Adaptive treadmill walking encourages persistent propulsion

BackgroundAdaptive treadmills allow real-time changes in walking speed by responding to changes in step length, propulsion, or position on the treadmill. The stride-to-stride variability, or persistence, of stride time during overground, fixed-speed, and adaptive treadmill walking has been studied, but persistence of propulsion during adaptive treadmill walking remains unknown. Because increased propulsion is often a goal of post-stroke rehabilitation, knowledge of the stride-to-stride variability may aid rehabilitation protocol design.Research questionHow do spatiotemporal and propulsive gait variables vary from stride to stride during adaptive treadmill walking, and how do they compare to fixed-speed treadmill walking?MethodsEighteen young healthy subjects walked on an instrumented split-belt treadmill in the adaptive and fixed-speed modes for 10 minutes at their comfortable speed. Kinetic data was collected from the treadmill. Detrended fluctuation analysis was applied to the time series data. Shapiro-Wilk tests assessed normality and one-way repeated measures ANOVAs compared between adaptive, fixed-speed, and randomly shuffled conditions at a Bonferroni-corrected significance level of 0.0055.ResultsStride time, stride length, step length, and braking impulse were persistent (α > 0.5) in the adaptive and fixed-speed conditions. Adaptive and fixed-speed were different from each other. Stride speed was persistent in the adaptive condition and anti-persistent (α < 0.5) in the fixed-speed condition. Peak propulsive force, peak braking force, and propulsive impulse were persistent in the adaptive condition but not the fixed-speed condition (α ≈ 0.5). Net impulse was non-persistent in the adaptive and fixed-speed conditions. All variables were non-persistent in the shuffled condition.SignificanceDuring adaptive treadmill walking, increases in propulsive force and impulse persist for multiple strides. Persistence was stronger on the adaptive treadmill, where increased propulsion translates into increased walking speed. For post-stroke gait rehabilitation where increasing propulsion and speed are goals, the stronger persistence of adaptive treadmill walking may be beneficial.     

Feasibility of a method for low contrast CT image quality assessment using difference detail curves for abdominal scans

This work describes a measurement method for assessing dose-related image-quality of CT scans based on the difference detail curve (DDC) method, and showcases its use in a low contrast setting. The method is based on a phantom consisting of elliptical slices of different sizes into which contrast object modules can be inserted. These modules contain contrast objects based on (synthetic) resin mixtures with sucrose (native) or sodium iodine (contrast medium). Mixing ratios are provided to achieve a range of clinically relevant CT-numbers with these materials. The phantom is characterized in terms of contrast accuracy, energy dependency and long-term drift with satisfying results. Contrast accuracy and energy dependency are similar to that of water or soft tissue. Image quality of 655 scans of the phantom acquired at 30 different clinical institutions and with 16 different CT scanner models from 4 manufacturers was assessed by calculating a difference detail curve (DDC) from evaluation of up to 5 human observers using a custom-made software (RadiVates) described in this work. Based on these measurements, inter-observer variability was quantified using a bootstrap method and was shown to be a large contributor to the overall variability. This work demonstrates that assessment of CT image quality is feasible with the aforementioned phantom and DDC method.     

Effectiveness and safety of extracorporeal shock wave treatment for low back pain：a systematic review and meta-analysis of RCTs

This meta-analysis was designed to assess the effectiveness and safety of extracorporeal shock wave therapy (ESWT) for patients with low back pain (LBP). Pubmed, Embase, Cochrane's library, PEDro (Physiotherapy Evidence Database), China National Knowledge Infrastructure (CNKI), and Wanfang Data were searched until December 2019 to identify studies assessing the effectiveness and safety of EPSW for LBP. The prime outcome is pain intensity measured by Visual Analog Scale (VAS) or numeric rating scale (NRS). Other outcomes included functional status, quality of life, psychological outcomes measured by Oswestry Disability Index (ODI), as well as the adverse events. Mean differences (MD) were calculated for continuous outcomes, while odd ratios (OR) were calculated for binary outcomes. Revman 5.3 software was used for statistical analysis. Five randomized controlled trials (RCTs) were finally included in this meta-analysis. The pooled mean difference in post-treatment pain scores was −2.37 (P ＜0.0001), indicating that post-treatment pain scores was significantly higher by 2.37 in control group than in ESWT group. At a mean follow-up time of 4–6 weeks, the pooled mean difference in ODI scores was −14.10 (P ＜0.00001), indicating that the pooled mean difference of post-treatment ODI scores was 14.10 higher in control group than in ESWT group. The use of ESWT is effective in alleviating pain and improving the general functional state for patients with LBP. However, more evidence was needed to verify its safety.     

