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

Effect of Qigong Exercise on Sleep Quality and Gait Performance in Parkinson's Disease

Background: Parkinson's disease (PD) involves a variety of motor and non-motor symptoms. Current medical therapy has been successful at managing a majority of these features; however, several issues, including gait complications and sleeping disorders, may involve impairments not fully resolved by standard therapy. This study aimed to determine the impact of Qigong as a potential complementary therapy in the management of gait and sleep related symptoms in PD. Methods: Seven subjects (age 66.86 ± 8.13 years) with PD participated in a six-week Qigong exercise intervention. Pre- and post-intervention testing was performed to assess sleep quality, fatigue, and gait performance in these subjects. Standard clinical assessments specific to PD were used for the assessment of sleep quality and fatigue. Gait performance was assessed using three-dimensional motion capture during the completion of several tasks. Overall gait performance (stride time, stride length, double support time, and velocity), gait variability (stride time variability and stride length variability), and turning performance (number of steps and total time to turn) were analyzed in the gait tasks. Results: Following the intervention, subjects showed a general trend of improvements in sleep quality. Fatigue remained unchanged. Assessment of gait performance showed significant improvement in overall gait function and gait variability, and no apparent change in turn performance. Gait function was improved by a significant reduction of stride time and a slight increase in stride length. Together these changes resulted in significant improvements to gait velocity. Additionally, time spent in double support was reduced following the intervention. Overall gait variability improved significantly, particularly in the reduction of stride time variability. Conclusions: These results suggest that the Qigong intervention implemented for this group may provide potential benefits to people with PD in regards to gait performance and sleep quality. Further studies are required to provide a more definitive measure of these results with increased statistical power

Postural automatisms and biomechanics of gait initiation and obstacle negotiation in parkinson’s disease : characterization and effects of different interventions

