Gait Impairment Research Articles

Spinocerebellar ataxia type 7: A case report

Introduction: Spinocerebellar ataxia type 7 is part of a rare group of neurodegenerative diseases, characterized by lesions in the brainstem, cerebellum, spinal cord, and retina, manifesting as motor disturbances associated with signs of pyramidal involvement and amaurosis. The dysfunction is caused by autosomal dominant genetic alterations, with disease severity and the age of symptom onset being directly linked to the patient’s genetic expression. Case Report: We present the case of a 24-year-old woman, previously healthy, who denied smoking, drinking alcohol, or taking any other drugs. She reported that approximately nine months, she had experienced a decline in dexterity for tasks requiring fine motor skills. She also exhibited impaired gait, frequent falls, and difficulties in performing basic activities of daily living (ADLs). On neurological examination, she presented with an ataxic and staggering gait, tremor during movement, dysmetria, dysdiadochokinesia, movement decomposition, dysarthria (scanning speech), dysphagia, dystasia, dysbasia, and nystagmus, all of which are indicative of cerebellar impairment. A genetic panel revealed the presence of 44 cytosine-adenine-guanine nucleotide repeat expansions on allele 2 of the ATXN7 gene, confirming the diagnosis of spinocerebellar ataxia type 7. Conclusion: In this case report, the diagnosis of spinocerebellar ataxia was established through a comprehensive assessment of the patient’s clinical history, neurological examination, imaging studies, and genetic profiling, all of which are essential for reaching a definitive diagnosis. The prognosis for this disease varies due to ongoing research into its pathophysiology. Furthermore, discussions within the scientific community regarding potential cures for this condition continue

Clinical, Radiological and Pathological Features of a Large American Cohort of Spinocerebellar Ataxia (SCA27B).

Spinocerebellar ataxia 27B due to GAA repeat expansions in the fibroblast growth factor 14 (FGF14) gene has recently been recognized as a common cause of late-onset hereditary cerebellar ataxia. Here we present the first report of this disease in the US population, characterizing its clinical manifestations, disease progression, pathological abnormalities, and response to 4-aminopyridine in a cohort of 102 patients bearing GAA repeat expansions. We compiled a series of patients with SCA27B, recruited from 5 academic centers across the United States. Clinical manifestations and patient demographics were collected retrospectively from clinical records in an unblinded approach using a standardized form. Post-mortem analysis was done on 4 brains of patients with genetically confirmed SCA27B. In our cohort of 102 patients with SCA27B, we found that SCA27B was a late-onset (57 ± 12.5 years) slowly progressive ataxia with an episodic component in 51% of patients. Balance and gait impairment were almost always present at disease onset. The principal finding on post-mortem examination of 4 brain specimens was loss of Purkinje neurons that was most severe in the vermis most particularly in the anterior vermis. Similar to European populations, a high percent of patients 21/28 (75%) reported a positive treatment response with 4-aminopyridine. Our study further estimates prevalence and further expands the clinical, imaging and pathological features of SCA27B, while looking at treatment response, disease progression, and survival in patients with this disease. Testing for SCA27B should be considered in all undiagnosed ataxia patients, especially those with episodic onset. ANN NEUROL 2024.

The association between peripheral neuropathy and daily-life gait quality characteristics in people with diabetes

