Motor and cognitive impairments in Parkinson disease: relationships with specific balance and mobility tasks

Neuroimaging and cognitive correlates of postural control in Parkinson's disease: a systematic review

Parkinson's disease (PD) can cause postural instability, which may result in falls. These issues have been associated with motor and non-motor symptoms (NMS), including cognitive dysfunction. Several techniques have been employed to investigate the underlying neural mechanisms involved in postural control in PD. These include behavioural studies assessing associations between cognition and postural control, functional neuroimaging studies, and resting-state neural correlates. This review provides an overview of these emerging bodies of research. Scopus, PubMed, and ProQuest were searched and detailed the brain-imaging technique, cohort, and postural control measures. A total of 79 studies were identified. Findings supported the notion of cortical involvement in postural control function to compensate for subcortical damage resulting from PD. Future studies should standardise their outcome measures and data analysis to allow comparisons of results across studies and ensure more comprehensive and robust data collection to enhance the reliability and validity of these findings.

Effects of a Concurrent Working Memory Task on Speech Acoustics in Parkinson's Disease

PURPOSE

The purpose of this study was to determine the effect of a concurrent working memory task on acoustic measures of speech in individuals with Parkinson's disease (PD).

METHOD

Individuals with PD and age- and sex-matched controls performed a speaking task with and without a Stroop-like concurrent working memory task. Cepstral peak prominence, low-to-high spectral energy ratio, fundamental frequency (fo) standard deviation, articulation rate, pause duration, articulatory-acoustic vowel space, relative fo, mean voice onset time (VOT), and VOT variability were calculated for each condition. Mixed-model analyses of variance were performed to determine the effects of group, condition (presence of the concurrent working memory task), and their interaction on the acoustic measures.

RESULTS

All measures except for VOT variability, mean pause duration, and relative fo offset differed between people with and without PD. Cepstral peak prominence, articulation rate, and relative fo offset differed as a function of condition. However, no measures indicated disparate effects of condition as a function of group.

CONCLUSION

Although differentially impactful on limb motor function in PD, here a concurrent working memory task was not found to be differentially disruptive to speech acoustics in PD.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.24759648.

Association of activities of daily living, mobility and balance ability, and symptoms of Parkinson's disease with the masses and amounts of intramuscular non-contractile tissue of the trunk and lower extremity muscles in patients with Parkinson's disease

PURPOSE

We examined the association of activities of daily living (ADL), mobility and balance ability, and symptoms of Parkinson's disease (PD) with the masses and amounts of intramuscular non-contractile tissue of the trunk and lower extremity muscles in patients with PD.

METHODS

The subjects were 11 community-dwelling patients with PD. ADL were assessed using the Functional Independence Measure. Mobility capacity was assessed based on measurement of maximal walking speed and timed up-and-go time, while balance ability was evaluated based on measurement of one-legged stance time. The symptoms of PD were assessed based on measurement of the Hoehn and Yahr stage and Unified Parkinson's Disease Rating Scale. Muscle thickness (MT) and echo intensity (EI) of the trunk and lower extremity muscles were also measured using an ultrasound imaging device.

RESULTS

Partial correlation analysis revealed an association between reduced ADL and increased EI of the lumbar erector spinae muscle; reduced mobility capacity and increased EI of the rectus abdominis and gluteus minimus muscles; and reduced balance ability and decreased MT of the lumbar erector spinae muscle and increased EI of the lumbar erector spinae, semitendinosus, and tibialis posterior muscles. Partial correlation analysis also showed an association between symptoms of severe PD and decreased MT of the tibialis anterior muscles and increased EI of the lumbar erector spinae, gluteus minimus, and tibialis posterior muscles.

CONCLUSION

The properties of the trunk and lower extremity muscles may be critical for ADL, mobility and balance ability, and symptoms of PD in patients with PD.

