Stride width and postural stability in frontal gait disorders and Parkinson's disease.

Older adults, as well as those with certain neurological disorders, may compensate for poor neural control of postural stability by widening their base of foot support while walking. However, the extent to which this wide-based gait improves postural stability or affects postural control strategies has not been explored. People with idiopathic Parkinson's disease (iPD, n = 72), frontal gait disorders (FGD, n = 16), and healthy older adults (n = 32) performed walking trials at their preferred speed over an 8-m-long, instrumented walkway.

Motor networks, but also non-motor networks predict motor signs in Parkinson's disease.

Objective: Investigate the brain functional networks associated with motor impairment in people with Parkinson's disease (PD).

Background: PD is primarily characterized by motor dysfunction. Resting-state functional connectivity (RsFC) offers a unique opportunity to non-invasively characterize brain function.

Digital measures of freezing of gait across the spectrum of normal, non-freezers, possible freezers and definite freezers.

Over the course of the disease, freezing of gait (FoG) will gradually impact over 80% of people with Parkinson's disease (PD). Clinical decision-making and research design are often based on classification of patients as 'freezers' or 'non-freezers'. We derived an objective measure of FoG severity from inertial sensors on the legs to examine the continuum of FoG from absent to possible and severe in people with PD and in healthy controls.

Gait and turning characteristics from daily life increase ability to predict future falls in people with Parkinson's disease.

Objectives: To investigate if digital measures of gait (walking and turning) collected passively over a week of daily activities in people with Parkinson's disease (PD) increases the discriminative ability to predict future falls compared to fall history alone.

Methods: We recruited 34 individuals with PD (17 with history of falls and 17 non-fallers), age: 68 ± 6 years, MDS-UPDRS III ON: 31 ± 9. Participants were classified as fallers (at least one fall) or non-fallers based on self-reported falls in past 6 months.

Effect of Levodopa and Environmental Setting on Gait and Turning Digital Markers Related to Falls in People with Parkinson's Disease.

Background: It is unknown whether medication status ( and levodopa) or laboratory versus home settings plays a role in discriminating fallers and non-fallers in people with Parkinson's disease (PD).

Objectives: To investigate which specific digital gait and turning measures, obtained with body-worn sensors, best discriminated fallers from non-fallers with PD in the clinic and during daily life.

Methods: We recruited 34 subjects with PD (17 fallers and 17 non-fallers based on the past 6 month's falls).

Exploring the effects of dopamine on sensorimotor inhibition and mobility in older adults.

Dopaminergic activity decreases in older adults (OAs) with normal aging and is further reduced in Parkinson's disease (PD), affecting cortical motor and sensorimotor pathways. Levodopa is the prevailing therapy to counter dopamine loss in PD, though not all PD motor signs improve with levodopa. The purpose of this preliminary study was to explore the effects of levodopa on sensorimotor inhibition, gait and quiet standing in OAs and to investigate the relationships between sensorimotor inhibition and both gait and standing balance both OFF- and ON-levodopa.

Does Cueing Need Attention? A Pilot Study in People with Parkinson's Disease.

We previously showed that both open-loop (beat of a metronome) and closed-loop (phase-dependent tactile feedback) cueing may be similarly effective in reducing Freezing of Gait (FoG), assessed with a quantitative FoG Index, while turning in place in the laboratory in a group of people with Parkinson's disease (PD). Despite the similar changes on the FoG Index, it is not known whether both cueing responses require attentional control, which would explain FoG Index improvement. The mechanisms underlying cueing responses are poorly understood.

Effects of a Cognitively Challenging Agility Boot Camp Program on Balance and Gait in People With Parkinson's Disease: Does Freezing of Gait Status Matter?

Background And Aim: Individuals with Parkinson's disease (PD) with and without freezing of Gait (FoG) may respond differently to exercise interventions for several reasons, including disease duration. This study aimed to determine whether both people with and without FoG benefit from the Agility Boot Camp with Cognitive Challenges (ABC-C) program.

