Parkinson’s disease and the Stroop color word test: processing speed and interference algorithms

Objective: Processing speed alters the traditional Stroop calculations of interference. Consequently, alternative algorithms for calculating Stroop interference have been introduced to control for processing speed, and have done so in a multiple sclerosis sample. This study examined how these processing speed correction algorithms change interference scores for individuals with idiopathic Parkinson’s disease (PD, n = 58) and non-PD peers (n = 68). Method: Linear regressions controlling for demographics predicted group (PD vs. non-PD) differences for Jensen’s, Golden’s, relative, ratio, and residualized interference scores. To examine convergent and divergent validity, interference scores were correlated with standardized measures of processing speed and executive function. Results: PD–non-PD differences were found for Jensen’s interference score, but not Golden’s score, or the relative, ratio, and residualized interference scores. Jensen’s score correlated significantly with standardized processing speed but not executive function measures. Relative, ratio, and residualized scores correlated with executive function but not processing speed measures. Golden’s score did not correlate with any other standardized measures. Conclusions: The relative, ratio, and residualized scores were comparable for measuring Stroop interference in processing speed-impaired populations. Overall, the ratio interference score may be the most useful calculation method to control for processing speed in this population.     

Hybrid Assistive Limb® for sporadic inclusion body myositis: A case series

We evaluated the efficacy of rehabilitation therapy with Hybrid Assistive Limb® (HAL; hereafter HAL therapy) in three patients diagnosed with sporadic inclusion body myositis (sIBM) who were hospitalized to undergo HAL therapy. Among them, one patient participated in eight courses and the other two in two courses of HAL therapy between 2017 and 2020. We determined the mean rate of improvement in two-minute walking distance and 6 m walking speed at the time of hospital discharge. After HAL therapy, we confirmed the patients’ desire to continue the use of HAL. In one patient, we observed improvements of 146.0% and 120.0% in two-minute walk and 6 m walking speed, respectively, after the first course of HAL therapy; these values are 133.7% and 130% after the eighth course of HAL therapy. These values exceeded 90% in the other two patients after the second course of HAL therapy. HAL therapy maintained both quantity and quality of ambulation and showed positive psychological effects on patient conditions because it reduces exercise load and facilitates safety. While HAL therapy might be effective in maintaining and improving ambulation in patients with sIBM, we should consider to discontinue HAL therapy as it increased risk of falling.     

Flight and Seizure Motor Patterns in Drosophila Mutants: Simultaneous Acoustic and Electrophysiological Recordings of Wing Beats and Flight Muscle Activity

Tethered flies allow studies of biomechanics and electrophysiology of flight control. We performed microelectrode recordings of spikes in an indirect flight muscle (the dorsal longitudinal muscle, DLMa) coupled with acoustic analysis of wing beat frequency (WBF) via microphone signals. Simultaneous electrophysiological recording of direct and indirect flight muscles has been technically challenging; however, the WBF is thought to reflect in a one-to-one relationship with spiking activity in a subset of direct flight muscles, including muscle m1b. Therefore, our approach enables systematic mutational analysis for changes in temporal features of electrical activity of motor neurons innervating subsets of direct and indirect flight muscles. Here, we report the consequences of specific ion channel disruptions on the spiking activity of myogenic DLMs (firing at ～5 Hz) and the corresponding WBF (～200 Hz). We examined mutants of the genes enconding: 1) voltage-gated Ca²⁺ channels (cacophony, cac), 2) Ca²⁺-activated K⁺ channels (slowpoke, slo), and 3) voltage-gated K⁺ channels (Shaker, Sh) and their auxiliary subunits (Hyperkinetic, Hk and quiver, qvr). We found flight initiation in response to an air puff was severely disrupted in both cac and slo mutants. However, once initiated, slo flight was largely unaltered, whereas cac displayed disrupted DLM firing rates and WBF. Sh, Hk, and qvr mutants were able to maintain normal DLM firing rates, despite increased WBF. Notably, defects in the auxiliary subunits encoded by Hk and qvr could lead to distinct consequences, that is, disrupted DLM firing rhythmicity, not observed in Sh. Our mutant analysis of direct and indirect flight muscle activities indicates that the two motor activity patterns may be independently modified by specific ion channel mutations, and that this approach can be extended to other dipteran species and additional motor programs, such as electroconvulsive stimulation-induced seizures.     

