Mild-moderate Parkinson's Disease Research Articles

Brain network centrality and connectivity are associated with clinical subtypes and disease progression in Parkinson's disease.

To investigate brain network centrality and connectivity alterations in different Parkinson's disease (PD) clinical subtypes using resting-state functional magnetic resonance imaging (RS-fMRI), and to explore the correlation between baseline connectivity changes and the clinical progression. Ninety-two PD patients were enrolled at baseline, alongside 38 age- and sex-matched healthy controls. Of these, 85 PD patients underwent longitudinal assessments with a mean of 2.75 ± 0.59 years. Two-step cluster analysis integrating comprehensive motor and non-motor manifestations was performed to define PD subtypes. Degree centrality (DC) and secondary seed-based functional connectivity (FC) were applied to identify brain network centrality and connectivity changes among groups. Regression analysis was used to explore the correlation between baseline connectivity changes and clinical progression. Cluster analysis identified two main PD subtypes: mild PD and moderate PD. Two different subtypes within the mild PD were further identified: mild motor-predominant PD and mild-diffuse PD. Accordingly, the disrupted DC and seed-based FC in the left inferior frontal orbital gyrus and left superior occipital gyrus were severe in moderate PD. The DC and seed-based FC alterations in the right gyrus rectus and right postcentral gyrus were more severe in mild-diffuse PD than in mild motor-predominant PD. Moreover, disrupted DC were associated with clinical manifestations at baseline in patients with PD and predicted motor aspects progression over time. Our study suggested that brain network centrality and connectivity changes were different among PD subtypes. RS-fMRI holds promise to provide an objective assessment of subtype-related connectivity changes and predict disease progression in PD.

How Many Days Of Monitoring are Necessary to Accurately Characterize Activity of Parkinson's Disease Patients?

<h3>Research Objectives</h3> To determine a reliable sampling strategy to accurately characterize physical activity in individuals with Parkinson's disease (PD). <h3>Design</h3> Observational study with individuals with PD wearing a wrist worn activity monitor for 30 days. <h3>Setting</h3> General community. <h3>Participants</h3> Individuals with mild-Moderate Parkinson's disease (N=31). <h3>Interventions</h3> Not applicable. <h3>Main Outcome Measures</h3> A step/day measurement period of various lengths (2, 3, 4, 5, 6, 7, and 14 days) were selected for consecutive and random days. Two-way intraclass correlation coefficients (ICC) were calculated for ten samples of both consecutive and random days for each participant. The ten samples were averaged for ICC for each measurement period. <h3>Results</h3> The ICC averages for consecutive days ranged from 0.59-0.75, with stability of ICC starting at a 7-day measurement period (95% CI, 0.55- 0.80). The ICC averages for random days ranged from 0.59-0.71, with stability of ICC maintained starting with a random 7-day measurement period (95% CI, 0.51- 0.77). <h3>Conclusions</h3> PD-related variability in motor behavior, and conventional methods of a four day measurement period may not accurately reflect physical activity behavior. Identifying a method to accurately characterize level of physical activity in individuals with PD over time provides those conducting short- and long-term intervention studies and trials with a robust physical activity outcome. The results of this study indicate that seven consecutive days of physical activity monitoring was the most stable measure of physical activity. For random sampling days, seven days also resulted in the greatest and most stable ICC of that sampling method. Therefore, in PD a seven-day consecutive measurement period may be the most representative of physical activity behavior in individuals with PD. <h3>Author(s) Disclosures</h3> No authors have disclosures or conflicts.

