Worldviews and environmental ethics: Contributions of brain processing networks.

Research suggests that worldviews define our relationship to the environment, including our responsibility to the environment and our planet. This paper examines two specific worldviews and their potential environmental impact: the materialist worldview, considered to be the dominant worldview of Western society, and the so-called post-materialist worldview. We believe that changing the worldview of both individuals and society is key to changing environmental ethics, specifically attitudes, beliefs, and actions towards the environment. Recent neuroscience research suggests that brain filters and networks contribute to concealing an expanded nonlocal awareness. This creates self-referential thinking and contributes to the limited conceptual framework characteristic of a materialist worldview. We discuss the underlying concepts of both materialist and post-materialist worldviews including their impact on environmental ethics, then explore the various types of neural filters and processing networks that contribute to a materialist worldview, and finally explore methods for modifying neural filters and changing worldviews.

Spiritual awakening and transformation in scientists and academics.

The purpose of this study was to document both quantitatively and qualitatively the characteristics of spiritual awakenings and their transformational effects in scientists and academics who reported having experienced this phenomenon; it also aimed to explore barriers these individuals perceived to sharing their experiences with others within society. METHODS: An interview questionnaire was used to collect detailed descriptions of both the physical and metaphysical experiences of 54 scientists and academics having had a spiritually transformative experience (STE) (e.g., spontaneous energetic awakenings, awakenings occurring through near-death experiences (NDEs), and through spiritual practices). RESULTS AND CONCLUSIONS: Participants reported the STE as a mystical experience involving feelings of expansion (including conscious awareness leaving the body), energy rising up the spine, a sense of being enveloped in light, love or part of a unified energetic field. Principle triggers for these experiences included concentrating on spiritual matters, the presence of a spiritually developed person, and intense meditation or prayer. Transformational changes in participants included increased sensory sensitivity, creativity, and changes in beliefs, including a desire to serve others, a sense of unity with all, and the immortality of the spirit. Effects on career ranged from incorporating their new worldview and spiritual insights into the way they interacted with others within their current career, to radically changing their career to focus on questions related to the fundamental nature of consciousness or to serve others from this new perspective. Among barriers to sharing experiences, participants noted their concern that they would be misunderstood or ridiculed by others.

Reflections on extraordinary knowing: Insight into the nature of the mind.

Scientists have spent considerable time and effort studying and mapping the geography of the brain, with the expectation that this understanding will lead to insights related to the nature of the mind. This article discusses evidence that, while the mind utilizes sensory information processed by the brain, awareness is not limited to these structures. Research studies give evidence supporting the mind's ability to expand awareness to include perception of objects and events not available to the five senses. This awareness also extends to moments in the future, including the mind's ability to access information seconds or even days in advance of the occurrence. A major brain filter that limits this capacity for expanded awareness is the Default Mode Network (DMN). We summarize research showing that when the DMN activity is reduced, e.g., through meditation, ingestion of neuromodulatory drugs, or NDEs, filtering within the brain is reduced, there is a concomitant development of new connectivity, and these neural changes are correlated with access to expanded awareness.

Examining the relationship between medical diagnoses and patterns of performance on the modified Dynamic Gait Index.

BACKGROUND: In the original and modified Dynamic Gait Index (mDGI), 8 tasks are used to measure mobility; however, disagreement exists regarding whether all tasks are necessary. The relationship between mDGI scores and Centers for Medicare & Medicaid Services (CMS) severity indicators in the mobility domain has not been explored. OBJECTIVE: The study objectives were to examine the relationship between medical diagnoses and mDGI scores, to determine whether administration of the mDGI can be shortened on the basis of expected diagnostic patterns of performance, and to create a model in which mDGI scores are mapped to CMS severity modifiers. DESIGN: This was a cross-sectional, descriptive study. METHODS: The 794 participants included 140 people without impairments (control cohort) and 239 people with stroke, 140 with vestibular dysfunction, 100 with traumatic brain injury, 91 with gait abnormality, and 84 with Parkinson disease. Scores on the mDGI (total, performance facet, and task) for the control cohort were compared with those for the 5 diagnostic groups by use of an analysis of variance. For mapping mDGI scores to 7 CMS impairment categories, an underlying Rasch scale was used to convert raw scores to an interval scale. RESULTS: There was a main effect of mDGI total, time, and gait pattern scores for the groups. Task-specific score patterns based on medical diagnosis were found, but the range of performance within each group was large. A framework for mapping mDGI total, performance facet, and task scores to 7 CMS impairment categories on the basis of Rasch analysis was created. LIMITATIONS: Limitations included uneven sample sizes in the 6 groups. CONCLUSIONS: Results supported retaining all 8 tasks for the assessment of mobility function in older people and people with neurologic conditions. Mapping mDGI scores to CMS severity indicators should assist clinicians in interpreting mobility performance, including changes in function over time.

