Akinetic mutism and gait disturbance in a patient with delayed post-hypoxic leukoencephalopathy.

We report on a patient with delayed post-hypoxic leukoencephalopathy (DPHL) who showed akinetic mutism and gait disturbance, neural injuries that were demonstrated on diffusion tensor tractography (DTT). A patient was exposed to carbon monoxide (CO) and rapidly recovered; however, two weeks after onset, he began to show cognitive impairment and gait disturbance. At six weeks after CO exposure, he showed akinetic mutism and gait inability. DTT at 6-weeks post-exposure showed discontinuations in neural connectivities of the caudate nucleus to the medial prefrontal and orbitofrontal cortex in both hemispheres. In addition, the corticoreticulospinal tract revealed severe thinning in both hemispheres.

Stroke walking and balance characteristics via principal component analysis.

Balance impairment is associated gait dysfunction with several quantitative spatiotemporal gait parameters in patients with stroke. However, the link between balance impairments and joint kinematics during walking remains unclear. Clinical assessments and gait measurements using motion analysis system was conducted in 44 stroke patients. This study utilised principal component analysis to identify key joint kinematics characteristics of patients with stroke during walking using average joint angles of pelvis and bilateral lower limbs in every gait-cycle percentile related to balance impairments. Reconstructed kinematics showed the differences in joint kinematics in both paretic and nonparetic lower limbs that can be distinguished by balance impairment, particularly in the sagittal planes during swing phase. The impaired balance group exhibited greater joint variability in both the paretic and nonparetic limbs in the sagittal plane during entire gait phase and during terminal swing phase respectively compared with those with high balance scores. This study provides a more comprehensive understanding of stroke hemiparesis gait patterns and suggests considering both nonparetic and paretic limb function, as well as bilateral coordination in clinical practice. Principal component analysis can be a useful assessment tool to distinguish differences in balance impairment and dynamic symmetry during gait in patients with stroke.

Gait Training-Based Motor Imagery and EEG Neurofeedback in Lokomat: A Clinical Intervention With Complete Spinal Cord Injury Individuals.

Robotic systems, such as Lokomat® have shown promising results in people with severe motor impairments, who suffered a stroke or other neurological damage. Robotic devices have also been used by people with more challenging damages, such as Spinal Cord Injury (SCI), using feedback strategies that provide information about the brain activity in real-time. This study proposes a novel Motor Imagery (MI)-based Electroencephalogram (EEG) Visual Neurofeedback (VNFB) system for Lokomat® to teach individuals how to modulate their own µ (8-12 Hz) and ß (15-20 Hz) rhythms during passive walking. Two individuals with complete SCI tested our VNFB system completing a total of 12 sessions, each on different days. For evaluation, clinical outcomes before and after the intervention and brain connectivity were analyzed. As findings, the sensitivity related to light touch and painful discrimination increased for both individuals. Furthermore, an improvement in neurogenic bladder and bowel functions was observed according to the American Spinal Injury Association Impairment Scale, Neurogenic Bladder Symptom Score, and Gastrointestinal Symptom Rating Scale. Moreover, brain connectivity between different EEG locations significantly ( [Formula: see text]) increased, mainly in the motor cortex. As other highlight, both SCI individuals enhanced their µ rhythm, suggesting motor learning. These results indicate that our gait training approach may have substantial clinical benefits in complete SCI individuals.

Effects of ankle-foot orthosis with dorsiflexion resistance on the quasi-joint stiffness of the ankle joint and spatial asymmetry during gait in patients with hemiparesis.