Physical activity intensity is associated with cognition and functional connectivity in Parkinson's disease

BackgroundCognitive impairment is common in Parkinson's disease (PD) and often leads to dementia, with no effective treatment. Aging studies suggest that physical activity (PA) intensity has a positive impact on cognition and enhanced functional connectivity may underlie these benefits. However, less is known in PD. This cross-sectional study examined the relationship between PA intensity, cognitive performance, and resting state functional connectivity in PD and whether PA intensity influences the relationship between functional connectivity and cognitive performance. Methods96 individuals with mild-moderate PD completed a comprehensive neuropsychological battery. Intensity of PA was objectively captured over a seven-day period using a wearable device (ActiGraph). Time spent in light and moderate intensity PA was determined based on standardized actigraphy cut points. Resting-state fMRI was assessed in a subset of 50 individuals to examine brain-wide functional connectivity. ResultsModerate intensity PA (MIPA), but not light PA, was associated with better global cognition, visuospatial function, memory, and executive function. Individuals who met the WHO recommendation of ≥150 min/week of MIPA demonstrated better global cognition, executive function, and visuospatial function. Resting-state functional connectivity associated with MIPA included a combination of brainstem, hippocampus, and regions in the frontal, cingulate, and parietal cortices, which showed higher connectivity across the brain in those achieving the WHO MIPA recommendation. Meeting this recommendation positively moderated the associations between identified functional connectivity and global cognition, visuospatial function, and language. ConclusionEncouraging MIPA, particularly the WHO recommendation of ≥150 min of MIPA/week, may represent an important prescription for PD cognition.

Dual task effect on upper and lower extremity skills in different stages of Parkinson's disease.

Loss of automaticity and deteriorated executive function give rise to dual task deficits in Parkinson's disease (PD). This study aimed to compare single task and dual task upper and lower extremity skills in people with PD (PwPD) at different stages of PD and to examine the dual task effect (DTE) on upper and lower extremity skills in PwPD at different stages of PD. The second aim was to investigate the relationship between the DTE and the quality of life in PwPD. 30 patients divided into 2 groups as mild PD group and moderate PD group according to the Modified Hoehn & Yahr Scale. 15 age matched healthy adults were recruited as the control group. The Unified Parkinson's Disease Rating Scale (UPDRS), the Purdue Pegboard Test (PPT), the Timed Up and Go Test (TUG), the 10 Meter Walk Test (10MWT), and the Parkinson's Disease Questionnaire (PDQ-8) were used for assessments. Single task and dual task scores of all assessments of all groups were significantly different. The DTE on PPT was greater in mild and moderate PD groups than control group and significantly lower in mild PD group than moderate PD group. However, DTE on the TUG and 10MWT was not different in mild PD group than control group and DTE significantly lower in both groups than moderate PD group. Significant correlations between the DTE on PPT, TUG and 10MWT and the PDQ-8 in PwPD were observed. Dual task has a worsening effect on upper and lower extremity skills in PwPD. This effect can be observed earlier in upper extremity skills than lower extremity skills. Also, the DTE and the QoL in PwPD are related.

Managing freezing of gait in Parkinson's disease: a systematic review and network meta-analysis.

Freezing of gait (FOG) is one of the most disabling gait disorders affecting 80% of patients with Parkinson's disease (PD). Clinical guidelines recommend a behavioral approach for gait rehabilitation, but there is a wide diversity of behavioral modalities. The objective of this network meta-analysis was to compare the effectiveness of different behavioral interventions for FOG management in PD patients. Six databases were searched for randomized controlled trials of behavioral interventions for FOG management among PD patients from 1990 to December 2021. Bayesian network meta-analysis was used to combine both direct and indirect trial evidence on treatment effectiveness, while the surface under the cumulative ranking (SUCRA) score was used to estimate the ranked probability of intervention effectiveness. Forty-six studies were included in the qualitative synthesis. Among, 36 studies (1454 patients) of 72 interventions or control conditions (12 classes) were included in the network meta-analysis, with a mean intervention period of 10.3weeks. After adjusting for the moderating effect of baseline FOG severity, obstacle training [SMD -2.1; 95% credible interval (Crl): -3.3, -0.86], gait training with treadmill (SMD -1.2; 95% Crl: -2.0, -0.34), action observation training (SMD -1.0; 95% Crl: -1.9, -0.14), conventional physiotherapy (SMD -0.70; 95% Crl: -1.3, -0.12) and general exercise (SMD -0.64; 95% Crl: -1.2, -0.11) demonstrated significant improvement on immediate FOG severity compared to usual care. The SUCRA rankings suggest that obstacle training, gait training on treadmill and general exercises are most likely to reduce FOG severity. Obstacle training, gait training on treadmill, general exercises, action observation training and conventional physiotherapy demonstrated immediate real-life benefits on FOG symptoms among patients with mild-moderate PD. With the promising findings, the sustained effects of high complexity motor training combined with attentional/cognitive strategy should be further explored. Future trials with rigorous research designs using both subjective and objective outcome measures, long-term follow-up and cost-effective analysis are warranted to establish effective behavioral strategies for FOG management.

