Effect of Stimulus Rate on Cognitive and Motor Activity in Young Subjects, Elderly Subjects, and Patients With Parkinson's Disease
The purpose of this study is to investigate how changes in the brain associated with Parkinson's disease influence the control of motor and thinking speed. There is disagreement over whether patients with Parkinson's disease are slow in thinking as well as movement. This study may provide a new framework to explain the relationship between motor and cognitive aspects of human behavior and help to clarify the pathophysiology of Parkinson's disease.
There are two parts to the study: behavioral tests and functional magnetic resonance imaging (fMRI). All participants will be asked about their medical history, have a physical examination, and complete a questionnaire. They must not take regular medications, including levodopa and dopamine agonists, for 8 hours prior to the study.
The behavioral study involves computer-generated neuropsychological tasks, including hand movements, imagination of movements, and mental calculations. Response will be recorded and evaluated. Electrodes may be placed on the participant's skin to measure surface electromyogram (EMG).
The fMRI study involves MRI scanning in which motor and thinking tasks are performed. Electrodes may be placed on the skin to monitor muscle activity.
Thirty patients, ages 40 and up, with early-stage Parkinson's disease will be recruited. Sixty normal volunteers ages 21-75 will be included as well for comparison.
|Official Title:||Effect of Stimulus Rate on Cognitive and Motor Activity in Young Subjects, Elderly Subjects, and Patients With Parkinson's Disease|
|Study Start Date:||October 2001|
|Estimated Study Completion Date:||November 2003|
A high-level of motor control often requires complex processing of sensory information. Such a cognitive aspect of motor control is supposed to share underlying neural components with non-motor, cognitive operations. The present study is aimed to clarify the similarity and difference between cognitive processing for motor control and non-motor, cognitive processing, especially in terms of the speed of processing. From this standpoint, patients with Parkinson's disease who manifest motor slowing as well as possible cognitive slowing will provide an interesting model to explore similar control mechanisms of speed for motor and non-motor behavioral control. Using psychophysical observations, we will try to clarify normal and diseased control of motor and cognitive speed. Furthermore, using functional magnetic resonance imaging (fMRI), we will explore the neural correlates underlying control of motor and cognitive speed in normal brains as well as pathologic brains. Blood-oxygen-level-dependent signal changes measured by fMRI, as an index of the activity of a neural population, are expected to reveal underactivity or compensatory overactivity in the functionally impaired brain areas responsible for slowing of movement, thinking, or both. This study may provide a new framework to explain the relationship between motor and cognitive aspects of human behavior and help to clarify the pathophysiology of Parkinson's disease.
|United States, Maryland|
|National Institute of Neurological Disorders and Stroke (NINDS)|
|Bethesda, Maryland, United States, 20892|