Motor symptoms in Parkinson's disease: A unified framework

Parkinson’s disease (PD) is characterized by a range of motor symptoms. Besides the cardinal symptoms (akinesia and bradykinesia, tremor and rigidity), PD patients show additional motor deficits, including: gait disturbance, impaired handwriting, grip force and speech deficits, among others. Some of these motor symptoms (e.g., deficits of gait, speech, and handwriting) have similar clinical profiles, neural substrates, and respond similarly to dopaminergic medication and deep brain stimulation (DBS). Here, we provide an extensive review of the clinical characteristics and neural substrates of each of these motor symptoms, to highlight precisely how PD and its medical and surgical treatments impact motor symptoms. In conclusion, we offer a unified framework for understanding the range of motor symptoms in PD. We argue that various motor symptoms in PD reflect dysfunction of neural structures responsible for action selection, motor sequencing, and coordination and execution of movement

Investigating The Acute Levodopa Response In Early To Advanced Parkinson’s Disease

Parkinson’s disease (PD) is a neurogenerative movement disorder that often requires surgical interventions such as deep brain stimulation (DBS) when motor complications arise from long term levodopa therapy. Understanding the level of motor improvement received by patients from levodopa (levodopa response; LR) at each stage of disease duration is integral to optimizing both current treatment and DBS implementation. In this study, the levodopa challenge test was employed to investigate the LR in early to advanced stages of disease in 70 PD participants. The LR only moderately correlated with disease duration, suggesting large interindividual variability in the LR between patients of similar disease durations. The LR correlated most strongly with motor symptom severity in the OFF-medication state. We proposed that this was in part due to whether an individual relies more heavily on a nigral or extra-nigral control of dopamine in the PD brain. These findings offer support for implementing DBS in individuals earlier in disease and with smaller motor responses to levodopa

Effects of Coordinated Reset Deep Brain Stimulation of Subthalamic Nucleus on Parkinsonian Gait in the Non-Human Primate Model

Parkinson’s Disease (PD) is a neurodegenerative disorder that affects over 10 million people worldwide. Deep Brain Stimulation (DBS) has been a successful treatment for advanced PD, however, can be accompanied with current spread related side effects. Coordinated Reset (CR) DBS is a novel therapeutic approach that could reduce the risk of side-effects by using lower current. Previous research has shown therapeutic effects of CR DBS on PD motor symptoms including akinesia, bradykinesia, rigidity, and tremor that sustained after stimulation cessation (i.e., carryover effect), however its effect on gait dysfunction is unknown even though it can be one of the most difficult symptoms to treat. The goal of this study is to investigate the carryover effect of subthalamic CR DBS on PD gait. Two non-human primates (NHP) were rendered parkinsonian and implanted with a DBS lead in the subthalamic nucleus (STN). Each subject received STN CR DBS for 2 hours per day for 5 consecutive days. Gait was quantitatively assessed before and after the stimulation using a gait testing apparatus. A modified clinical rating scale (mUPDRS) was used to monitor carryover effects on other motor symptoms. Moreover, in one NHP, the differential effects of CR DBS using two additional burst frequencies were also explored. Our results showed that STN CR DBS induced carryover improvement in gait as well as in other symptoms. We also identified a significant impact of varying burst frequency on the effect of CR DBS in gait given that one burst frequency produced greater gait improvement than the others. Although preliminary, this study encourages the further advancement of CR DBS and emphasizes the importance of customizing parameter settings of CR DBS to treat specific symptoms of PD

L'impact de la chorée sur les mouvements alternés rapides des patients ayant la maladie de Huntington = The impact of chorea on rapid alternating movements in patients with Huntington's disease

Le but de cette étude était d'isoler l'impact de la chorée sur les mouvements volontaires, pour mieux évaluer le rôle des mouvements involontaires sur les perturbations motrices observées chez les patients ayant la maladie de Huntington. Les mouvements involontaires du corps ainsi que les actions motrices volontaires furent enregistrés simultanément, à l'aide d'un système de pistage magnétique, chez quinze patients choréiques ayant la maladie de Huntington ainsi que chez quinze sujets contrôle en bonne santé de même âge et sexe. Il a été demandé aux participants d'accomplir deux tâches distinctes; une de mouvements alternés rapides (RAM) qui permettra de quantifier l'hypokinésie et la bradykinésie, et une tâche de poursuite manuelle (MT) qui fournira une mesure quant à l'intrusion des chorées lors de mouvements précis. Les patients ayant la maladie de Huntington ont obtenu de meilleurs résultats comparativement aux sujets contrôles lors de la tâche RAM, démontrant ainsi l'absence de bradykinésie chez ces sujets. Lors de la tâche MT, les patients ayant la maladie de Huntington ont démontré une déviation par rapport à l'emplacement de la cible réduisant ainsi leur habileté à reproduire sa vitesse. De plus, une corrélation fût établie entre l'erreur au niveau des performances et l'amplitude des chorées du corps, illustrant l'effet néfaste des chorées lors de mouvements précis. Ces résultats démontrent clairement que la bradykinésie n'est pas un symptôme de la maladie de Huntington lorsque des chorées sont présentes, mais que les chorées sont la principale cause d'erreur de performance lors de mouvements précis. Donc, les patients atteints de la maladie de Huntington bénéficieraient grandement de traitements visant à réduire les chorées tout en maintenant une fonction motrice adéquate. ______________________________________________________________________________ MOTS-CLÉS DE L’AUTEUR : Huntington, Bradykinesia, Chorée, Quantification, Parkinson