Using Portable Voice Accumulators to Study Transfer of Speech Outcomes Following Intervention – A Feasibility Study

ObjectivesTo evaluate the process and scientific feasibility of using a portable voice accumulator (PVA) to study carry-over of treatment effects on speech and voice in people with mild-moderate Parkinson's disease. MethodsThe study was guided by the checklist in Consolidated Standards of Reporting Trials (CONSORT) 2010 statement: extension to randomized pilot and feasibility trials. Participants with Parkinson's disease were recruited within the context of a randomized controlled trial with random allocation to intervention with either HiCommunication, a program targeting speech and communication, or HiBalance, a program targeting balance and strength. Before and after intervention data was collected from standardized studio recordings of speech and registrations of voice use in daily life with the PVA VoxLog. ResultsFifteen participants were included in the study and sufficient data was yielded from six of them. Reasons for insufficient data included technical issues and difficulties handling the PVA. Changes in voice sound level from pre to post intervention differed at an individual level when assessed in daily life compared to studio recordings. Registrations in daily life provided information on phonation ratio and ability to adapt voice sound level to environmental noise. ConclusionThis study highlights the challenges of studying intervention effects on voice use in daily life using a PVA. Improvements of test protocols in future studies are suggested. We exemplify how PVA data may generate a more detailed and ecologically valid picture of voice use complementing studio recordings of speech. Finally, we encourage technical development of more user-friendly PVAs.

Smartphone-Based Neuropsychological Assessment in Parkinson's Disease: Feasibility, Validity, and Contextually Driven Variability in Cognition.

The prevalence of neurodegenerative disorders demands methods of accessible assessment that reliably captures cognition in daily life contexts. We investigated the feasibility of smartphone cognitive assessment in people with Parkinson's disease (PD), who may have cognitive impairment in addition to motor-related problems that limit attending in-person clinics. We examined how daily-life factors predicted smartphone cognitive performance and examined the convergent validity of smartphone assessment with traditional neuropsychological tests. Twenty-seven nondemented individuals with mild-moderate PD attended one in-lab session and responded to smartphone notifications over 10 days. The smartphone app queried participants 5x/day about their location, mood, alertness, exercise, and medication state and administered mobile games of working memory and executive function. Response rate to prompts was high, demonstrating feasibility of the approach. Between-subject reliability was high on both cognitive games. Within-subject variability was higher for working memory than executive function. Strong convergent validity was seen between traditional tests and smartphone working memory but not executive function, reflecting the latter's ceiling effects. Participants performed better on mobile working memory tasks when at home and after recent exercise. Less self-reported daytime sleepiness and lower PD symptom burden predicted a stronger association between later time of day and higher smartphone test performance. These findings support feasibility and validity of repeat smartphone assessments of cognition and provide preliminary evidence of the effects of context on cognitive variability in PD. Further development of this accessible assessment method could increase sensitivity and specificity regarding daily cognitive dysfunction for PD and other clinical populations.

Rationale and Design of the PAIRED Trial: Partnered Dance Aerobic Exercise as a Neuroprotective, Motor, and Cognitive Intervention in Parkinson's Disease.