Enlarged high frequency oscillations of the median nerve somatosensory evoked potential and survival in amyotrophic lateral sclerosis

ObjectiveA large N20 and P25 of the median nerve somatosensory evoked potential (SEP) predicts short survival in amyotrophic lateral sclerosis (ALS). We investigated whether high frequency oscillations (HFOs) over N20 are enlarged and associated with survival in ALS.MethodsA total of 145 patients with ALS and 57 healthy subjects were studied. We recorded the median nerve SEP and measured the onset-to-peak amplitude of N20 (N20o-p), and peak-to-peak amplitude between N20 and P25 (N20p-P25p). We obtained early and late HFO potentials by filtering SEP between 500 and 1 kHz, and measured the peak-to-peak amplitude. We followed up patients until endpoints (death or tracheostomy) and analyzed the relationship between SEP or HFO amplitudes and survival using a Cox analysis.ResultsPatients showed larger N20o-p, N20p-P25p, and early and late HFO amplitudes than the control values. N20p-P25p was associated with survival periods (p = 0.0004), while early and late HFO amplitudes showed no significant association with survival (p = 0.4307, and p = 0.6858, respectively).ConclusionsThe HFO amplitude in ALS is increased, but does not predict survival.SignificanceThe enlarged HFOs in ALS might be a compensatory phenomenon to the hyperexcitability of the sensory cortex pyramidal neurons.     

Contribution of different somatosensory afferent input to subcortical somatosensory evoked potentials in humans

ObjectivesTo investigate the subcortical somatosensory evoked potentials (SEPs) to electrical stimulation of either muscle or cutaneous afferents.MethodsSEPs were recorded in 6 patients suffering from Parkinson’s disease (PD) who underwent electrode implantation in the pedunculopontine (PPTg) nucleus area. We compared SEPs recorded from the scalp and from the intracranial electrode contacts to electrical stimuli applied to: 1) median nerve at the wrist, 2) abductor pollicis brevis motor point, and 3) distal phalanx of the thumb. Also the high-frequency oscillations (HFOs) were analysed.ResultsAfter median nerve and pure cutaneous (distant phalanx of the thumb) stimulation, a P1-N1 complex was recorded by the intracranial lead, while the scalp electrodes recorded the short-latency far-field responses (P14 and N18). On the contrary, motor point stimulation did not evoke any low-frequency component in the PPTg traces, nor the N18 potential on the scalp. HFOs were recorded to stimulation of all modalities by the PPTg electrode contacts.ConclusionsStimulus processing within the cuneate nucleus depends on modality, since only the cutaneous input activates the complex intranuclear network possibly generating the scalp N18 potential.SignificanceOur results shed light on the subcortical processing of the somatosensory input of different modalities.     

Predicting osimertinib‐treatment outcomes through EGFR mutant‐fraction monitoring in the circulating tumor DNA of EGFR T790M‐positive patients with non‐small cell lung cancer (WJOG8815L)

The WJOG8815L phase II clinical study involves patients with non‐small cell lung cancer (NSCLC) that harbored the EGFR T790M mutation, which confers resistance to EGFR tyrosine kinase inhibitors (TKIs). The purpose of this study was to assess the predictive value of monitoring EGFR genomic alterations in circulating tumor DNA (ctDNA) from patients with NSCLC that undergo treatment with the third‐generation EGFR‐TKI osimertinib. Plasma samples of 52 patients harboring the EGFR T790M mutation were obtained pretreatment (Pre), on day 1 of treatment cycle 4 (C4) or cycle 9 (C9), and at diagnosis of disease progression or treatment discontinuation (PD/stop). CtDNA was screened for EGFR‐TKI‐sensitizing mutations, the EGFR T790M mutation, and other genomic alterations using the cobas EGFR Mutation Test v2 (cobas), droplet digital PCR (ddPCR), and targeted deep sequencing. Analysis of the sensitizing—and T790M—EGFR mutant fractions (MFs) was used to determine tumor mutational burden. Both MFs were found to decrease during treatment, whereas rebound of the sensitizing EGFR MF was observed at PD/stop, suggesting that osimertinib targeted both T790M mutation‐positive tumors and tumors with sensitizing EGFR mutations. Significant differences in the response rates and progression‐free survival were observed between the sensitizing EGFR MF‐high and sensitizing EGFR MF‐low groups (cutoff: median) at C4. In conclusion, ctDNA monitoring for sensitizing EGFR mutations at C4 is suitable for predicting the treatment outcomes in NSCLC patients receiving osimertinib (Clinical Trial Registration No.: UMIN000022076).