BackgroundPeripheral neuropathy is a common complication of diabetes and increases the risk of falls, possibly through gait (quality) impairments in daily life. Characteristics of gait quality have been associated with peripheral neuropathy in a laboratory setting, but little is known about the more relevant association with gait quality in daily life. Research questionWhat is the association between peripheral neuropathy and gait quality characteristics in daily life in people with diabetes? MethodsData from two cross-sectional studies were combined in an exploratory analysis, including a total of 98 participants with diabetes (mean age: 68 (SD 7) years, 32 females), of which 68 with peripheral neuropathy. Participants wore a tri-axial accelerometer for seven consecutive days. Walking episodes ≥5 seconds were identified and analysed to determine various gait quality characteristics. Associations were assessed using linear regression analyses, adjusted for walking speed and other potential confounders. ResultsPeripheral neuropathy was significantly associated with a lower walking speed (people with neuropathy: 0.81 vs without neuropathy: 0.88 m/s; β (95 % confidence interval (CI)): −0.114 (−0.202 to −0.026)), a lower stride frequency (0.81 vs 0.85 strides/s; β (95 % CI): −0.030 (−0.057 to −0.003)), lower gait intensity (i.e. lower root mean square) in vertical direction (1.38 vs 1.63 m/s2; β (95 % CI): −0.074 (−0.143 to −0.006)), and less gait symmetry (i.e. lower harmonic ratio) in vertical direction (1.82 vs 2.27; β (95 % CI): −0.322 (−0.474 to −0.170)). People with peripheral neuropathy had non-significantly poorer gait quality for most of the other 21 gait quality characteristics. SignificancePeripheral neuropathy seems to negatively affect several gait quality characteristics measured in daily life. These results need to be replicated in future studies and may help to develop targeted gait training to improve gait quality and potentially reduce fall risk in people with diabetes and peripheral neuropathy.

Slow Gait Speed Predicts Incident Dementia, Mortality, and Long-Term Functional Outcome in Cerebral Small-Vessel Disease.

Gait impairment is observed in patients with small vessel disease (SVD); however, the association between gait function and long-term outcome remains unclear. This study aimed to clarify the predictive value of gait function on incident dementia, survival and functional outcome. Data were derived from a Japanese cohort of patients with SVD. This study included 522 participants who underwent 3-m timed up and go test (TUG), and gait speed, TUG time, was divided into tertiles. Magnetic resonance imaging was used to evaluate severity of white matter hyperintensities, lacunes, and medial temporal atrophy. Primary outcome was dementia. All-cause death and functional outcome by modified Rankin scale at the last visit was also evaluated. The median age was 71 years, and median TUG time was 9.91 s. During follow-up period of 4.8 years, 32 cases of dementia occurred. Cox proportional hazard analysis revealed that slow gait speed (TUG time > 10.88 s) was associated with a significantly higher risk of incident dementia than fast (TUG time < 9.03) and middle (TUG time, 9.04-10.87 s) speeds after adjusting risk factors, Mini-Mental State Examination, SVD severity and brain atrophy (adjusted hazard ratio, 2.73; 95% confidence interval, 1.16-6.42, p = 0.022). Slow speed was also associated with mortality and poor functional outcome compared with other speeds (adjusted odds ratio, 4.19; 95% confidence interval 1.92-9.18, p < 0.001). Gait function was associated with incident dementia, mortality and poor functional outcome independently of cognitive function, brain atrophy, and SVD severity.

A confounding pediatric spinal cord injury: Anterior, central, or both?

Pediatric spinal cord injury (SCI) most commonly affects the cervical region. Central cord syndrome most often occurs in the lower cervical injury due to hyperextension injury, while anterior cord syndrome is primarily due to vascular infarction after hyperextension injury. An unusual case of a pediatric patient who physically presented with central cord syndrome but radiologically had evidence of anterior spinal artery syndrome is described. A two-year-old male presented after a fall from three feet with flaccid upper extremities and dysesthesias but maintained functional strength in bilateral lower extremities. Although his clinical presentation was that of central cord syndrome, he was found to have an anterior spinal artery infarct spanning from C2-T3 with a ligamentous injury at C3 and an incidental finding of Chiari I malformation on MRI. Given the negative evaluation for a cardiac or hematologic source of embolus and normal angiography, it was theorized that compression of vertebral arteries by previously undiagnosed Chiari I malformation in the setting of trauma could have made the patient more vulnerable to this complication. During inpatient rehabilitation, he regained scapular movement and shoulder flexion. However, he regained distal movement in supination, wrist extension, and finger flexion instead of the more usual proximal-to-distal motor recovery observed in SCI. While he had a relative sparing of strength in his legs, he had impaired proprioception and balance, leading to gait impairment. This case highlights the complexity of pediatric cervical SCI diagnosis and prognostication. While classic SCI subtypes are well described, many pediatric and adult patients will present and recover in unexpected ways. All with SCI should be evaluated thoroughly for common etiologies and transitioned to rehabilitation therapies to assist in recovery.

