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Key points The central and peripheral nervous systems are specialized to conduct electrical currents that underlie behaviour. When this multidimensional electrical system is disrupted by degeneration, damage, or disuse, externally applied electrical currents may act to modulate neural structures and provide therapeutic benefit. The administration of electrical stimulation can exert precise and multi‐faceted effects at cellular, circuit and systems levels to restore or enhance the functionality of the central nervous system by providing an access route to target specific cells, fibres of passage, neurotransmitter systems, and/or afferent/efferent communication to enable positive changes in behaviour. Here we examine the neural mechanisms that are thought to underlie the therapeutic effects seen with current neuromodulation technologies. To gain further insights into the mechanisms associated with electrical stimulation, we summarize recent findings from genetic dissection studies conducted in animal models. Electricity is everywhere around us and is essential for how our nerves communicate within our bodies. When nerves are damaged or not working properly, using exogenous electricity can help improve their function at distinct levels – inside individual cells, within neural circuits, and across entire systems. This method can be tailored to target specific types of cells, nerve fibres, neurotransmitters and communication pathways, offering significant therapeutic potential. This overview explains how exogenous electricity affects nerve function and its potential benefits, based on research in animal studies. Understanding these effects is important because electrical neuromodulation plays a key role in medical treatments for neurological conditions. [ABSTRACT FROM AUTHOR]

• Hippocampal β-adrenergic system modulates reconsolidation of recognition memories. • Infusion of propranolol in the hippocampus impairs updating recognition memory trace. • Propranolol may affect elemental and conjunctive components of the memory. Targeting reconsolidation with propranolol, a blocker of β-adrenergic receptors (β-ARs), emerged as a potential treatment for maladaptive memories such as those involved in posttraumatic stress disorder (PTSD). Reconsolidation targeting treatments for PTSD are becoming a common practice in the clinic and it is important to unveil any side effects upon 'non-targeted' memories. While previous studies have focused on propranolol's effects on the reconsolidation of emotional/distressful memories, the present study asked whether propranolol is involved in the reconsolidation of recognition memories - by assessing its effects on distinct memory components and the role of the dorsal hippocampus. Rats performed an object recognition (OR) task where they were exposed to different objects: A and B presented during the sample phase; A and C presented during the reactivation phase; and D in combination of either A, B, or C during a final test. Intra-hippocampal injections of propranolol (5 µg or 10 µg) were conducted immediately after the reactivation session. Propranolol infusions consistently impaired the addition of novel information to the previously consolidated memory trace regardless of dose, and the retention of familiar objects was not affected. Higher doses of propranolol also hindered memory of a familiar object that was not presented during the reactivation session, but was previously placed at the same location where novel information was presented during reactivation. The present results shed light on the role of β-ARs on the reconsolidation of different memory components and argue for the need for further studies examining possible recognition memory deficits following propranolol treatment. [ABSTRACT FROM AUTHOR]

The Graded Redefined Assessment of Strength, Sensibility, and Prehension Version 1 (GRASSP v1) is a validated measure of upper extremity impairment shown to be sensitive and responsive for traumatic cervical spinal cord injury (SCI) in both North American (NA) and European (EU) cohorts. The minimal clinically important difference (MCID) is the quantitative change in an assessment scale that patients perceive as being beneficial. Our aim was to establish the MCID of all subtests of the GRASSP v1 for cervical SCI. We prospectively analyzed 127 patients from NA and EU for up to six months after motor complete and incomplete cervical SCI using the GRASSP v1, Spinal Cord Independence Measure, and International Standards of Neurological Classification of Spinal Cord Injury. We used a patient global rating of change and the anchor-based method to calculate MCID of GRASSP v1 at six months post-injury. The MCID was established for the whole group, dividing the sample by "better" and "much better." Improvement in GRASSP v1 Strength and Prehension Performance scores of 13 and 3 are the MCID for the better category, and 19 and 7 are the MCID for the much better category, respectively. The MCID was also established for the motor complete and incomplete groups. Improvement in GRASSP v1 Strength and Prehension Performance scores of 12 and 6 are the MCID for the motor complete group, and 17 and 12 are the MCID for the motor incomplete group, respectively. The GRASSP v1 Strength subscore is the most sensitive for detecting meaningful clinical change in patients and is most closely related to measures of independence. Thus, use of GRASSP v1 Strength and Prehension Performance as measures of change is substantiated by this study. [ABSTRACT FROM AUTHOR]

