Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 40.535
Filtrar
Más filtros

Intervalo de año de publicación
1.
Elife ; 132024 Sep 02.
Artículo en Inglés | MEDLINE | ID: mdl-39219499

RESUMEN

Real-world actions often comprise a series of movements that cannot be entirely planned before initiation. When these actions are executed rapidly, the planning of multiple future movements needs to occur simultaneously with the ongoing action. How the brain solves this task remains unknown. Here, we address this question with a new sequential arm reaching paradigm that manipulates how many future reaches are available for planning while controlling execution of the ongoing reach. We show that participants plan at least two future reaches simultaneously with an ongoing reach. Further, the planning processes of the two future reaches are not independent of one another. Evidence that the planning processes interact is twofold. First, correcting for a visual perturbation of the ongoing reach target is slower when more future reaches are planned. Second, the curvature of the current reach is modified based on the next reach only when their planning processes temporally overlap. These interactions between future planning processes may enable smooth production of sequential actions by linking individual segments of a long sequence at the level of motor planning.


Asunto(s)
Brazo , Movimiento , Desempeño Psicomotor , Humanos , Brazo/fisiología , Movimiento/fisiología , Desempeño Psicomotor/fisiología , Masculino , Femenino , Adulto , Adulto Joven
2.
Eplasty ; 24: e39, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-39224407

RESUMEN

This case report presents a 72-year-old female with a unique anatomical variation of the median nerve recurrent motor branch that has not been described in the literature. During her open carpal tunnel release, the recurrent motor branch was found to divide from the median nerve within the carpal tunnel, pierce the proximal aspect of the transverse carpal ligament in a transligamentous fashion, and then immediately divide into one branch that pierced the thenar muscles and another branch that traveled superficial to the transverse carpal ligament before piercing the thenar muscles more distal. This variation in anatomy stresses the importance of thoughtful incision design and direct visualization of all structures during carpal tunnel release.

3.
Front Neurol ; 15: 1429929, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-39224885

RESUMEN

Introduction: Stroke-induced upper limb disabilities can be characterized by both motor impairments and activity limitations, commonly assessed using Fugl-Meyer Motor Assessment for Upper Extremity (FMMA-UE) and Action Research Arm Test (ARAT), respectively. The relationship between the two assessments during recovery is largely unstudied. Expectedly they diverge over time when recovery of impairment (restitution) plateaus, but compensation-driven improvements still occur. The objective of this study is to evaluate the alignment between FMMA-UE and ARAT in defining upper limb functional recovery categories by ARAT scores. We aimed to establish cut-off scores for both measures from the acute/early subacute, subacute and chronic stages of stroke recovery. Methods: Secondary analysis of four prospective cohort studies (acute/early subacute: n = 133, subacute: n = 113, chronic: n = 92) stages post-stroke. Receiver operating characteristic curves calculated the area under the curve (AUC) to establish optimal FMMA-UE cut-offs based on predefined ARAT thresholds distinguishing five activity levels from no activity to full activity. Weighted kappa was used to determine agreement between the two assessments. We used minimally clinically important difference (MCID) and minimal detectable change (MDC95) for comparison. Results: FMMA-UE and ARAT scores showed no relevant divergence across all recovery stages. Results indicated similar cut-off scores in all recovery stages with variability below MCID and MDC95 levels. Cut-off scores demonstrated robust AUC values from 0.77 to 0.86 at every recovery stage. Only in highly functional patients at the chronic stage, we found a reduced specificity of 0.55. At all other times sensitivity ranged between 0.68 and 0.99 and specificity between 0.71 and 0.99. Weighted kappa at the acute/early subacute, subacute and chronic stages was 0.76, 0.83, and 0.81, respectively. Discussion: Our research shows a strong alignment between FMMA-UE and ARAT cut-off scores throughout stroke recovery, except among the subgroup of highly recovered patients at the chronic stage. Discrepancies in specificity potentially stem from fine motor deficits affecting dexterity outcomes that are not captured by FMMA-UE. Additionally, the high congruence of both measures suggests they are not suited to distinguish between restitution and compensation. Calling for more comprehensive assessment methods to better understand upper limb functionality in rehabilitation.