BACKGROUND: Reduced ankle quasi-joint stiffness affects propulsion in the paretic side of patients with hemiparesis, contributing to gait asymmetry. We investigated whether the use of an ankle-foot orthosis with dorsiflexion resistance to compensate for reduced stiffness would increase quasi-joint stiffness and spatiotemporal symmetry in patients with hemiparesis. METHODS: Seventeen patients walked along a 7-m walkway in both ankle-foot orthosis with dorsiflexion resistance and control (i.e., ankle-foot orthosis) conditions. Dorsiflexion resistance by spring and cam was set to increase linearly from zero-degree ankle dorsiflexion. Gait data were analyzed using a three-dimensional motion analysis system. FINDINGS: Ankle-foot orthosis with dorsiflexion resistance significantly increased the quasi-joint stiffness in the early and middle stance phase (P = 0.028 and 0.040). Furthermore, although ankle power generation in the ankle-foot orthosis with dorsiflexion resistance condition was significantly lower than in the control condition (P = 0.003), step length symmetry significantly increased in the ankle-foot orthosis with dorsiflexion resistance condition (P = 0.016). There was no significant difference in swing time ratio between conditions. INTERPRETATION: Applying dorsiflexion resistance in the paretic stance phase increased quasi-joint stiffness but did not lead to an increase in ankle power generation. On the other hand, applying dorsiflexion resistance also resulted in a more symmetrical step length, even though the ankle joint power generation on the paretic side did not increase as expected. Future research should explore whether modifying the magnitude and timing of dorsiflexion resistance, considering the biomechanical characteristics of each patients' ankle joint during gait, enhances ankle joint power generation.

Effect of stiffness-optimized ankle foot orthoses on joint work in adults with neuromuscular diseases is related to severity of push-off deficits.

BACKGROUND: People with plantar flexor weakness generate less ankle push-off work during walking, resulting in inefficient proximal joint compensations. To increase push-off work, spring-like ankle foot orthoses (AFOs) can be provided. However, whether and in which patients AFOs increase push-off work and reduce compensatory hip and knee work is unknown. METHODS: In 18 people with bilateral plantar flexor weakness, we performed a 3D gait analysis at comfortable walking speed with shoes-only and with AFOs of which the stiffness was optimized. To account for walking speed differences between conditions, we compared relative joint work of the hip, knee and ankle joint. The relationships between relative work generated with shoes-only and changes in joint work with AFO were tested with Pearson correlations. RESULTS: No differences in relative ankle, knee and hip work over the gait cycle were found between shoes-only and AFO (p>0.499). Percentage of total ankle work generated during pre-swing increased with the AFO (AFO: 85.3±9.1% vs Shoes: 72.4±27.1%, p=0.026). At the hip, the AFO reduced relative work in pre-swing (AFO: 31.9±7.4% vs Shoes: 34.1±10.4%, p=0.038) and increased in loading response (AFO: 18.0±11.0% vs Shoes: 11.9±9.8%, p=0.022). Ankle work with shoes-only was inversely correlated with an increase in ankle work with AFO (r=-0.839, p<0.001) and this increase correlated with reduction in hip work with AFO (r=-0.650, p=0.004). DISCUSSION: Although stiffness-optimized AFOs did not alter the work distribution across the ankle, knee and hip joint compared to shoes-only walking, relative more ankle work was generated during push-off, causing a shift in hip work from pre-swing to loading response. Furthermore, larger ankle push-off deficits when walking with shoes-only were related with an increase in ankle work with AFO and reduction in compensatory hip work, indicating that more severely affected individuals benefit more from the energy storing-and-releasing capacity of AFOs.

Low and high-order topological disruption of functional networks in multiple system atrophy with freezing of gait: A resting-state study.

OBJECTIVE: Freezing of gait (FOG), a specific survival-threatening gait impairment, needs to be urgently explored in patients with multiple system atrophy (MSA), which is characterized by rapid progression and death within 10 years of symptom onset. The objective of this study was to explore the topological organisation of both low- and high-order functional networks in patients with MAS and FOG. METHOD: Low-order functional connectivity (LOFC) and high-order functional connectivity FC (HOFC) networks were calculated and further analysed using the graph theory approach in 24 patients with MSA without FOG, 20 patients with FOG, and 25 healthy controls. The relationship between brain activity and the severity of freezing symptoms was investigated in patients with FOG. RESULTS: Regarding global topological properties, patients with FOG exhibited alterations in the whole-brain network, dorsal attention network (DAN), frontoparietal network (FPN), and default network (DMN), compared with patients without FOG. At the node level, patients with FOG showed decreased nodal centralities in sensorimotor network (SMN), DAN, ventral attention network (VAN), FPN, limbic regions, hippocampal network and basal ganglia network (BG), and increased nodal centralities in the FPN, DMN, visual network (VIN) and, cerebellar network. The nodal centralities of the right inferior frontal sulcus, left lateral amygdala and left nucleus accumbens (NAC) were negatively correlated with the FOG severity. CONCLUSION: This study identified a disrupted topology of functional interactions at both low and high levels with extensive alterations in topological properties in MSA patients with FOG, especially those associated with damage to the FPN. These findings offer new insights into the dysfunctional mechanisms of complex networks and suggest potential neuroimaging biomarkers for FOG in patients with MSA.