Stroke in Parkinson's disease: a review of epidemiological studies and potential pathophysiological mechanisms

Parkinson's disease (PD) is the fastest growing neurological disorder and one of the leading neurological causes of disability worldwide following stroke. An overall aging global population, as well as general changes in lifestyle associated with mass industrialization in the last century, may be linked to both increased incidence rates of PD and an increase in cumulative cardiovascular risk. Recent epidemiological studies show an increased risk of stroke, post-stroke complications, and subclinical ischemic insults in PD. PD patients have a host of characteristics that might contribute to increasing the risk of developing ischemic stroke including motor impairment, dysautonomia, and sleep disorders. This increases the urgency to study the interplay between PD and other neurological disorders, and their combined effect on mortality, morbidity, and quality of life. In this review, we provide a comprehensive overview of the studied etiological factors and pathological processes involved in PD, specifically with regard to their relationship to stroke. We hope that this review offers an insight into the relationship between PD and ischemic stroke and motivates further studies in this regard.

Assessment of Force Production in Parkinson's Disease Subtypes

Muscle weakness is a secondary motor symptom of Parkinson's disease (PD), especially in the subtype characterized by postural instability and gait difficulty (PIGD). Since the PIGD subtype also presents worse bradykinesia, we hypothesized that it also shows a decreased rate of force development, which is linked to an increased risk of falling in PD. Therefore, we investigated the effects of PD and PD subtypes on a force production profile and correlated the force production outcomes with clinical symptoms for each PD subtype. We assessed three groups of participants: 14 healthy older adults (OA), 10 people with PD composing the PIGD group, and 14 people with PD composing the tremor-dominant group. Three knee extension maximum voluntary isometric contractions were performed in a leg extension machine equipped with a load cell to assess the force production. The outcome measures were: peak force and rate of force development (RFD) at 50 ms (RFD50), 100 ms (RFD100), and 200 ms (RFD200). We observed lower peak force, RFD50, RFD100, and RFD200 in people with PD, regardless of subtypes, compared with the OA group (p < 0.05 for all comparisons). Together, our results indicated that PD affects the capacity to produce maximal and rapid force. Therefore, future interventions should consider rehabilitation programs for people with PD based on muscle power and fast-force production, and consequently reduce the likelihood of people with PD falling from balance-related events, such as from an unsuccessful attempt to avoid a tripping hazard or a poor and slower stepping response.

Differences in predictors for gait speed and gait endurance in Parkinson's disease

INTRODUCTION

Both gait speed and gait endurance directly impact independence and community engagement for individuals with Parkinson's disease (PD). However, factors accounting for variability in gait speed and gait endurance performance are unclear. The purpose of this study was to investigate whether key factors associated with gait speed in individuals with PD also predicted gait endurance.

METHODS

Community dwelling ambulatory individuals with PD were recruited for a single session. Key measures included 10 Meter Walk Test (10MWT) and 6 Minute Walk Test (6MWT) and key factors: age, disease severity [Movement Disorders Society United Parkinson's Disease Rating Scale (motor scale only) (MDS-UPDRS motor)], plantar flexor strength [Calf Raise Senior (CRS)], fatigue [Fatigue Severity Scale (FSS)], cognition [Montreal Cognitive Assessment (MoCA)], and balance [Four Square Step Test (FSST)]. Multiple linear regression analyses were conducted to determine clinical relationships.

RESULTS

Seventy-two individuals with PD (mean (standard deviation) (age = 70.83 (7.91) years; 50 males; MDS-UPDRS motor = 30.67 (13.50)) completed all assessments. The model predicting gait speed was significant, F(6, 65) = 15.143, p <.001, accounting for 54 % of the variance. Of the predictor variables age, MDS-UPDRS motor, CRS, MoCA and FSST scores were significant predictors. The model predicting gait endurance was significant, F(6, 65) = 15.608, p <.001, accounting for 55 % of the variance. Of the predictor variables, age, MDS-UPDRS motor scale, and CRS scores were significant predictors.