• Surface electromyography (sEMG) is used to explore promising neurorehabilitation strategies in spinal cord injury (SCI) by the assessment of spontaneous muscle activity and/or volitional effort – including patterns of multi-muscle activation. • There is a limited use of sEMG in clinical trials and day-to-day clinical routines. • The barriers to the use of sEMG in more clinical studies focused on SCI include normatization, cultural, educational, technical, and economic/administrative aspects. Surface electromyography (sEMG) is a common electrophysiological assessment used in clinical trials in individuals with spinal cord injury (SCI). This scoping review summarizes the most common sEMG techniques used to address clinically relevant neurorehabilitation questions. We focused on the role of sEMG assessments in the clinical practice and research studies on neurorehabilitation after SCI, and how sEMG reflects the changes observed with rehabilitation. Additionally, this review emphasizes the limitations and pitfalls of the sEMG assessments in the field of neurorehabilitation after SCI. A comprehensive search of Medline (Ovid), Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, Embase, Emcare, Cumulative Index to Nursing & Allied Health Literature, and PubMed was conducted to find peer-reviewed journal articles that included individuals post-SCI that participated in neurorehabilitation interventions using sEMG assessments. This is a scoping review using a systematic search (hybrid review). Of 4522 references captured in the primary database searches, 100 references were selected and included in the scoping review. The main focus of the studies was on neurorehabilitation using sEMG biofeedback, brain stimulation, locomotor training, neuromuscular electrical stimulation (NMES), paired-pulse stimulation, pharmacology, posture and balance training, spinal cord stimulation, upper limb training, vibration, and photobiomodulation. Most studies employed sEMG amplitude to understand the effects of neurorehabilitation on muscle activation during volitional efforts or reduction of spontaneous muscle activity (e.g., spasms, spasticity, and hypertonia). Further studies are needed to understand the long-term reliability of sEMG amplitude, to circumvent normalization issues, and to provide a deeper physiological background to the different sEMG analyses. This scoping review reveals the potential of sEMG in exploring promising neurorehabilitation strategies following SCI and discusses the barriers limiting its widespread use in the clinic. [ABSTRACT FROM AUTHOR]

Disruptions in the brain's connections to the hands resulting from a cervical spinal cord injury (cSCI) can lead to severe and persistent functional impairments. The integrity of these connections is an important predictor of upper extremity recovery in stroke and may similarly act as a biomarker in cSCI. In this perspective article, we review recent findings from a large cohort of individuals with cSCI, demonstrating the predictive value of corticospinal tract (CST) integrity in cSCI—CST sparing. This research underscores that, akin to stroke, the integrity of brain-to-hand connections is crucial for predicting upper extremity recovery following cSCI. We address the limitations of commonly used metrics, such as sacral sparing and the concept of central cord syndrome. Furthermore, we offer insights on emerging metrics, such as tissue bridges, emphasizing their potential in assessing the integrity of brain connections to the spinal cord. [ABSTRACT FROM AUTHOR]

Traumatic spinal cord injury (SCI) disrupts spinal and supraspinal pathways, and this process is reflected in changes in surface electromyography (sEMG). sEMG is an informative complement to current clinical testing and can capture the residual motor command in great detail-including in muscles below the level of injury with seemingly absent motor activities. In this comprehensive review, we sought to describe how the sEMG properties are changed after SCI. We conducted a systematic literature search followed by a narrative review focusing on sEMG analysis techniques and signal properties post-SCI. We found that early reports were mostly focused on the qualitative analysis of sEMG patterns and evolved to semi-quantitative scores and a more detailed amplitude-based quantification. Nonetheless, recent studies are still constrained to an amplitude-based analysis of the sEMG, and there are opportunities to more broadly characterize the time- and frequency-domain properties of the signal as well as to take fuller advantage of high-density EMG techniques. We recommend the incorporation of a broader range of signal properties into the neurophysiological assessment post-SCI and the development of a greater understanding of the relation between these sEMG properties and underlying physiology. Enhanced sEMG analysis could contribute to a more complete description of the effects of SCI on upper and lower motor neuron function and their interactions, and also assist in understanding the mechanisms of change following neuromodulation or exercise therapy. [ABSTRACT FROM AUTHOR]