Abnormal Vestibulo-Ocular Reflex Function Correlates with Balance and Gait Impairment in People with Multiple Sclerosis.

Multiple Sclerosis (MS) is the most prevalent autoimmune neurological condition in the world, leading to a wide variety of symptoms, including balance disorders. To evaluate the angular vestibulo-ocular reflex (aVOR) of all six semicircular canals (SCCs) through Head Impulse (HIMP) and Suppression HIMP (SHIMP) paradigms and any correlations with clinical balance scales. All participants were assessed using the Expanded Disability Status Scale (EDSS), Berg Balance Scale (BBS), and Mini-BESTest (MBT). Vestibular function was measured by video Head Impulse Test (vHIT), obtaining aVOR gain for each SSC. Twenty-seven PwMS (mean age 47.93 ± 8.51 years old, 18 females) were recruited. Most of the patients (81.48%) presented abnormal aVOR gains for at least one SSC. A moderate to strong correlation between aVOR gains of the left anterior SSC and, respectively, the MBT and the BBS was found. The subgroup analysis, based on the EDSS class, confirmed the correlation with the BBS in the patients with the most significant disability. People with MS may present impairments of the aVOR in one or more semicircular canals. The aVOR gain impairment of the vertical semicircular canals correlates with balance and gait disorders identified through clinical scales in PwMS.

Effect of a soft exosuit on daily life gait performance in people with incomplete spinal cord injury: study protocol for a randomized controlled trial

BackgroundPeople with incomplete spinal cord injury (iSCI) often have gait impairments that negatively affect daily life gait performance (i.e., ambulation in the home and community setting) and quality of life. They may benefit from light-weight lower extremity exosuits that assist in walking, such as the Myosuit (MyoSwiss AG, Zurich, Switzerland). A previous pilot study showed that participants with various gait disorders increased their gait speed with the Myosuit in a standardized environment. However, the effect of a soft exosuit on daily life gait performance in people with iSCI has not yet been evaluated.ObjectiveThe primary study objective is to test the effect of a soft exosuit (Myosuit) on daily life gait performance in people with iSCI. Second, the effect of Myosuit use on gait capacity and the usability of the Myosuit in the home and community setting will be investigated. Finally, short-term impact on both costs and effects will be evaluated.MethodsThis is a two-armed, open label, randomized controlled trial (RCT). Participants will be randomized (1:1) to the intervention group (receiving the Myosuit program) or control group (initially receiving the conventional program). Thirty-four people with chronic iSCI will be included. The Myosuit program consists of five gait training sessions with the Myosuit at the Sint Maartenskliniek. Thereafter, participants will have access to the Myosuit for home use during 6 weeks. The conventional program consists of four gait training sessions, followed by a 6-week home period. After completing the conventional program, participants in the control group will subsequently receive the Myosuit program. The primary outcome is walking time per day as assessed with an activity monitor at baseline and during the first, third, and sixth week of the home periods. Secondary outcomes are gait capacity (10MWT, 6MWT, and SCI-FAP), usability (D-SUS and D-QUEST questionnaires), and costs and effects (EQ-5D-5L).DiscussionThis is the first RCT to investigate the effect of the Myosuit on daily life gait performance in people with iSCI.Trial registrationClinicaltrials.gov NCT05605912. Registered on November 2, 2022.

