Quantifying upper limb motor impairment in people with Parkinson's disease: a physiological profiling approach

Sensorimotor functioning changes in response to global exercise versus handwriting upper limb exercise training in Parkinson's disease, results from a phase II randomised controlled trial

INTRODUCTION

People with Parkinson's disease (PwPD) present motor alterations which can impact daily life tasks that require speed and/or accuracy of movement.

OBJECTIVE

A sub analysis of NCT01439022, aiming to estimate the extent to which two different exercise training protocols (global and handwriting upper limb exercise training) impact reaction time, travel speed, and accuracy in PwPD.

METHODS

Seventy PwPD, right-side dominant were randomised 1:1 into two six-month training protocol groups; 35 PwPD performed global exercise training and 35 performed specific training (handwriting upper limb exercise movements). Assessments of speed-accuracy and trade-off were carried out at baseline, after 3 and 6 months of training, and at a 12-month follow-up. The current study used data from a previous publication of a randomised controlled trial that included a 6-month self-managed community exercise programme for PwPD. For the present study we included only the participants who completed the Fitts' task during the baseline assessment.

RESULTS

In the upper limb assessments, no main effects were found for the number of touches, but the exercise group showed a marginal increase over time on the left side. Error averages on the left side decreased significantly for the exercise group from baseline to 6 and 12 months. The exercise group also presented a lower Error CoV and the Reaction Time CoV increased on the right side. Significant findings for Fitts r on the left side indicated lower values for the exercise group, with improvements continuing at 12 months.

CONCLUSION

We report the potential of global exercise interventions to facilitate improvements in reaction time and travel speed, as well as other motor control metrics, with lasting effects at 12 months, particularly on the non-dominant side.

Force Control Issues in Upper and Lower Limbs in Parkinson's Disease and Freezing of Gait

Parkinson's Disease (PD) has been found to cause force control deficits in upper and lower limbs. About 50% of patients with advanced PD develop a debilitating symptom called freezing of gait (FOG), which has been linked to force control problems in the lower limbs, and some may only have a limited response to the gold standard pharmaceutical therapy, levodopa, resulting in partially levodopa-responsive FOG (PLR-FOG). There has been limited research on investigating upper-limb force control in people with PD with PLR-FOG, and without FOG. In this pilot study, force control was explored using an upper-and-lower-limb haptics-enabled robot in a reaching task while people with PD with and without PLR-FOG were on their levodopa medication. A healthy control group was used for reference, and each cohort completed the task at three different levels of assistance provided by the robot. Similar significant proportional force control deficits were found in the upper and lower limbs in patients with PLR-FOG versus those without FOG. Some aspects of force control were found to be retained, including an ability to increase or decrease force in response to changes in resistance while completing a reaching task. Overall, these results suggest there are force control deficits in both the upper and lower limbs in people with PLR-FOG.

Feasibility of virtual low-cost quantitative continuous measurement of movements in the extremities of people with Parkinson's disease

A low-cost quantitative continuous measurement of movements in the extremities of people with Parkinson's disease, a structured motor assessment administered by a trained examiner to a patient physically present in the same room, utilizes sensors to generate output to facilitate the evaluation of the patient. However, motor assessments with the patient and the examiner in the same room may not be feasible due to distances between the patient and the examiner and the risk of transmission of infections between the patient and the examiner. Therefore, we propose a protocol for the remote assessment by examiners in different locations of both (A) videos of patients recorded during in-person motor assessments and (B) live virtual assessments of patients in different locations from examiners. The proposed procedure provides a framework for providers, investigators, and patients in vastly diverse locations to conduct optimal motor assessments required to develop treatment plans utilizing precision medicine tailored to the specific needs of each individual patient. The proposed protocol generates the foundation for providers to remotely perform structured motor assessments necessary for optimal diagnosis and treatment of people with Parkinson's disease and related conditions.

Medication only improves limb movements while deep brain stimulation improves eye and limb movements during visually-guided reaching in Parkinson's disease

Background

Antiparkinson medication and subthalamic nucleus deep brain stimulation (STN-DBS), two common treatments of Parkinson's disease (PD), effectively improve skeletomotor movements. However, evidence suggests that these treatments may have differential effects on eye and limb movements, although both movement types are controlled through the parallel basal ganglia loops.

Objective

Using a task that requires both eye and upper limb movements, we aimed to determine the effects of medication and STN-DBS on eye and upper limb movement performance.

Methods

Participants performed a visually-guided reaching task. We collected eye and upper limb movement data from participants with PD who were tested both OFF and ON medication (n = 34) or both OFF and ON bilateral STN-DBS while OFF medication (n = 11). We also collected data from older adult healthy controls (n = 14).

Results

We found that medication increased saccade latency, while having no effect on reach reaction time (RT). Medication significantly decreased saccade peak velocity, while increasing reach peak velocity. We also found that bilateral STN-DBS significantly decreased saccade latency while having no effect on reach RT, and increased saccade and reach peak velocity. Finally, we found that there was a positive relationship between saccade latency and reach RT, which was unaffected by either treatment.