Combined diagnosis for Parkinson's disease via gait and eye movement disorders.

BACKGROUND AND OBJECTIVES: With the discovery of the potential role of gait and eye movement disorders in Parkinson's disease (PD) recognition, we intend to investigate the combined diagnostic value of gait and eye movement disorders for PD. METHODS: We enrolled some Chinese PD patients and healthy controls and separated them into the training and validation sets based on enrollment time. Performance in five oculomotor paradigms and in one gait paradigm was examined using an infrared eye tracking device and a wearable gait analysis device. We developed and validated a combined model for PD diagnosis via multivariate stepwise logistic regression analysis. Furthermore, subgroup comparisons and multi-model comparison were performed to assess its applicability and advantages. RESULTS: A total of 145 PD patients and 80 healthy controls in China were recruited. The pro-saccade velocity, the trunk-sway max, and the turn mean angular velocity were finally screened out for the model development. Incorporating age factor, the ternary model demonstrated more satisfactory performance on ROC (AUC of 0.953 in the training set and AUC of 0.972 in the validation set), calibration curve, and decision curve. A nomogram was drawn to visualize the model. The combined model outperforms individual models with a broad application and the unique diagnostic value for early detection of PD patients, especially TD-PD patients. CONCLUSION: We demonstrated the presence of gait and eye movement disorders, as well as the feasibility, applicability, and superiority of employing them together to diagnose PD.

Predicting slight freezing of gait in Parkinson's disease with anticipatory postural adjustments and limits of stability.

INTRODUCTION: Gait initiation (GI) includes automatic and voluntary movements. However, research on their impact on the first step in patients with Parkinson's disease (PD) and their relationship to freezing of gait (FOG) is lacking. We examined the effects of automatic movements (anticipatory postural adjustments [APAs]) and voluntary movements (limits of stability [LOS]) on the first step (first-step duration and first-step range of motion), along with their early recognition and prediction of slight FOG. METHODS: Twenty-three patients with PD and slight freezing (PD + FOG) and 25 non-freezing patients with PD (PD-FOG) were tested while off medications and compared with 24 healthy controls (HC). All participants completed a 7-m Stand and Walk Test (7 m SAW) and wore inertial sensors to quantify the APAs and first step. LOS was quantified by dynamic posturography in different directions using a pressure platform. We compared differences among all three groups, analysed correlations, and evaluated their predictive value for slight FOG. RESULTS: In PD + FOG, APAs and LOS were worse than those in the PD-FOG and HC groups (p < 0.001), and the first step was worse than that in HC (p < 0.001). APAs were correlated mainly with the first-step duration. APAs and LOS were correlated with the first-step range of motion. APAs have been recognized as independent predictors of FOG, and their combination with LOS enhances predictive sensitivity. CONCLUSION: APAs and LOS in patients with PD directly affect the first step during GI. In addition, the combination of APAs and LOS helped predict slight FOG.

Predicting post-surgical outcomes in idiopathic normal pressure hydrocephalus using clinically important changes from the cerebrospinal fluid tap test.

OBJECTIVE: Patients diagnosed with idiopathic Normal Pressure Hydrocephalus (iNPH) typically experience symptom improvements after undergoing a cerebrospinal fluid-tap test (CSF-TT), These improvements are recognized as indicative of potential improvements following surgical intervention. As gait disturbance is the most common iNPH symptom, gait improvements are of predominant interest. The purpose of this study was to examine if clinically important changes in gait and balance from CSF-TT predict meaningful changes following surgery. METHOD: The study involved analysis of data collected in a prospective observational study for 34 iNPH patients who underwent a CSF-TT and subsequent surgery. Linear regression, logistic regression and classification trees were used for predictive modelling comparing changes from CSF-TT with post-surgical changes in Tinetti, Timed Up and Go (TUG) and Berg Balance Scale (BBS) outcomes. RESULTS: Predictive models for minimal clinically important differences (MCIDs) from CSF-TT to surgery were significant for Tinetti (odds ratio = 1.42, p = 0.02) and BBS (odds ratio = 1.57, p < 0.01). Four items on Tinetti and two items on BBS were identified with a predictive accuracy of 79% and 76% respectively. BBS has the highest sensitivity (85%) and negative predictive value (77%). TUG had a 100% specificity and 100% positive predictive value. The predictive model using MCIDs for TUG was not significant (odds ratio = 1.13, p = 0.06). CONCLUSION: Clinically important changes from CSF-TT are useful in predicting post-surgical outcomes in iNPH patients. Tinetti and BBS, both have predictive value using MCID scores as cut off values, of which BBS is a stronger outcome measure for prediction.