Integrating digital gait data with metabolomics and clinical data to predict outcomes in Parkinson’s disease

Parkinson’s disease (PD) presents diverse symptoms and comorbidities, complicating its diagnosis and management. The primary objective of this cross-sectional, monocentric study was to assess digital gait sensor data’s utility for monitoring and diagnosis of motor and gait impairment in PD. As a secondary objective, for the more challenging tasks of detecting comorbidities, non-motor outcomes, and disease progression subgroups, we evaluated for the first time the integration of digital markers with metabolomics and clinical data. Using shoe-attached digital sensors, we collected gait measurements from 162 patients and 129 controls in a single visit. Machine learning models showed significant diagnostic power, with AUC scores of 83–92% for PD vs. control and up to 75% for motor severity classification. Integrating gait data with metabolomics and clinical data improved predictions for challenging-to-detect comorbidities such as hallucinations. Overall, this approach using digital biomarkers and multimodal data integration can assist in objective disease monitoring, diagnosis, and comorbidity detection.

Self-supervised learning of wrist-worn daily living accelerometer data improves the automated detection of gait in older adults

Progressive gait impairment is common among aging adults. Remote phenotyping of gait during daily living has the potential to quantify gait alterations and evaluate the effects of interventions that may prevent disability in the aging population. Here, we developed ElderNet, a self-supervised learning model for gait detection from wrist-worn accelerometer data. Validation involved two diverse cohorts, including over 1000 participants without gait labels, as well as 83 participants with labeled data: older adults with Parkinson's disease, proximal femoral fracture, chronic obstructive pulmonary disease, congestive heart failure, and healthy adults. ElderNet presented high accuracy (96.43 ± 2.27), specificity (98.87 ± 2.15), recall (82.32 ± 11.37), precision (86.69 ± 17.61), and F1 score (82.92 ± 13.39). The suggested method yielded superior performance compared to two state-of-the-art gait detection algorithms, with improved accuracy and F1 score (p < 0.05). In an initial evaluation of construct validity, ElderNet identified differences in estimated daily walking durations across cohorts with different clinical characteristics, such as mobility disability (p < 0.001) and parkinsonism (p < 0.001). The proposed self-supervised method has the potential to serve as a valuable tool for remote phenotyping of gait function during daily living in aging adults, even among those with gait impairments.

IP3T: an interpretable multimodal time-series model for enhanced gait phase prediction in wearable exoskeletons.

Wearable exoskeletons assist individuals with mobility impairments, enhancing their gait and quality of life. This study presents the iP3T model, designed to optimize gait phase prediction through the fusion of multimodal time-series data. The iP3T model integrates data from stretch sensors, inertial measurement units (IMUs), and surface electromyography (sEMG) to capture comprehensive biomechanical and neuromuscular signals. The model's architecture leverages transformer-based attention mechanisms to prioritize crucial data points. A series of experiments were conducted on a treadmill with five participants to validate the model's performance. The iP3T model consistently outperformed traditional single-modality approaches. In the post-stance phase, the model achieved an RMSE of 1.073 and an R2 of 0.985. The integration of multimodal data enhanced prediction accuracy and reduced metabolic cost during assisted treadmill walking. The study highlights the critical role of each sensor type in providing a holistic understanding of the gait cycle. The attention mechanisms within the iP3T model contribute to its interpretability, allowing for effective optimization of sensor configurations and ultimately improving mobility and quality of life for individuals with gait impairments.

Assessing gait dysfunction severity in Parkinson’s Disease using 2-Stream Spatial-Temporal Neural Network