4.
Proc Natl Acad Sci U S A ; 121(37): e2401531121, 2024 Sep 10.
Artículo en Inglés | MEDLINE | ID: mdl-39226364

RESUMEN

Many RNA-binding proteins (RBPs) are linked to the dysregulation of RNA metabolism in motor neuron diseases (MNDs). However, the molecular mechanisms underlying MN vulnerability have yet to be elucidated. Here, we found that such an RBP, Quaking5 (Qki5), contributes to formation of the MN-specific transcriptome profile, termed "MN-ness," through the posttranscriptional network and maintenance of the mature MNs. Immunohistochemical analysis and single-cell RNA sequencing (scRNA-seq) revealed that Qki5 is predominantly expressed in MNs, but not in other neuronal populations of the spinal cord. Furthermore, comprehensive RNA sequencing (RNA-seq) analyses revealed that Qki5-dependent RNA regulation plays a pivotal role in generating the MN-specific transcriptome through pre-messenger ribonucleic acid (mRNA) splicing for the synapse-related molecules and c-Jun N-terminal kinase/stress-activated protein kinase (JNK/SAPK) signaling pathways. Indeed, MN-specific ablation of the Qki5 caused neurodegeneration in postnatal mice and loss of Qki5 function resulted in the aberrant activation of stress-responsive JNK/SAPK pathway both in vitro and in vivo. These data suggested that Qki5 plays a crucial biological role in RNA regulation and safeguarding of MNs and might be associated with pathogenesis of MNDs.


Asunto(s)
Neuronas Motoras , Proteínas de Unión al ARN , Médula Espinal , Transcriptoma , Animales , Proteínas de Unión al ARN/metabolismo , Proteínas de Unión al ARN/genética , Neuronas Motoras/metabolismo , Ratones , Médula Espinal/metabolismo , Precursores del ARN/metabolismo , Precursores del ARN/genética , Empalme del ARN , Ratones Noqueados
5.
J Neurol Sci ; 465: 123208, 2024 Aug 30.
Artículo en Inglés | MEDLINE | ID: mdl-39226712

RESUMEN

BACKGROUND: C9orf72 gene repeat expansion (C9RE) is the most frequent gene variant associated with amyotrophic lateral sclerosis (ALS). We aimed to study the phenotype of motor neurone disease (MND) patients with C9RE in a Portuguese cohort. METHODS: Demographical and clinical data of MND patients with (C9RE+) and without C9RE were compared. ALS al Rating Scale-Revised (ALSFRS-R) and Edinburgh Cognitive and Behavioural ALS Screen (ECAS) were used to evaluate functional and cognitive performance, respectively. Survival analysis was performed using Kaplan Meier log-rank test and Cox proportional hazards model. RESULTS: We included 761 patients of whom 61 (8.0 %) were C9RE+. C9RE+ patients had a higher frequency of ALS (95.1 vs 78.4 %, p = 0.002), and lower frequency of progressive muscular atrophy (3.3 vs 16.7 %, p = 0.006). C9RE+ was associated with earlier age of onset (58.1 vs 62.6 years, p = 0.003) and more frequent MND family history (65.5 vs 11.4 %, p < 0.001). Gender, ethnicity, onset site, diagnostic delay, disease progression rate until diagnosis (ΔF), ALSFRS-R and time until non-invasive ventilation did not differ between groups. Cognitive/behavioural symptoms and ECAS did not differ between groups, except a worse visuospatial score in C9RE+ group (p = 0.035). Death rate was 1.8 and 1.6 times higher in C9RE+ patients with MND and ALS, respectively. Significant survival prognostic factors in C9RE+ group were diagnosis delay (HR = 0.96, 95 %CI 0.92-0.99, p = 0.008) and ΔF (HR = 1.93, 95 %CI 1.26-2.96, p = 0.002). CONCLUSION: Our study corroborates most previous cohorts' findings, but harbours some singularities regarding onset site, phenotype, and cognitive profile, that contribute to a better understanding of C9RE epidemiology.