A doença de Parkinson (DP) é uma doença neurodegenerativa relacionada à perda da independência funcional, com fenômenos motores, como rigidez, desequilíbrio e alterações na marcha. Os automatismos posturais, incluindo os ajustes posturais antecipatórios (APA) e compensatórios (CPA) são essenciais para o equilíbrio em resposta a uma perturbação e seu uso eficiente pode reduzir a ocorrência de quedas em tarefas cotidianas, como iniciação da marcha e negociação de obstáculos. Evidências apontam os benefícios de programas de exercícios na melhora da locomoção e controle postural na DP, entretanto, poucos estudos investigaram os efeitos sobre os automatismos posturais. Assim, a presente dissertação tem o objetivo de caracterizar as estratégias de automatismos posturais e comportamento motor relacionados à iniciação da marcha e negociação de obstáculos de pessoas com DP e comparar os efeitos de três programas de treinamento sobre esses parâmetros. No capítulo I é feita a apresentação geral e contextualização do estudo. No capítulo II é apresentada uma revisão de literatura, com informações compiladas sobre a DP, os automatismos posturais, a locomoção e como diferentes intervenções podem auxiliar na melhora dos parâmetros alterados. As lacunas identificadas na literatura motivaram a escrita de dois estudos originais. Os objetivos dos estudos foram: 1) analisar e comparar os ajustes posturais e os parâmetros biomecânicos durante a iniciação da marcha e negociação de obstáculos de pessoas com DP rígido-acinética e hipercinética; e 2) analisar e comparar os efeitos de três programas baseados em exercício físico (dança, exercícios em água funda e caminhada Nórdica) sobre os ajustes posturais e os parâmetros biomecânicos na iniciação da marcha e negociação de obstáculos em pessoas com DP. No estudo 1, foram avaliadas, de forma transversal, pessoas com DP divididas por subtipos clínicos (rígidos-acinéticos e hipercinéticos). Para o estudo 2, um ensaio clínico, estes sujeitos foram randomizados em três grupos de intervenção de 22 sessões, sendo avaliados antes e depois. Em ambos os estudos as avaliações incluíram variáveis eletromiográficas, cinéticas e cinemáticas. No estudo I, observamos que o grupo rígido-acinético apresentou maior comprometimento neuromotor, refletido por menor ação antecipatória e compensatória de músculos estabilizadores, menor deslocamento do centro de pressão, maior tempo de duplo apoio e menores comprimento e altura de passo durante as tarefas. Além disso, no estudo II as três intervenções mostraram melhoras nos parâmetros avaliados, sendo mais evidentes nos parâmetros espaço-temporais e músculos de tronco para exercícios em água funda e caminhada Nórdica, enquanto que a Dança promoveu melhores resultados na ação dos músculos de quadril. Nossos resultados são importantes para entender as diferenças no controle motor de pacientes com diferentes manifestações clínicas da DP e para auxiliar na prescrição de programas terapêuticos. Ainda, sugerimos que as três intervenções propostas possuem potencial para a manutenção e melhora neuromotora de pessoas com DP.Parkinson's disease (PD) is a neurodegenerative disease related to loss of functional independence, with motor phenomena such as rigidity, imbalance and changes in gait. Postural automatisms, including anticipatory (APA) and compensatory (CPA) postural adjustments are essential for balance in response to a disturbance and their effective use can reduce the occurrence of falls in everyday tasks, such as gait initiation and obstacle negotiation. Evidence points to the benefits of exercise programs in improving locomotion and postural control in PD, however, few studies have investigated the effects on postural automatisms. Thus, the present dissertation aims to characterize the strategies of postural automatisms and motor behavior related to the gait initiation and obstacle negotiation in people with PD and to compare the effects of three training programs on these parameters. Chapter I presents the general presentation and context of the study. Chapter II presents a literature review, with information compiled about PD, postural automatisms, locomotion and how different interventions can help to improve altered parameters. The gaps identified in the literature motivated the writing of two original studies. The aims of the studies were: 1) to analyze and compare postural adjustments to biomechanical parameters during gait initiation and obstacle negotiation in people with akinetic-rigid (AK-R) and hyperkinetic (HYP) PD; and 2) to analyze and compare the effects of three programs based on physical exercise (Brazilian dance, deep water exercises and Nordic walking) on postural adjustments and biomechanical parameters in gait initiation and obstacle negotiation in people with PD. In study 1, people with PD divided by clinical subtypes (AK-R and HYP) were evaluated in a cross-sectional research. . For study 2, a clinical trial, these subjects were randomized into three intervention groups of 22 sessions, being assessed pre and post. In both studies, evaluations included electromyographic, kinetic and kinematic variables. In study I, we observed that the AK-R group showed greater neuromotor impairment, reflected by less anticipatory and compensatory action of stabilizing muscles, less displacement of the center of pressure, longer double support time and shorter step length and height during tasks. Furthermore, in study II, the three interventions showed improvements in the parameters evaluated, being more evident in spatiotemporal parameters and trunk muscles for deep water exercises and Nordic walking, while dance promoted better results in the action of the hip muscles. Our results are important to understand the differences in motor control of patients with different clinical manifestations of PD and to assist in the prescription of therapeutic programs. In addition, we suggest that the three proposed interventions have the potential to maintain and improve neuromotor performance in people with PD

Does practice of multi-directional stepping with auditory stimulation improve movement performance in patients with Parkinson\u27s disease

Parkinson’s disease (PD) is a debilitating neurodegenerative disorder causing many physical limitations. Rhythmic auditory stimulation (RAS) influences motor complications not alleviated by medicine and has been used to modify straight line walking in this population. However, motor complications are exacerbated during more complex movements including those involving direction changes. Thus immediate RAS effects on direction switch duration (DSD) and other kinematic measures during a multi-directional step task were investigated in PD patients. Long term RAS application was also explored by evaluating functional gait and balance and kinematic step measures before and after 6 weeks of multi-directional stepping either with (Cue, C group) or without (No cue, NC group) RAS use. Evaluations were also administered 1, 4 and 8 weeks after training termination. Kinematic measures were collected during stepping without, then with RAS for the C group and without RAS for the NC group. Step testing/training was performed at slow, normal and fast speeds in forward, back and side directions. Participants with PD switched step direction during the stepping task faster with RAS use before training. Like straight line walking RAS application influenced the more complex task of direction switching and counteracted the well-known bradykinesia in PD. After training both groups improved their functional gait and balance measures and maintained balance improvements for at least 8 weeks. Only the C group retained gait improvements for at least 8 weeks after training termination. Adding RAS resulted in functional benefits not observed in training without it. Kinematic measures compared before and after step training clarified the underlying contributors to functional performances. Both groups reduced the variability of DSD. The C group participants maintained this alteration longer. DSD reduction also occurred after training and was retained for at least 8 weeks for this group. These outcomes further support the advantages of adding RAS to training regiments for those with PD. The current results indicate that RAS effects are not limited to simple activities like straight line walking. Moreover, RAS can be used for improving and maintaining improvements longer in activities involving various forms of transition which present most difficulties for those with PD