Parkinson’s Disease (PD), a neurodegenerative disorder, significantly impacts the quality of life for millions of people worldwide. PD primarily impacts dopaminergic neurons in the brain’s substantia nigra, resulting in dopamine deficiency and gait impairments such as bradykinesia and rigidity. Currently, several well-established tools, such as the Movement Disorder Society-Unified Parkinson’s Disease Rating Scale (MDS-UPDRS) and Hoehn and Yahr (H&Y) Scale, are used for evaluating gait dysfunction in PD. While insightful, these methods are subjective, time-consuming, and often ineffective in early-stage diagnosis. Other methods using specialized sensors and equipment to measure movement disorders are cumbersome and expensive, limiting their accessibility. This study introduces a hierarchical approach to evaluating gait dysfunction in PD through videos. The novel 2-Stream Spatial-Temporal Neural Network (2S-STNN) leverages the spatial–temporal features from the skeleton and silhouette streams for PD classification. This approach achieves an accuracy rate of 89% and outperforms other state-of-the-art models. The study also employs saliency values to highlight critical body regions that significantly influence model decisions and are severely affected by the disease. For a more detailed analysis, the study investigates 21 specific gait attributes for a more nuanced quantification of gait disorders. Parameters such as walking pace, step length, and neck forward angle are found to be strongly correlated with PD gait severity categories. This approach offers a comprehensive and convenient solution for PD management in clinical settings, enabling patients to receive a more precise evaluation and monitoring of their gait impairments.

An observational study of the impact of professional walking aid prescription on gait parameters for individuals with suspected balance impairments

BackgroundThe primary management strategy for gait impairment is the adoption of a walking aid. However, there are no established criteria upon which to base a decision regarding the need for a walking aid. It appears clinicians prescribe aids based on preference, clinical experience and intuition rather than standardised objective rationale. This may contribute to the inconsistent gait response to walking aids reported in the published literature. Understanding gait changes resulting from gait aid usage may have significant impact on clinical practice by improving confidence of prescribing clinicians and compliance of walking aid usage by patients, maximising the benefits of use, and reducing any risks associated with non-use or inappropriate use, of the walking aid. Research questionDo professionally prescribed walking aids improve gait parameters? MethodsThis is a secondary data analysis of a cross-sectional study where participants, identified by healthcare staff requiring a mobility assessment due to potential balance impairment of any cause, walked a 20-m straight walking course under three different walking conditions (no aid, walking stick and 4-wheeled walker). Fifty-eight participants were recruited. Commonly reported spatial and temporal gait parameters were assessed using a validated gait analysis device. Changes in gait parameters across the three conditions were compared, noting the individual's professionally prescribed aid and interpreting changes in parameters towards outcomes of the ‘no aid required group’. Results and significanceGait cycle, cadence, stance, swing and stride length during unaided walking were significantly changed when a walking stick was prescribed (p < 0.05). Stance, swing, double support, stride length, speed, max toe clearance and minimum toe clearance were significantly changed when a 4-wheel walker was prescribed (p < 0.05). Professional walking aid prescription improves some gait parameters. A greater number and magnitude of gait parameter improvements were seen in people requiring a 4-wheel walker than people requiring a walking stick.

The effect of ankle-foot orthoses on gait characteristics in people with Charcot-Marie-Tooth disease: A systematic review and meta-analysis.

Ankle-foot orthoses (AFOs) are commonly prescribed for people with Charcot-Marie-Tooth disease (CMT) to improve gait efficiency and reduce the occurrence of tripping and falls. The aim of this study was to systematically review evidence on the effects of AFOs on gait kinematics and kinetics and postural stability/balance in people with CMT. Studies were identified from electronic databases and screened for inclusion online using Rayyan. Data from all eligible studies were extracted into a standardised Excel spreadsheet. Methodological quality was assessed using the Joanna Briggs Institute Critical Appraisal Checklists. Where available, continuous outcomes were pooled to estimate standardised mean differences in random-effects meta-analyses. A total of 15 studies were included with variable methodological quality. Sample sizes ranged from 1 to 32 with significant variability in participant characteristics, AFO designs and testing procedures. Data from eight studies were available for meta-analysis. Although AFOs impacted walking velocity, stride length, step length, cadence, ankle dorsiflexion, plantarflexion, knee and hip flexion and ankle plantarflexion and dorsiflexion moments, the effect sizes were small-to-moderate and non-significant. There were insufficient data available for pooled analyses of outcomes related to postural stability/balance. Although AFOs positively affect a number of gait and balance parameters, the small participant numbers, variability in participant characteristics, AFO designs and testing procedures adopted by the available studies resulted in the absence of statistically significant effects when data were pooled. The results from this review also highlight the importance of device customisation based on the individual needs of people with CMT and their degree of gait impairment.