Methods: This secondary analysis of our ABC-C trial included 86 PD subjects: 44 without FoG (PD-FoG) and 42 with FoG (PD + FoG).

Resting state functional networks predict different aspects of postural control in Parkinson's disease.

Background: Parkinson's disease (PD) is a neurodegenerative disorder causing postural control impairments. Postural control involves multiple domains, such as control of postural sway in stance, automatic postural responses (APRs) and anticipatory postural adjustments (APAs). We hypothesize that impairments in each postural domain is associated with resting-state functional connectivity (rsFC), accounted by predictive modeling and that cortical and cerebellar networks would predict postural control in people with PD (PwPD).

Discussion of Research Priorities for Gait Disorders in Parkinson's Disease.

Gait and balance abnormalities develop commonly in Parkinson's disease and are among the motor symptoms most disabling and refractory to dopaminergic or other treatments, including deep brain stimulation. Efforts to develop effective therapies are challenged by limited understanding of these complex disorders. There is a major need for novel and appropriately targeted research to expedite progress in this area.

Relationship Between Brain Volumes and Objective Balance and Gait Measures in Parkinson's Disease.

Background: Instrumented measures of balance and gait measure more specific balance and gait impairments than clinical rating scales. No prior studies have used objective balance/gait measures to examine associations with ventricular and brain volumes in people with Parkinson's disease (PD).

Objective: To test the hypothesis that larger ventricular and smaller cortical and subcortical volumes are associated with impaired balance and gait in people with PD.

Functional limits of stability and standing balance in people with Parkinson's disease with and without freezing of gait using wearable sensors.

Background: People with from Parkinson's disease (PD) and freezing of gait (FoG) have more frequent falls compared to those who do not freeze but there is no consensus on which, specific objective measures of postural instability are worse in freezers (PD + FoG) than non-freezers (PD-FoG).

Research Question: Are functional limits of stability (fLoS) or postural sway during stance measured with wearable inertial sensors different between PD + FoG versus PD-FoG, as well as between PD versus healthy control subjects (HC)?

Methods: Sixty-four PD subjects with FoG (MDS-UPDRS Part III: 45.9 ± 12.

Changes in prefrontal cortical activity and turning in response to dopaminergic and cholinergic therapy in Parkinson's disease: A randomized cross-over trial.

Introduction: Cholinergic dysfunction contributes to mobility deficits in Parkinson's disease (PD). People with PD rely on limited prefrontal executive-attentional resources for the control of locomotion, including turning. Cortical and behavioral responses to cholinergic augmentation during turning remains unclear.

Measuring freezing of gait during daily-life: an open-source, wearable sensors approach.

Background: Although a growing number of studies focus on the measurement and detection of freezing of gait (FoG) in laboratory settings, only a few studies have attempted to measure FoG during daily life with body-worn sensors. Here, we presented a novel algorithm to detect FoG in a group of people with Parkinson's disease (PD) in the laboratory (Study I) and extended the algorithm in a second cohort of people with PD at home during daily life (Study II).

Methods: In Study I, we described of our novel FoG detection algorithm based on five inertial sensors attached to the feet, shins and lumbar region while walking in 40 participants with PD.

Dual-Task Costs of Quantitative Gait Parameters While Walking and Turning in People with Parkinson's Disease: Beyond Gait Speed.

Background: There is a lack of recommendations for selecting the most appropriate gait measures of Parkinson's disease (PD)-specific dual-task costs to use in clinical practice and research.

Objective: We aimed to identify measures of dual-task costs of gait and turning that best discriminate performance in people with PD from healthy individuals. We also investigated the relationship between the most discriminative measures of dual-task costs of gait and turning with disease severity and disease duration.

Effects of the agility boot camp with cognitive challenge (ABC-C) exercise program for Parkinson's disease.

Few exercise interventions practice both gait and balance tasks with cognitive tasks to improve functional mobility in people with PD. We aimed to investigate whether the Agility Boot Camp with Cognitive Challenge (ABC-C), that simultaneously targets both mobility and cognitive function, improves dynamic balance and dual-task gait in individuals with Parkinson's disease (PD). We used a cross-over, single-blind, randomized controlled trial to determine efficacy of the exercise intervention.

