly spreading fires exhibit detectable symptoms of critical slowing down prior to transitioning to intense, feedback-stabilized fires?”     

软组织修复耳道后壁鼓室成形术的临床分析(附1037例报告)

目的 探讨开放式鼓室成形术中应用软壁式外耳道后壁重建方法的可行性,及其对术后干耳时间的影响.方法 对1037例(耳)行软壁式(软组织修复耳道后壁)开放式鼓室成形术的慢性化脓性中耳炎患者的临床资料进行回顾性分析.结果 术后随访3个月至4年,随访率为61.4%.术后干耳率为98.75%(1024例);术后听力提高平均为15dB;69例进行二次手术,其中5例为胆脂瘤复发,9例术腔感染,8例鼓膜穿孔,47例因术后听力提高不满意而再次手术.结论 软壁开放式鼓室成形术在治疗慢性中耳炎可有效地获得干耳术腔,减少术后复诊并能保持较好的外耳道形状.     

不同浓度右美托咪定联合瑞芬太尼辅助局部浸润麻醉对老年腹股沟疝开放修补术患者的镇静作用及安全性分析

目的探究不同浓度右美托咪定联合瑞芬太尼辅助局部浸润麻醉对老年腹股沟疝开放修补术患者的镇静作用及安全性。 方法2019年1至10月于重庆医科大学附属永川医院行局部浸润麻醉下腹股沟疝修补术治疗的90例老年腹股沟疝患者。通过随机数字表法将其分为对照组（45例）和观察组（45例）。对照组予以高剂量[0.6 μg/(kg·h）]盐酸右美托咪定注射液联合注射用盐酸瑞芬太尼辅助局部浸润麻醉;观察组予以低剂量[0.3μg/(kg·h）]盐酸右美托咪定注射液联合注射用盐酸瑞芬太尼辅助局部浸润麻醉。比较2组患者用药前（T1）、用药后10 min（T2）、20 min（T3）、30 min（T4）、患者清醒后（T5）的警觉/镇静（OAA/S）评分和血流动力学指标;观察2组局麻时、切皮时、手术中、缝皮时的疼痛程度及治疗期间的安全性。 结果T1～T4 2组OAA/S评分呈降低趋势,T5时OAA/S评分升高,差异有统计学意义（P<0.05）;T1～T4观察组平均动脉压（MAP）、心率（HR）呈降低趋势,T5时MAP、HR升高,差异有统计学意义（P<0.05）;且T3、T4时,观察组OAA/S评分、MAP、HR低于对照组,差异有统计学意义（P<0.05）。观察组在各时间点（局麻时、切皮时、手术中、缝皮时）的视觉模拟评分（VAS）均低于对照组,差异有统计学意义（P<0.05）。观察组患者躁动、恶性呕吐的发生率为2.22%、4.44%,低于对照组的17.78%、17.78%,差异有统计学意义（P<0.05）。 结论低剂量右美托咪定联合瑞芬太尼辅助局部浸润麻醉可显著改善老年腹股沟疝患者的血流动力学,镇静、镇痛效果显著,安全性高。     

Genetic Etiologies of Mental Retardation: Issues for Interventions and Interventionists

This paper outlines some practical implications of new work on the behavioral effects of genetic mental retardation disorders. After describing historical and definitional issues concerning so-called behavioral phenotypes, we use Down syndrome and Williams syndrome to illustrate how specific genetic disorders might differentially predispose individuals to particular, etiology-related behaviors. We then explore educational and other intervention implications of such etiology-related behaviors, before ending with a discussion of the area's critical unresolved issues.