Carotid flow pulsatility is higher in women with greater decrement in gait speed during multi-tasking

AimCentral arterial hemodynamics is associated with cognitive impairment. Reductions in gait speed during walking while performing concurrent tasks known as dual-tasking (DT) or multi-tasking (MT) is thought to reflect the cognitive cost that exceeds neural capacity to share resources. We hypothesized that central vascular function would associate with decrements in gait speed during DT or MT.MethodsGait speed was measured using a motion capture system in 56 women (30–80y) without mild-cognitive impairment. Dual-tasking was considered walking at a fast-pace while balancing a tray. Multi-tasking was the DT condition plus subtracting by serial 7′s. Applanation tonometry was used for measurement of aortic stiffness and central pulse pressure. Doppler-ultrasound was used to measure blood flow velocity and β-stiffness index in the common carotid artery.ResultsThe percent change in gait speed was larger for MT than DT (14.1 ± 11.2 vs. 8.7 ± 9.6%, p < 0.01). Tertiles were formed based on the percent change in gait speed for each condition. No vascular parameters differed across tertiles for DT. In contrast, carotid flow pulsatility (1.85 ± 0.43 vs. 1.47 ± 0.42, p = 0.02) and resistance (0.75 ± 0.07 vs. 0.68 ± 0.07, p = 0.01) indices were higher in women with more decrement (third tertile) as compared to women with less decrement (first tertile) in gait speed during MT after adjusting for age, gait speed, and task error. Carotid pulse pressure and β-stiffness did not contribute to these tertile differences.ConclusionElevated carotid flow pulsatility and resistance are characteristics found in healthy women that show lower cognitive capacity to walk and perform multiple concurrent tasks.     

Visual working memory and perception speed of 3- to 6-year-old children tested with a Matrix Film Battery Test

In this study the visual working memory (VWM) and perception speed of 60 children between the ages of three and six years were tested with an age-based, easy-to-handle Matrix Film Battery Test (reliability R?=?.71). It was thereby affirmed that the VWM is age dependent (correlation coefficient r?=?.66***) as expected. Furthermore, a significant gender effect was found (partial correlation coefficient r_p?=?.42***) indicating that boys generally have a better VWM: they are able to memorise more items and they can process visual information faster. Given that the test was repeated during a period of eight months, strong learning effects could be detected which show that the VWM can be trained and that the test itself is also a good training tool.     

Thalamic diffusion differences related to cognitive function in white matter lesions

Cerebral white matter lesions (WMLs) are related to cognitive deficits, probably due to a disruption of frontal–subcortical circuits. We explored thalamic diffusion differences related to white matter lesions (WMLs) and their association with cognitive function in middle-aged individuals. Ninety-six participants from the Barcelona-AsIA Neuropsychology Study were included. Participants were classified into groups based on low grade and high grade of periventricular hyperintensities (PVHs) and deep white matter hyperintensities (DWMHs). Tract-Based Spatial Statistics was used to study thalamic diffusion differences between groups. Mean fractional anisotropy (FA) values in significant areas were calculated for each subject and correlated with cognitive performance. Participants with high-grade PVHs and DWMHs showed lower FA thalamic values compared to those with low-grade PVHs and DWMHs, respectively. Decreased FA thalamic values in high-grade DWMHs, but not high-grade PVH, were related to lower levels of performance in psychomotor speed, verbal fluency, and visuospatial skills. Thalamic diffusion differences are related to lower cognitive function only in participants with high-grade DWMHs. These results support the hypothesis that fronto–subcortical disruption is associated with cognitive function only in DWMHs.     

北京地区健康女性跟骨超声速率的正常参考值及其分析

目的建立北京地区健康成年女性的跟骨骨超声速率(speed of sound,SOS)的正常参考值。方法用日本吉野电器公司生产的CM-100型跟骨骨超声测定仪对912名北京地区健康女性志愿者进行跟骨SOS测定,并对其中110名志愿者用双能X线骨密度仪(DXA)进行腰椎I_(2-4)和髋部的骨密度测定。结果健康女性跟骨SOS在26～30岁年龄组达到峰值[(1 533.4±34.2)m/s],达峰值后开始下降,46～50岁后下降速度加快。绝经期前、后跟骨SOS差异有统计学意义。跟骨SOS下降分为快速下降期、稳定下降期和再下降期。经DXA测定的骨密度值与跟骨SOS值相关(r=0.323～0.506,P0.01)。结论本研究建立了北京地区健康妇女跟骨SOS正常值,跟骨SOS和DEXA测定骨密度之间存在良好的相关性。     

关于骨质疏松超声诊断仪器亟待厘清的若干基本概念

继双能X线吸收仪之后,定量超声测骨仪器逐渐从群体筛查发展为筛查兼诊断手段,从补充、辅助工具进化成为潜在的主力。然而,在骨质疏松和骨折问题的本质,超声测骨仪器的产品名称、检测参数、派生参数、声学特性参数与骨矿密度相关性、产品性能表征与检验等方面,国内外均存在严重误读。本文就所涉及的一系列基本概念作了系统厘清,以期推动该类产品的科学、健康发展。