Multidisciplinary Delphi Panel on Rehabilitation Approaches and Unmet Needs for Chronic Stroke Walking Impairment and the Role of Rhythmic Auditory Stimulation.

Walking or gait impairment is a common consequence of stroke that persists into the chronic phase of recovery for many stroke survivors. The goals of this work were to obtain consensus from a multidisciplinary panel on current practice patterns and treatment options for walking impairment after stroke, to better understand the unmet needs for rehabilitation in the chronic phase of recovery and to explore opportunities to address them, and to discuss the potential role of rhythmic auditory stimulation (RAS) in gait rehabilitation. A panel of eight experts specializing in neurology, physical therapy, and physiatry participated in this three-part, modified Delphi study. Survey 1 focused on gathering information to develop statements that were discussed and polled during Survey 2 (interactive session), after which revised and new statements were polled in Survey 3. Consensus was defined as ≥75% (6/8 of panelists) agreement or disagreement with a statement. Consensus agreement was ultimately reached on all 24 statements created and polled during this process. The panelists agreed that individuals with gait or walking impairment in the chronic phase of stroke recovery can achieve meaningful improvement in walking by utilizing various evidence-based interventions. Barriers to treatment included cost, access, participation in long-term treatment, and safety. Consensus was achieved for interventions that have the following features challenging, personalized, accessible, and engaging. Improvement of gait speed and quality, durability of effect, safety, affordability, and ability for home or community use also emerged as important treatment features. In addition to conventional treatments (e.g., physical therapy, including mobility-task training and walking/exercise therapy), RAS was recognized as a potentially valuable treatment modality. Discussion: This panel highlighted limitations of current treatments and opportunities to improve access, participation, and outcomes through a consideration of newer treatment strategies and patient/healthcare provider education and engagement.

Functional impairments in NBIA patients: Preliminary results.

Neurodegeneration with brain iron accumulation (NBIA) is a heterogeneous group (genetically and phenotypically) of genetically determined disorders. Up to date there is no cure for this disease, so the applied treatments focus on symptoms control and palliative care. The main problems are delayed motor development, gait deterioration, postural instability, cognitive dysfunctions, abnormal muscle tone and many others. As gait and balance deficits are predominant features of NBIA patients this study aimed at the use of the objective, instrumented functional tests as well as functional assessment scales to assess their functional impairments. Twenty three NBIA patients recruited for the study underwent objective, instrumented gait analysis, balance assessment, pedobarography and functional evaluation with Gross Motor Function Measure (GMFM-88). The results showed high variability and heterogeneity of NBIA functional status (GMFM from 27.5 to 100.0), but also showed some differences in gait pattern between their types (p < 0.05 at the pelvis, hip and knee). We think that these results could help design objective assessment protocols in future clinical studies.

Dynamic balance and gait impairments in Parkinson's disease: novel cholinergic patterns.