DISCUSSION

Gait speed and gait endurance are similarly influenced by age, motor impairment, and plantarflexion strength. However, cognition and balance were predictors only of gait speed, which may suggest unique task differences exist between gait speed and gait endurance.

Plantarflexor strength, gait speed, and step length change in individuals with Parkinson's disease

Parkinson's disease affects the ability to walk often resulting in decreased independence and low quality of life. The purpose of this study was to examine differences in plantarflexor strength (PFS), gait speed, and step length in persons with Parkinson's disease (PwP) and healthy peers using clinical measures. A secondary purpose was to examine the relationship between these gait components across disease severity. The study was a convenience sample of 71 PwP and 25 community healthy peers. Outcome measures included 10-Meter Walk, step length, and Calf-Raise Senior Test. PwP were separated into mild and moderate impairment groups using the Movement Disorders Society United Parkinson's Disease Rating Scale Motor Subscale. Between group differences for gait speed (F2,93 = 24.560, P = 0.000), step length (F2,93 = 21.93, P = 0.000) and PFS (F2,93 = 19.49, P < 0.000) were observed. Post hoc testing determined a difference (P < 0.00) in gait speed, step length, and PFS testing between moderate impairment versus healthy peers and mild impairment. A difference (P = 0.045) in step length and a trend towards significance (P = 0.064) for PFS was found between healthy peers and mild impairment group. This study revealed that PwP with mild impairment also have significant changes in step length and trends toward plantarflexor weakness without a significant difference in gait speed. These early changes may warrant early assessment and intervention to prevent decline. This study may bring clinical focus onto the plantarflexor and step length for early comprehensive assessment and treatment of gait and mobility for PwP.

Fourier-Based Footfall Placement Variability in Parkinson's Disease

The current investigation examined whether Parkinson's patients (PD) have greater Fourier-based footfall placement gait with the greatest mobility dysfunction variability (FPV) than the age and gender matched control group and that variability would be the greatest in the PD participants with the greatest mobility dysfunction indexed Hoehn/Yahr scale. 35 persons undergoing PD and 30 age-matched controls participated in this investigation. Participants repeated two trials' normal walking and average and variability parameters of gait were measured using a 3.66 m electronic walkway. FPV was quantified as a change in the center of pressure during gait. Persons with PD were divided into two groups based on Hoehn/Yahr scale. Overall, persons with PD had smaller average performance indexed by mean and greater gait variability than controls as indexed by CV and Fourier-based variability (p's<0.05). Moreover, PD with higher mobility dysfunction had not only greater variability in traditional parameters but also greater Fourier-based variability than nonfallers with MS (p<.001) with higher effect size (η²=0.37 vs.0.18-0.29). These observations highlight the fact that footfall placement variability is related to mobility dysfunction in PD. Further study is necessary to determine contributing factors to an increased FPV and whether targeted interventions such as exercise can reduce FPV.

Augmented visual feedback-aided interventions for motor rehabilitation in Parkinson's disease: a systematic review

PURPOSE

A systematic review was performed to (1) evaluate the effectiveness of augmented visual feedback-based treatments for motor rehabilitation in Parkinson's disease, and (2) examine treatment design factors associated with enhanced outcomes following these treatments.

METHODS

Eight databases were searched from their start-date up to January 2017 using the key terms Parkinson's Disease and augmented visual feedback. Two independent raters screened the abstracts and full articles for inclusion. Relevant data were extracted and summarized, and methodological quality of accepted articles was assessed.

RESULTS

Eight single-group studies and 10 randomized control trials were included in the review. Augmented visual feedback-based treatments resulted in improved outcomes with small to large effect sizes post-treatment for the majority of impairment, activity, participation, and global motor function measures, and these improvements were often superior to traditional rehabilitation/education programs. Enhanced treatment outcomes were observed in studies that provided large amounts and high intensities of treatment; gamified feedback; and provided knowledge of performance feedback in real-time on 100% of practice trials.