6.
Schizophr Bull ; 2024 Sep 02.
Artículo en Inglés | MEDLINE | ID: mdl-39222718

RESUMEN

BACKGROUND AND HYPOTHESIS: Abnormal psychomotor behavior is a core schizophrenia symptom. However, assessment of motor abnormalities with expert rating scales is challenging. The Positive and Negative Syndrome Scale (PANSS) includes 3 items broadly related to hypokinetic motor behavior. Here, we tested whether a sum score of the PANSS items mannerisms and posturing (G5), motor retardation (G7), and disturbance of volition (G13) corresponds to expert ratings, potentially qualifying as a proxy-marker of motor abnormalities. STUDY DESIGN: Combining baseline datasets (n = 196) of 2 clinical trials (OCoPS-P, BrAGG-SoS), we correlated PANSS motor score (PANSSmot) and 5 motor rating scales. In addition, we tested whether the cutoff set at ≥3 on each PANSS motor item, ie, "mild" on G05, G07, and G13 (in total ≥9 on PANSSmot) would differentiate the patients into groups with high vs low scores in motor scales. We further sought for replication in an independent trial (RESIS, n = 102), tested the longitudinal stability using week 3 data of OCoPS-P (n = 75), and evaluated the validity of PANSSmot with instrumental measures of physical activity (n = 113). STUDY RESULTS: PANSSmot correlated with all motor scales (Spearman-Rho-range 0.19-0.52, all P ≤ .007). Furthermore, the cutoff set at ≥3 on each PANSS motor item was able to distinguish patients with high vs low motor scores in all motor scales except using Abnormal Involuntary Movement Scale (Mann-Whitney-U-Tests: all U ≥ 580, P ≤ .017). CONCLUSIONS: Our findings suggest that PANSSmot could be a proxy measure for hypokinetic motor abnormalities. This might help to combine large datasets from clinical trials to explore whether some interventions may hold promise to alleviate hypokinetic motor abnormalities in psychosis.

7.
Phys Ther ; 2024 Sep 03.
Artículo en Inglés | MEDLINE | ID: mdl-39223953

RESUMEN

OBJECTIVE: Physical therapists routinely deliver and prescribe motor practice to improve function. The ability to select optimal practice regimens is limited by a current lack of detail in the measurement of motor practice. The objective of this study was to quantify the type, amount, and timing of gross motor practice during physical therapist sessions. METHODS: A secondary video coding analysis of physical therapist sessions from the iMOVE clinical trial (NCT02340026) in young children with cerebral palsy (CP) was conducted. The 37 children who completed the treatment phase were included (mean age = 22.1 months). Children could initiate pulling to stand but were unable to walk. Videos of randomly selected therapy sessions were coded for gross motor activity (422 videos total). The 10 gross motor activity codes included lying, sitting, four point, crawling, kneeling, knee walking, standing, walking, transitions between floor postures, and transitions to/from an upright posture. Twenty percent of each video was double coded for reliability. Time per session, number of bouts, and median time per bout were calculated for each gross motor activity and for 2 aggregate measures: movement time and upright time. RESULTS: Participants spent more than half of therapy time in sitting and standing combined (60.3%). Transitions occurred more frequently than any other motor activity (49.3 total transitions per session). Movement time accounted for 16.3% of therapy time. Upright time accounted for 53.3% of therapy time. CONCLUSIONS: Critical practice time to gain motor skill is not equivalent to chronological time or time spent in therapy. Toddlers with CP spent a small amount of therapy time moving. Future work should explore the relations between motor practice and rehabilitation outcomes. IMPACT: Physical therapists are ideally suited to detail the content of motor practice and ultimately to prescribe optimal patterns of motor practice. We report the characteristics of gross motor practice during therapy in children with CP.