Conclusion

These findings show that medication worsens saccade performance and benefits reaching performance, while STN-DBS benefits both saccade and reaching performance. We explore what the differential beneficial and detrimental effects on eye and limb movements suggest about the potential physiological changes occurring due to treatment.

Age-related changes in mobility assessments correlate with repetitive goal-directed arm-movement performance

BACKGROUND

There is ample evidence that mobility abilities between healthy young and elderly people differ. However, we do not know whether these differences are based on different lower leg motor capacity or instead reveal a general motor condition that could be detected by monitoring upper-limb motor behavior. We therefore captured body movements during a standard mobility task, namely the Timed Up and Go test (TUG) with subjects following different instructions while performing a rapid, repetitive goal-directed arm-movement test (arm-movement test). We hypothesized that we would be able to predict gait-related parameters from arm motor behavior, even regardless of age.

METHODS

Sixty healthy individuals were assigned to three groups (young: mean 26 ± 3 years, middle-aged 48 ± 9, old 68 ± 7). They performed the arm-movement and TUG test under three conditions: preferred (at preferred movement speed), dual-task (while counting backwards), and fast (at fast movement speed). We recorded the number of contacts within 20 s and the TUG duration. We also extracted TUG walking sequences to analyze spatiotemporal gait parameters and evaluated the correlation between arm-movement and TUG results.

RESULTS

The TUG condition at preferred speed revealed differences in gait speed and step length only between young and old, while dual-task and fast execution increased performance differences significantly among all 3 groups. Our old group's gait speed decreased the most doing the dual-task, while the young group's gait speed increased the most during the fast condition. As in our TUG results, arm-movements were significant faster in young than in middle-aged and old. We observed significant correlations between arm movements and the fast TUG condition, and that the number of contacts closely predicts TUG timefast and gait speedfast. This prediction is more accurate when including age.

CONCLUSION

We found that the age-related decline in mobility performance that TUG reveals strongly depends on the test instruction: the dual-task and fast condition clearly strengthened group contrasts. Interestingly, a fast TUG performance was predictable by the performance in a fast repetitive goal-directed arm-movements test, even beyond the age effect. We assume that arm movements and the fast TUG condition reflect similarly reduced motor function.

TRIAL REGISTRATION

German Clinical Trials Register (DRKS) number: DRKS00016999, prospectively registered on March, 26, 2019.

The quality of life in individuals with Parkinson's Disease: is it related to functionality and tremor severity? A cross-sectional study

BACKGROUND

Symptoms seen in Parkinson's Disease (PD) affect the quality of life (QoL) of individuals.

OBJECTIVES

This study aimed to examine the relationship of QoL with tremor severity and upper limb functionality in individuals with PD.

METHODS

Parkinson's Disease Quality of Life Questionnaire (PDQ-39) was used to examine the QoL of the participants, electromyography was used to measure the tremor amplitude, Nine-Hole Peg Test (NHPT) was used to evaluate the upper limb functionality and dynamometer was used to evaluate grip and pinch strength. Resting and postural tremor amplitudes were recorded from both sides of the hand and forearm. The relationship between QoL and other parameters was tested with Spearman Correlation Analysis. Mann-Whitney U test was used to compare individuals with and without tremor.

RESULTS

It was obtained that tremor amplitude was significantly related to: activities of daily living (rho = 0.597); emotional well-being (rho = 0.694); stigma (rho = 0.524); social support (rho = 0.595 and 0.559), and communication [rho = 0.532 (right forearm), 0.564 (left forearm), and 0.527 (right hand)] sub-parameters of PDQ-39 (p < .05). The relationship of the grip and pinch strength with the PDQ-39 sub-parameters was significant (p < .05), except for social support and communication. The relationship between NHPT and almost all parameters of PDQ-39 (p < .05), except bodily discomfort and social support, was significant.

CONCLUSION

It was concluded that future studies focusing on QoL could also consider tremor severity and grip strength as well as dexterity in individuals with PD.

Use of a physiological profile to document upper limb motor impairment in ageing and in neurological conditions

Profiling performance in the physiological domains underpinning upper limb function (such as strength, sensation, coordination) provides insight into an individual's specific impairments. This compliments the traditional medical 'diagnosis' model that is currently used in contemporary medicine. From an initial battery of 13 tests in which data were collected across the adult lifespan (n = 367, 20-95 years) and in those with neurological conditions (specifically, multiple sclerosis (n = 40), Parkinson's disease (n = 34), and stroke (n = 50)), six tests were selected to comprise a core upper limb physiological profile assessment (PPA). This comprised measures of handgrip strength, simple reaction time, finger dexterity, tactile sensation, bimanual coordination, and a functional task. Individual performance in each of these tests can be compared to a reference population score (devised from our database of healthy individuals aged under 60 years), informing the researcher or clinician how to best direct an intervention or treatment for the individual based on their specific impairment(s). Lastly, a composite score calculated from the average performance across the six tests provides a broad overview of an individual's overall upper limb function. Collectively, the upper limb PPA highlights specific impairments that are prevalent within distinct pathologies and reveals the magnitude of upper limb motor impairment specific to each condition.