Parkinson's disease (PD), an intractable condition impairing motor and cognitive function, is imperfectly treated by drugs and surgery. Two priority issues for many people with PD are OFF-time and cognitive impairment. Even under best medical management, three-fourths of people with PD experience “OFF-time” related to medication-related motor fluctuations, which severely impacts both quality of life and cognition. Cognitive deficits are found even in newly diagnosed people with PD and are often intractable. Our data suggest that partnered dance aerobic exercise (PDAE) reduces OFF-time on the Movement Disorders Society Unified Parkinson Disease Rating Scale-IV (MDS-UPDRS-IV) and ameliorates other disease features, which motivate the PAIRED trial. PDAE provides AE during an improvisational, cognitively engaging rehabilitative physical activity. Although exercise benefits motor and cognitive symptoms and may be neuroprotective for PD, studies using robust biomarkers of neuroprotection in humans are rare. We propose to perform a randomized, controlled trial in individuals with diagnosed mild–moderate PD to compare the efficacy of PDAE vs. walking aerobic exercise (WALK) for OFF-time, cognition, and neuroprotection. We will assess neuroprotection with neuromelanin-sensitive MRI (NM-MRI) and iron-sensitive (R2*) MRI sequences to quantify neuromelanin loss and iron accumulation in substantia nigra pars compacta (SNc). We will use these biomarkers, neuromelanin loss, and iron accumulation, as tools to chart the course of neurodegeneration in patients with PD who have undergone long-term (16 months) intervention. We will randomly assign 102 individuals with mild–moderate PD to 16 months of PDAE or WALK. The 16-month intervention period will consist of Training (3 months of biweekly sessions) and Maintenance (13 months of weekly sessions) phases. We will assess participants at baseline, 3 months (immediately post-Training), and 16 months (immediately post-Maintenance) for OFF-time and behaviorally and physiologically measured cognition. We will acquire NM-MRI and R2* imaging data at baseline and 16 months to assess neuroprotection. We will (1) examine effects of Training and Maintenance phases of PDAE vs. WALK on OFF-time, (2) compare PDAE vs. WALK at 3 and 16 months on behavioral and functional MRI (fMRI) measures of spatial cognition, and (3) compare PDAE vs. WALK for effects on rates of neurodegeneration.

Hatha yoga training improves standing balance but not gait in Parkinson's disease

Background and purposeComplementary therapies, such as yoga, have been proposed to address gait and balance problems in Parkinson's disease (PD). However, the effects of yoga on gait and static balance have not been studied systematically in people with PD (PWP). Here we evaluated the effects of a 12-week long Hatha yoga intervention on biomechanical parameters of gait and posture in PWP. MethodsWe employed a pilot randomized controlled trial design with two groups of mild-to-moderate PWP (immediate treatment, waitlist control; N = 10 each; Mean Hoehn and Yahr score = 2 for each group). Baseline Unified Parkinson's Disease Rating Scale (UPDRS) motor scores, and gait and postural kinematics including postural sway path length, cadence, walking speed, and turning time were obtained. The immediate treatment group received a 60-min Hatha yoga training twice a week for 12 weeks, while the waitlisted control group received no training. After 12 weeks, gait and postural kinematics were assessed (post-test for treatment group and second-baseline for waitlist group). Then, the waitlist group received the same yoga training and was evaluated post-training. ResultsAfter Hatha yoga training, UPDRS motor scores improved with an 8-point mean decrease which is considered as a moderate clinically important change for mild-moderate PD. Sway path length during stance decreased significantly (mean reduction: -34.4%). No significant between-group differences or improvements in gait kinematics were observed. ConclusionThis study showed that a 12-week Hatha yoga training can improve static balance in PWP. We found no evidence that it systematically improves gait performance in PWP.