Investigating the validity of the environmental framework underlying the original and modified Dynamic Gait Index.

BACKGROUND: The modified Dynamic Gait Index (mDGI), developed from a person-environment model of mobility disability, measures mobility function relative to specific environmental demands. The framework for interpreting mDGI scores relative to specific environmental dimensions has not been investigated. OBJECTIVE: The aim of this study was to examine the person-environmental model underlying the development and interpretation of mDGI scores. DESIGN: This was a cross-sectional, descriptive study. METHODS: There were 794 participants in the study, including 140 controls. Out of the total study population, 239 had sustained a stroke, 140 had vestibular dysfunction, 100 had sustained a traumatic brain injury, 91 had gait abnormality, and 84 had Parkinson disease. Exploratory factor analysis was used to investigate whether mDGI scores supported the 4 environmental dimensions. RESULTS: Factor analysis showed that, with some exceptions, tasks loaded on 4 underlying factors, partially supporting the underlying environmental model. LIMITATIONS: Limitations of this study included the uneven sample sizes in the 6 groups. CONCLUSIONS: Support for the environmental framework underlying the mDGI extends its usefulness as a clinical measure of functional mobility by providing a rationale for interpretation of scores that can be used to direct treatment and infer change in mobility function.

Evidence for the validity of the modified dynamic gait index across diagnostic groups.

BACKGROUND: The modified Dynamic Gait Index (mDGI) measures the capacity to adapt gait to complex tasks utilizing 8 tasks and 3 facets of performance. The measurement stability of the mDGI in specific diagnostic groups is unknown. OBJECTIVE: This study examined the psychometric properties of the mDGI in 5 diagnostic groups. DESIGN: This was a cross-sectional, descriptive study. METHODS: A total of 794 participants were included in the study: 140 controls, 239 with stroke, 140 with vestibular dysfunction, 100 with traumatic brain injury, 91 with gait abnormality, and 84 with Parkinson disease. Differential item functioning analysis was used to examine the comparability of scores across diagnoses. Internal consistency was computed using Cronbach alpha. Factor analysis was used to examine the factor loadings for the 3 performance facet scores. Minimal detectable change at the 95% confidence level (MDC95%) was calculated for each of the groups. RESULTS: Less than 5% of comparisons demonstrated moderate to large differential item functioning, suggesting that item scores had the same order of difficulty for individuals in all 5 diagnostic groups. For all 5 patient groups, 3 factors had eigenvalues >1.0 and explained 80% of the variability in scores, supporting the importance of characterizing mobility performance with respect to time, level of assistance, and gait pattern. LIMITATIONS: There were uneven sample sizes in the 6 groups. CONCLUSIONS: The strength of the psychometric properties of the mDGI across the 5 diagnostic groups further supports the validity and usefulness of scores for clinical and research purposes. In addition, the meaning of a score from the mDGI, regardless of whether at the task, performance facet, or total score level, was comparable across the 5 diagnostic groups, suggesting that the mDGI measured mobility function independent of medical diagnosis.

The ability of people with Parkinson's disease to modify dual-task performance in response to instructions during simple and complex walking tasks.

Gait impairments are a common and consequential motor symptom in Parkinson's disease (PD). A cognitive strategy that incorporates instructions to concentrate on specific parameters of walking is an effective approach to gait rehabilitation for persons with PD during single-task and simple dual-task walking conditions. This study examined the ability to modify dual-task walking in response to instructions during a complex walking task in people with PD compared to healthy older adults (HOA). Eleven people with PD and twelve HOA performed a cognitive task while walking with either a usual base or a narrow base of support. Dual-task walking and cognitive task performance were characterized under two conditions-when participants were instructed focus on walking and when they were instructed to focus on the cognitive task. During both usual base and narrow base walking, instructions affected cognitive task response latency, with slower performance when instructed to focus on walking compared to the cognitive task. Regardless of task or instructions, cognitive task performance was slower in participants with PD compared to HOA. During usual base walking, instructions influenced gait speed for both people with PD and HOA, with faster gait speed when instructed to focus on walking compared to the cognitive task. In contrast, during the narrow base walking, instructions affected gait speed only for HOA, but not for people with PD. This suggests that among people with PD the ability to modify walking in response to instructions depends on the complexity of the walking task.

