-
Annals of Neurology May 2023Bradykinesia is the major cardinal motor sign of Parkinson disease (PD), but its neural underpinnings are unclear. The goal of this study was to examine whether changes...
OBJECTIVE
Bradykinesia is the major cardinal motor sign of Parkinson disease (PD), but its neural underpinnings are unclear. The goal of this study was to examine whether changes in bradykinesia following long-term subthalamic nucleus (STN) deep brain stimulation (DBS) are linked to local STN beta (13-30 Hz) dynamics or a wider bilateral network dysfunction.
METHODS
Twenty-one individuals with PD implanted with sensing neurostimulators (Activa® PC + S, Medtronic, PLC) in the STN participated in a longitudinal 'washout' therapy study every three to 6 months for an average of 3 years. At each visit, participants were withdrawn from medication (12/24/48 hours) and had DBS turned off (>60 minutes) before completing a repetitive wrist-flexion extension task, a validated quantitative assessment of bradykinesia, while local field potentials were recorded. Local STN beta dynamics were investigated via beta power and burst duration, while interhemispheric beta synchrony was assessed with STN-STN beta coherence.
RESULTS
Higher interhemispheric STN beta coherence, but not contralateral beta power or burst duration, was significantly associated with worse bradykinesia. Bradykinesia worsened off therapy over time. Interhemispheric STN-STN beta coherence also increased over time, whereas beta power and burst duration remained stable. The observed change in bradykinesia was related to the change in interhemispheric beta coherence, with greater increases in synchrony associated with further worsening of bradykinesia.
INTERPRETATION
Together, these findings implicate interhemispheric beta synchrony as a neural correlate of the progression of bradykinesia following chronic STN DBS. This could imply the existence of a pathological bilateral network contributing to bradykinesia in PD. ANN NEUROL 2023;93:1029-1039.
Topics: Humans; Hypokinesia; Deep Brain Stimulation; Parkinson Disease; Subthalamic Nucleus
PubMed: 36641645
DOI: 10.1002/ana.26605 -
Journal of Parkinson's Disease 2022Parkinson's disease (PD) is known to affect the brain motor circuits involving the basal ganglia (BG) and to induce, among other signs, general slowness and paucity of... (Review)
Review
Parkinson's disease (PD) is known to affect the brain motor circuits involving the basal ganglia (BG) and to induce, among other signs, general slowness and paucity of movements. In upper limb movements, PD patients show a systematic prolongation of movement duration while maintaining a sufficient level of endpoint accuracy. PD appears to cause impairments not only in movement execution, but also in movement initiation and planning, as revealed by abnormal preparatory activity of motor-related brain areas. Grasping movement is affected as well, particularly in the coordination of the hand aperture with the transport phase. In the last fifty years, numerous behavioral studies attempted to clarify the mechanisms underlying these anomalies, speculating on the plausible role that the BG-thalamo-cortical circuitry may play in normal and pathological motor control. Still, many questions remain open, especially concerning the management of the speed-accuracy tradeoff and the online feedback control. In this review, we summarize the literature results on reaching and grasping in parkinsonian patients. We analyze the relevant hypotheses on the origins of dysfunction, by focusing on the motor control aspects involved in the different movement phases and the corresponding role played by the BG. We conclude with an insight into the innovative stimulation techniques and computational models recently proposed, which might be helpful in further clarifying the mechanisms through which PD affects reaching and grasping movements.
Topics: Basal Ganglia; Hand; Humans; Motor Cortex; Movement; Parkinson Disease; Psychomotor Performance
PubMed: 35253780
DOI: 10.3233/JPD-213082 -
Neuroscience Bulletin Feb 2012Parkinson's disease (PD) is a chronic progressive neurodegenerative disease that is clinically manifested by a triad of cardinal motor symptoms - rigidity, bradykinesia... (Review)
Review
Parkinson's disease (PD) is a chronic progressive neurodegenerative disease that is clinically manifested by a triad of cardinal motor symptoms - rigidity, bradykinesia and tremor - due to loss of dopaminergic neurons. The motor symptoms of PD become progressively worse as the disease advances. PD is also a heterogeneous disease since rigidity and bradykinesia are the major complaints in some patients whereas tremor is predominant in others. In recent years, many studies have investigated the progression of the hallmark symptoms over time, and the cardinal motor symptoms have different rates of progression, with the disease usually progressing faster in patients with rigidity and bradykinesia than in those with predominant tremor. The current treatment regime of dopamine-replacement therapy improves motor symptoms and alleviates disability. Increasing the dosage of dopaminergic medication is commonly used to combat the worsening symptoms. However, the drug-induced involuntary body movements and motor complications can significantly contribute to overall disability. Further, none of the currently-available therapies can slow or halt the disease progression. Significant research efforts have been directed towards developing neuroprotective or disease-modifying agents that are intended to slow the progression. In this article, the most recent clinical studies investigating disease progression and current progress on the development of disease-modifying drug trials are reviewed.
