Effect of Stimulus Rate on Cognitive and Motor Activity in Young Subjects, Elderly Subjects, and Patients With Parkinson's Disease
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.
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.
INCLUSION CRITERIA:

 Imaging methods (e.g., structural MRI) may be included as a part of the pre-study
 evaluation. PD patients should be at a relatively early stage of the disease and must be
 devoid of any other neuropsychiatric symptoms, especially dementia. To assure this, they
 are to be rated by UPDRS (motor sub-scale) and standard neuropsychological batteries (e.g.,
 mini-mental test).

 Thirty PD patients with age 40 and higher will be recruited. Patients may be male or
 female. Patients will be asked to withhold any medication that can influence central
 nervous system (e.g. levodopa) at least 8 hours prior to the examination. They will also
 asked to abstain from alcohol for 24 hours before the study.

 Sixty normal volunteers ranging from 21-75 will be included. Normal volunteers will be
 recruited from people who are registered as HMCS Normal Volunteers. Patients would be
 referred from the HMCS Clinic. All subjects participating in MR studies should have a valid
 Clinical Center Medical Record Number. Procedures for the fMRI experiment will follow the
 Standard Operating Procedures of the HMCS Neuroimaging group.

 EXCLUSION CRITERIA:

 PD patients younger than 40 years will be excluded from the study since they are considered
 to be young-onset PD and have slightly different characteristics from typical idiopathic
 PD. Normal subjects younger than 21 years old will also be excluded.

 Patients with MRI findings consistent with organic brain lesions such as brain tumors,
 stroke, trauma or AVM's will be excluded.

 Patients with progressive neurological disorders other than PD will be excluded.

 Patients with a history of significant medical disorders such as cancers, or requiring
 continuous treatment with drugs other than antiparkinsonian medication, will be excluded.

 Subjects who have any contraindications to MRI will be excluded from the fMRI part of the
 study. We will not scan pregnant women because safety of high magnetic field to fetus is
 not established. Therefore, we will administer a urine pregnancy test for any female
 subjects of childbearing potential prior to functional MRI scan.

 Patients not capable of giving informed consent will be excluded.