Accelerometer-based gait characteristics and their discrimination of gait independence in inpatients with subacute stroke.

BACKGROUND: Gait analysis using inertial measurement devices can identify multifaceted gait disorders after a stroke. Although the usefulness of gait assessment using inertial measurement devices has been reported, its accuracy in discriminating gait independence in patients hospitalized for subacute stroke has not yet been validated. RESEARCH QUESTION: Can trunk acceleration indices discriminate between dependent and independent walking in patients with subacute stroke? METHODS: Thirty-five patients with subacute stroke (mean ± standard deviation, 75.5 ± 9.8 years, 19 males), who were able to understand instructions, had a premorbid modified Rankin scale <3, and were able to walk 16 m straight ahead under supervision were included. The stride regularity, harmonic ratio, and normalized root mean square of trunk accelerations were measured in three directions (mediolateral, vertical, and anterioposterior) during comfortable walking. The Functional Ambulation Categories were used as the dependent variable to classify the patients into two groups (dependent and independent walking groups), and each trunk acceleration index was used as the independent variable to calculate the area under the curve using receiver operating characteristic curves. RESULTS: Twelve patients were in the dependent group and 23 were in the independent group. The normalized root mean square in both the mediolateral and vertical directions were excellent discriminators of walking independence, with an area under the curve greater than 0.8. The cutoff values (sensitivity/specificity) were 2.20 m2/s2 (0.783/0.833) and 2.82 m2/s2 (0.739/0.833), respectively. SIGNIFICANCE: The magnitude of vertical and lateral acceleration during gait in patients with subacute stroke, has excellent accuracy in discriminating between dependent and independent gaits. The results of this study will be useful for inexperienced clinicians working with stroke patients presenting with gait disturbances to accurately determine gait independence based on objective data.

Multi-segment foot kinematics during gait in children with spastic cerebral palsy.

BACKGROUND: Foot deformities (e.g. planovalgus and cavovarus) are very common in children with spastic cerebral palsy (CP), with the midfoot often being involved. Dynamic foot function can be assessed with 3D gait analysis including a multi-segment foot model. Incorporating a midfoot segment in such a model, allows quantification of separate Chopart and Lisfranc joint kinematics. Yet, midfoot kinematics have not previously been reported in CP. RESEARCH QUESTIONS: What is the difference in multi-segment kinematics including midfoot joints between common foot deformities in CP and typically-developing feet? METHODS: 103 feet of 57 children with spastic CP and related conditions were retrospectively included and compared with 15 typically-developing children. All children underwent clinical gait analysis with the Amsterdam Foot Model marker set. Multi-segment foot kinematics were calculated for three strides per foot and averaged. A k-means cluster analysis was performed to identify foot deformity groups that were present within CP data. The deformity type represented by each cluster was based on the foot posture index. Kinematic output of the clusters was compared to typically-developing data for a static standing trial and for the range of motion and kinematic waveforms during walking, using regular and SPM independent t-tests respectively. RESULTS: A neutral, planovalgus and varus cluster were identified. Neutral feet showed mostly similar kinematics as typically-developing data. Planovalgus feet showed increased ankle valgus and Chopart dorsiflexion, eversion and abduction. Varus feet showed increased ankle varus and Chopart inversion and adduction. SIGNIFICANCE: This study is the first to describe Chopart and Lisfranc joint kinematics in different foot deformities of children with CP. It shows that adding a midfoot segment can provide additional clinical and kinematic information. It highlights joint angles that are more distinctive between deformities, which could be helpful to optimize the use of multi-segment foot kinematics in the clinical decision making process.

Machine learning applied to gait analysis data in cerebral palsy and stroke: A systematic review.

