A novel rank-based non-parametric method for longitudinal ordinal data

A novel longitudinal rank-sum test for multiple primary endpoints in clinical trials: Applications to neurodegenerative disorders

Neurodegenerative disorders such as Alzheimer's disease (AD) present a significant global health challenge, characterized by cognitive decline, functional impairment, and other debilitating effects. Current AD clinical trials often assess multiple longitudinal primary endpoints to comprehensively evaluate treatment efficacy. Traditional methods, however, may fail to capture global treatment effects, require larger sample sizes due to multiplicity adjustments, and may not fully exploit multivariate longitudinal data. To address these limitations, we introduce the Longitudinal Rank Sum Test (LRST), a novel nonparametric rank-based omnibus test statistic. The LRST enables a comprehensive assessment of treatment efficacy across multiple endpoints and time points without multiplicity adjustments, effectively controlling Type I error while enhancing statistical power. It offers flexibility against various data distributions encountered in AD research and maximizes the utilization of longitudinal data. Extensive simulations and real-data applications demonstrate the LRST's performance, underscoring its potential as a valuable tool in AD clinical trials. Nonparametrics, Global test, rank-sum-type test, U-Statistics.

Antisense oligonucleotides targeting basal forebrain ATXN2 enhances spatial memory and ameliorates sleep deprivation-induced fear memory impairment in mice

INTRODUCTION

Regulation of brain-derived neurotrophic factor (BDNF) in the basal forebrain ameliorates sleep deprivation-induced fear memory impairments in rodents. Antisense oligonucleotides (ASOs) targeting ATXN2 was a potential therapy for spinocerebellar ataxia, whose pathogenic mechanism associates with reduced BDNF expression. We tested the hypothesis that ASO7 targeting ATXN2 could affect BDNF levels in mouse basal forebrain and ameliorate sleep deprivation-induced fear memory impairments.

METHODS

Adult male C57BL/6 mice were used to evaluate the effects of ASO7 targeting ATXN2 microinjected into the bilateral basal forebrain (1 μg, 0.5 μL, each side) on spatial memory, fear memory and sleep deprivation-induced fear memory impairments. Spatial memory and fear memory were detected by the Morris water maze and step-down inhibitory avoidance test, respectively. Immunohistochemistry, RT-PCR, and Western blot were used to evaluate the changes of levels of BDNF, ATXN2, and postsynaptic density 95 (PSD95) protein as well as ATXN2 mRNA. The morphological changes in neurons in the hippocampal CA1 region were detected by HE staining and Nissl staining.

RESULTS

ASO7 targeting ATXN2 microinjected into the basal forebrain could suppress ATXN2 mRNA and protein expression for more than 1 month and enhance spatial memory but not fear memory in mice. BDNF mRNA and protein expression in basal forebrain and hippocampus was increased by ASO7. Moreover, PSD95 expression and synapse formation were increased in the hippocampus. Furthermore, ASO7 microinjected into the basal forebrain increased BDNF and PSD95 protein expression in the basal forebrain of sleep-deprived mice and counteracted sleep deprivation-induced fear memory impairments.

CONCLUSION

ASOs targeting ATXN2 may provide effective interventions for sleep deprivation-induced cognitive impairments.

EEG reveals deficits in sensory gating and cognitive processing in asymptomatic adults with a history of concussion

OBJECTIVE

Individuals with a concussion history tend to perform worse on dual-tasks compared controls but the underlying neural mechanisms contributing to these deficits are not understood. This study used event-related potentials (ERPs) to investigate sensory gating and cognitive processing in athletes with and without a history of concussion while they performed a challenging dual-task.

METHODS

We recorded sensory (P50, N100) and cognitive (P300) ERPs in 30 athletes (18 no previous concussion; 12 history of concussion) while they simultaneously performed an auditory oddball task and a working memory task that progressively increased in difficulty.

RESULTS

The concussion group had reduced auditory performance as workload increased compared to the no-concussion group. Sensory gating and cognitive processing were reduced in the concussion group indicating problems with filtering relevant from irrelevant information and appropriately allocating resources. Sensory gating (N100) was positively correlated with cognitive processing (P300) at the hardest workload in the no-concussion group but negatively correlated in the concussion group.

CONCLUSION

Concussions result in long-term problems in behavioral performance, which may be due to poorer sensory gating that impacts cognitive processing.

SIGNIFICANCE

Problems effectively gating sensory information may influence the availability or allocation of attention at the cognitive stage in those with a concussion.