8.
Mov Disord ; 2024 Sep 03.
Artículo en Inglés | MEDLINE | ID: mdl-39225564

RESUMEN

BACKGROUND: The cardinal motor symptoms of Parkinson's disease (PD) include rigidity, bradykinesia, and rest tremor. Rigidity and bradykinesia correlate with contralateral nigrostriatal degeneration and striatal dopamine deficit, but association between striatal dopamine function and rest tremor has remained unclear. OBJECTIVE: The aim of this study was to investigate the possible link between dopamine function and rest tremor using Parkinson's Progression Markers Initiative dataset, the largest prospective neuroimaging cohort of patients with PD. METHODS: Clinical, [123I]N-ω-fluoropropyl-2ß-carbomethoxy-3ß-(4-iodophenyl)nortropane ([123I]FP-CIT) single photon emission computed tomography (SPECT), and structural magnetic resonance imaging data from 354 early PD patients and 166 healthy controls were included in this study. We employed a novel approach allowing nonlinear registration of individual scans accurately to a standard space and voxelwise analyses of the association between motor symptoms and striatal dopamine transporter (DAT) binding. RESULTS: Severity of both rigidity and bradykinesia was negatively associated with contralateral striatal DAT binding (PFWE < 0.05 [FWE, family-wise error corrected]). However, rest tremor amplitude was positively associated with increased ipsilateral DAT binding (PFWE < 0.05). The association between rest tremor and binding remained the same controlling for Hoehn & Yahr stage, Movement Disorder Society Unified Parkinson's Disease Rating Scale (MDS-UPDRS) part III score, bradykinesia-rigidity score, or motor phenotype. The association between rest tremor and binding was independent of bradykinesia-rigidity and replicated using 2-year follow-up data (PFWE < 0.05). CONCLUSION: In agreement with the existing literature, we did not find a consistent association between rest tremor and contralateral dopamine defect. However, our results demonstrate a link between rest tremor and increased or less decreased ipsilateral DAT binding. Our findings provide novel information about the association between dopaminergic function and parkinsonian rest tremor. © 2024 The Author(s). Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

9.
J Neurophysiol ; 2024 Sep 04.
Artículo en Inglés | MEDLINE | ID: mdl-39230338

RESUMEN

Recent studies combining high-density surface electromyography (HD-sEMG) and ultrasound imaging have yielded valuable insights into the relationship between motor unit activity and muscle contractile properties. However, limited evidence exists on the relationship between motor unit firing properties and tendon morpho-mechanical properties. This study aimed to determine the relationship between triceps surae motor unit firing properties and the morpho-mechanical properties of the Achilles tendon (AT). Motor unit firing properties (i.e. mean discharge rate (DR) and coefficient of variation of the interspike interval (COVisi)) and motor unit firing-torque relationships (cross-correlation between cumulative spike train (CST) and torque, and the delay between motor unit firing and torque production (neuromechanical delay)) of the medial gastrocnemius (MG), lateral gastrocnemius (LG), and soleus (SO) muscles were assessed using HD-sEMG during isometric plantarflexion contractions at 10% and 40% of maximal voluntary contraction (MVC). The morpho-mechanical properties of the AT (i.e. length, thickness, cross-sectional area and resting stiffness) were determined using B-mode ultrasonography and shear-wave elastography. Multiple linear regression analysis showed that at 10% MVC, the DR of the triceps surae muscles explained 41.7% of the variance in resting AT stiffness. Additionally, at 10% MVC, COVisi SO predicted 30.4% of the variance in AT length. At 40% MVC, COVisi MG and COVisi SO explained 48.7% of the variance in AT length. Motor unit-torque relationships were not associated with any morpho-mechanical parameter. This study provides novel evidence of a contraction-intensity dependent relationship between motor unit firing parameters of the triceps surae muscle and the morpho-mechanical properties of the AT.