Rate control deficits during pinch grip and ankle dorsiflexion in early-stage Parkinson's disease

BACKGROUND

Much of our understanding of the deficits in force control in Parkinson's disease (PD) relies on findings in the upper extremity. Currently, there is a paucity of data pertaining to the effect of PD on lower limb force control.

OBJECTIVE

The purpose of this study was to concurrently evaluate upper- and lower-limb force control in early-stage PD and a group of age- and gender-matched healthy controls.

METHODS

Twenty individuals with PD and twenty-one healthy older adults participated in this study. Participants performed two visually guided, submaximal (15% of maximum voluntary contractions) isometric force tasks: a pinch grip task and an ankle dorsiflexion task. PD were tested on their more affected side and after overnight withdrawal from antiparkinsonian medication. The tested side in controls was randomized. Differences in force control capacity were assessed by manipulating speed-based and variability-based task parameters.

RESULTS

Compared with controls, PD demonstrated slower rates of force development and force relaxation during the foot task, and a slower rate of relaxation during the hand task. Force variability was similar across groups but greater in the foot than in the hand in both PD and controls. Lower limb rate control deficits were greater in PD with more severe symptoms based on the Hoehn and Yahr stage.

CONCLUSIONS

Together, these results provide quantitative evidence of an impaired capacity in PD to produce submaximal and rapid force across multiple effectors. Moreover, results suggest that force control deficits in the lower limb may become more severe with disease progression.

Virtual Reality for Motor and Cognitive Rehabilitation

Virtual Reality (VR) affords clinicians the ability to deliver safe, controlled, task-specific customised interventions that are enjoyable, motivating and engaging. Elements of training in VR comply with principles of learning implicated in new skill acquisition and re-learning skills post-neurological disorders. However, heterogeneity in the description of VR systems and the description and control of 'active' ingredients of interventions (like dosage, type of feedback, task specificity, etc.) have led to inconsistency in the synthesis and interpretation of evidence related to the effectiveness of VR-based interventions, particularly in post-stroke and Parkinson's Disease (PD) rehabilitation. This chapter attempts to describe VR interventions with respect to their compliance with principles of neurorehabilitation, with the goal of optimising interventions for effective training and facilitation of maximum functional recovery. This chapter also advocates using a uniform framework to describe VR systems to promote homogeneity in literature in order to help in the synthesis of evidence. An overview of the evidence revealed that VR systems are effective in mediating deficits in upper extremity, posture and gait function seen in people post-stroke and PD. Generally, interventions were more effective when they were delivered as an adjunct to conventional therapy and were customised for rehabilitation purposes, in addition to complying with principles of learning and neurorehabilitation. Although recent studies imply that their VR intervention is compliant with principles of learning, only a few explicitly describe how these principles are incorporated as 'active ingredients' of the intervention. Finally, VR interventions targeting community ambulation and cognitive rehabilitation are yet limited and therefore warrant attention.

Quantifying upper limb motor impairment in chronic stroke: a physiological profiling approach

Upper limb motor impairments, such as muscle weakness, loss of dexterous movement, and reduced sensation, are common after a stroke. The extent and severity of these impairments differ among individuals, depending on the anatomical location and size of lesions. Identifying impairments specific to the individual is critical to optimize their functional recovery. The upper limb Physiological Profile Assessment (PPA) provides quantitative measures of key physiological domains required for adequate function in the upper limbs. The present study investigates the use of the upper limb PPA in a chronic stroke population. Fifty participants with chronic stroke completed all tests of the upper limb PPA with both their affected and less affected upper limbs. Performance in each test was compared to that of 50 age- and sex-matched control subjects with no history of a stroke. Correlations between test performance and validated measures of stroke, sensorimotor function, and disability were examined. Compared with control subjects, people with stroke demonstrated substantially impaired upper limb PPA performance for both their affected and less affected limbs. Performance in the upper limb PPA was associated with validated measures of sensorimotor function specific to the stroke population (Fugl-Meyer Assessment) and stroke-related disability (Stroke Impact Scale). The upper limb PPA shows good concurrent validity as a means to quantify upper limb function in a chronic stroke population. These tests identify domain-specific deficits and could be further tailored to an individual patient by the clinician to inform rehabilitation and track recovery.NEW & NOTEWORTHY Upper limb motor impairment is a common manifestation after stroke, compromising independence in fundamental daily activities involving the ability to reach, grasp, and manipulate objects. The upper limb Physiological Profile Assessment (PPA) offers a means of quantifying performance of the individual sensorimotor domains that are essential for upper limb function. Establishing individual performance profiles based on age- and sex-based normative scores may facilitate individualized treatment decisions by identifying the stroke patient's specific strengths and limitations.