Outcome Evaluation of Highly Challenging Balance Training for People With Parkinson Disease: A Multicenter Effectiveness-Implementation Study

In order for people with Parkinson disease (PwPD) to benefit from neurorehabilitation research, interventions tested in research settings require assessment in real-world clinical practice. There is little evidence for whether efficacious exercise interventions for PwPD remain effective when transferred to standard clinical settings. The aim of this study was to assess the clinical effectiveness of the adapted HiBalance program on balance control and gait among PwPD. Participants (n = 117) with mild-moderate Parkinson disease were consecutively included into either the 10-week HiBalance group training (n = 61) or the control (n = 56) group. The main outcome was balance performance (Mini-BESTest). Secondary outcomes were comfortable gait speed (10-m Walk Test); functional mobility (Timed Up and Go [TUG] test) and dual-task interference (cognitive TUG test); physical activity level (steps per day); perceived balance confidence (Activities-specific Balance Confidence scale) and perceived walking difficulty (Walk-12G) and self-rated health (EQ-5D visual analog scale). In total, 98 people completed the trial. Compared with controls, the training group showed significant improvement in balance performance (P < 0.001), gait speed (P = 0.001), and dual-task interference (P = 0.04) following the intervention. No group differences were observed for physical activity level or any patient-reported measures. Highly challenging balance training is effective at improving balance, gait, and dual-task performance when delivered at a clinically feasible dose, in a range of rehabilitation settings, without direct involvement of the research group.Video Abstract available for more insights from the authors (see the Video, Supplementary Digital Content 1, available at: http://links.lww.com/JNPT/A299).

Differentiating Parkinson Disease Subtypes Using Clinical Balance Measures.

People with Parkinson disease (PD) present phenotypes that are characterized as tremor-dominant (TD) or postural instability/gait difficulty (PIGD) subtypes. Differentiation of subtypes allows clinicians to predict disease course and adjust treatment. We examined whether brief mobility and balance measures can discriminate PIGD from TD phenotypes. We performed a cross-sectional study with individuals with PD (n = 104). Blinded raters assessed participants with the Unified Parkinson's Disease Rating Scale (UPDRS) or Movement Disorders Society revision (MDS-UPDRS), and balance assessments: 360° turn test, one-leg stance, a reactive postural control test, and tandem walk. Participants were classified as PIGD or TD based on the UPDRS or MDS-UPDRS assessment results. Differences in balance variables between subtypes were assessed with univariate analyses. Receiver operating characteristic (ROC) curve analyses were performed to investigate the ability of balance variables to differentiate PD subtypes. No differences between subtypes were observed for tandem walk or reactive postural control. Participants with PIGD performed worse on number of steps and time to complete the 360° turn test and on one-leg stance time. ROC curves showed only the 360° turn test discriminated PIGD from TD with high specificity (0.84). Post hoc analyses revealed that the 360° turn test is the most discriminatory for classifying PD subtypes in early stages of the disease. ROC analyses based on combined models including both the 360° test and tandem walk test performance increased the specificity to 0.97. The 360° turn test requires minimal time to administer and may be useful in mild-moderate PD for distinguishing PIGD from TD subtypes.Video Abstract available for more insights from the authors (see the Video, Supplemental Digital Content 1, available at: http://links.lww.com/JNPT/A295).

Pain in persons with mild-moderate Parkinson's disease: a cross-sectional study of pain severity and associated factors.

The aims of this study were to determine pain severity in persons with mild-moderate Parkinson's disease compared with healthy age- and sex-matched controls, and identify related factors, that is, demographic, disease severity, and functioning, of pain severity in the Parkinson's disease group. A cross-sectional study design was adopted to assess pain severity in 100 persons with Parkinson's disease and 47 healthy controls. Bodily pain was assessed using item 21 of the Short Form 36, whereas pain severity was determined using the entire Short Form 36 Bodily Pain subscale (score ranging from 0 to 100). Self-report questionnaires and clinical tests were completed to determine factors, that is, demographic and disease severity characteristics as well as physical functioning indicators, related to pain severity. Based on fulfillment of assumptions of data normality, both univariate and multivariate regression analysis were carried out. Pain severity (P < 0.001) was significantly higher in persons with Parkinson's disease than healthy controls. Among persons with Parkinson's disease, the multivariate predictor model, explaining 34% of the variance in pain severity scores, identified three independently associated factors. Poorer balance performance, a shorter disease duration, and poorer health-related quality of life were independently associated with pain severity. Pain severity is higher in those living with Parkinson's disease than controls, and severity appears to be associated with disease characteristics and overall health. Further research is required to assess pain origin in Parkinson's disease with the aim of developing targeted interventions.