10.
J Neurophysiol ; 2024 Sep 04.
Artículo en Inglés | MEDLINE | ID: mdl-39230337

RESUMEN

Motor learning involves both explicit and implicit processes that are fundamental for acquiring and adapting complex motor skills. However, stroke may damage the neural substrates underlying explicit and/or implicit learning, leading to deficits in overall motor performance. While both learning processes are typically used in concert in daily life and rehabilitation, no gait studies have determined how these processes function together after stroke when tested during a task that elicits dissociable contributions from both. Here, we compared explicit and implicit locomotor learning in individuals with chronic stroke to age- and sex-matched neurologically intact controls. We assessed implicit learning using split-belt adaptation (where two treadmill belts move at different speeds). We assessed explicit learning (i.e., strategy-use) using visual feedback during split-belt walking to help individuals explicitly correct for step length errors created by the split-belts. After the first 40 strides of split-belt walking, we removed the visual feedback and instructed individuals to walk comfortably, a manipulation intended to minimize contributions from explicit learning. We utilized a multi-rate state-space model to characterize individual explicit and implicit process contributions to overall behavioral change. The computational and behavioral analyses revealed that, compared to controls, individuals with chronic stroke demonstrated deficits in both explicit and implicit contributions to locomotor learning, a result that runs counter to prior work testing each process individually during gait. Since post-stroke locomotor rehabilitation involves interventions that rely on both explicit and implicit motor learning, future work should determine how locomotor rehabilitation interventions can be structured to optimize overall motor learning.

11.
Int J Neurosci ; : 1-18, 2024 Sep 04.
Artículo en Inglés | MEDLINE | ID: mdl-39230589

RESUMEN

OBJECTIVES: Magnetic seizure therapy (MST) is more benign than electroconvulsive therapy (ECT) in terms of cognitive impairment. However, whether these two "artificial seizures" facilitate the central motor neural pathway and the motor cortical effects have not been investigated. The study aimed to compare the effects of ECT and MST on motor-evoked potential (MEP) in patients with mental disorders. METHODS: Forty-nine patients with mental disorders (major depressive disorder, bipolar disorder type II, and schizophrenia) received 6 treatment sessions of vertex MST versus 6 bifrontal ECT treatments in a nonrandomized comparative clinical design. Data on the duration of motor seizures were collected for each treatment. Motor-evoked potential (MEP) latency and the resting motor threshold (rMT) were measured at baseline and after every two treatments. Comparisons were performed between or within the groups. RESULTS: Seizure durations were significantly longer in the ECT group compared to the MST group across multiple sessions. Both MST and ECT demonstrated a significant reduction in rMT in the left and right hemispheres after the fourth (T3) and sixth treatments (T4) compared to baseline (T1). However, there were no significant changes in MEP latency within or between the groups throughout the treatment sessions. The only difference was that the rMT in the left cerebral hemisphere was significantly lower after T4 than after the second treatment (T2). There was no difference in rMT between the ECT and MST groups. CONCLUSIONS: Both ECT and MST facilitate the central motor pathway, with a shared mechanism of increased motor cortex excitability.

12.
Spine Deform ; 2024 Sep 04.
Artículo en Inglés | MEDLINE | ID: mdl-39230663

RESUMEN

PURPOSE: Neurological deficits developing years after pedicle screw misplacement is a rare phenomenon. Here, we report level IV evidence of a previously asymptomatic medial thoracic pedicle screw resulting in paraparesis after a motor vehicle accident. METHODS: A 21-year-old male presented with acute onset of paraparesis following a motor vehicle collision. Six years prior this incident, the patient underwent a thoracolumbar fusion T4-L4 for AIS performed by an outside orthopedic surgeon. CT scan and CT myelogram illustrated decreased spinal canal diameter and cord compression from a medial T8 pedicle screw. RESULTS: Surgical removal of the misplaced pedicle screw resulted in a gradual complete recovery sustained over a period of 2 years. This case is compared to those reported in the literature review between 1981 and 2019 concerning delayed neurological deterioration related to misplaced pedicle screw. CONCLUSION: This case reports a delayed neurological deficit implicating a misplaced pedicle screw. This phenomenon remains rare since 5 cases were reported in the literature over the last 4 decades. It calls into focus the need for confirmation of safe instrumentation during the intraoperative period. It also illustrates the potential difficult decision-making in regard to asymptomatic misplaced instrumentation. LEVEL OF EVIDENCE: IV.