Postural Control in Individuals with Parkinson’s Disease

Parkinson’s disease is the second most common neurodegenerative disorder in the elderly population. It is a complex, progressive, multisystem disease associated with motor and nonmotor impairments. Postural instability is a crucial component of functional mobility, often overlooked by both clinicians and patients with Parkinson’s disease. It is a refractory drug complication for which rehabilitation is the most effective nonpharmacological aid. However, many interventions are based on empirical experience. Improving knowledge on the pathophysiology of postural control disorders is crucial to understand the multifaceted components affected and thus design specific rehabilitation protocols. This chapter intends to offer a comprehensive overview of the current knowledge on this topic starting from the pathophysiology of postural control disorders occurring in various ecological conditions to the most innovative multidisciplinary rehabilitation approaches

Multimodal response to levodopa treatment in advanced and late Parkinson’s disease

Parkinson’s disease (PD) is a progressive age-dependent neurodegenerative disease. Life expectancy increasing and a better knowledge in PD treatment management, including the advent of device-aided therapies, are likely to increase the number of patients who can reach an advanced disease stage and eventually enter the late stage (LS) of the disease in the next decades. LSPD is a recently recognized disease stage, in which patients are severely disable and dependent on activities of daily life (ADLs) due to the presence of poor treatment responsive motor and non-motor symptoms (NMS) thus highly impacting caregiver’s burden and social/health care system. Hence an operational clinical criteria to identify LSPD patients has been recently proposed suggesting adopt a Schwab and England activity of daily life score (S&E) < 50 in the MED ON condition. LSPD patients’ treatment management is challenging. Treatment-related adverse effects (AEs) are frequent and few evidence in terms of phamacological and non-pharmacological treatment efficacy are available as they are barely included in clinical or research studies and even the participation into routine hospital-based visits can be an unsurmountable limit. At the same time, even if general PD disease severity milestones have been described, we do not know how LSPD patients specifically progress, if they do evolve and if there are clinical markers or biomarkers of poor outcome that could be useful to focus specific therapeutic interventions for this specific disease stage. We aimed to deeply characterize the clinical phenotype, needs along with clinical markers or biomarkers of poor outcome of LSPD patients. As levodopa (L-dopa) is the mainstay of PD treatment and a simplification of treatment regimen in later disease stages has been suggested, we also aimed to investigate the real effect of L-dopa on motor symptoms and NMS among LSPD patients, if compared to advanced stage patients. Among NMS, we focused our work particularly on speech impairment, exploring speech response to L-dopa among LSPD patients and to fine stimulation parameters adjustment, in combination with L-dopa, in advanced PD patients submitted to deep brain stimulation (DBS). Participants were LSPD (Schwab and England ADL Scale [S&E] 3 in “MED ON” state) and advanced stage PD patients previously submitted to DBS. Cross-sectional data were obtained by means of a comprehensive clinical assessment including a L-dopa challenge test with a suprathreshold dose. A subgroup of thirteen LSPD patients underwent a neuroimaging study in order to study neuromelanin (NM) substantia nigra (SN) area changes in the latest disease stage if compared to previous ones. Automated analysis of speech were used to study the effect of a supramaximal L-dopa dose in twenty-four LSPD patients as well as L-dopa and frequency stimulation adjustment in twenty deep brain stimulated patients. Longitudinal data were collected only for LSPD patients. Descriptive, regression and survival curves analysis were performed. Fifty LSPD patients (female 46%) were included. Mean age was 77.5 ± 5.9 years and mean disease duration was 15.5± 6.5 years. At baseline, 76% had L-dopa-induced motor complications (MCs), mainly non-troublesome, 68%were demented, 54% had psychosis and 68% depression. Caregiver distress was high. L-dopa responsiveness was mild (18% ± 12 of improvement on MDS-UPDRS-III) and present only for appendicular signs, being tremor and rigidity the most responsive ones, while axial signs did not change. The clinical significance of this better motor response was marginal according to the Clinical Global Improvement Scale and the change in the S&E between OFF and ON state. The magnitude of L-dopa response correlated with the acute appearance of dyskinesias and the severity of MCs. After one-year, 20% of the patients were dead, 