Dopamine replacement improves motor learning of an upper extremity task in people with Parkinson disease

BackgroundDopamine replacement medication has positive effects on existing motor skills for people with Parkinson disease (PD), but may have detrimental effects on the learning of motor skills necessary for effective rehabilitation according to the dopamine overdose hypothesis. ObjectivesThis study aimed to determine whether dopamine replacement medication (i.e. levodopa) affects: learning of a novel upper extremity task, decrements in skill following withdrawal of practice, the rate of learning, and the transfer of movement skill to untrained upper extremity tasks compared to training “off” medication, in people with PD. MethodsParticipants with mild-moderate PD (Hoehn and Yahr stage 2) were randomized to train “on” (n = 12) or “off” (n = 11) levodopa medication. Participants practiced 10 blocks of five trials of a functional motor task with their non-dominant upper extremity over three consecutive days (acquisition period), followed by a single block of five trials two and nine days later. Participants were also assessed “on” levodopa with two transfer tasks (the nine-hole peg test and a functional dexterity task) prior to any practice and nine days after the end of the acquisition period. ResultsParticipants who practiced “on” levodopa medication learned the upper extremity task to a greater extent that those who practiced “off” medication, as determined by retained performance two days after practice. Skill decrement and skill transfer were not significantly different between groups. Rate of learning was unable to be modelled in this sample. ConclusionsLevodopa medication improved the learning of an upper extremity task in people with mild-moderate PD.

The Body Position Spatial Task, a Test of Whole-Body Spatial Cognition: Comparison Between Adults With and Without Parkinson Disease

Background. The Body Position Spatial Task (BPST) is a novel measure of whole-body spatial cognition involving multidirectional steps and turns. Individuals with Parkinson disease (PD) are affected by motor and cognitive impairments, particularly in spatial function, which is important for mental imagery and navigation. Performance on the BPST may inform understanding of motor-cognitive and spatial cognitive function of individuals with PD. Objectives. We conducted this study to determine feasibility and validity of the BPST with standard, validated, and reliable measures of spatial cognition and motor-cognitive integration and to compare BPST performance in adults with and without PD. Methods. A total of 91 individuals with mild-moderate PD and 112 neurotypical (NT) adults of similar age were recruited for the study to complete the BPST and other measures of mobility and cognition. Correlations were used to determine construct and concurrent validity of BPST with valid measures of spatial cognition and motor-cognitive integration. Performance was compared between PD and NT adults using independent t-tests. Results. BPST was feasible to administer. Analyses show evidence of construct validity for spatial cognition and for motor-cognitive integration. Concurrent validity was demonstrated with other tests of mobility and cognition. Relationships were stronger and more significant for individuals with PD than for NT individuals. BPST performance was not significantly different between groups. Conclusion. Tests that integrate cognitive challenge in mobility contexts are necessary to assess the health of spatial cognitive and motor-cognitive integration. The BPST is a feasible and valid test of whole-body spatial cognition and motor-cognitive integration in individuals with PD.

Patient-reported and performance-based measures of walking in mild-moderate Parkinson's disease.

BackgroundKnowledge of the relationships between patient‐reported and performance‐based walking measures in Parkinson's disease (PD) should inform clinical decision‐making. The Walk‐12G reliably captures perceived walking difficulties but has not been compared to performance‐based walking in laboratory or free‐living settings or across different groups.ObjectivesTo investigate the relationship between patient‐reported walking difficulties (Walk‐12G) and performance‐based walking in laboratory and free‐living conditions and to determine whether the Walk‐12G can distinguish between the subgroups, (i) people with/without PD and (ii) mild/moderate disease stages.MethodsForty‐seven people without and 49 people with PD (Hoehn and Yahr stage II and III) were assessed in relation to patient‐reported walking difficulties (Walk‐12G scale); spatiotemporal gait characteristics (Pace; Rhythm; Asymmetry; Variability; and Postural control) using a laboratory‐based electronic walkway; and walking behavior (mean steps/day and minutes of brisk walking/day) using accelerometers in free‐living conditions.ResultsThe Walk‐12G correlated moderately with the spatiotemporal domain step velocity (r = −0.46) and walking behavior, measured as mean steps/day (r = −0.46). Weaker correlations were observed for step length and minutes spent in brisk walking (r = −0.36 and r = −0.35, respectively). Poor correlations were observed for all other spatiotemporal domains. The Walk‐12G could distinguish between people with and without PD (Effect size, r = 0.82) and between those at mild/moderate disease stages (r = 0.34).ConclusionsPerceived walking difficulties showed weak to moderate associations with performance‐based measures of walking in mild–moderate PD. As the strongest associations were observed for step velocity and walking behavior, targeting these specific gait aspects could improve perceived walking difficulties in daily life.