Extrapyramidal signs in normal pressure hydrocephalus: an objective assessment

<p>Abstract</p> <p>Background</p> <p>Beyond the classic Normal Pressure Hydrocephalus (NPH) triad of gait disturbance, incontinence, and dementia are characteristic signs of motor dysfunction in NPH patients. We used highly sensitive and objective methods to characterize upper limb extrapyramidal signs in a series of NPH subjects compared with controls. Concentrated evaluation of these profound, yet underappreciated movement disorders of NPH before and after techniques of therapeutic intervention may lead to improved diagnosis, insight into pathophysiology, and targeted treatment.</p> <p>Methods</p> <p>Twenty-two (22) consecutive NPH patients and 17 controls performed an upper limb motor task battery where highly sensitive and objective measures of akinesia/bradykinesia, tone, and tremor were conducted. NPH subjects performed this test battery before and more than 36 h after continuous CSF drainage via a spinal catheter over 72 h and, in those subjects undergoing permanent ventriculo-peritoneal shunt placement, at least 12 weeks later. Control subjects performed the task battery at the same dates as the NPH subjects. Statistical analyses were applied to group populations of NPH and control subjects and repeated measures for within subject performance.</p> <p>Results</p> <p>Twenty (20) NPH subjects remained in the study following CSF drainage as did 14 controls. NPH subjects demonstrated akinesia/bradykinesia (prolonged reaction and movement times) and increased resting tone compared with controls. Furthermore, the NPH group demonstrated increased difficulty with self-initiated tasks compared with stimulus-initiated tasks. Following CSF drainage, some NPH subjects demonstrated reduced movement times with greater improvement in self- versus stimulus-initiated tasks. Group reaction time was unchanged. Resting tremor present in one NPH subject resolved following shunt placement. Tone measures were consistent for all subjects throughout the study.</p> <p>Conclusion</p> <p>Clinical motor signs of NPH subjects extend beyond gait deficits and include extrapyramidal manifestations of bradykinesia, akinesia, rigidity, and propensity to perform more poorly when external cues to move are absent. Objective improvement of some but not all of these features was seen following temporary or permanent CSF diversion.</p

Objective evaluation of Parkinson's disease bradykinesia

Bradykinesia is the fundamental motor feature of Parkinson’s disease - obligatory for diagnosis and central to monitoring. It is a complex clinicalsign that describes movements with slow speed, small amplitude, irregular rhythm, brief pauses and progressive decrements. Clinical ascertainment of the presence and severity of bradykinesia relies on subjective interpretation of these components, with considerable variability amongst clinicians, and this may contribute to diagnostic error and inaccurate monitoring in Parkinson’s disease. The primary aim of this thesis was to assess whether a novel non-invasive device could objectively measure bradykinesia and predict diagnostic classification of movement data from Parkinson’s disease patients and healthy controls. The second aim was to evaluate how objective measures of bradykinesia correlate with clinical measures of bradykinesia severity. The third aim was to investigate the characteristic kinematic features of bradykinesia. Forty-nine patients with Parkinson’s disease and 41 healthy controls were recruited in Leeds. They performed a repetitive finger-tapping task for 30 seconds whilst wearing small electromagnetic tracking sensors on their finger and thumb. Movement data was analysed using two different methods - statistical measures of the separable components of bradykinesia and a computer science technique called evolutionary algorithms. Validation data collected independently from 13 patients and nine healthy controls in San Francisco was used to assess whether the results generalised. The evolutionary algorithm technique was slightly superior at classifying the movement data into the correct diagnostic groups, especially for the mildest clinical grades of bradykinesia, and they generalised to the independent group data. The objective measures of finger tapping correlated well with clinical grades of bradykinesia severity. Detailed analysis of the data suggests that a defining feature of Parkinson’s disease bradykinesia called the sequence effect may be a physiological rather than a pathological phenomenon. The results inform the development of a device that may support clinical diagnosis and monitoring of Parkinson’s disease and also be used to investigate bradykinesia