Topics: Animals; Disease Progression; Dopaminergic Neurons; Humans; Hypokinesia; Movement; Muscle Rigidity; Parkinson Disease; Tremor
PubMed: 22233888
DOI: 10.1007/s12264-012-1050-z -
Journal of Parkinson's Disease 2017The MDS-UPDRS (Movement Disorders Society - Unified Parkinson's Disease Rating Scale) is the most widely used scale for rating impairment in PD. Subscores measuring... (Review)
Review
BACKGROUND
The MDS-UPDRS (Movement Disorders Society - Unified Parkinson's Disease Rating Scale) is the most widely used scale for rating impairment in PD. Subscores measuring bradykinesia have low reliability that can be subject to rater variability. Novel technological tools can be used to overcome such issues.
OBJECTIVE
To systematically explore and describe the available technologies for measuring limb bradykinesia in PD that were published between 2006 and 2016.
METHODS
A systematic literature search using PubMed (MEDLINE), IEEE Xplore, Web of Science, Scopus and Engineering Village (Compendex and Inspec) databases was performed to identify relevant technologies published until 18 October 2016.
RESULTS
47 technologies assessing bradykinesia in PD were identified, 17 of which offered home and clinic-based assessment whilst 30 provided clinic-based assessment only. Of the eligible studies, 7 were validated in a PD patient population only, whilst 40 were tested in both PD and healthy control groups. 19 of the 47 technologies assessed bradykinesia only, whereas 28 assessed other parkinsonian features as well. 33 technologies have been described in additional PD-related studies, whereas 14 are not known to have been tested beyond the pilot phase.
CONCLUSION
Technology based tools offer advantages including objective motor assessment and home monitoring of symptoms, and can be used to assess response to intervention in clinical trials or routine care. This review provides an up-to-date repository and synthesis of the current literature regarding technology used for assessing limb bradykinesia in PD. The review also discusses the current trends with regards to technology and discusses future directions in development.
Topics: Biomedical Technology; Extremities; Humans; Hypokinesia; Neurology; Parkinson Disease
PubMed: 28222539
DOI: 10.3233/JPD-160878 -
Journal of Neural Transmission (Vienna,... Jun 2023Parkinson's disease (PD) is the second most common neurodegenerative disorder, with increasing numbers of affected patients. Many patients lack adequate care due to... (Review)
Review
Parkinson's disease (PD) is the second most common neurodegenerative disorder, with increasing numbers of affected patients. Many patients lack adequate care due to insufficient specialist neurologists/geriatricians, and older patients experience difficulties traveling far distances to reach their treating physicians. A new option for these obstacles would be telemedicine and wearables. During the last decade, the development of wearable sensors has allowed for the continuous monitoring of bradykinesia and dyskinesia. Meanwhile, other systems can also detect tremors, freezing of gait, and gait problems. The most recently developed systems cover both sides of the body and include smartphone apps where the patients have to register their medication intake and well-being. In turn, the physicians receive advice on changing the patient's medication and recommendations for additional supportive therapies such as physiotherapy. The use of smartphone apps may also be adapted to detect PD symptoms such as bradykinesia, tremor, voice abnormalities, or changes in facial expression. Such tools can be used for the general population to detect PD early or for known PD patients to detect deterioration. It is noteworthy that most PD patients can use these digital tools. In modern times, wearable sensors and telemedicine open a new window of opportunity for patients with PD that are easy to use and accessible to most of the population.
Topics: Humans; Parkinson Disease; Hypokinesia; Gait Disorders, Neurologic; Tremor; Wearable Electronic Devices
PubMed: 36609737
DOI: 10.1007/s00702-022-02575-5 -
Psychiatry Research Apr 2016Bradykinesia is associated with reduced quality of life and medication non-compliance, and it may be a prodrome for schizophrenia. Therefore, screening/monitoring for...