CONCLUSION

Augmented visual feedback appears to be a useful motor rehabilitation tool in Parkinson's disease; however, high-quality, rigorous studies remain limited. Future studies should consider factors that enhance rehabilitation outcomes when designing augmented visual feedback-based interventions. Implications for rehabilitation Augmented visual feedback is a useful tool for motor rehabilitation in Parkinson's disease; augmented visual feedback-based treatments are often superior to traditional programs. These treatments are associated with improved outcomes in impairment, activity, participation, and global motor function domains. Rehabilitation professionals can optimize their use of augmented visual feedback-based treatments by providing large amounts and a high intensity of treatment, gamifying feedback, and providing knowledge of performance feedback in real-time and at a high frequency.

Flexed Truncal Posture in Parkinson Disease: Measurement Reliability and Relationship With Physical and Cognitive Impairments, Mobility, and Balance

BACKGROUND AND PURPOSE

Flexed truncal posture is common in people with Parkinson disease (PD); however, little is known about the mechanisms responsible or its effect on physical performance. This cross-sectional study aimed to establish the reliability of a truncal posture measurement and explore relationships between PD impairments and truncal posture, as well as truncal posture and balance and mobility.

METHODS

A total of 82 people with PD participated. Truncal posture was measured in standing as the distance between vertebra C7 and a wall. Univariate and multivariate regression analyses were performed with truncal posture and impairments, including global axial symptoms, tremor, bradykinesia, rigidity, freezing of gait (FOG), reactive stepping and executive function, as well as truncal posture with balance and mobility measures.

RESULTS

The truncal posture measure had excellent test-retest reliability (ICC3,1 0.79, 95% CI 0.60-0.89, P < 0.001). Global axial symptoms had the strongest association with truncal posture (adjusted R = 0.08, P = 0.01), although the majority of the variance remains unexplained. Post hoc analysis revealed that several impairments were associated with truncal posture only in those who did not report FOG. Flexed truncal posture was associated with poorer performance of most balance and mobility tasks after adjustment for age, gender, disease severity, and duration (adjusted R = 0.24-0.33, P < 0.001-0.03).

DISCUSSION AND CONCLUSIONS

The C7 to wall measurement is highly reliable in people with PD. Global axial symptoms were independently associated with truncal posture. Greater flexed truncal posture was associated with poorer balance and mobility. Further studies are required to elucidate the mechanisms responsible for flexed truncal posture and the impact on activity.Video Abstract available for more insights from the authors (see Video, Supplemental Digital Content 1, http://links.lww.com/JNPT/A164).

Calibration of the Leg Muscle Responses Elicited by Predictable Perturbations of Stance and the Effect of Vision

Motor adaptation due to task practice implies a gradual shift from deliberate control of behavior to automatic processing, which is less resource- and effort-demanding. This is true both for deliberate aiming movements and for more stereotyped movements such as locomotion and equilibrium maintenance. Balance control under persisting critical conditions would require large conscious and motor effort in the absence of gradual modification of the behavior. We defined time-course of kinematic and muscle features of the process of adaptation to repeated, predictable perturbations of balance eliciting both reflex and anticipatory responses. Fifty-nine sinusoidal (10 cm, 0.6 Hz) platform displacement cycles were administered to 10 subjects eyes-closed (EC) and eyes-open (EO). Head and Center of Mass (CoM) position, ankle angle and Tibialis Anterior (TA) and Soleus (Sol) EMG were assessed. EMG bursts were classified as reflex or anticipatory based on the relationship between burst amplitude and ankle angular velocity. Muscle activity decreased over time, to a much larger extent for TA than Sol. The attenuation was larger for the reflex than the anticipatory responses. Regardless of muscle activity attenuation, latency of muscle bursts and peak-to-peak CoM displacement did not change across perturbation cycles. Vision more than doubled speed and the amount of EMG adaptation particularly for TA activity, rapidly enhanced body segment coordination, and crucially reduced head displacement. The findings give new insight on the mode of amplitude- and time-modulation of motor output during adaptation in a balancing task, advocate a protocol for assessing flexibility of balance strategies, and provide a reference for addressing balance problems in patients with movement disorders.