13.
J Autism Dev Disord ; 2024 Sep 04.
Artículo en Inglés | MEDLINE | ID: mdl-39230782

RESUMEN

Impaired joint attention is a common feature of autism spectrum disorder (ASD), affecting social interaction and communication. We explored if group basketball learning could enhance joint attention in autistic children, and how this relates to brain changes, particularly white matter development integrity. Forty-nine autistic children, aged 4-12 years, were recruited from special education centers. The experimental group underwent a 12-week basketball motor skill learning, while the control group received standard care. Eye-tracking and brain scans were conducted. The 12-week basketball motor skill learning improved joint attention in the experimental group, evidenced by better eye tracking metrics and enhanced white matter integrity. Moreover, reduced time to first fixation correlated positively with decreased mean diffusivity of the left superior corona radiata and left superior fronto-occipital fasciculus in the experimental group. Basketball-based motor skill intervention effectively improved joint attention in autistic children. Improved white matter fiber integrity related to sensory perception, spatial and early attention function may underlie this effect. These findings highlight the potential of group motor skill learning within clinical rehabilitation for treating ASD.

14.
Artículo en Inglés | MEDLINE | ID: mdl-39230862

RESUMEN

BACKGROUND: The COVID-19 pandemic has brought unprecedented changes globally, significantly affecting public health sectors, including paediatric road trauma. This study aims to explore the changes in paediatric road trauma presentations and outcomes before and after the COVID-19 lockdown. METHODS: This retrospective study analysed paediatric trauma data from the Saudi TraumA Registry (STAR) from August 2017 to December 2022, comparing pre- and post-COVID-19 lockdown periods (August 2017-March 2020 and July 2020-December 2022, respectively). The study analysed demographic data, mechanism of injury, severity, ICU admissions, and mortality rates using multivariate logistic regression models. RESULTS: Out of 950 paediatric trauma cases analysed, there was an 44.2 [561/389 = 1.442] % increase in the number of cases post-lockdown. A significant shift was noted in the age group of 5-9 years, with cases increasing from post-lockdown. Head injuries were the most prevalent type of injury, with their proportion slightly increasing from 163 (20.5%) pre-lockdown to 248 (23.2%) post-lockdown. The ICU admission were consistent across both periods, while the definitive care mode of arrival post-lockdown showed a notable shift towards private or government ambulances. CONCLUSION: Our study provides critical insights into the significant impact of the COVID-19 on paediatric road trauma. The observed increase in trauma cases post-pandemic, particularly among younger children and a notable rise in driver-related injuries among adolescents, underscores the profound effect of lockdown measures and subsequent societal changes on paediatric health. Efforts to reduce paediatric traffic injuries require collaboration among parents, educators, healthcare professionals, policymakers, and the community at large.

15.
Artículo en Inglés | MEDLINE | ID: mdl-39237791

RESUMEN

Functional gait disorders (FGDs) are a disabling subset of Functional Neurological Disorders in which presenting symptoms arise from altered high-level motor control. The dual-task paradigm can be used to investigate mechanisms of high-level gait control. The study aimed to determine the objective measures of gait that best discriminate between individuals with FGDs and healthy controls and the relationship with disease severity and duration. High-level spatiotemporal gait outcomes were analyzed in 87 patients with FGDs (79.3% women, average age 41.9±14.7 years) and 48 healthy controls (60.4% women, average age 41.9±15.7 years) on single and motor, cognitive, and visual-fixation dual tasks. The area under the curve (AUC) from the receiver operator characteristic plot and the dual-task effect (DTE) were calculated for each measure. Dual-task interference on the top single-task gait characteristics was determined by two-way repeated measures ANOVA. Stride time variability and its standard deviation (SD) failed to discriminate between the two groups in single and dual-task conditions (AUC<0.80 for all). Significant group x task interactions were observed for swing time SD and stride time on the cognitive dual tasks (p<0.035 for all). Longer disease duration was associated with poor gait performance and unsteadiness in motor and cognitive DTE (p<0.003) but improvement in stride length and swing time on the visual dual tasks (p<0.041). Our preliminary findings shed light on measures of gait automaticity as a diagnostic and prognostic gait biomarker and underline the importance of early diagnosis and management in individuals with FGDs.