BACKGROUND: Among neurological pathologies, cerebral palsy and stroke are the main contributors to walking disorders. Machine learning methods have been proposed in the recent literature to analyze gait data from these patients. However, machine learning methods still fail to translate effectively into clinical applications. This systematic review addressed the gaps hindering the use of machine learning data analysis in the clinical assessment of cerebral palsy and stroke patients. RESEARCH QUESTION: What are the main challenges in transferring proposed machine learning methods to clinical applications? METHODS: PubMed, Web of Science, Scopus, and IEEE databases were searched for relevant publications on machine learning methods applied to gait analysis data from stroke and cerebral palsy patients until February the 23rd, 2023. Information related to the suitability, feasibility, and reliability of the proposed methods for their effective translation to clinical use was extracted, and quality was assessed based on a set of predefined questions. RESULTS: From 4120 resulting references, 63 met the inclusion criteria. Thirty-one studies used supervised, and 32 used unsupervised machine learning methods. Artificial neural networks and k-means clustering were the most used methods in each category. The lack of rationale for features and algorithm selection, the use of unrepresentative datasets, and the lack of clinical interpretability of the clustering outputs were the main factors hindering the clinical reliability and applicability of these methods. SIGNIFICANCE: The literature offers numerous machine learning methods for clustering gait data from cerebral palsy and stroke patients. However, the clinical significance of the proposed methods is still lacking, limiting their translation to real-world applications. The design of future studies must take into account clinical question, dataset significance, feature and model selection, and interpretability of the results, given their criticality for clinical translation.

Is dynamic motor control clinically important for identifying gait deviations in individuals with cerebral palsy?

INTRODUCTION: Individuals with cerebral palsy (CP) often present with altered motor control. This can be assessed selectively during sitting/lying with the Selective Control Assessment of the Lower Extremity (SCALE), or dynamically with the dynamic motor control index during walking (walk-DMC). Both approaches suggest that altered selective motor control relate to larger gait deviations. RESEARCH QUESTION: Does the walk-DMC provide valuable information in addition to the SCALE for estimating gait deviations in individuals with CP. METHODS: Retrospective, treadmill-based gait analysis data of 157 children with spastic CP (mean 11.4±3.5 years) and Gross Motor Function Classification System levels I (n=45), II (n=88) or III (n=24) were extracted. Gait kinematic deviations were evaluated using the Gait Profile Score (GPS). The SCALE, walk-DMC and GPS were extracted for the more clinically involved leg (unilateral-analysis), and for both legs together (bilateral-analysis). RESULTS: GPS moderately correlated with both SCALE and walk-DMC scores, unilaterally and bilaterally (r≥0.4; p<0.001). Multivariate linear regression analyses were conducted, taking into account potential confounding factors. In the unilateral analysis, 54% of the GPS variance was explained (p<0.001), with both walk-DMC and SCALE significantly contributing to the GPS variance (p=0.006 and p=0.008, respectively). In the bilateral analysis, 61% of the GPS variance was explained (p<0.001), with both walk-DMC and SCALE significantly contributing to the GPS variance (p=0.006 and p<0.001, respectively). Dimensionless walking speed and use of assistive devices were the only confounding factors included in each analysis. SIGNIFICANCE: Both SCALE and walk-DMC significantly contribute to GPS variance, suggesting that they likely measure different components of motor control, and both may be useful in understanding the underlying relationship between motor control and deviations in gait kinematics.

Information processing speed and disease severity predict real-world ambulation in persons with multiple sclerosis.

BACKGROUND: Impairments in real-world gait quality and quantity are multifaceted for individuals with multiple sclerosis (MS), encompassing mobility, cognition, and fear of falling. However, these factors are often examined independently, limiting insights into the combined contributions they make to real-world ambulation. RESEARCH QUESTION: How do mobility, cognition, and fear of falling contribute to real-world gait quality and quantity in individuals with MS? METHODS: Twenty individuals with MS underwent a series of cognitive assessments, including the Paced Auditory Serial Addition Test (PASAT), Symbol Digits Modalities Test (SDMT), Stroop Test, and the Selective Reminding Test (SRT). Participants also completed the Falls Efficacy Scale - International (FES-I) and walking impairment using the Patient Determined Disease Steps (PDDS). Following the in-lab session, participants wore an inertial sensor on their lower back and asked to go about their typical daily routines for three days. Metrics of gait speed, stride regularity, time spent walking, and total bouts were extracted from the real-world data. RESULTS: Significant correlations were found between both real-world gait speed and stride regularity and the SDMT, FES-I, and PDDS. Backward linear regression analysis was conducted for gait speed and stride regularity, with PDDS and SDMT included in the final model for both metrics. These variables explained 63% of the variance in gait speed and 69% of the variance in stride regularity. Results were not significant for gait quantity after adjusting for age and sex. SIGNIFICANCE: The study's results provide insight regarding the roles of cognition, walking impairment, and fear of falling on real-world ambulation. Deeper understanding of these contributions can inform the development of targeted interventions that aim to improve walking. Additionally, the absence of significant correlations between gait metrics, cognition, and fear of falling with gait quantity underscores the need for further research to identify factors that increased walking in this population.