Relating Response Inhibition, Brain Connectivity, and Freezing of Gait in People with Parkinson's Disease.

Objective: Freezing of gait (FoG) in Parkinson's disease (PD) has been associated with response inhibition. However, the relationship between response inhibition, neural dysfunction, and PD remains unclear. We assessed response inhibition and microstructural integrity of brain regions involved in response inhibition [right hemisphere inferior frontal cortex (IFC), bilateral pre-supplementary motor areas (preSMA), and subthalamic nuclei (STN)] in PD subjects with and without FoG and elderly controls.

Laboratory versus daily life gait characteristics in patients with multiple sclerosis, Parkinson's disease, and matched controls.

Background And Purpose: Recent findings suggest that a gait assessment at a discrete moment in a clinic or laboratory setting may not reflect functional, everyday mobility. As a step towards better understanding gait during daily life in neurological populations, we compared gait measures that best discriminated people with multiple sclerosis (MS) and people with Parkinson's Disease (PD) from their respective, age-matched, healthy control subjects (MS-Ctl, PD-Ctl) in laboratory tests versus a week of daily life monitoring.

Methods: We recruited 15 people with MS (age mean ± SD: 49 ± 10 years), 16 MS-Ctl (45 ± 11 years), 16 people with idiopathic PD (71 ± 5 years), and 15 PD-Ctl (69 ± 7 years).

Inertial Sensor Algorithms to Characterize Turning in Neurological Patients With Turn Hesitations.

Background: One difficulty in turning algorithm design for inertial sensors is detecting two discrete turns in the same direction, close in time. A second difficulty is under-estimation of turn angle due to short-duration hesitations by people with neurological disorders. We aimed to validate and determine the generalizability of a: I.

Responsiveness of Objective vs. Clinical Balance Domain Outcomes for Exercise Intervention in Parkinson's Disease.

Balance deficits in people with Parkinson's disease (PD) are often not helped by pharmacological or surgical treatment. Although balance exercise intervention has been shown to improve clinical measures of balance, the efficacy of exercise on different, objective balance domains is still unknown. To compare the sensitivity to change in objective and clinical measures of several different domains of balance and gait following an Agility Boot Camp with Cognitive Challenges (ABC-C) intervention.

Effect of Bout Length on Gait Measures in People with and without Parkinson's Disease during Daily Life.

Although the use of wearable technology to characterize gait disorders in daily life is increasing, there is no consensus on which specific gait bout length should be used to characterize gait. Clinical trialists using daily life gait quality as study outcomes need to understand how gait bout length affects the sensitivity and specificity of measures to discriminate pathological gait as well as the reliability of gait measures across gait bout lengths. We investigated whether Parkinson's disease (PD) affects how gait characteristics change as bout length changes, and how gait bout length affects the reliability and discriminative ability of gait measures to identify gait impairments in people with PD compared to neurotypical Old Adults (OA).

Cortical thickness as predictor of response to exercise in people with Parkinson's disease.

We previously showed that dual-task cost (DTC) on gait speed in people with Parkinson's disease (PD) improved after 6 weeks of the Agility Boot Camp with Cognitive Challenge (ABC-C) exercise program. Since deficits in dual-task gait speed are associated with freezing of gait and gray matter atrophy, here we performed preplanned secondary analyses to answer two questions: (a) Do people with PD who are freezers present similar improvements compared to nonfreezers in DTC on gait speed with ABC-C? (b) Can cortical thickness at baseline predict responsiveness to the ABC-C? The DTC from 39 freezers and 43 nonfreezers who completed 6 weeks of ABC-C were analyzed. A subset of 51 participants (21 freezers and 30 nonfreezers) with high quality imaging data were used to characterize relationships between baseline cortical thickness and delta (Δ) DTC on gait speed following ABC-C.