Expanding the scoring system for the Dynamic Gait Index.

BACKGROUND: The Dynamic Gait Index (DGI) measures the capacity to adapt gait to complex tasks. The current scoring system combining gait pattern (GP) and level of assistance (LOA) lacks clarity, and the test has a limited range of measurement. OBJECTIVE: This study developed a new scoring system based on 3 facets of performance (LOA, GP, and time) and examined the psychometric properties of the modified DGI (mDGI). DESIGN: A cross-sectional, descriptive study was conducted. METHODS: Nine hundred ninety-five participants (855 patients with neurologic pathology and mobility impairments [MI group] and 140 patients without neurological impairment [control group]) were tested. Interrater reliability was calculated using kappa coefficients. Internal consistency was computed using the Cronbach alpha coefficient. Factor analysis and Rasch analysis investigated unidimensionality and range of difficulty. Internal validity was determined by comparing groups using multiple t tests. Minimal detectable change (MDC) was calculated for total score and 3 facet scores using the reliability estimate for the alpha coefficients. RESULTS: Interrater agreement was strong, with kappa coefficients ranging from 90% to 98% for time scores, 59% to 88% for GP scores, and 84% to 100% for LOA scores. Test-retest correlations (r) for time, GP, and LOA were .91, .91, and .87, respectively. Three factors (time, LOA, GP) had eigenvalues greater than 1.3 and explained 79% of the variance in scores. All group differences were significant, with moderate to large effect sizes. The 95% minimal detectable change (MDC95) was 4 for the mDGI total score, 2 for the time and GP total scores, and 1 for the LOA total score. LIMITATIONS: The limitations included uneven sample sizes in the 2 groups. The MI group were patients receiving physical therapy; therefore, they may not be representative of this population. CONCLUSIONS: The mDGI, with its expanded scoring system, improves the range, discrimination, and facets of measurement related to walking function. The strength of the psychometric properties of the mDGI warrants its adoption for both clinical and research purposes.

Participation in community walking following stroke: the influence of self-perceived environmental barriers.

BACKGROUND: Community walking is limited among survivors of stroke; however, the contributing factors are not clearly understood. OBJECTIVE: This study examined the association of features in the environment with frequency of community walking following stroke. DESIGN: An observational study design was used, with frequency of community walking data collected prospectively. METHOD: Thirty survivors of stroke (mean age=67 years; mean months since stroke=40), and 30 older adults without stroke (mean age=68 years) participated. Frequency of community walking (number of trips, walking-related activities [WRA], and the ratio of WRA to trips) and satisfaction were measured using self-report. The Environmental Analysis of Mobility Questionnaire (EAMQ) was used to determine frequency of encounter with versus avoidance of environmental features during community walking. Negative binomial and linear regression models were used to analyze the association of environmental features with measures of community walking. RESULTS: Survivors of stroke reported reduced community walking and fewer encounters with and greater avoidance of features within 8 dimensions of the environment compared with a control group of adults without stroke. Following stroke, avoidance of features in some environmental dimensions was associated with frequency of community walking as measured by number of trips, number of WRA, and the ratio of WRA to trips. Environmental features explained little of the variability in community walking. LIMITATIONS: Limitations included a small sample size and limited diversity among participants. This study examined only physical features in the environment and did not include other environmental factors, such as social support, which may influence participation. CONCLUSIONS: Avoidance of features within some, but not all, environmental dimensions was associated with self-reported frequency of community walking following stroke, suggesting that some environmental features may limit community walking more than others.

Factors influencing dynamic prioritization during dual-task walking in healthy young adults.

Appropriate prioritization during dual-task walking is necessary to achieve task goals and maintain walking stability. We examined the effects of increased walking task difficulty on dual-task walking prioritization in healthy young adults. Walking under simple usual-base conditions was similar between equal-focus and cognitive-focus instructions, but these differed from walking-focus instructions, consistent with cognitive task prioritization. In contrast, narrow-base walking was similar between equal-focus and walking-focus instructions, but these differed from cognitive-focus instructions. This shift in prioritization with increasing walking task difficulty suggests that prioritization is dynamic and flexible.

The effects of instructions on dual-task walking and cognitive task performance in people with Parkinson's disease.