Clinical effectiveness of Qilong capsule in patients with ischemic stroke: A prospective, multicenter, non-randomized controlled trial

BACKGROUND

The Qilong capsule (QLC) is a Chinese patented medicine characterized by an equal emphasis on replenishing Qi and activating blood circulation. In 2000, China's FDA approved the use of QLC for ischemic stroke (IS). However, there is not yet much high-quality evidence of the clinical effectiveness of QLC combined with conventional treatment (CT) for IS with Qi deficiency and blood stasis syndrome.

PURPOSE

In this study, we conducted a prospective, multicenter, non-randomized controlled trial at 7 hospitals in China to investigate the clinical effectiveness of QLC combined with CT for IS with Qi deficiency and blood stasis syndrome.

METHODS

Participants aged 35 to 80 years old diagnosed as IS with Qi deficiency and blood stasis syndrome in TCM were recruited. Participants were treated with QLC (intervention group) or non-QLC (control group). The intervention course of QLC was 12 weeks. All participants in two groups received standard treatment. All participants returned for in-person follow-up visits at the 12th week and 24th week. Primary outcome measures included a modified Rankin Scale (mRS), the National Institute of Health Stroke Scale (NIHSS), and the Barthel Index (BI). Secondary outcome measures included TCM syndromes (Qi deficiency syndrome score, blood stasis syndrome score), psychological index (self-rating depression scale, SDS; self-rating anxiety scale, SAS), blood lipid index, blood coagulation index, homocysteine, and favorable functional outcome (mRS 0 - 3). Multiple imputations were used for any missing data. Propensity score matching (PSM) was used to deal with any confounding factors (age, gender, scale score, etc.). Rank alignment transformation variance analysis (ART ANOVA) and generalized linear mixed model (GLMM) were introduced to improve the scientific and accuracy of repeated measurement data. All statistical calculations were carried out with R 3.6.1 statistical analysis software.

RESULTS

A total of 2468 participants were screened from November 2016 to January 2019. Finally, 2302 eligible participants were included in the analysis. There were 1260 participants in the intervention group (QLC group) and 1042 participants in the control group (non-QLC group). After PSM matching, sub-samples of 300 participants in the QLC group and 300 participants in the non-QLC group were finally formed. The final results of clinical effectiveness are the same results shared by the total samples and sub-samples after PSM. In the 24th week after treatment, QLC combined with CT proved to be significantly better than CT alone in reducing the scores of mRS (p < 0.05), NIHSS (p < 0.001), Qi deficiency syndrome (p < 0.01), and blood stasis syndrome (p < 0.001), SAS (p < 0.05), as well as in improving BI score (p < 0.05). The favourable functional outcome (mRS score of 0 to 3 at week 12) was statistically different between QLC and non-QLC group in the sub-samples (p < 0.01, 97% vs 91.7%). The results of the ART ANOVA showed that the improvement of mRS (p < 0.01), BI (p < 0.05) and NIHSS (p < 0.001) in QLC group was better than non-QLC group when the interaction effect was considered. The results of GLMM showed that the reduction of mRS and NIHSS scores of patients in the QLC group were better than those of the non-QLC group (p < 0.001). The BI score of the QLC group in the sub-samples after PSM increased more than the non-QLC group (p < 0.001). There was no evidence showing that QLC can cause serious adverse reactions (ADRs) in treating patients with IS.

CONCLUSION

QLC combined with CT was better than CT alone in reducing mRS score, NIHSS score, Qi deficiency syndrome score, blood stasis syndrome score, and SAS score, as well as improving BI score after treatment. Further high-quality RCTs are needed to confirm the positive results. The study protocol was embedded in a registry study that registered in the Clinical Trials USA Registry (registration No. NCT03174535).

Dalfampridine to Improve Balance in Multiple Sclerosis: Substudy from a Randomized Placebo-Controlled Trial

This was a substudy of a randomized, double-blind, placebo-controlled trial originally designed to explore the effect of dalfampridine on information processing speed (2013-002558-64 EU Clinical Trials Register) in patients with multiple sclerosis (MS). A total of 120 patients were originally randomized in a 2:1 ratio to receive dalfampridine 10 mg or placebo twice daily for 12 weeks. Here, we sought to explore the effect of dalfampridine on static balance in single-task and dual-task conditions in a subgroup of 41 patients. They underwent static posturography in quiet standing (single-task) and while performing the Stroop test (dual-task) at randomization (baseline), after 12 weeks and after a 4-week wash-out period. Baseline characteristics of active group (n = 27) did not differ from those of placebo group (n = 14). Dalfampridine treatment was associated with better balance control than placebo in both single-task (F = 4.80, p = 0.034) and dual-task (F = 6.42, p = 0.015) conditions, with small-to-moderate effect sizes (Cohen's f2 = 0.122-0.162). The beneficial effect of dalfampridine was not retained 4 weeks after its discontinuation. The rate of accidental falls per month did not differ between the two groups (p = 0.12). Our preliminary findings suggest that dalfampridine can be considered a potential option to treat balance impairment due to MS. Larger sample sizes are needed to verify if the beneficial effect of dalfampridine on balance can be translated into a reduced risk of accidental falls.