Abbreviations

CIs

confidence intervals

ctDNA

circulating tumor DNA

ddPCR

droplet digital PCR

EGFR

epidermal growth factor receptor

MFs

mutant fractions

NGS

next‐generation sequencing

NSCLC

non‐small cell lung cancer

ORR

overall response rate

OS

overall survival

PD

progressive disease

PFS

progression‐free survival

PR

partial response

SD

stable disease

TKI

tyrosine kinase inhibitor

     

玻切二期术后低视力人群的护理策略

目的对玻切二期术后低视力人群采取特殊的护理策略,来平复病人的负面情绪,提高治疗满意度。方法对2019年11月6日至2020年11月6日在我院接受玻璃体切割二次手术的96名低视力患者进行特殊护理干预,然后进行回顾性分析。结果在结合实际病情分析采取的特殊护理策略干预下,病人术后情绪稳定,未出现不良投诉事件,满意度较高。结论对玻切二期术后低视力人群采取特殊的护理干预策略十分必要。     

An economic analysis of the cost of survival of micro preemies: A systematic review

ObjectiveThis study aimed to systematically review the current literature on the economic costs of micro preemie as well as evidence on the cost-effectiveness of interventions to improve outcomes for micro preemie babies with a birth weight of ≤500 g.MethodWe searched MEDLINE, CINAHL, Scopus, ECONLIT, Business Source Premier and Cochrane Library for studies reporting costs of micro preemie from January 2000. Costs were inflated to 2019 United States dollars (US$). All full-text articles were assessed for eligibility and a quality assessment of included articles was conducted using the Drummond and the Larg and Moss checklists.ResultsThe search identified three studies that met the inclusion criteria; two cost-of-illness studies and one cost-effectiveness study. Across studies, the mean healthcare spending per micro preemie survivor (in 2019 US$) ranged from US$61,310 (birth admission) to US$263,958 (inpatient and outpatient for the first six months of life). One modelling study reported exclusive human milk diet for micro preemies at birth was more cost-effective compared to the standard approach with cow milk diet from the third-party payer and societal perspectives.ConclusionDespite significant advances in perinatal care and expanded access to life-saving equipment to improve survival outcomes of micro preemie, there remains a paucity of research on economic costs associated with these babies. No study has utilised quality-adjusted life-years as an outcome measure. Given the chronic conditions and long-term neurologic disability associated with micro preemie survivors, an estimate of the lifetime cost to the individual, healthcare providers and society would provide a benchmark of the potential cost-savings that could accrue from cost-effective interventions to improve the survival rate of micro preemies.     

Tedium vitae in stroke survivors: a comparative cross-sectional study

Objectives: Suicide is best studied by deconstructing the psychological experiences preceding suicidal death. We assessed the characteristics of tedium vitae (feeling tired of life) after first ever stroke in Nigerian survivors.

Methods: Using the Schedule for Clinical Assessment in Neuropsychiatry, tedium vitae was assessed in 130 stroke survivors attending rehabilitation in a large Nigerian university hospital. Global cognitive and executive dysfunctions were evaluated, respectively, using the Mini Mental State Examination and the modi?ed Indiana University Token test. All participants had their index stroke 3 to 24 months before recruitment into the study. We also examined a comparative group of 130 age, gender, and education matched apparently normal persons who were unrelated to the stroke survivors. Associations were explored using univariate and multivariate logistic regression analyses.

Results: Tedium vitae was experienced by 16 (12.3%) stroke survivors compared with 5 (3.9%) in the comparative group (O. R = 3.5, 95% C. I = 1.3–9.9, p = 0.018). Among stroke survivors, those who were retired were more likely to experience tedium vitae (56.2%, p = 0.045). In analyses adjusting for the effect of systemic hypertension, cognitive dysfunction, retirement and marital separation, there was a 3.5-fold increase in the odds of experiencing tedium vitae after surviving a stroke (O. R = 3.5, 95% C. I = 1.1–11.6, p = 0.042).

Conclusions: Tedium vitae is a common suicidal experience after stroke and may be among the earliest perceptible pointer to impending poststroke suicide. It is easy to assess and may be less costly to obtain an adequate sample size in studies aiming to understand the phenomenon of suicide in the stroke population.