Diagnosis and Treatment of Parkinson's Disease

Parkinson's disease is diagnosed by history and physical examination and there are no laboratory investigations available to aid the diagnosis of Parkinson's disease. Confirmation of diagnosis of Parkinson's disease thus remains a difficulty. This book brings forth an update of most recent developments made in terms of biomarkers and various imaging techniques with potential use for diagnosing Parkinson's disease. A detailed discussion about the differential diagnosis of Parkinson's disease also follows as Parkinson's disease may be difficult to differentiate from other mimicking conditions at times. As Parkinson's disease affects many systems of human body, a multimodality treatment of this condition is necessary to improve the quality of life of patients. This book provides detailed information on the currently available variety of treatments for Parkinson's disease including pharmacotherapy, physical therapy and surgical treatments of Parkinson's disease. Postoperative care of patients of Parkinson's disease has also been discussed in an organized manner in this text. Clinicians dealing with day to day problems caused by Parkinson's disease as well as other healthcare workers can use beneficial treatment outlines provided in this book

Effects of dance therapy on balance, gait and neuro-psychological performances in patients with Parkinson's disease and postural instability

Postural Instability (PI) is a core feature of Parkinson’s Disease (PD) and a major cause of falls and disabilities. Impairment of executive functions has been called as an aggravating factor on motor performances. Dance therapy has been shown effective for improving gait and has been suggested as an alternative rehabilitative method. To evaluate gait performance, spatial-temporal (S-T) gait parameters and cognitive performances in a cohort of patients with PD and PI modifications in balance after a cycle of dance therapy

Parkinson’s Disease Rehabilitation: Effectiveness Approaches and New Perspectives

Parkinson’s disease has been considered one of the most important and common neurodegenerative diseases in the world. Its motor and nonmotor signs determine a huge functional loss, leading the individuals to lose their independence. Although the treatment requires a pharmacological approach, physical therapy has confirmed its importance in this process. Today, neurorehabilitation is indispensable to increase many of the cardinal signs of the disease. Using traditional or technological approaches, physical therapy has reached good results in improving motor and nonmotor functions, as well as the quality of life of Parkinsonians. However, it is important to develop and to fortify the physical therapy approach so that we can provide stronger evidence about our practice

Evaluation of the Effects of Various Exercise Interventions on Parkinson’s Disease