16.
Sci Rep ; 14(1): 20814, 2024 Sep 06.
Artículo en Inglés | MEDLINE | ID: mdl-39242769

RESUMEN

To improve dynamic performance and steady-state accuracy of position leap control of the direct current (DC) servo motor, a fuzzy inference system (FIS) enabled artificial neural network (ANN) feedforward compensation control method is proposed in this study. In the method, a proportional-integral-derivative (PID) controller is used to generate the baseline control law. Then, an ANN identifier is constructed to online learn the reverse model of the DC servo motor system. Meanwhile, the learned parameters are passed in real-time to an ANN compensator to provide feedforward compensation control law accurately. Next, according to system tracking error and network modeling error, an FIS decider consisting of an FI basic module and an FI finetuning module is developed to adjust the compensation quantity and prevent uncertain disturbance from undertrained ANN adaptively. Finally, the feasibility and efficiency of the proposed method are verified by the tracking experiments of step and square signals on the DC servo motor testbed. Experimental results show that the proposed FIS-enabled ANN feedforward compensation control method achieves lower overshoot, faster adjustment, and higher precision than other comparative control methods.

17.
J Electromyogr Kinesiol ; 79: 102922, 2024 Aug 27.
Artículo en Inglés | MEDLINE | ID: mdl-39244815

RESUMEN

PURPOSE: This study aimed to better understand the coping strategy of the neuromuscular system under perturbed afferent feedback. To this end, the neuromechanical effects of transient blood flow restriction (BFR) compared to atmospheric pressure were investigated in an antagonistic muscle pair. METHODS: Perceived discomfort and neuromechanical parameters (torque and high-density electromyography) were recorded during submaximal isometric ankle dorsiflexion before, during and after BFR. The tibialis anterior and gastrocnemius lateralis muscles were studied in 14 healthy young adults. RESULTS: Discomfort increased during BFR and decreased to baseline level afterwards. The exerted torque and the co-activation index remained constant, whereas the EMG signal energy increased significantly during BFR. Coherence analysis of the delta band remained constant, whereas the alpha band shows an increase during BFR. Median frequency and muscle fibre conduction velocity showed a positive trend during the first minutes of BFR before significantly decreasing. Both parameters exceeded baseline values after cuff deflation. CONCLUSION: Perturbed afferent feedback leads to altered neuromechanical parameters. We assume that increased central drive is required to maintain force output, resulting in changed muscle fibre activity. Glycolytic fast-switch fibres are only active for a short time due to oxygen deprivation and hyperacidity, but fatigue effects predominate in the long term.