Background:Recently a new shoe design with air compartments at the insole has been developed and termed as toning shoes. However, it is unclear how this air compartments-based shoe could affect muscle activation and centre of pressure during treadmill walking or quiet standing. Purpose:The aim of this study was to compare muscular activation during treadmill walking and quiet standing between toning shoes and regular shoes. Methods:Ten participants performed treadmill walking at 4.5 km.h−1and unipodal standing wearing regular shoes and toning shoes in random order. Mean muscular activation of seven muscles from preferred lower limb (tibialis anterior,soleus,peroneus brevis,biceps femoris,gastrocnemius medialis,vastus lateralis, andrectus femoris) at different phases of the gait cycle (first half of contact, second half of contact and balance time) were assessed and compared between regular and toning shoes. Coefficient of variation and centre of pressure were calculated for temporal parameters and compared between regular and toning shoes. Principal results:Toning shoes led to higher coefficient of variation (20% during contact time; 15% during balance time), which may indicate a more unstable walking dynamic. Furthermore, the main muscular activation outcome was a 7% higher activation forrectus femorisand 7% lower activation forvastus lateralisat first half of contact time and higher activation forvastus lateralis(8%) and lower activation forrectus femoris(15%) at second half of contact time. Centre of pressure excursion and muscular activation during standing presented no significant differences. Conclusion:Toning shoe usage is increasing among the population and a better knowledge of effects on muscular activation and postural balance is fundamental. Toning shoes use resulted in a change in muscular activation during treadmill walking mainly for the quadriceps muscle. Some other muscle groups showed small differences in muscular activation patterns. There were no differences in postural balance and muscular activity during quiet standing with toning shoes use. [ABSTRACT FROM PUBLISHER]

Mobility smoothness assessed by the spectral arc length (SPARC) may reflect the complex biomechanical alterations that occur with aging and may help detect functional mobility changes after experiencing falls. Here, we sought to explore whether smoothness of angular velocities of the trunk measured using SPARC metrics in the instrumented timed-up-and-go (iTUG) test are assoacited with a history of falls in the oldest-old. A case-control study. The sample consisted of 64 community-dwelling oldest-old individuals who underwent the following assessments: clinical and sociodemographic questionnaire, Mini Mental State Examination (MMSE), Falls Efficacy-questionnaire International (FES I), the Activities-specific Balance Confidence (ABC), Functional Reaching Test (FRT), and the iTUG test. We used an inertial measurement unit (IMU) to obtain trunk angular velocities from the IMU's gyroscope, which was used to calculate mobility smoothness (SPARC). Standard deviation of the mobility smoothness around the anteroposterior axis of rotation (SPARC roll SD) (OR: 6.15 / CI 95 % = 1.58–23.94) and duration (OR: 1.11 / CI 95 % = 1.09–1.22) in the full iTUG test were associated with a history of falls in oldest-old. Using solely the full iTUG duration (59.19 ± 2.18) or SPARC (61.87 ± 2.40) resulted in lower probability to detect a history of falls in comparison with the combined measurement (66.21 ± 2.50). SPARC roll SD in the full iTUG may be a relevant biomarker to detect mobility smoothness changes in the oldest-old. This study provides evidence the oldest-old with a history of falls may change their functional mobility, in terms of movement duration and smoothness. • SPARC distills the complex functional mobility smoothness into a single measure. • SPARC and iTUG duration are linked with a history of falls in the oldest-old. • SPARC roll standard deviation better detect mobility smoothness in fallers. • iTUG time-based and SPARC metrics should be combined to assess functional mobility. [ABSTRACT FROM AUTHOR]

• We used a low-cost system for monitoring individual rat activities in home cage. • Prefrontal cortex damage resulted in behavioural flexibility deficits. • RFID tracking is a feasible tool to predict post-stroke impairment and recovery. Diminished cognitive flexibility is a common form of executive dysfunction that results from stroke in the prefrontal cortex. Potential therapies targeting this type of cognitive deficit following stroke are lacking. Here, we used environmental enrichment (EE) as a rehabilitation approach, integrated with a radio frequency identification (RFID)-based activity tracking system to evaluate the contribution of individual EE elements to promote cognitive recovery. Male and female Sprague–Dawley rats received either sham surgery or endothelin-1 (ET-1) induced focal ischemia targeting the medial prefrontal cortex (mPFC). Cognitive flexibility was assessed through an egocentric-spatial version of the Morris Water Maze (MWM) task. Prefrontal cortex damage resulted in impaired reversal learning using the egocentric MWM and reduced physical activity in the running wheel, while social interaction was not affected. EE exposure (2 h/day, 5 days/week, for 5 weeks) improved cognitive flexibility in reversal learning of egocentric MWM for both stroke and sham rats. As changes in cognition post-stroke can be subtle and difficult to detect using conventional behavioural assessment, we suggest that the implementation of individualized automated animal tracking as used herein will ultimately help decipher whether individual components of EE are important for promoting cognitive recovery post-stroke. This study represents an attempt to better align preclinical and clinical implementations of EE and facilitate the uptake of this intervention in the clinical setting. [ABSTRACT FROM AUTHOR]

An abstract of the article "Neuromuscular activation patterns exchange as effect of an unstable shoe construction during walking" by Gustavo Balbinot, Rudnei Palhano, and Milton Antonio Zaro is presented.