Bradykinesia is associated with reduced quality of life and medication non-compliance, and it may be a prodrome for schizophrenia. Therefore, screening/monitoring for subtle bradykinesia is of clinical and scientific importance. This study investigated the validity and reliability of such an instrument. Included were 70 patients with psychotic disorders. Inertial sensors captured mean cycle duration, amplitude and velocity of four movement tasks: walking, elbow flexion/extension, forearm pronation/supination and leg agility. The concurrent validity with the Unified Parkinson's Disease Rating Scale (UPDRS) bradykinesia subscale was determined using regression analysis. Reliability was investigated with the intra-class correlation coefficient. The duration, amplitude and velocities of the four tasks measured by the instrument explained 67% of the variance on the UPDRS bradykinesia subscale. The instrument test-retest reliability was high. The instrument investigated in this study is a valid and reliable alternative to observer-rated scales. It is an ideal tool for monitoring bradykinesia as it requires little training and experience to achieve reliable results.
Topics: Adult; Aged; Elbow; Exercise Test; Female; Forearm; Humans; Hypokinesia; Leg; Male; Middle Aged; Psychotic Disorders; Regression Analysis; Reproducibility of Results; Walking
PubMed: 27086232
DOI: 10.1016/j.psychres.2016.02.011 -
Neuroscience Letters Nov 2018People with Parkinson's disease (PD) have decreased arm swing movements during walking, which can be related to PD motor signs and symptoms. In this context, the aim of...
People with Parkinson's disease (PD) have decreased arm swing movements during walking, which can be related to PD motor signs and symptoms. In this context, the aim of this study was to determine the effects of an increased arm swing frequency or amplitude on the gait parameters in people with PD and healthy older adults. Seventeen individuals with PD and 19 older people were invited to walk on a 10 m pathway under three experimental conditions: (i) usual walking (no arm swing instructions); (ii) an increased arm swing amplitude; and (iii) an increased arm swing frequency. Both groups had an increased stride speed, vertical center of mass and arm swing accelerations and decreased double support time under the increased arm swing amplitude and frequency conditions. People with PD were able to modulate the gait parameters according to the experimental conditions, but at a smaller magnitude than the older individuals. These results indicate that bradykinesia and hypometria of gait can be positively overcome by increasing the amplitude and frequency of arm swing. Arm movements should be included in gait rehabilitation protocols for PD.
Topics: Adult; Arm; Biomechanical Phenomena; Female; Gait; Gait Disorders, Neurologic; Humans; Hypokinesia; Male; Middle Aged; Movement; Parkinson Disease; Walking
PubMed: 30287303
DOI: 10.1016/j.neulet.2018.09.051 -
NeuroImage. Clinical 2021Bradykinesia has been associated with beta and gamma band interactions in the basal ganglia-thalamo-cortical circuit in Parkinson's disease. In this present...
OBJECTIVE
Bradykinesia has been associated with beta and gamma band interactions in the basal ganglia-thalamo-cortical circuit in Parkinson's disease. In this present cross-sectional study, we aimed to search for neural networks with electroencephalography whose frequency-specific actions may predict bradykinesia.
METHODS
Twenty Parkinsonian patients treated with bilateral subthalamic stimulation were first prescreened while we selected four levels of contralateral stimulation (0: OFF, 1-3: decreasing symptoms to ON state) individually, based on kinematics. In the screening period, we performed 64-channel electroencephalography measurements simultaneously with electromyography and motion detection during a resting state, finger tapping, hand grasping tasks, and pronation-supination of the arm, with the four levels of contralateral stimulation. We analyzed spectral power at the low (13-20 Hz) and high (21-30 Hz) beta frequency bands and low (31-60 Hz) and high (61-100 Hz) gamma frequency bands using the dynamic imaging of coherent sources. Structural equation modelling estimated causal relationships between the slope of changes in network beta and gamma activities and the slope of changes in bradykinesia measures.
RESULTS
Activity in different subnetworks, including predominantly the primary motor and premotor cortex, the subthalamic nucleus predicted the slopes in amplitude and speed while switching between stimulation levels. These subnetwork dynamics on their preferred frequencies predicted distinct types and parameters of the movement only on the contralateral side.