The overall purpose of the current thesis was to evaluate the influence of various exercise strategies on Parkinson’s disease (PD). While countless exercise interventions have been investigated by PD, results have been weak and inconclusive at best. As such, there are currently no scientifically-validated recommendations for an optimal exercise intervention. The four studies comprising this thesis have attempted to address the shortcomings of previous literature, namely, inconsistent use of outcome measures, lack of PD symptomatic measures, varying lengths of exercise interventions, absence of a non-exercise control group, continued assessment of participants after exercise has ended, and verifying replicabilty of findings. The first study was focused on identifying objective outcome measures that are predictive or reflective of the classic symptoms associated with PD. Symptomatic assessment was conducted using the Unified Parkinson’s disease Rating Scale (UPDRS), the current gold standard for assessment of PD symptom severity. Objective outcome measures included the timed-up-and-go (TUG), grooved pegboard (GP), and spatiotemporal aspects of self-paced gait (velocity, step length). Backward elimination regression analysis demonstrated that the place phase of the GP was the most predictive of UPDRS score. Interestingly, no objective outcome measures were strongly correlated with change on the symptomatic subsets that they were believed to be theoretically evaluating. The results point to the continued need to identify objective outcome measures reflective of symptomatic assessment. Further, exercise rehabilitation trials should combine outcome measures with symptomatic assessment to ensure that improvements are reflective of symptomatic improvement. The second study compared the influence of four exercise interventions (in contrast to a non-exercising control group) on the symptoms of PD. The exercise interventions included aquatic exercise, aerobic training, strength training and sensory focused exercise (PD SAFEx). Each participant exercised three times per week for a twelve week period and the same trained evaluator (blinded to group assignment) performed symptomatic assessment of all participants before exercise began (pre-test), after exercise ended (post-test) and following a minimum six week non-exercise period (washout). Results displayed that the strength training and PD SAFEx interventions had the greatest symptomatic benefit from pre-test to post-test. The aerobic intervention had no apparent change to symptom severity across all three testing periods. Overall, the current study suggests that PD SAFEx and strength training are more beneficial for individuals with PD than aerobic or aquatic exercise. The third study attempted to determine the influence of increased focus on sensory feedback by comparing two identical exercise interventions that differed only in the presence (PD SAFEx) or absence (non-SAFE) of increased attention on sensory (specifically proprioceptive) feedback. Symptomatic assessment was combined with objective outcome measures that assessed upper limb motor control, functional gait and spatiotemporal aspects of self-paced gait. Findings suggested that both exercise interventions resulted in similar benefits on the objective outcome measures, including upper limb motor control (assessed using the grooved pegboard), functional gait (assessed using the timed-up-and-go) and velocity and step length of self-paced gait. Interestingly, only the PD SAFEx intervention resulted in improved PD symptoms assessed using the UPDRS and symptomatic improvement was maintained after a six week non-exercise period. Thus, the increased focus on sensory feedback present in the PD SAFEx intervention appears to have an important additional influence on the symptoms of PD. The final study assessed whether improved PD symptoms following a sensory attention focused exercise (PD SAFEx) intervention could be replicated across multiple administrations and secondly, whether the effect could be replicated when administered by minimally trained individuals in the community. The PD SAFEx intervention was administered to four separate groups at the Movement Disorders Research and Rehabilitation Center (MDRC) and twice at an exercise facility in the community (YMCA). Over the six administrations of the PD SAFEx intervention, similar symptomatic improvements were realized by participants. Interestingly, the community based intervention appeared to gain a greater symptomatic benefit than the PD SAFEx intervention administered by leaders knowledgeable in movement disorders and the underlying neurological deficits focused on in the PD SAFEx intervention suggests that the feasibility of global distribution of the PD SAFEx intervention would be a logical direction for future research. The methodological improvements employed in the current thesis allowed for detailed and thorough comparisons to be drawn between various exercise interventions. It has been shown that strength training and PD SAFEx interventions have the greatest symptomatic benefit for individuals with PD. Further, the beneficial effect of increased focus on sensory feedback and the simplicity of application of the PD SAFEx intervention suggest that the PD SAFEx intervention should be further explroed for its ability to be globally implemented

The computational neurology of movement under active inference

We propose a computational neurology of movement based on the convergence of theoretical neurobiology and clinical neurology. A significant development in the former is the idea that we can frame brain function as a process of (active) inference, in which the nervous system makes predictions about its sensory data. These predictions depend upon an implicit predictive (generative) model used by the brain. This means neural dynamics can be framed as generating actions to ensure sensations are consistent with these predictions-and adjusting predictions when they are not. We illustrate the significance of this formulation for clinical neurology through simulating a clinical examination of the motor system; i.e. an upper limb coordination task. Specifically, we show how tendon reflexes emerge naturally under the right kind of generative model. Through simulated perturbations, pertaining to prior probabilities of this model's variables, we illustrate the emergence of hyperreflexia and pendular reflexes, reminiscent of neurological lesions in the corticospinal tract and cerebellum. We then turn to the computational lesions causing hypokinesia and deficits of coordination. This in silico lesion-deficit analysis provides an opportunity to revisit classic neurological dichotomies (e.g. pyramidal versus extrapyramidal systems) from the perspective of modern approaches to theoretical neurobiology-and our understanding of the neurocomputational architecture of movement control based on first principles