The impact of anxiety on gait impairments in Parkinson's disease: insights from sensor-based gait analysis.

BACKGROUND: Sensor-based gait analysis provides a robust quantitative tool for assessing gait impairments and their associated factors in Parkinson's disease (PD). Anxiety is observed to interfere with gait clinically, but this has been poorly investigated. Our purpose is to utilize gait analysis to uncover the effect of anxiety on gait in patients with PD. METHODS: We enrolled 38 and 106 PD patients with and without anxiety, respectively. Gait parameters were quantitively examined and compared between two groups both in single-task (ST) and dual-task (DT) walking tests. Multiple linear regression was applied to evaluate whether anxiety independently contributed to gait impairments. RESULTS: During ST, PD patients with anxiety presented significantly shorter stride length, lower gait velocity, longer stride time and stance time, longer stance phase, smaller toe-off (TO) and heel-strike (HS) angles than those without anxiety. While under DT status, the differences were diminished. Multiple linear regression analysis demonstrated that anxiety was an independent factor to a serials of gait parameters, particularly ST-TO (B = -2.599, (-4.82, -0.38)), ST-HS (B = -2.532, (-4.71, -0.35)), ST-TO-CV (B = 4.627, (1.71, 7.64)), ST-HS-CV(B = 4.597, (1.66, 7.53)), ST stance phase (B = 1.4, (0.22, 2.58)), and DT stance phase (B = 1.749, (0.56, 2.94)). CONCLUSION: Our study discovered that anxiety has a significant impact on gait impairments in PD patients, especially exacerbating shuffling steps and prolonging stance phase. These findings highlight the importance of addressing anxiety in PD precision therapy to achieve better treatment outcomes.

Effects of a 12-week telehealth exercise intervention on gait speed and gait deviations in adults with Down syndrome.

BACKGROUND: Altered gait patterns and reduced walking speed are commonly reported in adults with Down syndrome (DS). Research on the effects of DS-specific exercise programmes on adults with DS is lacking. The purpose of this quasi-experimental study was to evaluate the changes in gait deviations and walking speed in adults with DS after a DS-specific exercise programme. METHODS: Twenty participants underwent a 12-week, DS-specific exercise programme in a telehealth format. Before and after the intervention, gait deviations were assessed with the Ranchos Los Amigos Observational Gait Analysis form, and comfortable walking speed was evaluated with the 4-m walk test. RESULTS: We observed increased comfortable walking speed and reduced gait deviations in the whole gait cycle in adults with DS after the intervention. There were fewer gait deviations during single-leg stance and swing-limb advancement and at the hip, knee and ankle joints after the 12-week exercise programme. CONCLUSIONS: Gait speed and observable gait impairments in adults with DS significantly improved following a 12-week telehealth exercise programme.

Botulinum neurotoxin type A responders among children with spastic cerebral palsy: Pattern-specific effects.