Investigation of factors impacting mobility and gait in Parkinson disease

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.

The effectiveness of physiotherapy treatment on balance dysfunction and postural instability in persons with Parkinson's disease: a systematic review and meta-analysis

Background

Balance dysfunction and postural instability in Parkinson’s disease are among the most relevant determinants of an impaired quality of life. Physiotherapy interventions are essential to reduce the level of disability by treating balance dysfunction and postural instability. The aim of this systematic review with meta-analysis was to test the effectiveness of conventional physiotherapy interventions in the management of balance dysfunction and postural instability in Persons with idiopathic Parkinson’s disease.

Method

A systematic literature search of the Cochrane Library, PubMed/Medline, PEDro, Rehadat, and Rehab Trials were performed by 2 reviewers (AY and AT) independently. Eligible randomised controlled trials published from September 2005 to June 2015 were included. The selected RCTs, which investigated the effects of conventional physiotherapy treatments in the management of postural instability and balance dysfunction in Persons with Parkinson’s disease, were assessed on a methodological quality rating scale. Included studies differed clearly from each other with regard to patient characteristics, intervention protocol, and outcome measures. Important characteristics and outcomes were extracted, summarized and analyzed.

Results

Eight trials with a total of 483 participants were eligible for inclusion of which 5 trials provide data for meta-analysis. Benefits from conventional physiotherapy treatment were reported for all of the outcomes assessed. The pooled estimates of effects showed significantly improved berg balance scale (SMD, 0.23; 95 % CI, 0.10–0.36; P < 0.001) after exercise therapy, in comparison with no exercise or sham treatment. Exercise interventions specifically addressing components of balance dysfunction demonstrated the largest efficacy with moderate effect size (SMD, 5.98; 95 % CI, 2.29–9.66; P < 0.001). Little effects were observed for interventions that specifically targeted Falls efficacy scale. The pooled data indicated that physiotherapy exercises decreased the incidence of falling by 6.73 (95 % CI: −14.00, 0.54, p = 0.07) with the overall effect of Z = 1.81.

Conclusion

Physiotherapy interventions like balance training combined with muscle strengthening, the range of movement and walking training exercise is effective in improving balance in patients with Parkinson’s disease and more effective than balance exercises alone. Highly challenging balance training and incremental speed-dependent treadmill training can also be part of a rehabilitation program for management of balance dysfunction and Postural instability in patients with idiopathic Parkinson’s disease.

Identification of genetic factors that modify motor performance and body weight using Collaborative Cross mice

Evidence has emerged that suggests a link between motor deficits, obesity and many neurological disorders. However, the contributing genetic risk factors are poorly understood. Here we used the Collaborative Cross (CC), a large panel of newly inbred mice that captures 90% of the known variation among laboratory mice, to identify the genetic loci controlling rotarod performance and its relationship with body weight in a cohort of 365 mice across 16 CC strains. Body weight and rotarod performance varied widely across CC strains and were significantly negatively correlated. Genetic linkage analysis identified 14 loci that were associated with body weight. However, 45 loci affected rotarod performance, seven of which were also associated with body weight, suggesting a strong link at the genetic level. Lastly, we show that genes identified in this study overlap significantly with those related to neurological disorders and obesity found in human GWA studies. In conclusion, our results provide a genetic framework for studies of the connection between body weight, the central nervous system and behavior.