The role of somatosensory afferences in Parkinson's disease

Parkinson’s disease (PD) is the second most common neurodegenerative disorder in the world. The primary motor symptom of PD is bradykinesia, a slowing and reduction in amplitude of voluntary movement. Here, I aim to test some neurophysiological aspects of PD. Furthermore, I explored the possibility to develop non-invasive treatment for this group of patients. The first two studies tested the contribution of a specific phenomenon labelled sensory attenuation or sensory gating in the motor symptoms of PD, especially bradykinesia. I found that the sensory attenuation is abnormal in this group of patients. Especially, PD patients OFF medications showed a reduced sensory attenuation measured as the amplitude of the somatosensory evoked potentials. Interestingly, I found that the sensory attenuation was equal to the healthy age matched controls when the patients were tested in ON pharmacological state. Additionally, this research tested a theory of the functional role of sensorimotor beta oscillations that could explain beta power modulations in healthy subjects and the increase in beta power observed in PD patients. My results were in line with the previous data presented in the literature. Indeed, I found the increase beta power in both my two cohorts of PD patients. Finally, I tested a potential correlation between the abnormalities of these two phenomena in PD: reduced sensory attenuation and increased beta oscillations. I did not find any significant correlation between the two phenomena. They might be two different neurophysiological mechanisms 5 underlying this disease. However, further studies are necessary to investigate this hypothesis. Having tested the influence of the somatosensory signal in some motor symptoms, the second part of the thesis was focused on the development of non-invasive treatments of bradykinesia in PD. I tested the impact of vibratory stimuli to improve these motor signs. In particular, several frequencies of vibration have been tested through different devices applied to the wrist. The device was called “Emma watch” and I found that the application of vibration with the modulation of 60 bpm improved the bradykinesia in PD patients Finally, I presented a case study regarding the benefit of vibratory stimulation on the freezing of gait thought shoe insoles generating vibration. The tested patient showed an improvement of the frequency of the freezing episodes after a week wearing the insoles, which generated vibration at 200 Hz

Biofeedback as a form of neurorehabilitation in Parkinson's disease

Parkinson's disease is a degenerative disease of the nervous system. An important element in the treatment of the disease is neurorehabilitation. One of the forms of neurorehabilitation may be biofeedback. The above technique uses electronic devices that allows an individual to learn how to change the body's function in order to reduce the clinical symptoms of the disease and improve health. Previous studies have confirmed that biofeedback has a beneficial effect on the health of patients with Parkinson's disease. The aim of the work was a review of the literature on biofeedback as a form of neurorehabilitation in this disease

Biomechanical Loading as an Alternative Treatment for Tremor: A Review of Two Approaches

Background: Tremor is the most common movement disorder and strongly increases in incidence and prevalence with aging. Although not life threatening, upper-limb tremors hamper the independence of 65% of people suffering from them affected persons, greatly impacting their quality of life. Current treatments include pharmacotherapy and surgery (thalamotomy and deep brain stimulation). However, these options are not sufficient for approximately 25% of patients. Therefore, further research and new therapeutic options are required to effectively manage pathological tremor. Methods: This paper presents findings of two research projects in which two different wearable robots for tremor management were developed based on force loading and validated. The first consisted of a robotic exoskeleton that applied forces to tremulous limbs and consistently attenuated mild and severe tremors. The second was a neuroprosthesis based on transcutaneous neurostimulation. A total of 22 patients suffering from parkinsonian or essential tremor (ET) of different severities were recruited for experimental validation, and both systems were evaluated using standard tasks employed for neurological examination. The inclusion criterion was a postural and/or kinetic pathological upper-limb tremor resistant to medication. Results: The results demonstrate that both approaches effectively suppressed tremor in most patients, although further research is required. The work presented here is based on clinical evidence from a small number of patients (n = 10 for robotic exoskeleton and n = 12 for the neuroprosthesis), but most had a positive response to the approaches. In summary, biomechanical loading is non-invasive and painless. It may be effective in patients who are insufficiently responsive (or have adverse reactions) to drugs or in whom surgery is contraindicated. Discussion: This paper identifies and evaluates biomechanical loading approaches to tremor management and discusses their potential

Pathological Tremor as a Mechanical System: Modeling and Control of Artificial Muscle-Based Tremor Suppression