Gait impairments are prevalent among people with Parkinson's disease (PD). Instructions to focus on walking can improve walking in PD, but the use of such a cognitive strategy may be limited under dual-task walking conditions, when walking is performed simultaneously with concurrent cognitive or motor tasks. This study examined how dual-task performance of walking and a concurrent cognitive task was affected by instructions in people with PD compared to healthy young and older individuals. Dual-task walking and cognitive task performance was characterized under two sets of instructions as follows: (1) focus on walking and (2) focus on the cognitive task. People with PD and healthy adults walked faster when instructed to focus on walking. However, when focused on walking, people with PD and young adults demonstrated declines in the cognitive task. This suggests that dual-task performance is flexible and can be modified by instructions in people with PD, but walking improvements may come at a cost to cognitive task performance. The ability to modify dual-task performance in response to instructions or other task and environmental factors is critical to mobility in daily life. Future research should continue to examine factors that influence dual-task performance among people with PD.

Understanding falls in multiple sclerosis: association of mobility status, concerns about falling, and accumulated impairments.

BACKGROUND: Falls in people with multiple sclerosis (MS) are a serious health concern, and the percentage of people who restrict their activity because of concerns about falling (CAF) is not known. Mobility function and accumulated impairments are associated with fall risk in older adults but not in people with stroke and have not been studied in people with MS. OBJECTIVE: The purposes of this study were: (1) to estimate the percentage of people who have MS and report falling, CAF, and activity restrictions related to CAF; (2) to examine associations of these factors with fall status; and (3) to explore associations of fall status with mobility function and number of accumulated impairments. DESIGN: A cross-sectional survey was conducted. METHODS: A total of 575 community-dwelling people with MS provided information about sociodemographics, falls, CAF, activity restrictions related to CAF, mobility function, and accumulated impairments. Chi-square statistics were used to explore associations among these factors. RESULTS: In all participants, about 62% reported CAF and about 67% reported activity restrictions related to CAF. In participants who did not experience falls, 25.9% reported CAF and 27.7% reported activity restrictions related to CAF. Mobility function was associated with fall status; participants reporting moderate mobility restrictions reported the highest percentage of falls, and participants who were nonwalkers (ie, had severely limited self-mobility) reported the lowest percentage. Falls were associated with accumulated impairments; the participants who reported the highest percentage of 2 or more falls were those with 10 impairments. LIMITATIONS: This cross-sectional study relied on self-reported falls, mobility, and impairment status, which were not objectively verified. CONCLUSIONS: Both CAF and activity restrictions related to CAF were common in people with MS and were reported by people who experienced falls and those who did not. The association of fall status with mobility function did not appear to be linear. Fall risk increased with declining mobility function; however, at a certain threshold, further declines in mobility function were associated with fewer falls, possibly because of reduced fall risk exposure.

A review of dual-task walking deficits in people with Parkinson's disease: motor and cognitive contributions, mechanisms, and clinical implications.

Gait impairments in Parkinson's disease (PD) are exacerbated under dual-task conditions requiring the simultaneous performance of cognitive or motor tasks. Dual-task walking deficits impact functional mobility, which often requires walking while performing concurrent tasks such as talking or carrying an object. The consequences of gait impairments in PD are significant and include increased disability, increased fall risk, and reduced quality of life. However, effective therapeutic interventions for dual-task walking deficits are limited. The goals of this narrative review are to describe dual-task walking deficits in people with PD, to discuss motor and cognitive factors that may contribute to these deficits, to review potential mechanisms underlying dual-task deficits, and to discuss the effect of therapeutic interventions on dual-task walking deficits in persons with PD.

Participation in community walking following stroke: subjective versus objective measures and the impact of personal factors.

BACKGROUND: Mobility, specifically community walking, is important, but often limited among survivors of stroke. The factors that influence the recovery of community walking are not clearly understood. OBJECTIVE: The purpose of this research was to examine mobility disability following stroke, specifically: (1) the association between subjective and objective measures of participation in community walking and (2) the association between personal factors and participation in community walking. DESIGN: A cross-sectional study design was used. METHODS: Fifty community-dwelling survivors of stroke, aged 50 to 79 years, were enrolled in the study. Participation in community walking was measured subjectively (perceived difficulty and satisfaction) and objectively using self-report data (number of trips and walking-related activities) and step data (pedometer). The association between subjective and objective measures of participation was analyzed using Pearson correlation. The association of personal factors (age, sex, number of comorbidities, fatigue, depression, balance and fall self-efficacy, and importance of walking) with measures of participation was analyzed using multiple linear regression. RESULTS: Subjective and objective measures of participation were weakly associated. Self-efficacy was the only personal factor that was strongly associated with both subjective and objective measures of participation. Personal factors explained 27% to 55% of the variability in participation in community walking. LIMITATIONS: Limitations included a small sample size and limited diversity among participants. Reliability of the pedometer used in this study has not been established in the stroke population. CONCLUSIONS: Subjective and objective measures of participation in community walking were only weakly correlated, suggesting that they measure different aspects of mobility; thus, to fully capture participation, it is critical to measure both. Personal factors were associated with subjective and objective measures of participation and are important in explaining variability in community walking following stroke.

Falls in multiple sclerosis.

OBJECTIVE: To examine incidence, associated factors, and health care provider (HCP) response to falls in persons with multiple sclerosis (MS). DESIGN: Cross-sectional retrospective design. SETTING: Community setting. PARTICIPANTS: Four hundred seventy-four persons with MS. METHODS: Mailed survey questionnaire examined incidence, risk factors, and HCP response to falls in persons with MS who were dwelling in the community. Univariate and multiple ordinal regression analysis identified variables associated with single and multiple falls. MAIN OUTCOME MEASUREMENTS: Falls, causes and perceived reasons for falls, and HCP response. RESULTS: A total of 265 participants (58.2%) reported one or more falls in the previous 6 months, and 58.5% of falls were medically injurious. Trips/slips while walking accounted for 48% of falls. Factors associated with falls included use of a cane or walker (odds ratio [OR] 2.62; 95% confidence interval [CI] 1.66-4.14), income <$25,000 (OR 1.85; 95% CI 1.13-3.04), balance problems (OR 1.28; 95% CI 1.11-1.49), and leg weakness (OR 1.26; 95% CI 1.09-1.46). Fifty-one percent of those who fell (135/265) reported speaking to an HCP about their falls; recommended strategies included safety strategies (53.2%), use of gait assistive devices (42.1%), exercise/balance training (22.2%), and home modifications (16.6%). CONCLUSIONS: Factors associated with falls in persons with MS are similar to those in other populations with neurologic diseases. Despite the high incidence of falls, fewer than 50% of people with MS receive information about prevention of falls from an HCP.

Understanding physical factors associated with participation in community ambulation following stroke.

PURPOSE: This study examined the association between impaired physical function and participation in community ambulation following stroke. We hypothesised that participation would be significantly less following stroke, and that physical impairments would be associated with participation. METHOD: Using a case-control design 30 survivors of stroke aged 45 and older and 30 controls provided health status information and a self-report of participation in community ambulation (number of trips and walking-related activities (WRA) reported prospectively over a 12-day period). The association of physical impairments (strength, range of motion, sensation, muscle tone, vision, and activity limitations (gait speed and performance on complex walking tasks)) with level of participation was analysed using negative binomial regression and goodness of fit. RESULTS: Participants included 30 individuals with and 30 without stroke, average age 68 years, majority were Caucasian women. Average time since stroke was 40 months. Participation in survivors of stroke was characterised by fewer trips and WRA and lower satisfaction (p < 0.001). Usual gait speed, balance, muscle strength and muscle length were impaired (p < 0.001) in stroke vs. controls, and associated with number of trips and WRA (p < 0.05). However, these factors explained less than very little of the variance in participation. CONCLUSIONS: While individual factors were associated with level of participation, results failed to accurately predict participation in community ambulation following stroke. Other factors, such as depression, cognition and self-efficacy may be stronger determinants of participation.

A translational research evaluation of the Stay Active and Independent for Life (SAIL) community-based fall prevention exercise and education program.

Falls in older adults are the leading cause of injury hospitalizations and fatalities in the United States; primary risk factors are muscle weakness, impaired mobility, and balance deficits. This article describes the 12-month translational research evaluation of the Stay Active and Independent for Life (SAIL) community-based public health, public domain fall prevention exercise and education program. Recruitment reached the target goal by 154%; 331 adults (mean age = 74.6) attended more than one class (mean classes attended = 24.8, SD = 26.6, range = 1-120) at nine community sites in one county in the 12-month period; 173 completed health and demographic forms, 132 completed program surveys, and 91 completed baseline and follow-up physical function tests. Physical function test results showed significant improvements in strength, balance, and mobility in those who were below normal limits at baseline, and in those who attended classes twice a week or more for more than 2 months. Survey results found that 93% of respondents reported improved performance of daily activities; 92% reported improved strength, balance, fitness, or flexibility; and 80% found the SAIL information guide education component helpful.

Effects of instructed focus and task difficulty on concurrent walking and cognitive task performance in healthy young adults.

Dual task paradigms can be used to examine the interactions between cognition and the control of posture and gait. Measuring and interpreting changes in dual task performance is challenging, however, because many factors can influence performance. This study examined the effects of instructed focus and walking task difficulty, and the interaction between these factors, on dual task performance in healthy young adults. Fifteen participants performed a cognitive task while walking with either a usual base or a narrow base of support. Participants were instructed to focus on either the cognitive task or walking. Trade-offs both within and between tasks were assessed using the modified attention allocation index and the performance operating characteristic. Instructed focus influenced both the cognitive task and walking. Performance on the cognitive task was faster with instructions to focus on the cognitive task, and walking was faster (and more accurate in the narrow-base condition) with instructions to focus on walking. Walking task difficulty did not affect cognitive performance but did affect walking, with faster walking in the usual-base versus narrow-base condition. There was evidence of an interaction, with greater effects of instructed focus on the cognitive task during usual versus narrow-base walking. These results support the idea that the ability to flexibly shift attention allocation and task performance in response to instructions depends on the difficulty of the postural control task. The modified attention allocation index and the performance operating characteristic were instrumental in fully characterizing trade-offs between and within tasks in order to understand dual task performance changes. A clearer understanding of the factors that affect dual task walking and the interactions between these factors has important implications for the assessment of dual task performance in both clinical and research settings.

The effects of a home-based exercise program on physical function in frail older adults.

BACKGROUND AND PURPOSE: Exercise has been shown to improve physical function in frail older adults; however, the effects of exercise may vary with degree of frailty, the format and intensity of the exercise intervention, and level of supervision. This cohort study describes the effects of participation in a 6-week home-based exercise program on measures of physical function as well as exercise-related beliefs, including exercise self-efficacy and outcomes expectation, in frail older adults. METHODS: Participants were 72 frail older adults who participated in a 6-week home-based exercise program supervised by graduate physical therapy students. Individualized home-based exercises targeted strength, flexibility, balance, gait, and cardiovascular fitness. Physical function was measured at baseline and after completion of the 6-week exercise program using the Functional Fitness Test (Biceps Curl, Chair Stand, 8-Foot Up and Go) and velocity on a 4-m walk. Measures of exercise-related beliefs included the Self-Rated Abilities for Health Practices Scale and Exercise Outcome Expectations. OUTCOMES: Participation in the 6-week home-based exercise program was associated with improvements in measures of physical function, including an average increase of 3 repetitions (35%) on the biceps curl, 2.4 repetitions (59%) on the chair stand, and an average increase of 0.17 m/s (33%) in gait velocity. Average decrease in Timed Up and Go test scores was 5.7 seconds (26%). Scores for exercise-related beliefs also improved (self-efficacy average increase was 7 points [40%], and average increase in outcome expectations was 3 [47%]). DISCUSSION: A supervised 6-week, multidimensional home-based exercise program was safe and associated with improvements in physical and exercise-related belief outcome measures in this cohort study of frail older adults.

Assessing the effects of subthalamic nucleus stimulation on gait and mobility in people with Parkinson disease.

PURPOSE: To determine the effects of unilateral and bilateral subthalamic nucleus (STN) stimulation on gait and mobility in persons with Parkinson disease (PD). METHOD: We examined eight individuals with advanced PD who underwent staged stimulator implantation surgeries. Gait and mobility were assessed in the medication-on state with a variety of clinical and laboratory measures (Unified Parkinson Disease Rating Scale items, Timed Up and Go Test, gait speed) at three time points: prior to surgery, after the first surgery (unilateral stimulation) and after the second surgery (bilateral stimulation). RESULTS: Despite overall improvements in motor function and reduction of dyskinesia, there were no significant group effects of unilateral or bilateral stimulation on gait and mobility compared to pre-surgical function. However, there were clinically meaningful changes, both improvements and declines, at the individual level. CONCLUSIONS: Because of the consequences of gait deficits and mobility limitations for people with PD, future research should examine the effects of STN stimulation on gait in the medication-on state using sensitive and specific measures such as gait speed. Accurate assessment of gait changes is necessary to improve the evaluation of STN effects and the prediction of individuals in need of rehabilitation services to manage gait and mobility deficits.