A Pilot Study of Gait Function in Farmworkers in Eastern North Carolina

Farmworkers endure many job-related hazards, including fall-related work injuries. Gait analysis may be useful in identifying potential fallers. The goal of this pilot study was to explore differences in gait between farmworkers and non-farmworkers. The sample included 16 farmworkers and 24 non-farmworkers. Gait variables were collected using the portable GAITRite system, a 16-foot computerized walkway. Generalized linear regression models were used to examine group differences. All models were adjusted for two established confounders, age and body mass index. There were no significant differences in stride length, step length, double support time, and base of support; but farmworkers had greater irregularity of stride length (P = .01) and step length (P = .08). Farmworkers performed significantly worse on gait velocity (P = .003) and cadence (P < .001) relative to non-farmworkers. We found differences in gait function between farmworkers and non-farmworkers. These findings suggest that measuring gait with a portable walkway system is feasible and informative in farmworkers and may possibly be of use in assessing fall risk.

Exercise for falls prevention in Parkinson disease: a randomized controlled trial

OBJECTIVE

To determine whether falls can be prevented with minimally supervised exercise targeting potentially remediable fall risk factors, i.e., poor balance, reduced leg muscle strength, and freezing of gait, in people with Parkinson disease.

METHODS

Two hundred thirty-one people with Parkinson disease were randomized into exercise or usual-care control groups. Exercises were practiced for 40 to 60 minutes, 3 times weekly for 6 months. Primary outcomes were fall rates and proportion of fallers during the intervention period. Secondary outcomes were physical (balance, mobility, freezing of gait, habitual physical activity), psychological (fear of falling, affect), and quality-of-life measures.

RESULTS

There was no significant difference between groups in the rate of falls (incidence rate ratio [IRR] = 0.73, 95% confidence interval [CI] 0.45-1.17, p = 0.18) or proportion of fallers (p = 0.45). Preplanned subgroup analysis revealed a significant interaction for disease severity (p < 0.001). In the lower disease severity subgroup, there were fewer falls in the exercise group compared with controls (IRR = 0.31, 95% CI 0.15-0.62, p < 0.001), while in the higher disease severity subgroup, there was a trend toward more falls in the exercise group (IRR = 1.61, 95% CI 0.86-3.03, p = 0.13). Postintervention, the exercise group scored significantly (p < 0.05) better than controls on the Short Physical Performance Battery, sit-to-stand, fear of falling, affect, and quality of life, after adjusting for baseline performance.

CONCLUSIONS

An exercise program targeting balance, leg strength, and freezing of gait did not reduce falls but improved physical and psychological health. Falls were reduced in people with milder disease but not in those with more severe Parkinson disease.

CLASSIFICATION OF EVIDENCE

This study provides Class III evidence that for patients with Parkinson disease, a minimally supervised exercise program does not reduce fall risk. This study lacked the precision to exclude a moderate reduction or modest increase in fall risk from exercise.

TRIAL REGISTRATION

Australian New Zealand Clinical Trials Registry (ACTRN12608000303347).

A systematic review and meta-analysis of strength training in individuals with multiple sclerosis or Parkinson disease

Strength training has, in recent years, been shown to be beneficial for people with Parkinson disease and multiple sclerosis. Consensus regarding its utility for these disorders nevertheless remains contentious among healthcare professionals. Greater clarity is required, especially in regards to the type and magnitude of effects as well as the response differences to strength training between individuals with Parkinson disease or multiple sclerosis. This study examines the effects, magnitude of those effects, and response differences to strength training between patients with Parkinson disease or multiple sclerosis. A comprehensive search of electronic databases including Physiotherapy Evidence Database scale, PubMed, EMBASE, Cochrane Central Register of Controlled Trials, and CINAHL was conducted from inception to July 2014. English articles investigating the effect of strength training for individuals with neurodegenerative disorders were selected. Strength training trials that met the inclusion criteria were found for individuals with Parkinson disease or multiple sclerosis. Individuals with Parkinson disease or multiple sclerosis were included in the study. Strength training interventions included traditional (free weights/machine exercises) and nontraditional programs (eccentric cycling). Included articles were critically appraised using the Physiotherapy Evidence Database scale. Of the 507 articles retrieved, only 20 articles met the inclusion criteria. Of these, 14 were randomized and 6 were nonrandomized controlled articles in Parkinson disease or multiple sclerosis. Six randomized and 2 nonrandomized controlled articles originated from 3 trials and were subsequently pooled for systematic analysis. Strength training was found to significantly improve muscle strength in people with Parkinson disease (15%-83.2%) and multiple sclerosis (4.5%-36%). Significant improvements in mobility (11.4%) and disease progression were also reported in people with Parkinson disease after strength training. Furthermore, significant improvements in fatigue (8.2%), functional capacity (21.5%), quality of life (8.3%), power (17.6%), and electromyography activity (24.4%) were found in individuals with multiple sclerosis after strength training. The limitations of the study were the heterogeneity of interventions and study outcomes in Parkinson disease and multiple sclerosis trials. Strength training is useful for increasing muscle strength in Parkinson disease and to a lesser extent multiple sclerosis.