Dual tasking in Parkinson's disease: Cognitive consequences while walking.

Cognitive deficits are common in Parkinson's disease (PD) and exacerbate the functional limitations imposed by PD's hallmark motor symptoms, including impairments in walking. Though much research has addressed the effect of dual cognitive-locomotor tasks on walking, less is known about their effect on cognition. The purpose of this study was to investigate the relation between gait and executive function, with the hypothesis that dual tasking would exacerbate cognitive vulnerabilities in PD as well as being associated with gait disturbances. Nineteen individuals with mild-moderate PD without dementia and 13 age- and education-matched normal control adults (NC) participated. Executive function (set-shifting) and walking were assessed singly and during dual tasking. Dual tasking had a significant effect on cognition (reduced set-shifting) and on walking (speed, stride length) for both PD and NC, and also on stride frequency for PD only. The impact of dual tasking on walking speed and stride frequency was significantly greater for PD than NC. Though the group by condition interaction was not significant, PD had fewer set-shifts than NC on dual task. Further, relative to NC, PD showed significantly greater variability in cognitive performance under dual tasking, whereas variability in motor performance remained unaffected by dual tasking. Dual tasking had a significantly greater effect in PD than in NC on cognition as well as on walking. The results suggest that assessment and treatment of PD should consider the cognitive as well as the gait components of PD-related deficits under dual-task conditions. (PsycINFO Database Record

Effects of levodopa on corticostriatal circuits supporting working memory in Parkinson's disease

Working memory dysfunction is common in Parkinson's disease, even in its early stages, but its neural basis is debated. Working memory performance likely reflects a balance between corticostriatal dysfunction and compensatory mechanisms. We tested this hypothesis by examining working memory performance with a letter n-back task in 19 patients with mild-moderate Parkinson's disease and 20 demographically matched healthy controls. Parkinson's disease patients were tested after an overnight washout of their usual dopamine replacement therapy, and again after a standard dose of levodopa. FMRI was used to assess task-related activation and resting state functional connectivity; changes in BOLD signal were related to performance to disentangle pathological and compensatory processes. Parkinson's disease patients off dopamine replacement therapy displayed significantly reduced spatial extent of task-related activation in left prefrontal and bilateral parietal cortex, and poorer working memory performance, compared to controls. Amongst the Parkinson's disease patients off dopamine replacement therapy, relatively better performance was associated with greater activation of right dorsolateral prefrontal cortex compared to controls, consistent with compensatory right hemisphere recruitment. Administration of levodopa remediated the working memory deficit in the Parkinson's disease group, and resulted in a different pattern of performance-correlated activity, with a shift to greater left ventrolateral prefrontal cortex activation in patients on, compared to off dopamine replacement therapy. Levodopa also significantly increased resting-state functional connectivity between caudate and right parietal cortex (within the right fronto-parietal attentional network). The strength of this connectivity contributed to better performance in patients and controls, suggesting a general compensatory mechanism. These findings argue that Parkinson's disease patients can recruit additional neural resources, here, the right fronto-parietal network, to optimize working memory performance despite impaired corticostriatal function. Levodopa seems to both boost engagement of a task-specific prefrontal region, and strengthen a putative compensatory caudate-cortical network to support this executive function.