18% institutionalized in nursing home and 6% passed to a HY 5. MDS-UPDRS-motor mean score worsened 7.2 ± 10.3 points, corresponding to a 15.7% (±23.0) increase, with no difference between tremor-dominant versus akinetic-rigid phenotype or PD patients with/without dementia (PDD/non-PDD) at baseline. However, there was heterogeneity between patients in terms of disease progression, as 12 patients (37.5%) had a motor deterioration ≤ 3 points and 14 (43%) ≤ 5 points with concomitant worsening of the MDS-UPDRS-II (Motor Aspects of Experiences of Daily Living), of 2.1±4.1. Conversely, eleven cases (32%) did not deteriorate and, in fact, 10 of these improved between 1-6 points at the MDS-UPDRS-III. Overall NMS worsened, mostly in cognition/mood, urinary and gastrointestinal domains. Conversely, MCs improved despite similar L-dopa equivalent dose. Functional independence and quality of life worsened. Dysphagia severity at baseline predicted a poor combined outcome (death, being institutionalized or developing HY 5) (Hazard ratio 2.3, 95% CI 1.12- 4.4; p = 0.01) or death alone (Hazard ratio of 2.9, 95% CI 1.12- 8.6, p=0.04), whereas magnitude of L-dopa response of LSPD patients did not. SN area evaluated by NM-sensitive magnetic resonance imaging (MRI), resulted able to differentiate LSPD patients from both de novo PD patients and controls, though not founding statistical differences between LSPD patients and patients with two-five year disease duration. Performing an indirect comparison of the effect of L-dopa on motor symptoms and NMS among twenty LSPD patients and twenty-two, not-matched, advanced PD patients, a milder response on motor symptoms (11% vs. 37% of improvement on MDS-UPDRS-III) and an absence of response on NMS, namely anxiety, fatigue and pain, were found among LSPD patients, with concomitant higher frequency of drug-related AEs. Indeed orthostatic hypotension (OH) or drowsiness occurred among 35% of LSPD patients versus 13% of advanced PD patients, who still presented a benefit from L-dopa intake on pain and anxiety, while fatigue did not change. Scales applicability and blood pressure assessment while standing resulted challenging among LSPD patients with consequent missing data on depression, anxiety, pain and OH identification and possible underestimation of those symptoms. No effect of L-dopa was found on speech and voice by means of both automated analysis and clinical evaluation in LSPD patients. Respiratory support for speech and voice stability were the most affected speech and voice features among LSPD patients. Among axial symptoms, speech seemed to be the most L-dopa unresponsive one. Speech unresponsiveness to L-dopa was confirmed also among subthalamic (STN)-DBS treated patients with both mild and severe dysarthria, at least in combination with stimulation. Conversely, PD patients with severe dysarthria under chronic STN-DBS treatment showed a benefit of lowering frequency of stimulation from 130 Hz (High frequency stimulation [HFS]) to 60Hz (low frequency stimulation [LFS]), with concomitant increment of voltage, in order to keep constant the total energy delivered. Indeed speech intelligibility and articulatory diadochokinesis presented an acute improvement passing from HFS to LFS, as assessed by automated speech analysis and such a benefit, when present and clinically meaningful, lasted during six months with no motor worsening, though requiring medication adjustment. The present study provides further evidence to better delineate a recently recognized and poorly described PD stage. An extensive cross-sectional and longitudinal observation is proposed. LSPD patients clearly differ from previous stages in terms of both clinical features, needs, therapeutic response and drugs’ tolerability profile. Over one year, a heterogeneous disease progression of motor symptoms is still present and it seems even steeper if compared to previous stages, while functional independence globally worsened. As well as mild motor improvements are still possible with treatment adjustment, it is also possible to identify a clinical phenotype of LSPD patients who are likely to have a better response to L-dopa if compared to the other ones. Clinical assessment and therapeutic interventions for swallowing problems should be a priority. PDD or living in a nursing home remain other indicators of poor outcome. In the next few years the number of LSPD patients who have been previously submitted to device-aided therapies is expected to increase, bringing new clinical scenarios, such as the fine parameters adjustment of invasive treatment for challenging motor and NMS and the difficult management or eventual interruption of those treatments among elderly and frail LSPD patients. Overall, future research and fund allocations should be specifically oriented on LSPD patients, usually not included or considered in clinical trials or research studies, and on L-dopa not-responsive aspects and caregivers’ need