AIM: To identify short-term effects of botulinum neurotoxin type A (BoNT) injections on gait and clinical impairments, in children with spastic cerebral palsy (CP), based on baseline gait pattern-specific subgroups. METHOD: Short-term effects of BoNT injections in the medial hamstrings and gastrocnemius were defined in a retrospective convenience sample of 117 children with CP (median age: 6 years 4 months; GMFCS I/II/III: 70/31/16; unilateral/bilateral: 56/61) who had received gait analyses before and 2 months post-BoNT. First, baseline gait patterns were classified. Statistical and meaningful changes were calculated between pre- and post-BoNT lower limb sagittal plane kinematic waveforms, the gait profile score, and non-dimensional spatiotemporal parameters for the entire sample and for pattern-specific subgroups. These gait waveforms per CP subgroup at pre- and post-BoNT were also compared to typically developing gait and composite scores for spasticity, weakness, and selectivity were compared between the two conditions. RESULTS: Kinematic improvements post-BoNT were identified at the ankle and knee for the entire sample, and for subgroups with apparent equinus and jump gait. Limbs with baseline patterns of dropfoot and to a lesser extent true equinus showed clear improvements only at the ankle. In apparent equinus, jump gait, and dropfoot, spasticity improved post-BoNT, without leading to increased weakness or diminished selectivity. Compared to typical gait, knee and hip motion improved in the crouch gait subgroup post-BoNT. CONCLUSION: This comprehensive analysis highlighted the importance of investigating BoNT effects on gait and clinical impairments according to baseline gait patterns. These findings may help identify good treatment responders.

Prefrontal Cortex Activity During Gait in People With Persistent Symptoms After Concussion.

BACKGROUND: Concussions result in transient symptoms stemming from a cortical metabolic energy crisis. Though this metabolic energy crisis typically resolves in a month, symptoms can persist for years. The symptomatic period is associated with gait dysfunction, the cortical underpinnings of which are poorly understood. Quantifying prefrontal cortex (PFC) activity during gait may provide insight into post-concussion gait dysfunction. The purpose of this study was to explore the effects of persisting concussion symptoms on PFC activity during gait. We hypothesized that adults with persisting concussion symptoms would have greater PFC activity during gait than controls. Within the concussed group, we hypothesized that worse symptoms would relate to increased PFC activity during gait, and that increased PFC activity would relate to worse gait characteristics. METHODS: The Neurobehavior Symptom Inventory (NSI) characterized concussion symptoms. Functional near-infrared spectroscopy quantified PFC activity (relative concentration changes of oxygenated hemoglobin [HbO2]) in 14 people with a concussion and 25 controls. Gait was assessed using six inertial sensors in the concussion group. RESULTS: Average NSI total score was 26.4 (13.2). HbO2 was significantly higher (P = .007) for the concussed group (0.058 [0.108]) compared to the control group (-0.016 [0.057]). Within the concussion group, HbO2 correlated with NSI total symptom score (ρ = .62; P = .02), sagittal range of motion (r = .79; P = .001), and stride time variability (r = -.54; P = .046). CONCLUSION: These data suggest PFC activity relates to symptom severity and some gait characteristics in people with persistent concussion symptoms. Identifying the neurophysiological underpinnings to gait deficits post-concussion expands our knowledge of motor behavior deficits in people with persistent concussion symptoms.

Structural connectivity of low-frequency subthalamic stimulation for improving stride length in Parkinson's disease.

BACKGROUND: A reduction in stride length is considered a key characteristic of gait kinematics in Parkinson's disease (PD) and has been identified as a predictor of falls. Although low-frequency stimulation (LFS) has been suggested as a method to improve gait characteristics, the underlying structural network is not well understood. OBJECTIVE: This study aims to investigate the structural correlates of changes in stride length during LFS (85 Hz). METHODS: Objective gait performance was retrospectively evaluated in 19 PD patients who underwent deep brain stimulation (DBS) at 85 Hz and 130 Hz. Individual DBS contacts and volumes of activated tissue (VAT) were computed using preoperative magnetic resonance imaging (MRI) and postoperative computed tomography (CT) scans. Structural connectivity profiles to predetermined cortical and mesencephalic areas were estimated using a normative connectome. RESULTS: LFS led to a significant improvement in stride length compared to 130 Hz stimulation. The intersection between VAT and the associative subregion of the subthalamic nucleus (STN) was associated with an improvement in stride length and had structural connections to the supplementary motor area, prefrontal cortex, and pedunculopontine nucleus. Conversely, we found that a lack of improvement was linked to stimulation volumes connected to cortico-diencephalic fibers bypassing the STN dorsolaterally. The robustness of the connectivity model was verified through leave-one-patient-out, 5-, and 10-fold cross cross-validation paradigms. CONCLUSION: These findings offer new insights into the structural connectivity that underlies gait changes following LFS. Targeting the non-motor subregion of the STN with LFS on an individual level may present a potential therapeutic approach for PD patients with gait disorders.