Effect of Tai Chi Ball Exercise on Functional Mobility in Mild-Moderate Parkinson Disease

Parkinson’s disease (PD) is a neurodegenerative disorder of the basal ganglia that affects approximately 1.5% of adults over the age of 65 . This proportion is higher in PD, where approximately 40% of patients use some form of alternative therapy for treatment of PD symptoms

Balance, Body Motion, and Muscle Activity After High-Volume Short-Term Dance-Based Rehabilitation in Persons With Parkinson Disease: A Pilot Study

The objectives of this pilot study were to (1) evaluate the feasibility and investigate the efficacy of a 3-week, high-volume (450 minutes per week) Adapted Tango intervention for community-dwelling individuals with mild-moderate Parkinson disease (PD) and (2) investigate the potential efficacy of Adapted Tango in modifying electromyographic (EMG) activity and center of body mass (CoM) displacement during automatic postural responses to support surface perturbations. Individuals with PD (n = 26) were recruited for high-volume Adapted Tango (15 lessons, 1.5 hour each over 3 weeks). Twenty participants were assessed with clinical balance and gait measures before and after the intervention. Nine participants were also assessed with support-surface translation perturbations. Overall adherence to the intervention was 77%. At posttest, peak forward CoM displacement was reduced (4.0 ± 0.9 cm, pretest, vs 3.7 ± 1.1 cm, posttest; P = 0.03; Cohen's d = 0.30) and correlated to improvements on Berg Balance Scale (ρ = -0.68; P = 0.04) and Dynamic Gait Index (ρ = -0.75; P = 0.03). Overall antagonist onset time was delayed (27 ms; P = 0.02; d = 0.90) and duration was reduced (56 ms, ≈39%, P = 0.02; d = 0.45). Reductions in EMG magnitude were also observed (P < 0.05). Following participation in Adapted Tango, changes in kinematic and some EMG measures of perturbation responses were observed in addition to improvements in clinical measures. We conclude that 3-week, high-volume Adapted Tango is feasible and represents a viable alternative to longer duration adapted dance programs.Video Abstract available for more insights from the authors (see Supplemental Digital Content 1, http://links.lww.com/JNPT/A143).

MRI appearances of aquaporin and its effect in different brain regions of patients with Parkinson's disease

Objective To investigate MRI appearances of aquaporin(AQP) and its effect in different brain regions of patients with Parkinson's disease(PD). Methods A prospective study was carried out in 33 PD patients(PD group) and 23 gender- and age-matched healthy controls(control group). Clinical data of PD patients were collected.The aquaporin imaging of diffusion-weighted magnetic resonance imaging(MR-DWI) with multiple b-values in different brain regions were performed to detect the apparent diffusion coefficient(AQP-ADC) values of aquaporin.The PD patients were assessed and graded by modified Hoehn-Yahr grading, then the AQP-ADC values of control group, mild PD group, moderate and severe PD group were analyzed using one-way analysis of variance.The correlation analysis was carried out to detect the relationship between AQP-ADC values in different brain regions and Hoehn-Yahr grading of PD patients. Results Compared with control group, mild PD group had significantly higher AQP-ADC values in red nucleus(RN) and globus pallidus(GP) ((0.24±0.04) vs (0.21±0.04), ( 0.21±0.04) vs (0.16±0.04); both P 0.05); and there was also no significant difference in substantianigra(SN), putamen(Pu) and thalamus(THA) among control group, mild PD group and moderate and severe PD group(P>0.05). The correlation analysis showed that there were negative correlations between the AQP-ADC values in RN and GP and Hoehn-Yahr grading(r=-0.479 and -0.395, P 0.05). Conclusion The AQP-ADC values are increased in RN and GP of mild PD patients, and decreased in moderate and severe PD patients, while there is no significant change in SN, Pu and THA of the two groups, suggesting that the expression of AQP in different brain regions may be related to the severity and pathological stage of PD. Key words: Parkinson's disease; Aquaporin; Molecular imaging; Diffusion-weighted magnetic resonance imaging