Corrigendum: Use of electroencephalogram, gait, and their combined signals for classifying cognitive impairment and normal cognition

[This corrects the article DOI: 10.3389/fnagi.2022.927295.].

Use of electroencephalogram, gait, and their combined signals for classifying cognitive impairment and normal cognition

Background

Early identification of people at risk for cognitive decline is an important step in delaying the occurrence of cognitive impairment. This study investigated whether multimodal signals assessed using electroencephalogram (EEG) and gait kinematic parameters could be used to identify individuals at risk of cognitive impairment.

Methods

The survey was conducted at the Veterans Medical Research Institute in the Veterans Health Service Medical Center. A total of 220 individuals volunteered for this study and provided informed consent at enrollment. A cap-type wireless EEG device was used for EEG recording, with a linked-ear references based on a standard international 10/20 system. Three-dimensional motion capture equipment was used to collect kinematic gait parameters. Mild cognitive impairment (MCI) was evaluated by Seoul Neuropsychological Screening Battery-Core (SNSB-C).

Results

The mean age of the study participants was 73.5 years, and 54.7% were male. We found that specific EEG and gait parameters were significantly associated with cognitive status. Individuals with decreases in high-frequency EEG activity in high beta (25-30 Hz) and gamma (30-40 Hz) bands increased the odds ratio of MCI. There was an association between the pelvic obliquity angle and cognitive status, assessed by MCI or SNSB-C scores. Results from the ROC analysis revealed that multimodal signals combining high beta or gamma and pelvic obliquity improved the ability to discriminate MCI individuals from normal controls.

Conclusion

These findings support prior work on the association between cognitive status and EEG or gait, and offer new insights into the applicability of multimodal signals to distinguish cognitive impairment.

A review of foot pose and trajectory estimation methods using inertial and auxiliary sensors for kinematic gait analysis

The use of foot mounted inertial and other auxiliary sensors for kinematic gait analysis has been extensively investigated during the last years. Although, these sensors still yield less accurate results than those obtained employing optical motion capture systems, the miniaturization and their low cost have allowed the estimation of kinematic spatiotemporal parameters in laboratory conditions and real life scenarios. The aim of this work was to present a comprehensive approach of this scientific area through a systematic literature research, breaking down the state-of-the-art methods into three main parts: (1) zero velocity interval detection techniques; (2) assumptions and sensors' utilization; (3) foot pose and trajectory estimation methods. Published articles from 1995 until December of 2018 were searched in the PubMed, IEEE Xplore and Google Scholar databases. The research was focused on two categories: (a) zero velocity interval detection methods; and (b) foot pose and trajectory estimation methods. The employed assumptions and the potential use of the sensors have been identified from the retrieved articles. Technical characteristics, categorized methodologies, application conditions, advantages and disadvantages have been provided, while, for the first time, assumptions and sensors' utilization have been identified, categorized and are presented in this review. Considerable progress has been achieved in gait parameters estimation on constrained laboratory environments taking into account assumptions such as a person walking on a flat floor. On the contrary, methods that rely on less constraining assumptions, and are thus applicable in daily life, led to less accurate results. Rule based methods have been mainly used for the detection of the zero velocity intervals, while more complex techniques have been proposed, which may lead to more accurate gait parameters. The review process has shown that presently the best-performing methods for gait parameter estimation make use of inertial sensors combined with auxiliary sensors such as ultrasonic sensors, proximity sensors and cameras. However, the experimental evaluation protocol was much more thorough, when single inertial sensors were used. Finally, it has been highlighted that the accuracy of setups using auxiliary sensors may further be improved by collecting measurements during the whole foot movement and not only partially as is currently the practice. This review has identified the need for research and development of methods and setups that allow for the robust estimation of kinematic gait parameters in unconstrained environments and under various gait profiles.