DISCUSSION
Concurrent subnetworks affected in bradykinesia and their activity changes in the different frequency bands are specific to the type and parameters of the movement; and the primary motor and premotor cortex are common nodes.
Topics: Cross-Sectional Studies; Deep Brain Stimulation; Humans; Hypokinesia; Parkinson Disease; Subthalamic Nucleus
PubMed: 34662779
DOI: 10.1016/j.nicl.2021.102857 -
Frontiers in Neurology 2020Amimia is one of the most typical features of Parkinson's disease (PD). However, its significance and correlation with motor and nonmotor symptoms is unknown. The aim...
Amimia is one of the most typical features of Parkinson's disease (PD). However, its significance and correlation with motor and nonmotor symptoms is unknown. The aim of this study is to evaluate the association between amimia and motor and nonmotor symptoms, including cognitive status, depression, and quality of life in PD patients. We also tested the blink rate as a potential tool for objectively measuring upper facial bradykinesia. We prospectively studied amimia in PD patients. Clinical evaluation was performed using the Unified Parkinson's Disease Rating Scale (UPDRS) and timed tests. Cognitive status, depression, and quality of life were assessed using the Parkinson's Disease Cognitive Rating Scale (PD-CRS), the 16-Item Quick Inventory of Depressive Symptomatology (QIDS-SR16), and the PDQ-39, respectively. Amimia was clinically evaluated according to item 19 of UPDRS III. Finally, we studied upper facial amimia by measuring resting blink frequency and blink rate during spontaneous conversation. We included 75 patients. Amimia (item 19 UPDRS III) correlated with motor and total UPDRS (r: 0.529 and 0.551 Spearman), and its rigidity, distal bradykinesia, and motor axial subscores (r: 0.472; r: 0.252, and r: 0.508, respectively); Hoehn and Yahr scale (r: 0.392), timed tests, gait freezing, cognitive status (r: 0.29), and quality of life (r: 0.268) correlated with amimia. Blinking frequency correlated with amimia (measured with item 19 UPDRS), motor and total UPDRS. Amimia correlates with motor (especially axial symptoms) and cognitive situations in PD. Amimia could be a useful global marker of overall disease severity, including cognitive decline.
PubMed: 33569034
DOI: 10.3389/fneur.2020.603582 -
Brain Communications 2024In patients with Parkinson's disease, the connectivity between the two primary motor cortices may be altered. However, the correlation between asymmetries of abnormal...
In patients with Parkinson's disease, the connectivity between the two primary motor cortices may be altered. However, the correlation between asymmetries of abnormal interhemispheric connections and bradykinesia features has not been investigated. Furthermore, the potential effects of dopaminergic medications on this issue remain largely unclear. The aim of the present study is to investigate the interhemispheric connections in Parkinson's disease by transcranial magnetic stimulation and explore the potential relationship between interhemispheric inhibition and bradykinesia feature asymmetry in patients. Additionally, we examined the impact of dopaminergic therapy on neurophysiological and motor characteristics. Short- and long-latency interhemispheric inhibition was measured in 18 Parkinson's disease patients and 18 healthy controls, bilaterally. We also assessed the corticospinal and intracortical excitability of both primary motor cortices. We conducted an objective analysis of finger-tapping from both hands. Correlation analyses were performed to explore potential relationships among clinical, transcranial magnetic stimulation and kinematic data in patients. We found that short- and long-latency interhemispheric inhibition was reduced (less inhibition) from both hemispheres in patients than controls. Compared to controls, finger-tapping movements in patients were slower, more irregular, of smaller amplitudes and characterized by a progressive amplitude reduction during movement repetition (sequence effect). Among Parkinson's disease patients, the degree of short-latency interhemispheric inhibition imbalance towards the less affected primary motor cortex correlated with the global clinical motor scores, as well as with the sequence effect on the most affected hand. The greater the interhemispheric inhibition imbalance towards the less affected hemisphere (i.e. less inhibition from the less to the most affected primary motor cortex than that measured from the most to the less affected primary motor cortex), the more severe the bradykinesia in patients. In conclusion, the inhibitory connections between the two primary motor cortices in Parkinson's disease are reduced. The interhemispheric disinhibition of the primary motor cortex may have a role in the pathophysiology of specific bradykinesia features in patients, i.e. the sequence effect.
PubMed: 38370448
DOI: 10.1093/braincomms/fcae020