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

A wearable biofeedback device to improve motor symptoms in Parkinson’s disease

Dissertação de mestrado em Engenharia BiomédicaThis dissertation presents the work done during the fifth year of the course Integrated Master’s in Biomedical Engineering, in Medical Electronics. This work was carried out in the Biomedical & Bioinspired Robotic Devices Lab (BiRD Lab) at the MicroElectroMechanics Center (CMEMS) established at the University of Minho. For validation purposes and data acquisition, it was developed a collaboration with the Clinical Academic Center (2CA), located at Braga Hospital. The knowledge acquired in the development of this master thesis is linked to the motor rehabilitation and assistance of abnormal gait caused by a neurological disease. Indeed, this dissertation has two main goals: (1) validate a wearable biofeedback system (WBS) used for Parkinson's disease patients (PD); and (2) develop a digital biomarker of PD based on kinematic-driven data acquired with the WBS. The first goal aims to study the effects of vibrotactile biofeedback to play an augmentative role to help PD patients mitigate gait-associated impairments, while the second goal seeks to bring a step advance in the use of front-end algorithms to develop a biomarker of PD based on inertial data acquired with wearable devices. Indeed, a WBS is intended to provide motor rehabilitation & assistance, but also to be used as a clinical decision support tool for the classification of the motor disability level. This system provides vibrotactile feedback to PD patients, so that they can integrate it into their normal physiological gait system, allowing them to overcome their gait difficulties related to the level/degree of the disease. The system is based on a user- centered design, considering the end-user driven, multitasking and less cognitive effort concepts. This manuscript presents all steps taken along this dissertation regarding: the literature review and respective critical analysis; implemented tech-based procedures; validation outcomes complemented with results discussion; and main conclusions and future challenges.Esta dissertação apresenta o trabalho realizado durante o quinto ano do curso Mestrado Integrado em Engenharia Biomédica, em Eletrónica Médica. Este trabalho foi realizado no Biomedical & Bioinspired Robotic Devices Lab (BiRD Lab) no MicroElectroMechanics Center (CMEMS) estabelecido na Universidade do Minho. Para efeitos de validação e aquisição de dados, foi desenvolvida uma colaboração com Clinical Academic Center (2CA), localizado no Hospital de Braga. Os conhecimentos adquiridos no desenvolvimento desta tese de mestrado estão ligados à reabilitação motora e assistência de marcha anormal causada por uma doença neurológica. De facto, esta dissertação tem dois objetivos principais: (1) validar um sistema de biofeedback vestível (WBS) utilizado por doentes com doença de Parkinson (DP); e (2) desenvolver um biomarcador digital de PD baseado em dados cinemáticos adquiridos com o WBS. O primeiro objetivo visa o estudo dos efeitos do biofeedback vibrotáctil para desempenhar um papel de reforço para ajudar os pacientes com PD a mitigar as deficiências associadas à marcha, enquanto o segundo objetivo procura trazer um avanço na utilização de algoritmos front-end para biomarcar PD baseado em dados inerciais adquiridos com o dispositivos vestível. De facto, a partir de um WBS pretende-se fornecer reabilitação motora e assistência, mas também utilizá-lo como ferramenta de apoio à decisão clínica para a classificação do nível de deficiência motora. Este sistema fornece feedback vibrotáctil aos pacientes com PD, para que possam integrá-lo no seu sistema de marcha fisiológica normal, permitindo-lhes ultrapassar as suas dificuldades de marcha relacionadas com o nível/grau da doença. O sistema baseia-se numa conceção centrada no utilizador, considerando o utilizador final, multitarefas e conceitos de esforço menos cognitivo. Portanto, este manuscrito apresenta todos os passos dados ao longo desta dissertação relativamente a: revisão da literatura e respetiva análise crítica; procedimentos de base tecnológica implementados; resultados de validação complementados com discussão de resultados; e principais conclusões e desafios futuros