Using a State-of-the-Art Toolbox to Evaluate Molecular and Functional Readouts of Antisense Oligonucleotide-Induced Exon Skipping in mdx Mice

Duchenne muscular dystrophy (DMD) is a severe childhood muscle disease primarily caused by the lack of functional dystrophin at the muscle fiber membranes. Multiple therapeutic approaches are currently in (pre)clinical development, aimed at restoring expression of (truncated) dystrophin. Key questions in this phase relate to route of drug administration, dose regimen, and levels of dystrophin required to improve muscle function. A series of studies applying antisense oligonucleotides (AONs) in the mdx mouse model for DMD has been reported over the last two decades, claiming a variable range of exon skipping and increased dystrophin levels correlated to some functional improvement. The aim of this study was to compare the efficacy of subcutaneous (SC) versus intravenous (IV) dosing routes of an mdx-specific AON at both the molecular and functional level, using state-of-the-art quantitative technologies, including digital droplet polymerase chain reaction, capillary Western immunoassay, magnetic resonance imaging, and automated kinematic analysis. The majority of all readouts we quantified, both molecular and functional, showed that IV dosing of the AON had a more pronounced beneficial effect than SC dosing in mdx mice. Last, but not least, the more quantitative molecular and functional data obtained in this study suggest that low levels of dystrophin protein of at least 2.5% of wild type may already have a beneficial effect on muscle leakiness and may improve motor performance of mdx mice.

The Immediate Effects of a Dynamic Orthosis on Gait Patterns in Children With Unilateral Spastic Cerebral Palsy: A Kinematic Analysis

This study analyzes the immediate effects of wearing a Therasuit on sagittal plane lower limb angular displacements during gait in children with unilateral spastic cerebral palsy (US-CP). Seven participants (median age = 7.00 years; ranging from 5.83 to 9.00 years) with US-CP, levels I and II of the Gross Motor Function Classification System, were assessed with kinematic gait analysis in three different conditions: (A) Baseline; (B) Therasuit without elastics and (C) Therasuit with elastics. Significant improvements were observed at the hip joint of both lower limbs during most of the gait cycle in participants wearing a Therasuit, including a decrease in the flexion pattern at the initial contact and swing phase in both lower limbs, and an increase in the extension pattern in the paretic lower limb during the stance phase. At the knee joint in the paretic lower limb, significant differences were found between the baseline and Therasuit with elastics conditions on the knee angle at initial contact, and between baseline and both Therasuit conditions on the flexion angle at swing phase. However, the inter-individual variability in kinematic patterns at the knee joint was high. At the ankle joint, decreased plantar flexion at initial contact and increased dorsiflexion during stance and swing phases were observed at the Therasuit with elastics condition, helping to correct the equinus-foot in the paretic lower limb during the whole gait cycle. The Z-values showed large effect sizes particularly for most of the angular hip variables in both lower limbs and for the angular ankle variables in the paretic lower limb. The Therasuit seems to have some positive immediate effects on gait kinematics in children with spastic unilateral cerebral palsy by providing a more functional and safer gait pattern. Future investigations with larger samples are recommended to further support these findings.

Kinematic gait analysis and lactation performance in dairy cows fed a diet supplemented with zinc, manganese, copper and cobalt

This study investigated how supplementation of the diet of dairy cows with trace minerals (zinc, manganese, copper and cobalt) affected kinematic gait parameters and lactation performance. Eight Holstein cows were divided into two groups, with each group receiving a different dietary treatment (control diet, or control diet supplemented with trace minerals) in a two-period crossover design. Kinematic gait parameters were calculated by using image analysis software. Compared to cows fed the control diet, cows that received the trace mineral-supplemented diet exhibited significantly increased walking and stepping rates, and had a shorter stance duration. Feed intake and milk production increased in cows fed the trace mineral-supplemented diet compared with control groups. The plasma manganese concentration was not different in control and experimental cows. In contrast, cobalt was only detected in the plasma of cows fed the supplemented diet. These results provide the first evidence that trace mineral supplementation of the diet of dairy cows affects locomotion, and that the associated gait changes can be detected by using kinematic gait analysis. Moreover, trace mineral supplementation improved milk production and only minimally altered blood and physiological parameters in dairy cows.