Continuous vestibular implant stimulation partially restores eye-stabilizing reflexes

BACKGROUNDBilateral loss of vestibular (inner ear inertial) sensation causes chronically blurred vision during head movement, postural instability, and increased fall risk. Individuals who fail to compensate despite rehabilitation therapy have no adequate treatment options. Analogous to hearing restoration via cochlear implants, prosthetic electrical stimulation of vestibular nerve branches to encode head motion has garnered interest as a potential treatment, but prior studies in humans have not included continuous long-term stimulation or 3D binocular vestibulo-ocular reflex (VOR) oculography, without which one cannot determine whether an implant selectively stimulates the implanted ear's 3 semicircular canals.METHODSWe report binocular 3D VOR responses of 4 human subjects with ototoxic bilateral vestibular loss unilaterally implanted with a Labyrinth Devices Multichannel Vestibular Implant System vestibular implant, which provides continuous, long-term, motion-modulated prosthetic stimulation via electrodes in 3 semicircular canals.RESULTSInitiation of prosthetic stimulation evoked nystagmus that decayed within 30 minutes. Stimulation targeting 1 canal produced 3D VOR responses approximately aligned with that canal's anatomic axis. Targeting multiple canals yielded responses aligned with a vector sum of individual responses. Over 350-812 days of continuous 24 h/d use, modulated electrical stimulation produced stable VOR responses that grew with stimulus intensity and aligned approximately with any specified 3D head rotation axis.CONCLUSIONThese results demonstrate that a vestibular implant can selectively, continuously, and chronically provide artificial sensory input to all 3 implanted semicircular canals in individuals disabled by bilateral vestibular loss, driving reflexive VOR eye movements that approximately align in 3D with the head motion axis encoded by the implant.TRIAL REGISTRATIONClinicalTrials.gov: NCT02725463.FUNDINGNIH/National Institute on Deafness and Other Communication Disorders: R01DC013536 and 2T32DC000023; Labyrinth Devices, LLC; and Med-El GmbH.

Signatures of divergent anti-malarial treatment responses in peripheral blood from adults and young children in Malawi

BACKGROUND

Heterogeneity in the immune response to parasite infection is mediated in part by differences in host genetics, gender, and age group. In infants and young children, ongoing immunological maturation often results in increased susceptibility to infection and variable responses to drug treatment, increasing the risk of complications. Even though significant age-associated effects on host cytokine responses to Plasmodium falciparum infection have been identified, age-associated effects on uncomplicated malaria infection and anti-malarial treatment remain poorly understood.

METHODS

In samples of whole blood from a cohort of naturally infected malaria-positive individuals with non-severe falciparum malaria in Malawi (n = 63 total; 34 infants and young children < 2 years old, 29 adults > 18 years old), blood cytokine levels and monocyte and dendritic cell frequencies were assessed at two timepoints: acute infection, and 4 weeks post anti-malarial treatment. The effects of age group, gender, and timepoint were modeled, and the role of these factors on infection and treatment outcomes was evaluated.

RESULTS

Regardless of treatment timepoint, in this population age was significantly associated with overall blood haemoglobin, which was higher in adults, and plasma nitric oxide metabolites, IL-10, and TNF levels, which were higher in young children. There was a significant effect of age on the haemoglobin treatment response, whereby after treatment, levels increased in young children and decreased in adults. Furthermore, there were significant age-associated effects on treatment response for overall parasite load, IFN-γ, and IL-12(p40), and these effects were gender-dependent. Significant age effects on the overall levels and treatment response of myeloid dendritic cell frequencies were observed. In addition, within each age group, results showed continuous age effects on gametocyte levels (Pfs16), TNF, and nitric oxide metabolites.

CONCLUSIONS

In a clinical study of young children and adults experiencing natural falciparum malaria infection and receiving anti-malarial treatment, age-associated signatures of infection and treatment responses in peripheral blood were identified. This study describes host markers that may indicate, and potentially contribute to, differential post-treatment outcomes for malaria in young children versus adults.