18.
Early Hum Dev ; 198: 106111, 2024 Sep 02.
Artículo en Inglés | MEDLINE | ID: mdl-39244966

RESUMEN

BACKGROUND: It is unknown whether ultra-early physiotherapy commenced during neonatal intensive care unit admission is of value for optimising developmental outcomes in preterm/term infants at high-risk of cerebral palsy or motor-delay. AIMS: To determine whether ultra-early parent-administered physiotherapy to preterm/term high- risk infants commenced at earliest from 34-weeks post menstrual age, improves motor outcomes at 16-weeks corrected age (CA) compared to usual care. METHODS: Single-blind randomised controlled pilot study with 30 infant participants. The primary outcome was the Alberta Infant Motor Scale (AIMS) total score at 16-weeks CA. Secondary outcomes included (i) parent Depression Anxiety and Stress Score and Parent Perceptions Survey at 16-weeks CA; and (ii) Bayley Scales of Infant Development at 12-months CA. RESULTS: There were no clinically worthwhile effects at 16-weeks CA on the AIMS (mean between-group difference, 95% CI: -0.2, -2.4 to 2.0) or most secondary outcomes. However, the parents' "perception of treatment effectiveness" and "perception of change" favoured the experimental group. CONCLUSIONS: In this pilot trial, there was no clinically worthwhile effect of ultra-early parent-administered physiotherapy over usual care on the AIMS. However, the intervention was feasible for infants, acceptable to parents and parents perceived a benefit of treatment. Whilst this trial did not demonstrate treatment effectiveness using the AIMS, these findings should be interpreted cautiously because of the small sample size, the low responsivity of the AIMS to change in motor performance and the heterogeneity of the participants. Therefore, the intervention should not be abandoned on the basis of this trial, but rather further evaluated in a larger trial that addresses some of the learnings from this one.

19.
J Psychosom Res ; 187: 111911, 2024 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-39244967

RESUMEN

INTRODUCTION: Motor imagery (MI) involves recreating a movement mentally without physically performing the movement itself. MI has a positive impact on motor performance, motor learning and neural plasticity. We analysed the connection between motor imagination and altered movement execution in individuals with dystonia, a complex sensorimotor disorder. The aim of our study was to examine MI ability in patients with functional dystonia (FD) in comparison to organic dystonia (OD). METHODS: Our case-control study involved 46 patients, 22 with FD and 24 with OD. The assessment consisted of specific questionnaire and standardized motor, cognitive and psychiatric scales. The KVIQ-20 was used to test MI in each patient. RESULTS: Patients with FD scored lower on both global visual and kinaesthetic scales of the KVIQ-20 exam compared to patients with OD (63.1 ± 18.5 vs. 73.7 ± 13.2, and 54.9 ± 21.9 vs. 68.8 ± 18.2, respectively). Patients with FD also exhibited visual and/or kinaesthetic MI impairment in different body segments. The internal perspective when imagining movements was preferred in both patients with FD and OD. CONCLUSION: FD patients showed global dysfunction of visual and kinaesthetic MI abilities. Techniques for MI improvements might have a potential role in dystonia rehabilitation.

20.
Brain Stimul ; 2024 Sep 06.
Artículo en Inglés | MEDLINE | ID: mdl-39245294

RESUMEN

BACKGROUND: Theta-gamma transcranial alternating current stimulation (tACS) was recently found to enhance thumb acceleration in young, healthy participants, suggesting a potential role in facilitating motor skill acquisition. Given the relevance of motor skill acquisition in stroke rehabilitation, theta-gamma tACS may hold potential for treating stroke survivors. OBJECTIVE: We aimed to examine the effects of theta-gamma tACS on motor skill acquisition in young, healthy participants and stroke survivors. METHODS: In a pre-registered, double-blind, randomized, sham-controlled study, 78 young, healthy participants received either theta-gamma peak-coupled (TGP) tACS, theta-gamma trough-coupled (TGT) tACS or sham stimulation. 20 individuals with a chronic stroke received either TGP or sham. TACS was applied over motor cortical areas while participants performed an acceleration-dependent thumb movement task. Stroke survivors were characterized using standardized testing, with a subgroup receiving additional anatomical brain imaging. RESULTS: Neither TGP nor TGT tACS significantly modified general motor skill acquisition in the young, healthy cohort. In contrast, in the stroke cohort, TGP diminished motor skill acquisition compared to sham. Exploratory analyses revealed that, independent of general motor skill acquisition, healthy participants receiving TGP or TGT exhibited greater peak thumb acceleration than those receiving sham. CONCLUSION: Although theta-gamma tACS increased thumb acceleration in young, healthy participants, consistent with previous reports, it did not enhance overall motor skill acquisition in a more complex motor task. Furthermore, it even had detrimental effects on motor skill acquisition in stroke survivors.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA