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Parkinson Disease: HELP
Articles by Gammon M. Earhart
Based on 72 articles published since 2010
(Why 72 articles?)
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Between 2010 and 2020, G. M. Earhart wrote the following 72 articles about Parkinson Disease.
 
+ Citations + Abstracts
Pages: 1 · 2 · 3
1 Review Impacts of dance on non-motor symptoms, participation, and quality of life in Parkinson disease and healthy older adults. 2015

McNeely, M E / Duncan, R P / Earhart, G M. ·Program in Physical Therapy, Washington University in St. Louis School of Medicine, St. Louis, MO 63108, USA; Department of Neurology, Washington University in St. Louis School of Medicine, St. Louis, MO 63108, USA. Electronic address: mcneelym@wusm.wustl.edu. · Program in Physical Therapy, Washington University in St. Louis School of Medicine, St. Louis, MO 63108, USA; Department of Neurology, Washington University in St. Louis School of Medicine, St. Louis, MO 63108, USA. Electronic address: duncanr@wusm.wustl.edu. · Program in Physical Therapy, Washington University in St. Louis School of Medicine, St. Louis, MO 63108, USA; Department of Anatomy & Neurobiology, Washington University in St. Louis School of Medicine, St. Louis, MO 63108, USA; Department of Neurology, Washington University in St. Louis School of Medicine, St. Louis, MO 63108, USA. Electronic address: earhartg@wusm.wustl.edu. ·Maturitas · Pubmed #26318265.

ABSTRACT: Evidence indicates exercise is beneficial for motor and non-motor function in older adults and people with chronic diseases including Parkinson disease (PD). Dance may be a relevant form of exercise in PD and older adults due to social factors and accessibility. People with PD experience motor and non-motor symptoms, but treatments, interventions, and assessments often focus more on motor symptoms. Similar non-motor symptoms also occur in older adults. While it is well-known that dance may improve motor outcomes, it is less clear how dance affects non-motor symptoms. This review aims to describe the effects of dance interventions on non-motor symptoms in older adults and PD, highlights limitations of the literature, and identifies opportunities for future research. Overall, intervention parameters, study designs, and outcome measures differ widely, limiting comparisons across studies. Results are mixed in both populations, but evidence supports the potential for dance to improve mood, cognition, and quality of life in PD and healthy older adults. Participation and non-motor symptoms like sleep disturbances, pain, and fatigue have not been measured in older adults. Additional well-designed studies comparing dance and exercise interventions are needed to clarify the effects of dance on non-motor function and establish recommendations for these populations.

2 Review A comparison of dance interventions in people with Parkinson disease and older adults. 2015

McNeely, M E / Duncan, R P / Earhart, G M. ·Program in Physical Therapy, Washington University School of Medicine in St. Louis, St. Louis, MO 63108, USA; Department of Neurology, Washington University School of Medicine in St. Louis, St. Louis, MO 63108, USA. Electronic address: mcneelym@wusm.wustl.edu. · Program in Physical Therapy, Washington University School of Medicine in St. Louis, St. Louis, MO 63108, USA; Department of Neurology, Washington University School of Medicine in St. Louis, St. Louis, MO 63108, USA. · Program in Physical Therapy, Washington University School of Medicine in St. Louis, St. Louis, MO 63108, USA; Department of Anatomy & Neurobiology, Washington University School of Medicine in St. Louis, St. Louis, MO 63108, USA; Department of Neurology, Washington University School of Medicine in St. Louis, St. Louis, MO 63108, USA. ·Maturitas · Pubmed #25771040.

ABSTRACT: It is important for our aging population to remain active, particularly those with chronic diseases, like Parkinson disease (PD), which limit mobility. Recent studies in older adults and people with PD suggest dance interventions provide various motor benefits. The literature for dance in PD is growing, but many knowledge gaps remain, relative to what is known in older adults. The purpose of this review is to: (1) detail results of dance intervention studies in older adults and in PD, (2) describe limitations of dance research in these populations, and (3) identify directions for future study. Generally, a wide variety of dance styles have been investigated in older adults, while a more limited subset has been evaluated in PD. Measures vary widely across studies and a lack of standardized outcomes measures hinders cross-studies comparisons. Compared to the dance literature in older adults, there is a notable absence of evidence in the PD literature in outcome domains related to cardiovascular health, muscle strength, body composition, flexibility, and proprioception. As a whole, the dance literature supports substantial and wide-ranging benefits in both populations, but additional effort should be dedicated to well-designed comparative studies using standardized outcome measures to identify optimal treatment programs.

3 Review Dynamic control of posture across locomotor tasks. 2013

Earhart, Gammon M. ·Program in Physical Therapy, Washington University in St. Louis School of Medicine, St. Louis, Missouri; Department of Anatomy and Neurobiology, Washington University in St. Louis School of Medicine, St. Louis, Missouri; Department of Neurology, Washington University in St. Louis School of Medicine, St. Louis, Missouri. ·Mov Disord · Pubmed #24132838.

ABSTRACT: Successful locomotion depends on postural control to establish and maintain appropriate postural orientation of body segments relative to one another and to the environment and to ensure dynamic stability of the moving body. This article provides a framework for considering dynamic postural control, highlighting the importance of coordination, consistency, and challenges to postural control posed by various locomotor tasks, such as turning and backward walking. The impacts of aging and various movement disorders on postural control are discussed broadly in an effort to provide a general overview of the field and recommendations for assessment of dynamic postural control across different populations in both clinical and research settings. Suggestions for future research on dynamic postural control during locomotion also are provided and include discussion of opportunities afforded by new and developing technologies, the need for long-term monitoring of locomotor performance in everyday activities, gaps in our knowledge of how targeted intervention approaches modify dynamic postural control, and the relative paucity of literature regarding dynamic postural control in movement disorder populations other than Parkinson's disease.

4 Review Parkinson disease and exercise. 2013

Earhart, Gammon M / Falvo, Michael J. ·Program in Physical Therapy, Washington University School of Medicine, St. Louis, Missouri, USA. earhartg@wusm.wustl.edu ·Compr Physiol · Pubmed #23720332.

ABSTRACT: Parkinson disease (PD) is a progressive, neurodegenerative movement disorder. PD was originally attributed to neuronal loss within the substantia nigra pars compacta, and a concomitant loss of dopamine. PD is now thought to be a multisystem disorder that involves not only the dopaminergic system, but other neurotransmitter systems whose role may become more prominent as the disease progresses (189). PD is characterized by four cardinal symptoms, resting tremor, rigidity, bradykinesia, and postural instability, all of which are motor. However, PD also may include any combination of a myriad of nonmotor symptoms (195). Both motor and nonmotor symptoms may impact the ability of those with PD to participate in exercise and/or impact the effects of that exercise on those with PD. This article provides a comprehensive overview of PD, its symptoms and progression, and current treatments for PD. Among these treatments, exercise is currently at the forefront. People with PD retain the ability to participate in many forms of exercise and generally respond to exercise interventions similarly to age-matched subjects without PD. As such, exercise is currently an area receiving substantial research attention as investigators seek interventions that may modify the progression of the disease, perhaps through neuroprotective mechanisms.

5 Clinical Trial Effects of exercise on gait and motor imagery in people with Parkinson disease and freezing of gait. 2018

Myers, Peter S / McNeely, Marie E / Pickett, Kristen A / Duncan, Ryan P / Earhart, Gammon M. ·Program in Physical Therapy, Washington University in St. Louis School of Medicine, Campus Box 8502, 4444 Forest Park Blvd, Suite 11101, St. Louis, MO 63108, USA. Electronic address: petersmyers@wustl.edu. · Program in Physical Therapy, Washington University in St. Louis School of Medicine, Campus Box 8502, 4444 Forest Park Blvd, Suite 11101, St. Louis, MO 63108, USA; Department of Neurology, Washington University in St. Louis School of Medicine, Campus Box 8111, 660 S. Euclid, St. Louis, MO 63110, USA. Electronic address: mcneelym@wustl.edu. · Occupational Therapy Program, Department of Kinesiology, University of Wisconsin- Madison School of Education, Unit II Gym, 2000 Observatory Drive, Madison, WI 53706, USA. Electronic address: kristen.pickett@wisc.edu. · Program in Physical Therapy, Washington University in St. Louis School of Medicine, Campus Box 8502, 4444 Forest Park Blvd, Suite 11101, St. Louis, MO 63108, USA; Department of Neurology, Washington University in St. Louis School of Medicine, Campus Box 8111, 660 S. Euclid, St. Louis, MO 63110, USA. Electronic address: duncanr@wustl.edu. · Program in Physical Therapy, Washington University in St. Louis School of Medicine, Campus Box 8502, 4444 Forest Park Blvd, Suite 11101, St. Louis, MO 63108, USA; Department of Neurology, Washington University in St. Louis School of Medicine, Campus Box 8111, 660 S. Euclid, St. Louis, MO 63110, USA; Department of Neuroscience, Washington University in St. Louis School of Medicine, Campus Box 8108, 660 S. Euclid, St. Louis, MO 63110, USA. Electronic address: earhartg@wustl.edu. ·Parkinsonism Relat Disord · Pubmed #29754837.

ABSTRACT: INTRODUCTION: Exercise improves gait in Parkinson disease (PD), but whether exercise differentially affects people with PD with (freezers) and without freezing of gait (non-freezers) remains unclear. This study examines exercise's effects on gait performance, neural correlates related to these effects, and potential neural activation differences between freezers and non-freezers during motor imagery (MI) of gait. METHODS: Thirty-seven participants from a larger exercise intervention completed behavioral assessments and functional magnetic resonance imaging (fMRI) scans before and after a 12-week exercise intervention. Gait performance was characterized using gait velocity and stride length, and a region of interest (ROI) fMRI analysis examined task-based blood oxygen-level dependent (BOLD) signal changes of the somatomotor network (SMN) during MI of forward (IMG-FWD) and backward (IMG-BWD) gait. RESULTS: Velocity (F(1,34) = 55.04, p < 0.001) and stride length (F(1,34) = 77.58, p < 0.001) were significantly lower for backward versus forward walking in all participants. The ROI analysis showed freezers had lower BOLD signal compared to non-freezers in the cerebellum (F(1,32) = 7.01, p = 0.01), primary motor (left: F(1,32) = 7.09, p = 0.01; right: F(1,32) = 7.45, p = 0.01), and primary sensory (left: F(1,32) = 9.59, p = 0.004; right: F(1,32) = 8.18, p = 0.007) cortices during IMG-BWD only. The evidence suggests the exercise intervention did not affect gait or BOLD signal during MI. CONCLUSION: While all participants had significantly slower and shorter backward velocity and stride length, respectively, the exercise intervention had no effect. Similarly, BOLD signal during MI did not change with exercise; however, freezers had significantly lower BOLD signal during IMG-BWD compared to non-freezers. This suggests potential decreased recruitment of the SMN during MI of gait in freezers.

6 Clinical Trial Effects of a short duration, high dose contact improvisation dance workshop on Parkinson disease: a pilot study. 2010

Marchant, David / Sylvester, Jennifer L / Earhart, Gammon M. ·Performing Arts Department, and School of Medicine, Program in Physical Therapy,Washington University in St. Louis, 4444 Forest Park Blvd., St. Louis, MO 63108-2212, USA. ·Complement Ther Med · Pubmed #21056841.

ABSTRACT: OBJECTIVES: This study explored the feasibility and possible benefits of contact improvisation (CI) as an exercise intervention for individuals with PD. DESIGN: This was an uncontrolled pilot study. INTERVENTION: Eleven people with PD (H&Y=2.4 ± 0.4) participated in a workshop of 10 1.5-h CI classes over 2 weeks, dancing with previously trained student CI dancers. MAIN OUTCOME MEASURES: Measures of disease severity, balance, functional mobility, and gait were compared 1 week before and after the workshop. RESULTS: Participants demonstrated improvements on the Unified Parkinson Disease Rating Scale-Motor Subsection and Berg balance scores, along with increased swing and decreased stance percentages during walking. Backward step length also increased. Participants expressed a high level of enjoyment and interest in taking future CI classes. CONCLUSIONS: This pilot study supports the feasibility of CI as an intervention to address mobility limitations associated with PD.

7 Article Yoga Improves Balance and Low-Back Pain, but Not Anxiety, in People with Parkinson's Disease. 2019

Myers, Peter S / Harrison, Elinor C / Rawson, Kerri S / Horin, Adam P / Sutter, Ellen N / McNeely, Marie E / Earhart, Gammon M. ·1. Department of Neurology, Washington University School of Medicine; formerly, Program in Physical Therapy, Washington University School of Medicine, St. Louis. · 2. Program in Physical Therapy, Washington University School of Medicine, St. Louis. · 3. Department of Rehabilitation Medicine, University of Minnesota, Minneapolis; formerly, Program in Physical Therapy, Washington University School of Medicine, St. Louis. · 4. Unfold Productions, LLC, St. Louis; formerly, Program in Physical Therapy, Washington University School of Medicine, and Department of Neurology, Washington University School of Medicine, St. Louis. · 5. Program in Physical Therapy; Department of Neurology; and Department of Neuroscience, Washington University School of Medicine, St. Louis. ·Int J Yoga Therap · Pubmed #31584838.

ABSTRACT: Individuals with Parkinson's disease (PD) experience postural instability, low-back pain (LBP), and anxiety. These symptoms increase the risk of falls and decrease quality of life. Research shows yoga improves balance and decreases LBP and anxiety in healthy adults, but its effects in PD are poorly understood. All participants were part of a larger intervention study. Participants received pretest and posttest evaluations, including the Balance Evaluation Systems Test (BESTest), Beck Anxiety Inventory (BAI), and Revised Oswestry Disability Index (ROSW). Total scores for each measure, as well as individual balance system section scores from the BESTest (biomechanical constraints, stability limits/verticality, transitions/anticipatory, reactive, sensory orientation, and stability in gait) were compared within groups pre- to posttest. Participants in the yoga group (

8 Article Usability of a daily mHealth application designed to address mobility, speech and dexterity in Parkinson's disease. 2019

Horin, Adam P / McNeely, Marie E / Harrison, Elinor C / Myers, Peter S / Sutter, Ellen N / Rawson, Kerri S / Earhart, Gammon M. ·Program in Physical Therapy, Washington University School of Medicine, St Louis, MO, USA. · Department of Neurology, Washington University School of Medicine, St Louis, MO, USA. · Change in affiliation: Unfold Productions, LLC, St. Louis, MO, USA. · Change in affiliation: Department of Rehabilitation Medicine, University of Minnesota, Minneapolis, MN, USA. · Department of Neuroscience, Washington University School of Medicine, St Louis, MO, USA. ·Neurodegener Dis Manag · Pubmed #30998100.

ABSTRACT:

9 Article Predictors of self-perceived stigma in Parkinson's disease. 2019

Salazar, Robert D / Weizenbaum, Emma / Ellis, Terry D / Earhart, Gammon M / Ford, Matthew P / Dibble, Leland E / Cronin-Golomb, Alice. ·Department of Psychological and Brain Sciences, Boston University, USA. · Department of Psychological and Brain Sciences, Boston University, USA; Department of Physical Therapy and Athletic Training, Boston University College of Health and Rehabilitation Sciences: Sargent College, USA. · Program in Physical Therapy, Washington University in St. Louis-School of Medicine, St. Louis, MO, USA. · Department of Physical Therapy, School of Health Professions, Samford University, Birmingham, AL, USA. · Department of Physical Therapy, University of Utah, Salt Lake City, UT, USA. · Department of Psychological and Brain Sciences, Boston University, USA. Electronic address: alicecg@bu.edu. ·Parkinsonism Relat Disord · Pubmed #30297211.

ABSTRACT: OBJECTIVE: The burden of PD extends beyond physical limitations and includes significant psychosocial adjustments as individuals undergo changes to their self-perception and how others perceive them. There is limited quantitative evidence of the factors that contribute to self-perceived stigma, which we addressed in the present study. METHODS: In 362 individuals with PD (157 women, 205 men), self-perceived stigma was measured by the four-item stigma subscale of the Parkinson's Disease Questionnaire (PDQ-39). Hierarchical linear modeling was used to assess predictors of stigma including demographics (age, gender) and disease characteristics: duration, stage (Hoehn & Yahr Scale), motor severity (Unified Parkinson's Disease Rating Scale, UPDRS, Part 3), activities of daily living (UPDRS Part 2), and depression (Geriatric Depression Scale). Predictor variables were chosen based on their significant correlations with the stigma subscale. Further analyses were conducted for men and women separately. RESULTS: For the total sample, the full model accounted for 14% of the variance in stigma perception (p < .001). Younger age and higher depression scores were the only significant predictors (both p < .001). This pattern was also seen for the men in the sample. For the women, only depression was a significant predictor. Depression mediated the relation between stigma and activities of daily living. CONCLUSIONS: Younger age (men) and depression (men and women) were the primary predictors of self-perceived stigma in PD. Disease characteristics (motor and ADL) did not contribute to stigma perception. Depression is a potential treatment target for self-perceived stigma in PD.

10 Article Internal cueing improves gait more than external cueing in healthy adults and people with Parkinson disease. 2018

Harrison, Elinor C / Horin, Adam P / Earhart, Gammon M. ·Program in Physical Therapy, Washington University School of Medicine, St Louis, Missouri, United States of America. · Program in Physical Therapy, Washington University School of Medicine, St Louis, Missouri, United States of America. earhartg@wustl.edu. · Department of Neurology, Washington University School of Medicine, St Louis, Missouri, United States of America. earhartg@wustl.edu. · Department of Neuroscience, Washington University School of Medicine, St Louis, Missouri, United States of America. earhartg@wustl.edu. ·Sci Rep · Pubmed #30341367.

ABSTRACT: Walking can be challenging for aging individuals and people with neurological disorders such as Parkinson disease (PD). Gait impairment characterized by reduced speed and higher variability destabilizes gait and increases the risk of falls. External auditory cueing provides an effective strategy to improve gait, as matching footfalls to rhythms typically increases gait speed and elicits larger steps, but the need to synchronize to an outside source often has a detrimental effect on gait variability. Internal cueing in the form of singing may provide an alternative to conventional gait therapy. In the present study, we compare the effects of internal and external cueing techniques on forward and backward walking for both people with PD and healthy controls. Results indicate that internal cueing was associated with improvements in gait velocity, cadence, and stride length in the backward direction, and reduced variability in both forward and backward walking. In comparison, external cueing was associated with minimal improvement in gait characteristics and a decline in gait stability. People with gait impairment due to aging or neurological decline may benefit more from internal cueing techniques such as singing as compared to external cueing techniques.

11 Article Freezing of Gait Boot Camp: feasibility, safety and preliminary efficacy of a community-based group intervention. 2018

Rawson, Kerri S / Creel, Patricia / Templin, Lizbeth / Horin, Adam P / Duncan, Ryan P / Earhart, Gammon M. ·Program in Physical Therapy, Washington University School of Medicine in St. Louis, St. Louis, MO 631082, USA. · Greater St. Louis Chapter, American Parkinson Disease Association, Chesterfield, MO 630173, USA. · Department of Neurology, Washington University School of Medicine in St. Louis, St. Louis, MO 631104, USA. · Department of Neuroscience, Washington University School of Medicine in St. Louis, St. Louis, MO 63110, USA. ·Neurodegener Dis Manag · Pubmed #30223709.

ABSTRACT: AIM: In this pilot study, we evaluated the feasibility, safety and preliminary efficacy of a 6-week, community-based group intervention designed to reduce freezing of gait (FOG) for people with Parkinson's disease (PD). METHODS: Seven people with PD completed 'FOG Boot Camp' provided by the St. Louis Chapter of the American Parkinson Disease Association. We recorded attendance, participant's acceptance of the intervention and adverse events during classes. Pre and post-tests included measures of freezing, balance, motor severity, quality-of-life and gait speed. RESULTS: No falls or injuries occurred and attendance was high. Participants had favorable feedback and showed reduced freezing and improvements in balance and gait. CONCLUSION: Preliminary data suggest the FOG boot camp was feasible, safe and effective.

12 Article Modeling, Detecting, and Tracking Freezing of Gait in Parkinson Disease Using Inertial Sensors. 2018

Prateek, G V / Skog, Isaac / McNeely, Marie E / Duncan, Ryan P / Earhart, Gammon M / Nehorai, Arye. · ·IEEE Trans Biomed Eng · Pubmed #29989948.

ABSTRACT: In this paper, we develop new methods to automatically detect the onset and duration of freezing of gait (FOG) in people with Parkinson disease (PD) in real time, using inertial sensors. We first build a physical model that describes the trembling motion during the FOG events. Then, we design a generalized likelihood ratio test framework to develop a two-stage detector for determining the zero-velocity and trembling events during gait. Thereafter, to filter out falsely detected FOG events, we develop a point-process filter that combines the output of the detectors with information about the speed of the foot, provided by a foot-mounted inertial navigation system. We computed the probability of FOG by using the point-process filter to determine the onset and duration of the FOG event. Finally, we validate the performance of the proposed system design using real data obtained from people with PD who performed a set of gait tasks. We compare our FOG detection results with an existing method that only uses accelerometer data. The results indicate that our method yields 81.03% accuracy in detecting FOG events and a threefold decrease in the false-alarm rate relative to the existing method.

13 Article Effects of Parkinson disease and antiparkinson medication on central adaptations to repetitive grasping. 2018

Falvo, Michael J / Rohrbaugh, John W / Alexander, Thomas / Earhart, Gammon M. ·War Related Illness and Injury Study Center, VA New Jersey Health Care System; East Orange, NJ, United States; New Jersey Medical School, Rutgers Biomedical and Health Sciences, Newark, NJ, United States. · Department of Psychiatry, Washington University School of Medicine, St. Louis, MO, United States. · Program in Physical Therapy, Washington University School of Medicine, St. Louis, MO, United States; Department of Neuroscience, Washington University School of Medicine, St. Louis, MO, United States; Department of Neurology, Washington University School of Medicine, St. Louis, MO, United States. Electronic address: earhartg@wustl.edu. ·Life Sci · Pubmed #29526800.

ABSTRACT: Cortical activity during motor task performance is attenuated in individuals with Parkinson disease (PD) relative to age-matched adults without PD, and this activity is enhanced with antiparkinson medication. It remains unclear, however, whether the relative change in cortical activity over the duration of the task, i.e., central adaptation, is affected individuals with PD, and if so, whether medication corrects for any unique behaviors. Movement-related cortical potentials (MRCPs) were recorded from scalp electrode sites Cz and C1 during 150 repetitive handgrip contractions at 70% of maximal voluntary contraction, in individuals with PD (n = 10) both ON and OFF of their PD medication, and neurologically normal age- and sex-matched controls (n = 10). Repetitions were divided into two Blocks (Block 1 and 2: repetitions 1-60 and 91-150, respectively), and the composite MRCP slopes were calculated during periods representing movement initiation (-2 s to movement onset) and execution (movement onset to 1 s). No significant interactions were noted for either comparison (PD OFF vs. control; PD OFF vs. PD ON), irrespective of electrode site (Cz or C1) or movement period (initiation or execution). Despite similar MRCP slopes and task performance, PD OFF endorsed greater perceived exertion during task performance than controls. In the present study, we observed attenuated task-related cortical activity among individuals with PD OFF relative to controls, but a similar relative adaptive response to a fatiguing task. Additionally, although antiparkinson medication enhanced cortical activity (PD OFF vs. PD ON), central adaptation was similar.

14 Article Physical therapy and deep brain stimulation in Parkinson's Disease: protocol for a pilot randomized controlled trial. 2018

Duncan, Ryan P / Van Dillen, Linda R / Garbutt, Jane M / Earhart, Gammon M / Perlmutter, Joel S. ·1Program in Physical Therapy, Washington University School of Medicine in Saint Louis, Campus Box 8502, 4444 Forest Park Blvd, St. Louis, MO 63108 USA. · 0000 0001 2355 7002 · grid.4367.6 · 2Department of Neurology, Washington University School of Medicine in Saint Louis, St. Louis, MO USA. · 3Department of Orthopaedic Surgery, Washington University School of Medicine in Saint Louis, St. Louis, MO USA. · 4Department of Medicine, Washington University School of Medicine in Saint Louis, St. Louis, MO USA. · 5Department of Pediatrics, Washington University School of Medicine in Saint Louis, St. Louis, MO USA. · 6Department of Neuroscience, Washington University School of Medicine in Saint Louis, St. Louis, MO USA. · 7Department of Radiology, Washington University School of Medicine in Saint Louis, St. Louis, MO USA. · 8Program in Occupational Therapy, Washington University School of Medicine in Saint Louis, St. Louis, MO USA. ·Pilot Feasibility Stud · Pubmed #29484198.

ABSTRACT: Background: Subthalamic nucleus deep brain stimulation (STN-DBS) reduces tremor, muscle stiffness, and bradykinesia in people with Parkinson's Disease (PD). Walking speed, known to be reduced in PD, typically improves after surgery; however, other important aspects of gait may not improve. Furthermore, balance may worsen and falls may increase after STN-DBS. Thus, interventions to improve balance and gait could reduce morbidity and improve quality of life following STN-DBS. Physical therapy (PT) effectively improves balance and gait in people with PD, but studies on the effects of PT have not been extended to those treated with STN-DBS. As such, the efficacy, safety, and feasibility of PT in this population remain to be determined. The purpose of this pilot study is to address these unmet needs. We hypothesize that PT designed to target balance and gait impairment will be effective, safe, and feasible in this population. Methods/design: Participants with PD treated with STN-DBS will be randomly assigned to either a PT or control group. Participants assigned to PT will complete an 8-week, twice-weekly PT program consisting of exercises designed to improve balance and gait. Control group participants will receive the current standard of care following STN-DBS, which does not include prescription of PT. The primary aim is to assess preliminary efficacy of PT on balance (Balance Evaluation Systems Test). A secondary aim is to assess efficacy of PT on gait (GAITRite instrumented walkway). Participants will be assessed OFF medication/OFF stimulation and ON medication/ON stimulation at baseline and at 8 and 12 weeks after baseline. Adverse events will be measured over the duration of the study, and adherence to PT will be measured to determine feasibility. Discussion: To our knowledge, this will be the first study to explore the preliminary efficacy, safety, and feasibility of PT for individuals with PD with STN-DBS. If the study suggests potential efficacy, then this would justify larger trials to test effectiveness and safety of PT for those with PD with STN-DBS. Trial registration: NCT03181282 (clinicaltrials.gov). Registered on 7 June 2017.

15 Article Maximum Step Length Test Performance in People With Parkinson Disease: A Cross-sectional Study. 2017

Duncan, Ryan P / McNeely, Marie E / Earhart, Gammon M. ·Program in Physical Therapy, Washington University School of Medicine in Saint Louis, Missouri (R.P.D., M.E.M., G.M.E.) · Department of Neurology, Washington University School of Medicine in Saint Louis, Missouri (R.P.D., M.E.M., G.M.E.) · and Department of Neuroscience, Washington University School of Medicine in Saint Louis, Missouri (G.M.E.). ·J Neurol Phys Ther · Pubmed #28922312.

ABSTRACT: BACKGROUND AND PURPOSE: The Maximum Step Length Test (MSLT), a measure of one's capacity to produce a large step, has been studied in older adults, but not in people with Parkinson disease (PD). We characterized performance and construct validity of the MSLT in PD. METHODS: Forty participants (mean age: 65.12 ± 8.20 years; 45% female) with idiopathic PD completed the MSLT while "OFF" and "ON" anti-PD medication. Construct validity was investigated by examining relationships between MSLT and measures of motor performance. The following measures were collected: Mini-Balance Evaluation Systems Test (Mini-BESTest), Activities-specific Balance Confidence (ABC) scale, gait velocity, 6-minute walk test (6MWT), Movement Disorder Society-Unified Parkinson Disease Rating Scale subsection III (MDS-UPDRS III), and Timed Up and Go (TUG) test. A repeated-measures analysis of variance tested for main effects of medication and stepping direction and the interaction between the 2. Pearson or Spearman correlations were used to assess the relationships between MSLT and motor performance measures (α = 0.05). RESULTS: Regardless of medication status, participants stepped further in the forward direction compared with the backward and lateral directions (P < 0.001). Participants increased MSLT performance when ON-medication compared with OFF-medication (P = 0.004). Regardless of medication status, MSLT was moderately to strongly related to Mini-BESTest, TUG, and 6MWT. DISCUSSION AND CONCLUSIONS: People with PD stepped furthest in the forward direction when performing the MSLT. Increased MSLT performance was observed in the ON-medication state compared with OFF-medication; however, the small increase may not be clinically meaningful. Given the relationships between the MSLT and the Mini-BESTest, 6MWT, and TUG, MSLT performance appears to be associated with balance and gait hypokinesia in people with PD.Video Abstract available for more insights from the authors (see Video, Supplemental Digital Content 1, http://links.lww.com/JNPT/A186).

16 Article Low to moderate relationships between gait and postural responses in Parkinson disease. 2017

Sutter, Ellen N / Seidler, Katie J / Duncan, Ryan P / Earhart, Gammon M / McNeely, Marie E. ·Program in Physical Therapy, Washington University School of Medicine, St. Louis, USA. ·J Rehabil Med · Pubmed #28553677.

ABSTRACT: OBJECTIVE: To evaluate the relationship between spatiotemporal parameters of forward and backward gait and quality of compensatory stepping responses in forward and backward directions in people with Parkinson's disease with and without freezing of gait. DESIGN: Cross-sectional analysis. SUBJECTS: A total of 111 individuals with mild to moderate Parkinson's disease. METHODS: Forward and backward gait velocity and step length were evaluated using a GAITRite walkway. Forward and backward postural responses were evaluated using items from the Mini Balance Evaluation Systems Test and the Movement Disorders Society Unified Parkinson Disease Rating Scale motor subsection. Relationships between gait and postural responses were examined for the full sample and for sub-groups with and without freezing of gait. RESULTS: There were significant (p < 0.05) low to moderate correlations between postural responses and gait overall. Correlations were similar in the freezer and non-freezer sub-groups. Freezers performed worse than non-freezers on all gait parameters and backward postural response items (p < 0.05). CONCLUSION: Low to moderate relationships between gait and postural responses indicate the complexity of postural control and the potential involvement of different neural circuitry across these tasks. Better understanding of the relationships between gait and postural deficits in Parkinson's disease may inform the future development of targeted interventions to address these impairments.

17 Article The feasibility of singing to improve gait in Parkinson disease. 2017

Harrison, Elinor C / McNeely, Marie E / Earhart, Gammon M. ·Program in Physical Therapy, Washington University in St. Louis School of Medicine, St. Louis, MO, USA. Electronic address: harrisonel@wustl.edu. · Program in Physical Therapy, Washington University in St. Louis School of Medicine, St. Louis, MO, USA; Department of Neurology, Washington University in St. Louis School of Medicine, St. Louis, MO, USA. · Program in Physical Therapy, Washington University in St. Louis School of Medicine, St. Louis, MO, USA; Department of Neurology, Washington University in St. Louis School of Medicine, St. Louis, MO, USA; Department of Neuroscience, Washington University in St. Louis School of Medicine, St. Louis, MO, USA. Electronic address: earhartg@wustl.edu. ·Gait Posture · Pubmed #28226309.

ABSTRACT: Brain regions important for controlling movement are also responsible for rhythmic processing. In Parkinson disease (PD), defective internal timing within the brain has been linked to impaired beat discrimination, and may contribute to a loss of ability to maintain a steady gait rhythm. Less rhythmic gait is inherently less efficient, and this may lead to gait impairment including reduced speed, cadence, and stride length, as well as increased variability. While external rhythmic auditory stimulation (e.g. a metronome beat) is well-established as an effective tool to stabilize gait in PD, little is known about whether self-generated cues such as singing have the same beneficial effect on gait in PD. Thus, we compared gait patterns of 23 people with mild to moderate PD under five cued conditions: uncued, music only, singing only, singing with music, and a verbal dual-task condition. In our single-session study, singing while walking did not significantly alter velocity, cadence, or stride length, indicating that it was not excessively demanding for people with PD. In addition, walking was less variable when singing than during other cued conditions. This was further supported by the comparison between singing trials and a verbal dual-task condition. In contrast to singing, the verbal dual-task negatively affected gait performance. These findings suggest that singing holds promise as an effective cueing technique that may be as good as or better than traditional cueing techniques for improving gait among people with PD.

18 Article Cerebellar Volume and Executive Function in Parkinson Disease with and without Freezing of Gait. 2017

Myers, Peter S / McNeely, Marie E / Koller, Jonathan M / Earhart, Gammon M / Campbell, Meghan C. ·Program in Physical Therapy, Washington University in St. Louis School of Medicine, St. Louis, MO, USA. · Department of Neurology, Washington University in St. Louis School of Medicine, St. Louis, MO, USA. · Department of Psychiatry, Washington University in St. Louis School of Medicine, St. Louis, MO, USA. · Department of Neuroscience, Washington University in St. Louis School of Medicine, St. Louis, MO, USA. · Department of Radiology, Washington University in St. Louis School of Medicine, St. Louis, MO, USA. ·J Parkinsons Dis · Pubmed #28106569.

ABSTRACT: BACKGROUND: Freezing of gait (FOG) affects approximately 50% of people with Parkinson Disease (PD), impacting quality of life and placing financial and emotional strain on the individual and caregivers. People with PD and FOG have similar deficits in motor adaptation and cognition as individuals with cerebellar lesions, indicating the cerebellum may play a role in FOG. OBJECTIVE: To examine potential differences in cerebellar volumes and their relationships with cognition between PD with (FOG+) and without FOG (FOG-). METHODS: Sixty-three participants were divided into two groups, FOG+ (n = 25) and FOG- (n = 38), based on the New Freezing of Gait Questionnaire. Cognitive assessment included Trail Making, Stroop, Verbal Fluency, and Go-NoGo executive function tasks. All participants completed structural T1- and T2-weighted MRI scans. Imaging data were processed with FreeSurfer and the Spatially Unbiased Infratentorial toolbox to segment the cerebellum into individual lobules. RESULTS: FOG+ performed significantly worse on phonemic verbal fluency (F(1, 22)  =  7.06, p = 0.01) as well as the Go-NoGo task (F(1, 22)  =  9.00, p = 0.004). We found no differences in cerebellar volumes between groups (F(4, 55)  = 1.42, p = 0.24), but there were significant relationships between verbal fluency measures and lobule volumes in FOG-. CONCLUSIONS: These findings underscore the need for longitudinal studies to better characterize potential changes in cerebellar volume, cognitive function, and functional connectivity between people with PD with and without FOG.

19 Article Are the average gait speeds during the 10meter and 6minute walk tests redundant in Parkinson disease? 2017

Duncan, Ryan P / Combs-Miller, Stephanie A / McNeely, Marie E / Leddy, Abigail L / Cavanaugh, James T / Dibble, Leland E / Ellis, Terry D / Ford, Matthew P / Foreman, K Bo / Earhart, Gammon M. ·Washington University School of Medicine in St. Louis, Program in Physical Therapy, United States; Washington University School of Medicine in St. Louis, Department of Neurology, United States. Electronic address: duncanr@wustl.edu. · University of Indianapolis, Krannert School of Physical Therapy, United States. · Washington University School of Medicine in St. Louis, Program in Physical Therapy, United States; Washington University School of Medicine in St. Louis, Department of Neurology, United States. · Rehabilitation Hospital of the Pacific, Department of Physical Therapy, United States. · University of New England, Department of Physical Therapy, United States. · University of Utah, Department of Physical Therapy, United States. · Boston University, Department of Physical Therapy and Athletic Training, United States. · Samford University, Department of Physical Therapy, United States. · Washington University School of Medicine in St. Louis, Program in Physical Therapy, United States; Washington University School of Medicine in St. Louis, Department of Neurology, United States; Washington University School of Medicine in St. Louis, Department of Neuroscience, United States. ·Gait Posture · Pubmed #27915221.

ABSTRACT: We investigated the relationships between average gait speed collected with the 10Meter Walk Test (Comfortable and Fast) and 6Minute Walk Test (6MWT) in 346 people with Parkinson disease (PD) and how the relationships change with increasing disease severity. Pearson correlation and linear regression analyses determined relationships between 10Meter Walk Test and 6MWT gait speed values for the entire sample and for sub-samples stratified by Hoehn & Yahr (H&Y) stage I (n=53), II (n=141), III (n=135) and IV (n=17). We hypothesized that redundant tests would be highly and significantly correlated (i.e. r>0.70, p<0.05) and would have a linear regression model slope of 1 and intercept of 0. For the entire sample, 6MWT gait speed was significantly (p<0.001) related to the Comfortable 10 Meter Walk Test (r=0.75) and Fast 10Meter Walk Test (r=0.79) gait speed, with 56% and 62% of the variance in 6MWT gait speed explained, respectively. The regression model of 6MWT gait speed predicted by Comfortable 10 Meter Walk gait speed produced slope and intercept values near 1 and 0, respectively, especially for participants in H&Y stages II-IV. In contrast, slope and intercept values were further from 1 and 0, respectively, for the Fast 10Meter Walk Test. Comfortable 10 Meter Walk Test and 6MWT gait speeds appeared to be redundant in people with moderate to severe PD, suggesting the Comfortable 10 Meter Walk Test can be used to estimate 6MWT distance in this population.

20 Article Feasibility and preliminary efficacy of a telerehabilitation approach to group adapted tango instruction for people with Parkinson disease. 2017

Seidler, Katie J / Duncan, Ryan P / McNeely, Marie E / Hackney, Madeleine E / Earhart, Gammon M. ·1 Program in Physical Therapy, Washington University School of Medicine in St Louis, St. Louis, MO, USA. · 2 Department of Neurology, Washington University School of Medicine in St Louis, St. Louis, MO, USA. · 3 Center of Excellence for Visual and Neurocognitive Rehabilitation, Atlanta Veterans Affairs Rehabilitation R&D, Decatur, GA, USA. · 4 Division of General Medicine and Geriatrics, Emory University, Atlanta, GA, USA. · 5 Department of Neuroscience, Washington University School of Medicine in St Louis, St. Louis, MO, USA. ·J Telemed Telecare · Pubmed #27624469.

ABSTRACT: People with Parkinson disease (PD) demonstrate improvements in motor function following group tango classes, but report long commutes as a barrier to participation. To increase access, we investigated a telerehabilitation approach to group tango instruction. Twenty-six people with mild-to-moderate PD were assigned based on commute distance to either the telerehabilitation group (Telerehab) or an in-person instruction group (In-person). Both groups followed the same twice-weekly, 12-week curriculum with the same instructor. Feasibility metrics were participant retention, attendance and adverse events. Outcomes assessed were balance, PD motor sign severity and gait. Participant retention was 85% in both groups. Attendance was 87% in the Telerehab group and 84% in the In-person group. No adverse events occurred. Balance and motor sign severity improved significantly over time ( p < 0.001) in both groups, with no significant group × time effects. Gait did not significantly change. Since a priori feasibility criteria were met or exceeded, and there were no notable outcome differences between the two instruction approaches, this pilot study suggests a telerehabilitation approach to group tango class for people with PD is feasible and may have similar outcomes to in-person instruction.

21 Article Investigation of factors impacting mobility and gait in Parkinson disease. 2016

Christofoletti, Gustavo / McNeely, Marie E / Campbell, Meghan C / Duncan, Ryan P / Earhart, Gammon M. ·Federal University of Mato Grosso do Sul, Program in Health and Development, Campo Grande, MS 79060-900, Brazil; Washington University School of Medicine in Saint Louis, Program in Physical Therapy, St. Louis, MO 63108, USA. · Washington University School of Medicine in Saint Louis, Program in Physical Therapy, St. Louis, MO 63108, USA; Washington University School of Medicine in Saint Louis, Department of Neurology, St. Louis, MO 63110, USA. · Washington University School of Medicine in Saint Louis, Department of Neurology, St. Louis, MO 63110, USA; Washington University School of Medicine in Saint Louis, Department of Radiology, St. Louis, MO 63110, USA. · Washington University School of Medicine in Saint Louis, Program in Physical Therapy, St. Louis, MO 63108, USA; Washington University School of Medicine in Saint Louis, Department of Neurology, St. Louis, MO 63110, USA; Washington University School of Medicine in Saint Louis, Department of Neuroscience, St. Louis, MO 63110, USA. Electronic address: earhartg@wustl.edu. ·Hum Mov Sci · Pubmed #27551818.

ABSTRACT: Mobility and gait limitations are major issues for people with Parkinson disease (PD). Identification of factors that contribute to these impairments may inform treatment and intervention strategies. In this study we investigated factors that predict mobility and gait impairment in PD. Participants with mild to moderate PD and without dementia (n=114) were tested in one session 'off' medication. Mobility measures included the 6-Minute Walk test and Timed-Up-and-Go. Gait velocity was collected in four conditions: forward preferred speed, forward dual task, forward fast as possible and backward walking. The predictors analyzed were age, gender, disease severity, balance, balance confidence, fall history, self-reported physical activity, and executive function. Multiple regression models were used to assess the relationships between predictors and outcomes. The predictors, in different combinations for each outcome measure, explained 55.7% to 66.9% of variability for mobility and 39.5% to 52.8% for gait velocity. Balance was the most relevant factor (explaining up to 54.1% of variance in mobility and up to 45.6% in gait velocity). Balance confidence contributed to a lesser extent (2.0% to 8.2% of variance) in all models. Age explained a small percentage of variance in mobility and gait velocity (up to 2.9%). Executive function explained 3.0% of variance during forward walking only. The strong predictive relationships between balance deficits and mobility and gait impairment suggest targeting balance deficits may be particularly important for improving mobility and gait in people with PD, regardless of an individual's age, disease severity, fall history, or other demographic features.

22 Article Freezing of gait is associated with increased saccade latency and variability in Parkinson's disease. 2016

Nemanich, Samuel T / Earhart, Gammon M. ·Program in Physical Therapy, Washington University School of Medicine in St. Louis, 4444 Forest Park Ave., Campus Box 8502, St. Louis, MO 63108, USA. · Program in Physical Therapy, Washington University School of Medicine in St. Louis, 4444 Forest Park Ave., Campus Box 8502, St. Louis, MO 63108, USA; Department of Neuroscience, Washington University School of Medicine in St. Louis, 660 S. Euclid Ave., Campus Box 8108, St. Louis, MO 63110, USA; Department of Neurology, Washington University School of Medicine in St. Louis, 660 S. Euclid Ave., Campus Box 8111, St. Louis, MO 63110, USA. Electronic address: earhartg@wustl.edu. ·Clin Neurophysiol · Pubmed #27178858.

ABSTRACT: OBJECTIVE: Freezing of gait (FOG) is a locomotor disturbance in Parkinson disease (PD) related to impaired motor automaticity. In this study, we investigated the impact of freezing on automaticity in the oculomotor system using an anti-saccade paradigm. METHODS: Subjects with PD with (PD-FOG, n=13) and without (PD-NON, n=13) FOG, and healthy age-matched controls (CTRL, n=12) completed automatic pro-saccades and non-automatic anti-saccades. Primary outcomes were saccade latency, velocity, and gain. RESULTS: PD-FOG (pro-saccade latency=271ms, anti-saccade latency=412ms) were slower to execute both types of saccades compared to PD-NON (253ms, 330ms) and CTRL (246ms, 327ms). Saccade velocity and gain variability was also increased in PD-FOG. CONCLUSIONS: Saccade performance was affected in PD-FOG for both types of saccades, indicating differences in automaticity and control in the oculomotor system related to freezing. SIGNIFICANCE: These results and others show that FOG impacts non-gait motor functions, suggesting global motor impairment in PD-FOG.

23 Article Obtaining Reliable Estimates of Ambulatory Physical Activity in People with Parkinson's Disease. 2016

Paul, Serene S / Ellis, Terry D / Dibble, Leland E / Earhart, Gammon M / Ford, Matthew P / Foreman, K Bo / Cavanaugh, James T. ·Department of Physical Therapy, University of Utah, Salt Lake City, UT, USA. · The George Institute for Global Health, Sydney Medical School, The University of Sydney, Sydney, NSW, Australia. · Department of Physical Therapy and Athletic Training, Boston University, Boston, MA, USA. · Program in Physical Therapy, Department of Neuroscience, Department of Neurology, Washington University in St. Louis-School of Medicine, St Louis, MO, USA. · Department of Physical Therapy, Samford University, Birmingham, AL, USA. · Department of Physical Therapy, University of New England, Portland, ME, USA. ·J Parkinsons Dis · Pubmed #27164042.

ABSTRACT: We determined the number of days required, and whether to include weekdays and/or weekends, to obtain reliable measures of ambulatory physical activity in people with Parkinson's disease (PD). Ninety-two persons with PD wore a step activity monitor for seven days. The number of days required to obtain a reliable estimate of daily activity was determined from the mean intraclass correlation (ICC2,1) for all possible combinations of 1-6 consecutive days of monitoring. Two days of monitoring were sufficient to obtain reliable daily activity estimates (ICC2,1 > 0.9). Amount (p = 0.03) but not intensity (p = 0.13) of ambulatory activity was greater on weekdays than weekends. Activity prescription based on amount rather than intensity may be more appropriate for people with PD.

24 Article Impact of limiting visual input on gait: Individuals with Parkinson disease, age-matched controls, and healthy young participants. 2016

Pilgram, Laura M / Earhart, Gammon M / Pickett, Kristen A. ·a Program in Physical Therapy , Washington University School of Medicine in St Louis , St Louis , USA ; · b Department of Neurology-Movement Disorders Section , Washington University School of Medicine in St Louis , St Louis , USA ; · c Department of Neuroscience , Washington University School of Medicine in St Louis , St Louis , USA. ·Somatosens Mot Res · Pubmed #26987577.

ABSTRACT: Normal and limited vision gait was investigated in individuals with Parkinson disease (PD), healthy older and healthy young individuals. Participants walked a GAITRite mat with normal vision or vision of lower limbs occluded. Results indicate individuals with PD walked more slowly, with shorter and wider steps, and spent more time in double support with limited vision as compared to full vision. Healthy young and old individuals took shorter steps but were otherwise unchanged between conditions.

25 Article The Effect of Dopaminergic Medication on Beat-Based Auditory Timing in Parkinson's Disease. 2016

Cameron, Daniel J / Pickett, Kristen A / Earhart, Gammon M / Grahn, Jessica A. ·Brain and Mind Institute, University of Western Ontario , London, ON , Canada. · Occupational Therapy Program, Department of Kinesiology, University of Wisconsin-Madison , Madison, WI , USA. · Program in Physical Therapy, Department of Neuroscience, Department of Neurology, Washington University School of Medicine in St. Louis , St. Louis, MO , USA. · Brain and Mind Institute, University of Western Ontario, London, ON, Canada; Department of Psychology, University of Western Ontario, London, ON, Canada. ·Front Neurol · Pubmed #26941707.

ABSTRACT: Parkinson's disease (PD) adversely affects timing abilities. Beat-based timing is a mechanism that times events relative to a regular interval, such as the "beat" in musical rhythm, and is impaired in PD. It is unknown if dopaminergic medication influences beat-based timing in PD. Here, we tested beat-based timing over two sessions in participants with PD (OFF then ON dopaminergic medication) and in unmedicated control participants. People with PD and control participants completed two tasks. The first was a discrimination task in which participants compared two rhythms and determined whether they were the same or different. Rhythms either had a beat structure (metric simple rhythms) or did not (metric complex rhythms), as in previous studies. Discrimination accuracy was analyzed to test for the effects of beat structure, as well as differences between participants with PD and controls, and effects of medication (PD group only). The second task was the Beat Alignment Test (BAT), in which participants listened to music with regular tones superimposed, and responded as to whether the tones were "ON" or "OFF" the beat of the music. Accuracy was analyzed to test for differences between participants with PD and controls, and for an effect of medication in patients. Both patients and controls discriminated metric simple rhythms better than metric complex rhythms. Controls also improved at the discrimination task in the second vs. first session, whereas people with PD did not. For participants with PD, the difference in performance between metric simple and metric complex rhythms was greater (sensitivity to changes in simple rhythms increased and sensitivity to changes in complex rhythms decreased) when ON vs. OFF medication. Performance also worsened with disease severity. For the BAT, no group differences or effects of medication were found. Overall, these findings suggest that timing is impaired in PD, and that dopaminergic medication influences beat-based and non-beat-based timing differently. Judging the beat in music does not appear to be affected by PD or by dopaminergic medication.

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