The cholinergic system has been implicated in postural deficits, in particular falls, in Parkinson's disease (PD). Falls and freezing of gait typically occur during dynamic and challenging balance and gait conditions, such as when initiating gait, experiencing postural perturbations, or making turns. However, the precise cholinergic neural substrate underlying dynamic postural and gait changes remains poorly understood. The aim of this study was to investigate whether brain vesicular acetylcholine transporter binding, as measured with [18F]-fluoroethoxybenzovesamicol binding PET, correlates with dynamic gait and balance impairments in 125 patients with PD (mean age 66.89 ± 7.71 years) using the abbreviated balance evaluation systems test total and its four functional domain sub-scores (anticipatory postural control, reactive postural control, dynamic gait, and sensory integration). Whole brain false discovery-corrected (P < 0.05) correlations for total abbreviated balance evaluation systems test scores included the following bilateral or asymmetric hemispheric regions: gyrus rectus, orbitofrontal cortex, anterior part of the dorsomedial prefrontal cortex, dorsolateral prefrontal cortex, cingulum, frontotemporal opercula, insula, fimbria, right temporal pole, mesiotemporal, parietal and visual cortices, caudate nucleus, lateral and medial geniculate bodies, thalamus, lingual gyrus, cerebellar hemisphere lobule VI, left cerebellar crus I, superior cerebellar peduncles, flocculus, and nodulus. No significant correlations were found for the putamen or anteroventral putamen. The four domain-specific sub-scores demonstrated overlapping cholinergic topography in the metathalamus, fimbria, thalamus proper, and prefrontal cortices but also showed distinct topographic variations. For example, reactive postural control functions involved the right flocculus but not the upper brainstem regions. The anterior cingulum associated with reactive postural control whereas the posterior cingulum correlated with anticipatory control. The spatial extent of associated cholinergic system changes were least for dynamic gait and sensory orientation functional domains compared to the anticipatory and reactive postural control functions. We conclude that specific aspects of dynamic balance and gait deficits in PD associate with overlapping but also distinct patterns of cerebral cholinergic system changes in numerous brain regions. Our study also presents novel evidence of cholinergic topography involved in dynamic balance and gait in PD that have not been typically associated with mobility disturbances, such as the right anterior temporal pole, right anterior part of the dorsomedial prefrontal cortex, gyrus rectus, fimbria, lingual gyrus, flocculus, nodulus, and right cerebellar hemisphere lobules VI and left crus I.

Cortical networks of parkinsonian gait: a metabolic and functional connectivity study.

Locomotion is an automated voluntary movement sustained by coordinated neural synchronization across a distributed brain network. The cerebral cortex is central for adapting the locomotion pattern to the environment and alterations of cortical network dynamics can lead to gait impairments. Gait problems are a common symptom with a still unclear pathophysiology and represent an unmet therapeutical need in Parkinson's disease. Little is known about the cortical network dynamics of locomotor control in these patients. We studied the cortical basis of parkinsonian gait by combining metabolic brain imaging with high-density EEG recordings and kinematic measurements performed at rest and during unperturbed overground walking. We found significant changes in functional connectivity between frontal, sensorimotor, and visuomotor cortical areas during walking as compared to resting. Specifically, hypokinetic gait was associated with poor information flow from the supplementary motor area (SMA) to precuneus and from calcarine to lingual gyrus, as well as high information flow from calcarine to cuneus. Our findings support a role for visuomotor integration processes in PD-related hypokinetic gait and suggest that reinforcing visual information may act as a compensatory strategy to allow SMA-mediated feedforward locomotor control in PD.

Pain hypersensitivity, sensorimotor impairment, and decreased muscle force in a novel rat model of radiation-induced peripheral neuropathy.

Radiation-induced peripheral neuropathy is a rare, but serious complication often resulting in profound morbidity, life-long disability, and chronic debilitating pain. Unfortunately, this type of peripheral neuropathy is usually progressive, and almost always irreversible. To date, a standardized rat model of radiation-induced peripheral neuropathy has not been established. The purpose of the present study was to examine neuropathic pain, sensorimotor impairment, and muscle force parameters following the administration of a clinically relevant radiation dose in a rat model. Ten rats were randomly assigned to one of two experimental groups: (1) radiation and (2) sham-radiated controls. Radiated animals were given a clinically relevant dose of 35 Gray (Gy) divided into five daily doses of 7 Gy/day. This regimen represents a human equivalent dose of 70 Gy, approximating the same dosage utilized for radiotherapy in oncologic patients. Sham-radiated controls were anesthetized and placed in the radiation apparatus but were not given radiation. All animals were tested for baseline values in both sensorimotor and pain behavioral tests. Sensorimotor testing consisted of the evaluation of walking tracks with the calculation of the Sciatic Functional Index (SFI). Pain-related behavioral measures consisted of mechanical allodynia (von Frey test), cold allodynia (Acetone test), and thermal allodynia (Hargreaves test). Animals were tested serially over an 8-week period. At the study endpoint, electrophysiological and muscle force assessments were completed, and histomorphometric analysis was performed on all sciatic nerves. Animals that underwent radiation treatment displayed significantly greater pain hypersensitivity to mechanical stimulation as compared to sham radiated controls from weeks 4 to 8 of testing. SFI values indicated sensorimotor impairments in the overground gait of radiated animals as compared to non-radiated animals. Furthermore, radiated animals displayed reduced twitch and tetanic muscle force when compared to sham radiated controls. A clinically relevant human equivalent dose of fractionated 35 Gy in rats established significant pain hypersensitivity, impairments in sensorimotor locomotion, and decreased muscle force capacity. This novel rodent model of radiation-induced peripheral neuropathy can be utilized to assess the potential efficacy of therapeutic treatments to either prevent or remediate this clinically debilitating condition.