Current clinical practice guidelines support structured, progressive protocols for improving walking after stroke. Technology enables monitoring of exercise and therapy intensity, but safety concerns could also be addressed. This study explores functional mobility in post-stroke individuals using wearable technology to quantify movement smoothness—an indicator of safe mobility.Observational cohort study.A movement analysis and rehabilitation laboratory.A total of 56 chronic post-stroke individuals and 51 healthy controls.Participants performed the mobility test while wearing an inertial measurement unit attached to their waist. Thirty-two healthy participants also engaged in a steady-state walking task.Functional mobility smoothness by examining angular velocities in the yaw, pitch, and roll axes, employing the spectral arc length metrics.Our findings reveal that post-stroke individuals extend the duration of the timed-up-and-go test (≈9 s and 23 s longer compared to the controls) to ensure safe mobility—greater mobility smoothness (p < 0.001). Notably, for mild and severe impairments, post-stroke mobility demonstrated ≈8% and ≈11% greater smoothness in pitch movements, respectively (p = 0.025 and p = 0.002). In the roll direction, mobility was ≈12% smoother in cases of severe strokes (p = 0.006).This study addresses a crucial gap in the understanding of mobility smoothness in chronic stroke survivors using wearable technology. Our study suggests the potential utility of spectral arc length to predict challenging mobility situations in real-world situations. We highlight the potential for automated monitoring of safety offering promising avenues for real-time, real-life monitoring. [ABSTRACT FROM AUTHOR]

Background: Walking speed is often used in the clinic to assess the level of gait impairment following stroke. Nonetheless, post-stroke individuals may employ the same walking speed but at a distinct movement quality. The main objective of this study was to explore a novel movement quality metric, the estimation of gait smoothness by the spectral arc length (SPARC), in individuals with a chronic stroke displaying mild/moderate or severe motor impairment while walking in an outdoor environment. Also, to quantify the correlation between SPARC, gait speed, motor impairment, and lower limb spasticity focused on understanding the relationship between the movement smoothness metric and common clinical assessments. Methods: Thirty-two individuals with a chronic stroke and 32 control subjects participated in this study. The 10 meters walking test (10 MWT) was performed at the self-selected speed in an outdoor environment. The 10 MWT was instrumented with an inertial measurement unit system (IMU), which afforded the extraction of trunk angular velocities (yaw, roll, and pitch) and subsequent SPARC calculation. Results: Movement smoothness was not influenced by gait speed in the control group, indicating that SPARC may constitute an additional and independent metric in the gait assessment. Individuals with a chronic stroke displayed reduced smoothness in the yaw and roll angular velocities (lower SPARC) compared with the control group. Also, severely impaired participants presented greater variability in smoothness along the 10 MWT. In the stroke group, a smoother gait in the pitch angular velocity was correlated with lower limb spasticity, likely indicating adaptive use of spasticity to maintain the pendular walking mechanics. Conversely, reduced smoothness in the roll angular velocity was related to pronounced spasticity. Conclusions: Individuals with a chronic stroke displayed reduced smoothness in the yaw and roll angular velocities while walking in an outdoor environment. The quantification of gait smoothness using the SPARC metric may represent an additional outcome in clinical assessments of gait in individuals with a chronic stroke. [ABSTRACT FROM AUTHOR]

Background: Impairments of functional mobility may affect locomotion and quality of life in subjects with Parkinson's disease (PD). Movement smoothness measurements, such as the spectral arc length (SPARC), are novel approaches to quantify movement quality. Previous studies analyzed SPARC in simple walking conditions. However, SPARC outcomes during functional mobility tasks in subjects with PD and freezing of gait (FOG) were never investigated. This study aimed to analyze SPARC during the Timed Up and Go (TUG) test in individuals with PD and FOG.Methods: Thirty-one participants with PD and FOG and six healthy controls were included. SPARC during TUG test was calculated for linear and angular accelerations using an inertial measurement unit system. SPARC data were correlated with clinical parameters: motor section of the Unified Parkinson's Disease Rating Scale, Hoehn & Yahr scale, Freezing of Gait Questionnaire, and TUG test.Results: We reported lower SPARC values (reduced smoothness) during the entire TUG test, turn and stand to sit in subjects with PD and FOG, compared to healthy controls. Unlike healthy controls, individuals with PD and FOG displayed a broad spectral range that encompassed several dominant frequencies. SPARC metrics also correlated with all the above-mentioned clinical parameters.Conclusion: SPARC values provide valid and relevant clinical data about movement quality (e.g., smoothness) of subjects with PD and FOG during a functional mobility test. [ABSTRACT FROM AUTHOR]