Central nervous system disorders produce the undesired, approximately rhythmic movement of body parts known as pathological tremor. This undesired motion inhibits the patient\u27s ability to perform tasks of daily living and participate in society. Typical treatments are medications and deep brain stimulation surgery, both of which include risks, side effects, and varying efficacy. Since the pathophysiology of tremor is not well understood, empirical investigation drives tremor treatment development. This dissertation explores tremor from a mechanical systems perspective to work towards theory-driven treatment design. The primary negative outcome of pathological tremor is the undesired movement of body parts: mechanically suppressing this motion provides effective tremor treatment by restoring limb function. Unlike typical treatments, the mechanisms for mechanical tremor suppression are well understood: applying joint torques that oppose tremor-producing muscular torques will reduce tremor irrespective of central nervous system pathophysiology. However, a tremor suppression system must also consider voluntary movements. For example, mechanically constraining the arm in a rigid cast eliminates tremor motion, but also eliminates the ability to produce voluntary motions. Indeed, passive mechanical systems typically reduce tremor and voluntary motions equally due to the close proximity of their frequency content. Thus, mechanical tremor suppression requires active actuation to reduce tremor with minimal influence on voluntary motion. However, typical engineering actuators are rigid and bulky, preventing clinical implementations. This dissertation explores dielectric elastomers as tremor suppression actuators to improve clinical implementation potential of mechanical tremor suppression. Dielectric elastomers are often called artificial muscles due to their similar mechanical properties as human muscle; these similarities may enable relatively soft, low-profile implementations. The primary drawback of dielectric elastomers is their relatively low actuation levels compared to typical actuators. This research develops a tremor-active approach to dielectric elastomer-based tremor suppression. In a tremor-active approach, the actuators only actuate to oppose tremor, while the human motor system must overcome the passive actuator dynamics. This approach leverages the low mechanical impedance of dielectric elastomers to overcome their low actuation levels. Simulations with recorded tremor datasets demonstrate excellent and robust tremor suppression performance. Benchtop experiments validate the control approach on a scaled system. Since dielectric elastomers are not yet commercially available, this research quantifies the necessary dielectric elastomer parameters to enable clinical implementations and evaluates the potential of manufacturing approaches in the literature to achieve these parameters. Overall, tremor-active control using dielectric elastomers represents a promising alternative to medications and surgery. Such a system may achieve comparable tremor reduction as medications and deep brain stimulation with minimal risks and greater efficacy, but at the cost of increased patient effort to produce voluntary motions. Parallel advances in scaled dielectric elastomer manufacturing processes and high-voltage power electronics will enable consumer implementations. In addition to tremor suppression, this dissertation investigates the mechanisms of central nervous system tremor generation from a control systems perspective. This research investigates a delay-based model for parkinsonian tremor. Besides tremor, Parkinson\u27s disease generally inhibits movement, with typical symptoms including rigidity, bradykinesia, and increased reaction times. This fact raises the question as to how the same disease produces excessive movement (tremor) despite characteristically inhibiting movement. One possible answer is that excessive central nervous system inhibition produces unaccounted feedback delays that cause instability. This dissertation develops an optimal control model of human motor control with an unaccounted delay between the state estimator and controller. This delay represents the increased inhibition projected from the basal ganglia to the thalamus, delaying signals traveling from the cerebellum (estimator) to the primary motor cortex (controller). Model simulations show increased delays decrease tremor frequency and increase tremor amplitude, consistent with the evolution of tremor as the disease progresses. Simulations that incorporate tremor resetting and random variation in control saturation produce simulated tremor with similar characteristics as recorded tremor. Delay-induced tremor explains the effectiveness of deep brain stimulation in both the thalamus and basal ganglia since both regions contribute to the presence of feedback delay. Clinical evaluation of mechanical tremor suppression may provide clinical evidence for delay-induced tremor: unlike state-independent tremor, suppression of delay-induced tremor increases tremor frequency. Altogether, establishing the mechanisms for tremor generation will facilitate pathways towards improved treatments and cure development