Effects of Cueing on Sit to Stand Transfers in Parkinson Disease

Problem Statement: Individuals with Parkinson Disease (PD) often experience difficulty transferring from sit to stand (STS). Current evidence suggests cues which promote an external attentional focus improve gait and transfers for individuals with PD. However, this research utilizes cues which are difficult to replicate in clinical or natural environments making the findings difficult to generalize or implement. Purpose: The primary purpose of this study is to determine the effect of 3 different explicit cues on STS for individuals with PD. Additionally we sought to determine if, in this population, a relationship exists between latency of movement initiation and postural sway in early standing, changes in joint angle between conditions and postural sway in early standing, and cue provided during the transfer and postural sway in early standing. Procedures/Methodology: Thirteen individuals in both the experimental and control groups participated in this cross-over design study. Both groups completed trials of self-initiated uncued STS transfers. Those in the experimental group also completed trials of STS transfers in 3 conditions: with an external attentional focus of reaching to targets, with an external attentional focus of concurrent modeling, and with an explicit cue for an internal attentional focus. Data was collected by trained testers and utilized valid and reliable body worn inertial measurement unit sensors. ANOVAs were used to compare performance between conditions and to the performance of the healthy control group. Bonferroni corrections were completed to reduce the likelihood of accepting a false positive. Results: Both cues that elicit an external attentional focus improved motor control during the sit to stand transfer. However, only modeling was able to improve both motor control and postural control. Cueing that promoted an internal attentional focus resulted in decreased motor control and postural control. Additionally, a moderate positive correlation was found between standing taller than typical and postural sway. Clinical Implications: Our results provide evidence for clinicians to better tailor treatment methodologies to the needs of individuals with PD. Optimal cueing can be utilized as compensations that reduce caregiver burden and increase independence of individuals with PD

Assessing impaired bed mobility in patients with Parkinson’s disease: a scoping review

Background: Although most patients with Parkinson’s disease (PD) experience difficulties in bed mobility, evidence on the suitability of the methods for assessing impaired bed mobility in PD are lacking. Objectives: To identify objective methods for assessing impaired bed mobility in PD and to discuss their clinimetric properties and feasibility for use in clinical practice. Data sources: PubMed, Web of Science, and Cochrane Library were searched between 1995 and 2022. Selection criteria: Studies were included if they described an objective assessment method for assessing impaired bed mobility in PD. Data extraction and data synthesis: Characteristics of the identified measurement methods such as clinimetric properties and feasibility were extracted by two authors. The methodological quality of studies was evaluated using the Appraisal of studies tool. Results: Twenty-three studies were included and categorised into three assessment methods: sensor-based assessments (48%), rating scales (39%), and timed-tests (13%). The risk of bias was low for all but one study, which was medium. Limitations: Despite applying wide selection criteria, a relatively small number of studies were identified in our results. Conclusion: Rating scales may be the most preferred for assessing impaired bed mobility in PD in clinical practice, until clinimetric validity are adequately demonstrated in the other assessment methods.Pre-proofTaniguchi Seira, Yamamoto Ariko, D'cruz Nicholas. Assessing impaired bed mobility in patients with Parkinson’s disease: a scoping review. Physiotherapy 20, 3 (2023); https://doi.org/10.1016/j.physio.2023.10.005

Wearable Platform for Automatic Recognition of Parkinson Disease by Muscular Implication Monitoring

The need for diagnostic tools for the characterization of progressive movement disorders - as the Parkinson Disease (PD) - aiming to early detect and monitor the pathology is getting more and more impelling. The parallel request of wearable and wireless solutions, for the real-time monitoring in a non-controlled environment, has led to the implementation of a Quantitative Gait Analysis platform for the extraction of muscular implications features in ordinary motor action, such as gait. The here proposed platform is used for the quantification of PD symptoms. Addressing the wearable trend, the proposed architecture is able to define the real-time modulation of the muscular indexes by using 8 EMG wireless nodes positioned on lower limbs. The implemented system “translates” the acquisition in a 1-bit signal, exploiting a dynamic thresholding algorithm. The resulting 1-bit signals are used both to define muscular indexes both to drastically reduce the amount of data to be analyzed, preserving at the same time the muscular information. The overall architecture has been fully implemented on Altera Cyclone V FPGA. The system has been tested on 4 subjects: 2 affected by PD and 2 healthy subjects (control group). The experimental results highlight the validity of the proposed solution in Disease recognition and the outcomes match the clinical literature results