Exercise for falls prevention in Parkinson disease: a randomized controlled trial

OBJECTIVE

To determine whether falls can be prevented with minimally supervised exercise targeting potentially remediable fall risk factors, i.e., poor balance, reduced leg muscle strength, and freezing of gait, in people with Parkinson disease.

METHODS

Two hundred thirty-one people with Parkinson disease were randomized into exercise or usual-care control groups. Exercises were practiced for 40 to 60 minutes, 3 times weekly for 6 months. Primary outcomes were fall rates and proportion of fallers during the intervention period. Secondary outcomes were physical (balance, mobility, freezing of gait, habitual physical activity), psychological (fear of falling, affect), and quality-of-life measures.

RESULTS

There was no significant difference between groups in the rate of falls (incidence rate ratio [IRR] = 0.73, 95% confidence interval [CI] 0.45-1.17, p = 0.18) or proportion of fallers (p = 0.45). Preplanned subgroup analysis revealed a significant interaction for disease severity (p < 0.001). In the lower disease severity subgroup, there were fewer falls in the exercise group compared with controls (IRR = 0.31, 95% CI 0.15-0.62, p < 0.001), while in the higher disease severity subgroup, there was a trend toward more falls in the exercise group (IRR = 1.61, 95% CI 0.86-3.03, p = 0.13). Postintervention, the exercise group scored significantly (p < 0.05) better than controls on the Short Physical Performance Battery, sit-to-stand, fear of falling, affect, and quality of life, after adjusting for baseline performance.

CONCLUSIONS

An exercise program targeting balance, leg strength, and freezing of gait did not reduce falls but improved physical and psychological health. Falls were reduced in people with milder disease but not in those with more severe Parkinson disease.

CLASSIFICATION OF EVIDENCE

This study provides Class III evidence that for patients with Parkinson disease, a minimally supervised exercise program does not reduce fall risk. This study lacked the precision to exclude a moderate reduction or modest increase in fall risk from exercise.

TRIAL REGISTRATION

Australian New Zealand Clinical Trials Registry (ACTRN12608000303347).

Leg muscle power is enhanced by training in people with Parkinson’s disease: a randomized controlled trial

Objective:

To determine the effects of leg muscle power training in people with Parkinson’s disease.

Design:

Randomized controlled trial.

Setting:

University laboratory (outcome measures and experimental intervention), community (control intervention).

Subjects:

Community-dwelling people with Parkinson’s disease.

Interventions:

Leg muscle power training using pneumatic variable resistance equipment (experimental) was compared with low intensity sham exercise (control). Both groups exercised twice weekly for 12 weeks.

Main measures:

Primary outcomes were peak power of four leg muscle groups. Secondary outcomes were measures of muscle strength, mobility, balance and falls.

