| Repetitive Movement in Parkinson's Disease | Movement Initiation and Multi-joint Reflexes | Deep Brain Stimulation | | The principal focus of this laboratory is the examination of the spatial and temporal patterns of motor cortical activity preceding voluntary movement and the function of this activity in shaping and controlling movement initiation. In particular we are interested in the function of the primary and supplementary motor areas and their interactions with the basal-ganglia in the feedforward and feedback control of movement. We use a variety of non-invasive techniques to assess these systems in humans such as: high-resolution EEG recordings and MRI-based source reconstruction techniques, transcranial magnetic stimulation, peripheral nerve stimulation, multi-channel EMG, and measures of movement kinematics and kinetics. Experiments are currently being conducted to examine the role of the primary and supplementary motor areas and brainstem in the timing and selection of agonist and antagonist muscle activity during voluntary ballistic movements. Neurological diseases that affect the basal ganglia have a significant impact upon the function of the primary and supplementary motor areas. For this reason, our research is also focused on the assessment of motor cortical function in neurological disorders such as Parkinson’s disease and dystonia. This work is conducted in collaboration with The Parkinson’s Disease and Movement Disorders Center at Northwestern, the Department of Kinesiology at the University of Illinois at Chicago, and the Movement Disorders Center at Rush Presbyterian-St. Luke’s Medical Center. We are currently examining the control of repetitive movements in patients with Parkinson’s disease and the effects of dopaminergic replacement therapy and deep brain stimulation of the subthalamic nucleus (a neurosurgical treatment for advanced Parkinson’s disease) on the control of these movements. | Elizabeth Stegemöller, Tanya Simuni, Joshua Rosenow, Colum MacKinnon
Funding: NIH (NINDS), The Parkinson Alliance | | Parkinson's disease (PD) affects more than a million people in the United States. Voluntary movement in these patients is characterized by a lack of spontaneous volitional movement (akinesia) and slowness and reduced amplitude of movement (bradykinesia). Movement impairment is most evident during the performance of repetitive movements. The purpose of this project is to examine the mechanisms contributing to impaired repetitive movement in patients with PD. High resolution EEG recordings from the scalp surface and local field potentials recorded from electrodes implanted in the subthalamic nucleus of patients who have undergone neurosurgery to implant deep brain stimulators for the treatment of PD are used to examine the cortical and subcortical control of repetitive movement. This project is examining the effects of movement cueing, frequency, timing, and complexity on movement performance and brain activity and how these effects are altered by antiparkinsonian medications and neurosurgery. | | | (back to top) | | Gwyn Lewis, Eric Perreault, Takako Shiratori, Mark Rogers, Colum MacKinnon |  | One of the cardinal symptoms of Parkinson's disease (PD) is an absence of volitional movement, termed akinesia. For this reason, we are interested in studying the mechanisms by which the brain plans, prepares and then initiates voluntary actions. Self-initiated movements are preceded by a slow rising cerebral potential (that can be recorded using EEG) that reflects brain activity associated with the preparation for movement. Currently, the function of this activity is unknown. We are using a variety of measurement techniques (high resolution EEG, transcranial magnetic stimulation, startle acoustic stimulation) and movement paradigms to examine the role of movement timing and complexity on movement preparation. Improved understanding of the structures and mechanisms contributing to movement initiation will be translated into novel therapeutic interventions in patients with PD. | | | |
Elizabeth Stegemöller, Tanya Simuni, Joshua Rosenow, Colum MacKinnon
Funding: NIH (NINDS), The Parkinson Alliance | Deep brain stimulation (DBS) has emerged as one of the most effective treatments for Parkinson’s disease in patients with advanced disease who no longer get sufficient relief of symptoms with medication. This procedure requires neurosurgery to implant an electrical stimulator into target structures deep in the brain (e.g. subthalamic nucleus, globus pallidus, ventral thalamus). DBS normally lessens the severity of disease symptoms by 30-60%. Currently, the mechanisms by which DBS improves symptoms are poorly understood. In addition, not all symptoms are affected equally. The purpose of this project is to examine the mechanisms of action of DBS and its effects on movement performance and cortical activity in patients with PD. The findings of these experiments will be translated into improvements in the targeting and delivery of DBS. | | (back to top) | Janey Prodoehl, Daniel Corcos, Colum MacKinnon | Dystonia is a movement disorder characterized by prolonged muscle contractions causing sustained twisting movements and abnormal postures of the affected body part(s). These contractions are often painful and interfere with the performance of voluntary movement. We have shown that voluntary movements, even in the absence of muscle spasms, are slow in both the affected and unaffected joints of these patients, suggesting that the disorder affects movement control throughout the body. The purpose of these studies is to characterize and examine mechanisms contributing to disordered control of voluntary movement in patients with dystonia. | | (back to top) |
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