Flexed Truncal Posture in Parkinson’s Disease: Associations with Motor and Non-Motor Impairments and Relationships with Activity

Flexed posture is twice as common people with Parkinson’s disease (PD) than in the general older population. Little is known about the mechanisms responsible for this high incidence, or the association with activity limitations in people with PD. In the general older population, flexed posture is known to be associated with poorer performance of several activities of daily living, reduced quality of life and increased mortality. The two studies in this thesis explored the associations between flexed posture and the motor and non-motor impairments of PD. They revealed that axial motor impairment, age, gender, spinal proprioception and postural fatigue make significant contributions to flexed truncal posture, although a large proportion of the variance in flexed posture remains unexplained. None of the cardinal motor impairments of PD (tremor, rigidity, bradykinesia and postural instability) or the additional non-motor features of cognition, pain, depression, and overall fatigue demonstrated a significant association with flexed posture. Additionally, greater flexed posture demonstrated a significant association with poorer performance of several balance and mobility tasks, upper limb task performance and restrictive lung dysfunction. Given the negative influence of flexed posture on these activities, clinicians should consider assessing and monitoring truncal posture in people with PD. The C7 to wall measure of truncal posture was found to have high test-retest reliability, making it a suitable method to use in this population. Interventions to improve flexed posture may include exercise, education and interventions targeting spinal proprioception

The therapeutic contributions of somatosensory feedback during exercise for those with Parkinson\u27s disease

Previous research has proposed that the somatosensory feedback generated during exercise is a key component in regards to the mechanism underlying the therapeutic effects of exercise on the motor symptoms of Parkinson’s disease (PD). This thesis aimed to further examine the contributions of different forms of somatosensory feedback during exercise in PD in order to understand the mechanism for symptom improvements that certain exercise studies report. This randomized, controlled exercise study consisted of three treadmill groups, with the RATE and MAGNITUDE groups serving as the experimental conditions, while the CONTROL condition was an active comparator treadmill walking group. The RATE group attempted to elicit a rapid sampling rate from somatosensory afferents by having participants walk at a high cadence. The MAGNITUDE group attempted to generate a signal from somatosensory receptors that was larger or richer in magnitude by having participants wear ankle weights with the premise that the additional weight would cause tension sensitive golgi tendon organs to increase signaling. The CONTROL treadmill group served as an active comparator control group where participants walked regularly. Each condition finished with 13 participants with idiopathic PD. All treadmill groups trained at the same aerobic intensity, duration, and frequency. however, only the RATE group improved in the primary outcome measure (motor section of the Unified Parkinson’s Disease Rating Scale (UPDRS-III)) after exercise. Furthermore, this same condition improved on the upper limb score of the UPDRS-III, possibly indicative of an overall improvement in basal ganglia (BG) functioning. Main effects of time were reported for step length in velocity across all treadmill training groups during both self-paced and maximal walking speeds. No changes in any measures of postural control were detected. This study demonstrates that exercise that generates a high rate of somatosensory feedback from appears to be the most capable of improving motor symptoms of PD. Furthermore, gait improvements from treadmill training were independent of improvements in UPDRS-III, and are likely an effect of motor learning