MP-Gait: Fine-grained Parkinson's Disease Gait Impairment Assessment with Robust Feature Analysis

Patients with Parkinson's disease (PD) often show gait impairments including shuffling gait, festination, and lack of arm and leg coordination. Quantitative gait analysis can provide valuable insights for PD diagnosis and monitoring. Prior work has utilized 3D motion capture, foot pressure sensors, IMUs, etc. to assess the severity of gait impairment in PD patients These sensors, despite their high precision, are often expensive and cumbersome to wear which makes them not the best option for long-term monitoring and naturalistic deployment settings. In this paper, we introduce mP-Gait, a millimeter-wave (mmWave) radar-based system designed to detect the gait features in PD patients and predict the severity of their gait impairment. Leveraging the high frequency and wide bandwidth of mmWave radar signals, mP-Gait is able to capture high-resolution reflected signals from different body parts during walking. We develop a pipeline to detect walking, extract gait features using signal analysis methods, and predict patients' UPDRS-III gait scores with a machine learning model. As gait features from PD patients with gait impairment are correctly and robustly extracted, mP-Gait is able to observe the fine-grained gait impairment severity fluctuation caused by medication response. To evaluate mP-Gait, we collected gait features from 144 participants (with UPDRS-III gait scores between 0 and 2) containing over 4000 gait cycles. Our results show that mP-Gait can achieve a mean absolute error of 0.379 points in predicting UPDRS-III gait scores.

Associations between white and grey matter damage and gait impairment in cerebral amyloid angiopathy

BackgroundCerebral amyloid angiopathy (CAA) is associated with white matter damage and neurodegeneration. Gait is impaired in CAA; however, the neural basis of this impairment is unclear. Research questionAre gait impairments in patients with CAA associated with altered cerebral white matter diffusivity and/or atrophy of cortical and subcortical grey matter. MethodsParticipants with CAA (n=29), Alzheimer’s disease (AD; n=16), and normal controls (n=47) were included. Gait was assessed using a 6 m walkway with parameters categorized into rhythm, pace, postural control, and variability domains. The dual-task cost (DTC) of gait speed was calculated for counting backwards, animal fluency, and serial sevens tasks. Whole-brain white matter disruption was quantified using the peak width of skeletonized mean diffusivity (PSMD), and thickness and volume of select cortical, subcortical, and cerebellar regions were quantified using FreeSurfer. ResultsIn CAA participants, associations were found between PSMD and pace (standardized parameter estimate (β), 95 % confidence interval (CI): 0.17, 0.03–0.32), and medial orbital frontal cortical thickness and counting backwards DTC (parameter estimate (PE), 95 % CI: −5.7 %/SD, −0.24 to −11.23). Across all groups, including CAA, associations were found between PSMD and pace, variability, counting backwards DTC, and animal fluency DTC; between frontal cortical thickness and pace, counting backwards DTC, and animal fluency DTC; between cortical regions affected by AD (inferior parietal cortex, inferior and middle temporal gyrus) and counting backwards DTC; and between thalamus volume and postural control. SignificanceReduced white matter structural integrity and grey matter loss is associated with poor overall gait performance in CAA, AD, and normal controls.