Results:

Exercise adherence was high in both groups. Leg muscle power was significantly better in the experimental group than the control group in all four primary outcome measures at 12 weeks after adjusting for baseline values: leg extensors (57.9 watts, 95% confidence interval (CI) 22.0–93.7, p = 0.002); knee flexors (29.6 watts, 95% CI 7.4–51.8, p = 0.01); hip flexors (68.1 watts, 95% CI 19.6–116.5, p = 0.007); and hip abductors (37.4 watts, 95% CI 19.9–54.9, p < 0.001). The experimental group performed significantly better on tests of leg muscle strength ( p < 0.001 to 0.07) and showed trends toward better performance in the Timed Up and Go ( p = 0.13) and choice stepping reaction time ( p = 0.11). There was a non-significant reduction in the rate of falls in the experimental group compared with the control group (incidence rate ratio 0.84, p = 0.76).

Conclusions:

This programme significantly improved muscle power in all trained muscle groups.

Spatial-orientation priming impedes rather than facilitates the spontaneous control of hand-retraction speeds in patients with Parkinson's disease

Background

Often in Parkinson’s disease (PD) motor-related problems overshadow latent non-motor deficits as it is difficult to dissociate one from the other with commonly used observational inventories. Here we ask if the variability patterns of hand speed and acceleration would be revealing of deficits in spatial-orientation related decisions as patients performed a familiar reach-to-grasp task. To this end we use spatial-orientation priming which normally facilitates motor-program selection and asked whether in PD spatial-orientation priming helps or hinders performance.

Methods

To dissociate spatial-orientation- and motor-related deficits participants performed two versions of the task. The biomechanical version (DEFAULT) required the same postural- and hand-paths as the orientation-priming version (primed-UP). Any differences in the patients here could not be due to motor issues as the tasks were biomechanically identical. The other priming version (primed-DOWN) however required additional spatial and postural processing. We assessed in all three cases both the forward segment deliberately aimed towards the spatial-target and the retracting segment, spontaneously bringing the hand to rest without an instructed goal.

Results and Conclusions

We found that forward and retracting segments belonged in two different statistical classes according to the fluctuations of speed and acceleration maxima. Further inspection revealed conservation of the forward (voluntary) control of speed but in PD a discontinuity of this control emerged during the uninstructed retractions which was absent in NC. Two PD groups self-emerged: one group in which priming always affected the retractions and the other in which only the more challenging primed-DOWN condition was affected. These PD-groups self-formed according to the speed variability patterns, which systematically changed along a gradient that depended on the priming, thus dissociating motor from spatial-orientation issues. Priming did not facilitate the motor task in PD but it did reveal a breakdown in the spatial-orientation decision that was independent of the motor-postural path.

Gait variability and multiple sclerosis

Gait variability, that is, fluctuations in movement during walking, is an indicator of walking function and has been associated with various adverse outcomes such as falls. In this paper, current research concerning gait variability in persons with multiple sclerosis (MS) is discussed. It is well established that persons with MS have greater gait variability compared to age and gender matched controls without MS. The reasons for the increase in gait variability are not completely understood. Evidence indicates that disability level, assistive device use, attentional requirement, and fatigue are related to gait variability in persons with MS. Future research should address the time-evolving structure (i.e., temporal characteristics) of gait variability, the clinical importance of gait variability, and underlying mechanisms that drive gait variability in individuals with MS.

An evidence-based exercise regimen for patients with mild to moderate Parkinson's disease

Parkinson’s disease (PD) is a neurological disorder that is manifested in the form of both motor and non-motor symptoms such as resting tremor, bradykinesia, muscular rigidity, depression, and cognitive impairment. PD is progressive in nature, ultimately leading to debilitating disruption of activities of daily living. Recently, a myriad of research has been focused on non-pharmacological interventions to alleviate the motor and non-motor symptoms of the disease. However, while there is a growing body of evidence supporting exercise as a viable therapy option for the treatment of Parkinson’s disease, there is a lack of literature enumerating a specific exercise sequence for patients with PD. In this literature review, we analyze the success of specific modalities of exercise in order to suggest an optimal exercise regimen for Parkinson’s disease patients.